Woman's body during pregnancy. Physiological changes in a woman's body during pregnancy. Changes in the body during pregnancy: genitals, endocrine system, endocrine glands
In this case, the nerve endings embedded in the walls of the uterus are irritated. Mechanical stimulation is converted into electrical impulses that enter the central nervous system via centripetal nerves; the "information" received from the receptors is analyzed, after which certain "commands" are sent to various organs and systems along the centrifugal nerves. This is where the many different physiological changes in the woman's body begin, aimed at facilitating the functioning of organs and systems in new conditions for them. With the onset of pregnancy, the activity of the endocrine glands also changes somewhat; there are certain hormonal shifts that cannot but affect the body. Gradually, the body of a pregnant woman is, as it were, rebuilt. But adapting to new conditions is not the only goal of the "perestroika process"; changes that occur in various systems and organs are also necessary for the woman's body to acquire additional capabilities: a new organism has arisen, which must be provided with oxygen and nutrients and from which carbon dioxide and metabolic by-products must be removed in a timely manner. In other words, the restructuring in the mother's body is also aimed at ensuring the vital activity of the organism of the embryo, fetus.
Pregnancy and childbirth are a big burden on the body, which a healthy body of a woman can and should naturally cope with. But if health is undermined, then certain difficulties may arise, which, if possible, are corrected by doctors.
It is clear that with age we do not become younger or healthier, especially if we did not take care of our health in advance.
Theoretically, any extragenital pathology (Extragenital pathology - abnormalities in the work of organs and systems that are not related to the genital area.) Can negatively affect the reproductive function of a woman, because during pregnancy, our body works in a special mode.
Here we will briefly talk about the changes in the body of the expectant mother in general; Let's consider these changes systematically. In the future, talking about the course of pregnancy by months, we will talk about specific physiological changes in dynamics.
Changes in the nervous system of a woman during pregnancy
The nervous system of a woman during pregnancy is tuned to bear a baby, and fertility becomes a priority. The excitability of the uterus is reduced, which contributes to its relaxation until the onset of labor, when this organ again becomes more excitable to ensure labor. The work of other systems (cardiovascular, respiratory, excretory) is intensely stimulated by the nervous system to complete the task of bearing a child.
It is clear that if a woman is under stress, her nervous system will also not be able to coherently and adequately work on the task of carrying a child, and various disruptions in her work are possible (the tone of the uterus, for example, may increase due to negative emotional experiences).
As pregnancy progresses, the excitability of the cerebral cortex changes; excitability decreases slightly by about the middle of pregnancy, then this excitability begins to gradually increase, and twelve days before childbirth, the excitability of the cerebral cortex again decreases. Excitability of the spinal cord and reflex excitability of the brain, on the contrary, increase by the middle of pregnancy, then gradually become less and about two weeks before childbirth they increase again. The longer the gestation period, the more interoreceptors become in the uterus, and the sensitivity of these interoreceptors increases. The tone of the autonomic nervous system changes. As a result of all the changes described in a woman during pregnancy, there may be a frequent change in mood, opposite emotions can often replace each other; a woman is often irritable, at the same time, she is characterized by a state of drowsiness; sometimes she is worried about mild pains of a neuralgic nature; there are cramps in the calf muscles; there may be nausea that ends with vomiting; there are various changes in taste, increased salivation (hypersalivation), constipation may occur.
Changes in the endocrine system of a woman during pregnancy
During pregnancy, the amount of hormone secreted changes. It should be said that other hormones are released only during pregnancy. Thanks to hormones, certain changes occur in the metabolism; hormones affect the growth of the uterus, the preparation of the mammary glands for the secretion of milk, etc. Significant changes are undergone by such an important endocrine gland as the pituitary gland. The course of pregnancy is influenced by adrenocorticotropic hormone, gonadotropic hormones and lactogenic hormone, which are secreted by the anterior pituitary gland. In the ovaries, after the end of ovulation, the so-called corpus luteum is formed; It is a gland that produces progesterone, a hormone that helps a woman's body prepare for pregnancy. The mucous membrane of the uterus under the influence of progesterone becomes loose and moist, it accumulates nutrients; under the influence of the same hormone, the excitability of the uterus decreases; the corpus luteum hormone affects the mammary glands - it is under its influence that changes occur in the glands, preparing them for the process of milk formation. The corpus luteum functions actively for about twenty-four weeks of pregnancy, then the gland regresses; however, with a decrease in the activity of the corpus luteum, the activity of the placenta increases. The thyroid gland increases its activity with the onset of pregnancy, however, during the second half of pregnancy, the activity of the thyroid gland decreases. The parathyroid glands during pregnancy function somewhat more actively than usual. There is a significant increase in the adrenal glands during pregnancy; the size of the adrenal glands increases due to an increase in the number of cells and due to the accumulation of lipoids, in particular - cholesterol. Due to changes in the activity of the adrenal glands in many tissues in the body of a woman, tone increases during pregnancy.
Changes in a woman's metabolism during pregnancy
Under the influence of changes in the nervous and endocrine systems in the body of a pregnant woman, the course of metabolic processes (metabolism) changes. The activation of all metabolic processes is characteristic. The body accumulates proteins quickly enough; they are needed for the growth of the uterus, mammary glands and, of course, for the growth of the intrauterine fetus. The accumulation of carbohydrates is also very active; these substances are deposited not only in the liver and muscles (as usual), but also in the walls of the uterus and in the placenta. Fats also accumulate in the body of the expectant mother - mainly in the subcutaneous tissue. Vitamins (A, B, C, E, D) are retained. macro- and microelements necessary for the growth and development of the fetus - salts of calcium, phosphorus, potassium, magnesium, iron, iodine, zinc, etc. In the second half of pregnancy, water begins to linger in a woman's body more actively.
Changes in the woman's respiratory system during pregnancy
The load on the respiratory system is gradually increasing. This is due to the fact that as the fetus grows, it needs more and more oxygen, and at the same time, more and more carbon dioxide is required to be released. The following circumstance is also important: the uterus grows rather quickly and over time presses more and more on the internal organs from below, and they, in turn, press on the diaphragm; therefore, the diaphragm can no longer take on its former active participation in the act of breathing; in this regard, the excursion of the lungs is significantly reduced. In order to adapt to the changed conditions and ensure a sufficiently intensive gas exchange, a woman has to breathe more often; in addition, her chest expands somewhat - by the end of the second half of pregnancy this becomes more and more noticeable.
By the end of pregnancy, the expectant mother's oxygen demand almost doubles, and becomes even higher during childbirth. The volume of oxygen consumed increases, the respiratory muscles work in an enhanced mode to provide the pregnant woman and the baby with oxygen, the chest expands. Therefore, any chronic and acute diseases of the respiratory tract of a woman are likely to impede this function. The respiratory rate remains the same during pregnancy (16-18 times per minute).
Changes in a woman's cardiovascular system during pregnancy
The stress on the cardiovascular system increases with the course of pregnancy. This happens for several reasons: firstly, an additional circle of blood circulation appears in the body, which is called the placental, and this circle becomes larger as the fetus grows and the placenta develops; secondly, in a woman's body, the volume of blood gradually increases; thirdly, the network of blood vessels that feed the uterus grows strongly; fourthly, with the growth of the uterus, the heart experiences increasing pressure from the abdominal cavity, from the diaphragm. As a result of all these changes in the body of the expectant mother, new conditions are created to which the heart has to adapt. The number of heart contractions increases, the muscle layer of the heart is hypertrophied. In some women, blood pressure changes during pregnancy (however, these changes are of a short-term nature) - in the first months of pregnancy, blood pressure rises slightly, and in the last months of pregnancy it rises slightly. However, it should be said that in most women during pregnancy, blood pressure is stable.
Changes in the hematopoietic system, in the blood of a woman during pregnancy
With the course of pregnancy, the hematopoietic organs work more and more intensively. The total blood volume in a woman's body increases quite significantly (up to 20%). The number of erythrocytes increases, and with them the amount of hemoglobin, the number of leukocytes increases. But basically, the mass of blood becomes larger due to plasma.
Changes in a woman's digestive system during pregnancy
The restructuring of the functioning of the nervous system and the system of endocrine glands, which occurs from the very beginning of the pregnancy period, has, let me put it this way, some side effect. It is expressed in the appearance of nausea and vomiting in a woman, in certain changes in taste perception, in a violation of appetite, etc. Upon completion of the restructuring of the activity of organs and systems, the side effect also disappears by itself. During pregnancy, under the influence of the nervous and endocrine systems, the tone of not only the smooth muscles of the uterus decreases, but also the tone of smooth muscles embedded in the intestinal walls; as a result, the peristaltic activity of the intestine is significantly slowed down, which can lead to constipation. The glands that produce digestive juices do not change their activity. The liver of a woman during pregnancy works with a slightly greater load, since metabolic by-products (differing in toxicity) are retained and neutralized in it not only from the mother's body, but also from the body of the intrauterine developing fetus. Due to the increase in the size of the uterus, the organs of the digestive system will mix somewhat in the abdominal cavity, but this does not have any noticeable effect on their function.
Changes in the female urinary system during pregnancy
During pregnancy, the load on the kidneys gradually increases. The larger the fetus becomes, the greater the load on the mother's kidneys (due to the more intense activity of the kidneys, water exchange is regulated not only in the mother's body, but also in the body of the intrauterine fetus; also, the kidneys remove metabolic products from the body both from the body of the expectant mother, and from fetal organism). The volume of urine excreted by a pregnant woman during the day is approximately one and a half liters. Over time, the growing uterus takes up more and more space in the abdominal cavity, so the kidneys and bladder are somewhat displaced. As a result of some displacement of the bladder, the urethra stretches and straightens slightly. There is also a distension of the bladder. These changes are especially significant towards the end of the gestation period.
Changes in the skin of a woman during pregnancy
A very noticeable change in connection with pregnancy is the appearance of pigmentation. The greatest amount of pigment is deposited in the skin of the face, in the areoles (areola) and in the abdomen - along the so-called white line. The reason for the increased pigmentation is the intense activity of the pituitary gland and the adrenal cortex. Due to the rapid growth of the pregnant uterus and an increase in the abdomen, pregnancy stripes appear on the skin of the abdomen, which are also called stretch marks (the skin is stretched, its connective tissue and elastic elements are separated). Pregnancy stripes occur in most women, but these stripes are most pronounced in women with insufficiently elastic skin. The color of the pregnancy stripes varies from reddish to bluish-pink, the stripes do not have a specific direction. Similar stripes can occur on the skin of the mammary glands and on the skin of the thighs; the cause of these bands is different - an increase in fat deposits in the subcutaneous tissue.
Changes in the subcutaneous tissue of a woman during pregnancy
In the subcutaneous tissue, a gradual accumulation of fat occurs - provided, of course, that the woman's nutrition is well organized and sufficient. The main places of fat deposition are subcutaneous tissue in the abdomen, thighs and mammary glands. The role of fat deposition is very significant; they represent the reserves of the energy source and the reserves of building material; in addition, fat deposits successfully perform a protective function - they protect the pregnant uterus, various internal organs and mammary glands from injury, soften the mechanical effect; also, fatty deposits help a woman's body to retain heat, and hence the energy that is spent on heating the body.
Changes in the skeletal system and in the ligamentous apparatus of a woman during pregnancy
A very important change associated with pregnancy on the part of the support apparatus is a rather significant increase in mobility in the joints of the pelvic bones. The reason for the phenomenon is in serous impregnation and loosening of the symphyseal cartilage and in simultaneous serous impregnation, stretching of the so-called synovial membranes, ligaments of the joints. In addition, osteophytes appear on the inner surface of the frontal bone - pathological bone growths of small size; osteophytes also appear on the inner surface of the parietal bones. These growths arise and develop as a result of local productive inflammation of the periosteum. Osteophytes do not show any symptoms. Having reached a certain size, they stop growing and for quite a long time (many years) remain without any changes. There is no need for osteophyte therapy. If a woman does not eat properly during pregnancy, if her diet does not have enough products that are sources of calcium and phosphorus salts for the body, sources of vitamin D, then this woman may experience bone softening. The reason for the phenomenon is simple: the named substances are necessary for the proper growth and development of the intrauterine fetus, and if these substances do not enter the mother's body in the required amount (the physiological need for them is not covered), then they are simply "washed out" from the mother's bone tissue; the inorganic component of the bones becomes smaller, and they soften; at the same time teeth suffer greatly.
Changes in the mammary glands of a woman during pregnancy
Already in the first trimester of pregnancy, there may be some changes in the mammary glands. Let us recall that these changes are not the last in the list of possible signs of pregnancy. In the mammary gland, the number of glandular lobules gradually increases, the lobules themselves somewhat increase in size, so the gland at first seems to become more tense, but then the increase in the size of the gland is more and more noticeable. As the gland grows, it needs more nutrition; therefore, the vascular network develops intensively - the blood vessels become wider, branches and their network becomes denser. The dilated saphenous veins are visible through the skin covering the mammary gland with bluish bands. The nipples enlarge over time. As the smooth muscles embedded in the nipples become more excitable, there is an increased sensitivity of the nipples to touch. The pigmentation of the areola is gradually increasing. On the surface of the areola, there are special nodules known as the montgomeric glands. When you press on the mammary glands, colostrum is released from the nipples - a thick, sticky yellowish liquid.
Changes in the genitals of a woman during pregnancy
The uterus undergoes the most significant changes in the genital organs in connection with pregnancy. If before pregnancy the length of the organ is about 6-8 cm, and the width is within 4-5 cm, then by the end of pregnancy the uterus can reach 40 cm in length and 27 cm in width.If before pregnancy, the weight of the uterus rarely exceeds 100 grams , then at the end of pregnancy, the weight of the organ can be from 900 to 1200 grams. The size and weight of the uterus increases due to hypertrophy and hyperplasia of smooth muscles embedded in its walls. Muscle fibers become many times longer and thicker, in addition, the number of smooth muscle fibers increases. As the uterus grows, the blood and lymph vessels that feed the organ increase in length and thickness, and the number of nerve elements increases. The ligaments that fix the uterus become thicker and longer. The cervix is also preparing for the upcoming birth. Its tissues are loosened and softened, thereby increasing the extensibility of the neck. Similar processes - loosening and softening - take place in the walls of the vagina, as well as in the external genitalia. These processes are possible due to the retention of fluid in the tissues. Blood flows to the vagina and external genitals, therefore the color of the named organs changes noticeably; they turn bright red, they may even acquire a bluish tint. Due to the influx of fluid, the external genital organs become more and more edematous; puffiness is most pronounced at the end of pregnancy. There are characteristic changes in the ovaries; these organs are somewhat enlarged during pregnancy. In one of the ovaries, the corpus luteum functions, usually until the twenty-fourth week of pregnancy; then the corpus luteum regresses. During pregnancy, the fallopian tubes thicken. As the uterus grows, the tubes are straightened, at the same time their position changes - from slightly inclined to almost vertical.
Changes in the work of a woman's immune system during pregnancy
Immunity is the body's immunity to foreign (carrying other genetic information) agents.
There are two main types of immunity:
- congenital (or specific); passed on to us by inheritance, protects against diseases unusual for humans, and also introduces some individual characteristics of the immune response to disease;
- acquired, which we receive in the process of life year after year, encountering certain foreign microorganisms. Such immunity is acquired naturally, when we can directly face some kind of disease, as well as artificially in the form of a vaccine against a particular disease (well-known vaccinations to all).
When foreign proteins enter our body, it, having discovered their difference from its own, immediately reacts and begins to produce special cells (antibodies) to fight uninvited guests.
Sperm and a fertilized egg are also foreign cells for the female body, which must be combated, but under normal circumstances it does not.
The process of fertilization and implantation of an egg is an immune phenomenon, since our body rejects all foreign cells, except for sperm and a fertilized egg!
This is such a mystery of nature that allows us to become pregnant and give birth to children.
Obviously, a woman must have a good immune system, capable of not failing at a crucial moment and ensuring the implantation of a fertilized egg, its growth and development.
A woman's immunological problems can contribute to miscarriage.
Increasing the load on the excretory system of a woman during pregnancy
Due to the increasing load on the excretory system in a woman during the carrying of a child, changes in the work of the kidneys are noted. They begin to function with an increased load, since it becomes necessary to remove from the mother's body not only the products of her metabolism, not also the metabolic products of the developing baby. Such a "double" load can lead to the appearance of inflammatory diseases of the excretory system (urinary tract infections, pyelonephritis).
During pregnancy, both the anatomy and the function of the kidneys change: their size increases, the renal pelvis and ureter expand, the tone of the ureters and bladder decreases, and kidney filtration increases.
The body of a healthy woman copes well with such loads, but if a woman has some kind of kidney pathology, this can affect the course of pregnancy and the condition of the expectant mother.
Not only the kidneys, but also the liver are involved in removing the metabolic products of the mother and baby from the body. Therefore, if a woman had any liver problems before pregnancy, it is necessary to inform the doctor about it. Also pay attention to your own condition, if you feel heaviness in the right upper quadrant and aching pain, tell your doctor about it.
During pregnancy, a woman's body undergoes significant physiological changes that ensure the correct development of the fetus, prepare the body for the upcoming childbirth and feeding. During this difficult period, the load on all organs and systems of the woman's body increases significantly, which can lead to an exacerbation of chronic diseases and the development of complications. That is why you should register with the antenatal clinic as early as possible, go through all the necessary specialists and get tested. This will allow you to take adequate preventive measures and prepare for childbirth.
Heart during pregnancy
During pregnancy, the cardiovascular system performs more strenuous work, since an additional placental circulation appears in the body. Here, the blood flow is so great that 500 ml of blood passes through the placenta every minute. The heart of a healthy woman during pregnancy easily adapts to additional loads: the mass of the heart muscle and cardiac output of blood increase. To meet the increasing needs of the fetus for nutrients, oxygen and building materials, the mother's body begins to increase the volume of blood, reaching a maximum by the 7th month of pregnancy. Instead of 4000 ml of blood, 5300-5500 ml are now circulating in the body. In pregnant women with heart disease, this load can cause complications; that is why hospitalization in specialized maternity hospitals is recommended for a period of 27-28 weeks.
Change in blood pressure during pregnancy
Blood pressure practically does not change during a normal pregnancy. On the contrary, in women who have an increase in it before or in the early stages of pregnancy, it usually stabilizes in the middle of pregnancy and is in the range of 100 / 60-130 / 85 mm Hg. This is due to a decrease in the tone of peripheral blood vessels under the action of the hormone progesterone.
However, in the last trimester of pregnancy, blood pressure can rise, reaching very high values. High blood pressure (140/90 mm Hg and above) is one of the signs of late toxicosis in pregnant women. This condition is very dangerous and may require urgent delivery.
Lungs during pregnancy
Due to the increased oxygen demand of a woman's body> during pregnancy, the activity of the lungs increases. Despite the fact that as pregnancy progresses, the diaphragm rises upward and restricts the respiratory movement of the lungs, their capacity increases. This is due to the expansion of the chest, as well as due to the expansion of the bronchi. The increased volume of inhaled air during pregnancy facilitates the removal of used oxygen by the fetus through the placenta. The respiratory rate does not change, it remains 16-18 times per minute, slightly increasing towards the end of pregnancy. Therefore, if shortness of breath or other breathing disorders occurs, the pregnant woman must consult a doctor.
Kidneys during pregnancy
During pregnancy, the kidneys function with great stress, since they remove from the body the metabolic products of the pregnant woman herself and her growing fetus. The amount of urine excreted varies depending on the volume of fluid you drink. A healthy pregnant woman excretes an average of 1200-1600 ml of urine per day, while 950-1200 ml of urine is released during the daytime, the rest of the portion - at night.
Under the influence of the hormone progesterone, the tone of the bladder decreases, which can lead to stagnation of urine. Under these conditions, the introduction of infection into the urinary tract is facilitated, therefore, in pregnant women, an exacerbation of pyelonephritis often occurs. An infection of the urinary tract is indicated by the appearance of leukocytes in urine tests - more than 10-12 in the field of view.
In addition, the pregnant uterus, turning slightly to the right, can make it difficult for urine to drain from the right kidney. In this case, the risk of hydronephrosis increases, that is, the expansion of the pelvis and calyces due to excessive accumulation of urine in them.
Changes in the digestive organs
In many women, in the first 3 months of pregnancy, changes in the digestive organs are observed: nausea and often vomiting appear in the morning (signs of early toxicosis), taste sensations change, and there is a gravitation for unusual substances (clay, chalk). As a rule, these phenomena disappear by 3-4 months of pregnancy, sometimes at a later date. Under the influence of placental hormones, intestinal tone decreases, which often leads to constipation. The intestine is pushed up by the pregnant uterus, the stomach is also displaced upward and compressed, while part of its contents can be thrown into the esophagus and cause heartburn (especially in the second half of pregnancy). In such cases, it is recommended to take antacids (for example, Maalox, Rennie), eat 2 hours before bedtime, and sit in bed with the head end raised.
Liver during pregnancy works with greater stress, as it neutralizes the metabolic products of the woman herself and the fetus.
Joints during pregnancy
During pregnancy, women experience some laxity in their joints. The joints of the pelvis become especially mobile, which facilitates the passage of the fetus through it during childbirth. Sometimes the softening of the pelvic joints is so pronounced that there is a slight divergence of the pubic bones. Then the pregnant woman has pain in the bosom, "duck" gait. It is necessary to inform the doctor about this and receive appropriate recommendations.
Breast changes during pregnancy
During pregnancy, the mammary glands are prepared for the upcoming feeding. In them, the number of lobules, adipose tissue increases, blood supply improves. The mammary glands increase in size, the nipples become rough.
Genital changes during pregnancy
The greatest changes during pregnancy occur in the genitals and concern mainly the uterus. The pregnant uterus is constantly increasing in size, by the end of pregnancy its height reaches 35 cm instead of 7-8 cm outside of pregnancy, the weight increases to 1000-1200 g (without fetus) instead of 50-100 g. The volume of the uterine cavity by the end of pregnancy increases by about 500 once. The change in the size of the uterus occurs due to an increase in the size of muscle fibers under the influence of placental hormones. The blood vessels expand, their number increases, they seem to entwine the uterus. Irregular contractions of the uterus are observed, which become more active towards the end of pregnancy and are felt as "constriction". These so-called Braxton Hicks contractions, which are normal from the 30th week of pregnancy, are considered training before actual labor contractions in labor.
The position of the uterus changes according to its size. By the end of 3 months of pregnancy, it goes beyond the pelvis, and closer to childbirth reaches the hypochondrium. The uterus is held in the correct position by ligaments that thicken and stretch during pregnancy. The pain that occurs on the sides of the abdomen, especially during changes in body position, is often caused by the tension of the ligaments. The blood supply to the external genital organs increases, varicose veins may appear in the vagina and on the labia (the same varicose veins may also appear on the lower extremities and in the rectum).
Weight gain during pregnancy
Fetal growth and physiological changes in a pregnant woman's body affect her body weight. In a healthy woman, by the end of pregnancy, body weight increases by an average of 12 kg with fluctuations from 8 to 18 kg. Usually, in the first half of pregnancy, it increases by 4 kg, in the second half - 2 times more. Weekly weight gain up to 20 weeks is approximately 300 + 30 g, from 21 to 30 weeks - 330 + 40 g and after 30 weeks before childbirth - 340 + 30 g. In women with underweight before pregnancy, weekly weight gain may be more more.
Psychology of a woman
In addition to physiological changes in the body, the mental state of a pregnant woman changes.
A woman's attitude to pregnancy and childbirth is influenced by various factors, including social, moral, ethical, economic, etc., as well as the personality traits of the pregnant woman herself.
In the first half of pregnancy, most women are more concerned about their own health, in the second half, especially after the appearance of fetal movements, all the thoughts and concerns of the expectant mother are directed to the well-being of the fetus. A woman can address a child with affectionate words, she fantasizes, endowing him with individual characteristics. Along with this, many women deliberately give up some attachments and habits for the sake of the upcoming motherhood.
Also, pregnant women may have various concerns and fears. During this period, a woman may be worried about changes in appearance, loss of attractiveness, relationship with her husband. Close relatives (especially the husband) should become a reliable support for the pregnant woman and try to provide the woman with psychological comfort. In case of severe anxiety, a depressed state of a pregnant woman, it is recommended to seek advice from a specialist.
1st week
In most cases, women do not know the exact date of conception, but they can tell exactly when the last menstrual cycle began. Therefore, in most cases, the countdown is carried out precisely from the first day of the last menstruation, since the egg cell begins to ripen in the ovary, preparing for the upcoming fertilization.
2nd week
Fertilization occurs - the fusion of male (sperm) and female (oocyte) germ cells, as a result of which the set of chromosomes inherent in humans is restored and a qualitatively new cell is formed - a zygote (fertilized egg or unicellular embryo). Fertilization involves 1 oocyte and 300 million sperm.
3rd week
The embryo growing inside you is still very small - about the size of a pinhead. In fact, this is just a group of cells, but they multiply and grow very quickly. Theoretically, such an embryo can already be seen with the naked eye (its length is 0.15 mm), although the group of cells still does not at all look like a fetus, and even more so a child.
How your body is changing
You don't notice any changes in yourself yet. Too early! Some women at this stage do not even know they are pregnant yet. After all, not a single menstrual cycle has been missed yet.
Even in the early stages of pregnancy, there are many changes going on within you. The ovaries are located in the abdomen near the uterus and the fallopian tube. On the wall of the ovary, a mature egg is formed from the follicle (ovulation occurs), and at this moment the end of the fallopian tube opens to the ovary, covering the place of formation of the egg - stigma.
During intercourse, an average of 2 to 5 ml of semen enters the vagina, and each milliliter contains an average of 70 million sperm. Thus, during ejaculation (ejaculation), from 140 to 350 million sperm are formed, but only about 200 of them reach the place of fertilization of the egg (its connection with the sperm) in the fallopian tube.
How do you change
Some women notice when they ovulate. They feel mild cramps or pain, and sometimes have increased vaginal discharge. Sometimes, during the implantation of a fertilized cell, women notice slight bleeding.
The time has not yet come for the rest of the changes. Your breasts are not yet enlarging, and morning sickness will only begin to bother you after a few weeks.
4th week
How your baby's height and weight change
Your baby is still very small. At this age, his height can range from 0.36 to 1 mm. In other words, it is less than half of the letter "o".
How your body is changing
So far, your pregnancy is completely invisible to the eye. You have not put on weight, your figure has not changed either.
How your baby grows and develops
The fetus is at a very early stage of development, but big changes are already taking place in it. The implanted blastocyst sank deeper into the lining of the uterus, and the amniotic cavity began to form. This is where the placenta and the vasculature containing the maternal blood will form.
Various layers of cells begin to form. These layers, also called germ layers, will eventually evolve into different parts of your baby's sex and organs. There are three main germ layers - ectoderm, endoderm, and mesoderm. The ectoderm will develop into the nervous system (including the brain), skin and hair. The endoderm will become the lining of the intestinal tract, liver, pancreas, and thyroid glands. From the mesoderm, the skeleton, connective tissues, circulatory system, urigenital system, and most of the skeletal and smooth muscles will be obtained.
How do you change
You are probably still looking forward to your menstrual cycle later this week. When that doesn't happen, pregnancy is the first thing you think of.
5th week
How your baby's height and weight change
Your baby is still not grown up, his height is 1.25 mm.
How your body is changing
So far, there have been no significant changes in your body. Even if you have already realized that you have become pregnant, those around you will not notice it very soon.
How your baby grows and develops
This week, the baby's heart, central nervous system (brain), muscles and bones are just beginning to form. During this week, the base of his skeleton will form.
How do you change
There are many changes going on in you. You can already guess about some, others can only be identified with the help of analyzes.
6th week
How your baby's height and weight change
Your baby's size from crown to tailbone is now 2-4 mm. This is the so-called "sitting height", and is used instead of "standing height" (from the crown to the heels), since the knees of the child inside you are drawn to the chest and its full height is very difficult to measure.
If you have special acoustic equipment at the 6th week, you can already listen to the baby's heartbeat.
How your body is changing
By this time, you might have gained a little weight or, conversely, lost. If you were nauseous and didn’t eat much, you’re likely to lose weight. You have been pregnant for a month, and this is a long enough time to notice some changes in your body. If this is your first pregnancy, your abdomen is unlikely to be noticeably changed. But you may notice that your favorite clothes have become a little tight at the waist. It is possible that the weight is not building up in the waist, but in other places - in the legs or in the chest.
If you now show yourself to a gynecologist, he will notice an increase in the size of the uterus. Perhaps you yourself "feel" it.
How your baby grows and develops
The embryonic period has begun, which lasts from the 6th to the 10th week of pregnancy. This period of child development (4-8 weeks) is extremely important. During this critical period, the embryo is most susceptible to the effects of any factors that can affect its development. Most of the birth defects originate from this time.
The germ layers - ectodermal, mesodermal, and endodermic - continue to develop. Gradually, they begin to transform into various organs and tissues of the child. The size and shape of his body entirely depend on the formation of these organs.
The ectodermic germ layer will soon become the central nervous system, peripheral nervous system, skin, hair, nails, tooth enamel, pituitary gland, mammary glands, sweat glands, and the sensitive epithelium of the ears, nose and eyes.
The mesodermic germ layer will develop into muscles, cartilage, blood vessels, kidneys, genitals, and spleen. The endodermic germ layer will later become the gastrointestinal tract, respiratory tract, bladder, tonsils, thyroid, parathyroid, glands, liver, and pancreas.
As a result of this rapid growth, the body is formed - the head and loin appear. Around this time, the cerebral hemispheres and the optic vesicles of the eyes begin to form. The rudiments of the limbs are visible. The chambers of the heart formed, and it began to contract. The heartbeat can be heard with ultrasound.
7th week
How your baby's height and weight change
Your baby is growing at an incredible rate now! At the beginning of the 7th week, its growth from the crown to the coccyx is 4-5 mm. And by the end of this week, it will become the size of a pea - 11-13 mm.
How your body is changing
Although you probably dream of showing your pregnancy to the world, the time has not come yet - your figure has hardly changed. But soon this moment will come.
How your baby grows and develops
It has the buds of legs in the form of short fins. The rudiments of the arms become longer and are already divided into two segments - the shoulder and the forearm. The arms and legs have carpal membranes in which the fingers begin to develop.
The baby's brain grows and develops. The heart was divided into right and left chambers.
The heart protrudes from the body. By this time, it has already been divided into left and right chambers. In the lungs, the rudiments of the bronchi appeared - the channels through which air enters the human lungs.
The cerebral hemispheres also grow, the eyes and nostrils develop.
The intestines are developing, an appendix has appeared. The pancreas appeared, producing the hormone insulin. This gland partially protrudes into the umbilical cord, but later it will return to the abdominal region of the child.
How do you change
The changes are happening gradually. Outsiders are unlikely to notice that you are pregnant unless you tell them yourself. You are gaining weight gradually and evenly, but so far you have gained no more than a kilogram.
If your weight has not increased, or even vice versa, you have lost the same kilogram, do not worry. This is also in the order of things. In a week, everything will fall into place. You may still have nausea and other early pregnancy symptoms.
8th week
How your baby's height and weight change
At the 8th week of pregnancy, the length of your baby from crown to tailbone is 1.4-2 cm, that is, it is no longer the size of a pea, but a bean.
How your body is changing
Your uterus is getting bigger, but not yet so much that it can be seen from the outside, especially if this is your first pregnancy. Now you have probably noticed some change in the waistline, and the clothes are already clearly tight.
How your baby grows and develops
Your baby continues to grow and develop rapidly these weeks. Eyelids appeared on my face. The tip of the nose stood out. The inner ear and auricles are formed.
In the heart, the valves of the aorta and pulmonary artery are already present and working. The ducts from the trachea to the functioning part of the lungs, called the bronchi, have branched out like the crown of a tree. The main artery of the body has become longer.
Elbows are already visible, arms and legs are noticeably lengthened. The arms are bent at the elbows and embrace the heart. The finger rays will soon become the phalanges of the hands. The same rays are also noticeable on the legs.
How do you change
Before pregnancy, your uterus was the size of a fist. When the fetus is 6 weeks old, it already looks more like a grapefruit. As the uterus grows, you may feel cramping and even pain in your lower abdomen or sides. Some women feel a stretch or contraction of the uterus.
The uterus shrinks throughout pregnancy. If you don't feel it, don't worry. However, if the contractions are accompanied by bleeding from the vagina, this may indicate a threat of miscarriage.
9th week
How your baby's height and weight change
The length of the baby from the top of the head to the tailbone is 2.2-3 cm. This is already the size of an average olive.
How your body is changing
With each week, your uterus gets bigger as the baby grows inside it, and there is already a little more grapefruit. Your waist has increased slightly.
How your baby grows and develops
During this time, your child's organs and systems continue to form. This process is called organogenesis. If you could look inside the womb, you would notice many changes in the baby.
The child's arms and legs are lengthened. The hands are bent at the wrists and are located near the heart. The fingers have lengthened slightly and become thicker in areas where pads will form soon. The feet are noticeably lengthened. Legs are already clearly distinguishable, toes have formed on them. Length from crown to coccyx 25 mm.
The head gradually takes on the usual shape, the neck develops. The eyelids almost cover the eyes. The auricles are already clearly visible.
Your baby starts to change the position of the body and limbs. These movements can be detected with ultrasound.
In general, the child is already more like a human being, albeit extremely small. It is still impossible to determine whether it is a boy or a girl. The external genitals (genitals) are still tiny and cannot be "seen" for several weeks.
How do you change
Most women are very interested in their weight during pregnancy and are periodically weighed. As strange as it may seem, gaining your body weight is extremely important for the normal development of your child. Even if the weight gain is still small, your body is still changing.
Changes in your body - enlargement of the uterus, breast tissue, blood volume, and lymphatic fluid - produce the most weight gain. To ensure the life of the fetus, your body accumulates nutrients, and this increases the volume of blood and lymph. One of the reasons for the accumulation of fat in the body is preparation for feeding the baby with milk.
10th week
How your baby's height and weight change
At the 10th week of pregnancy, the length of the baby from crown to tailbone ranges from 3.1 to 4.2 cm.
From this time on, it is already possible to measure the weight of the child. Previously, it was too small to record changes from week to week. But now its weight is already about 5 g, and in size it resembles a small plum.
How your body is changing
The changes are happening gradually, and you still don't notice any tangible weight gain. If you are already considering trying on maternity clothes, then this is too early.
How your baby grows and develops
The end of the 10th week is the end of the embryonic period of development and the beginning of the fetal period. It is characterized by the rapid growth of a fruit of three germinal petals. During the embryonic period, the child was most susceptible to external factors that could affect his development. Most congenital malformations could form only up to the 10th week inclusive.
By the end of the 10th week, the formation of the child's organs and systems is in full swing - he begins to look more and more like a person. Although the critical stage has already passed, not all problems are behind. Malnutrition and drug use can still affect further development.
11th week
How your baby's height and weight change
By this time, the length of the child from crown to tailbone lies within 4.4-6 cm, weight is about 8 g. It resembles a small lemon in size.
How your body is changing
If big changes are happening in your child now, then very little changes in you. You are almost at the end of the first trimester. Your uterus expands as your baby grows in it. It already fills with itself almost the entire pelvic region, and it is easy to feel it in the lower abdomen above the joint of the pubic (pubic) bone.
So far, you do not feel the movements of the child. If your baby seems to be moving, it’s either gas formation, or the pregnancy is older than you thought.
How your baby grows and develops
The fruit grows very quickly at this time. Over the next three weeks, it will double in length from the crown to the buttocks. As you can see from the photo, the head makes up almost half of the entire body of the child. Now he begins to raise his head, the chin is separated from the chest, the neck gradually develops and strengthens. Fingernails also appear. The external distinctive features of the genitals are more and more clearly manifested. The final formation of a male or female fetus will be completed in three weeks.
At the embryonic stage, sexual characteristics are practically indistinguishable, and the development of an embryo into a male or female fetus is determined by the genetic information embedded in it at the time of fertilization. If the egg is fertilized by a male sperm, you will have a boy, if a female sperm, a girl. The process of sexual differentiation is accompanied by the release of the corresponding hormones, which lead to the formation of male or female genital organs.
How do you change
Some women experience changes in the hair and nails of the hands and feet during pregnancy: some notice accelerated growth of hair and nails, others - hair loss. Don't worry, it doesn't mean anything bad. These phenomena are explained in different ways.
Some doctors are sure that such changes during pregnancy are associated with increased blood circulation, others see the reason in hormonal changes, and others explain them by a change in "phases" in the hair or nail development cycle. In any case, don't panic. This is a temporary phenomenon and there is little or nothing you can do to counter it.
12th week
How your baby's height and weight change
Your baby now weighs between 8 and 14 g. Its length from crown to coccyx is approximately 60 mm. Baby's size has nearly doubled in the past three weeks! Fetal length is now a more reliable indicator of development than weight.
How your body is changing
During these 12 weeks, your weight may not have changed, but may have increased by a couple of kilograms. If you are suffering from morning sickness during pregnancy, you could even lose about a kilogram.
The average weight gain during pregnancy is 11.4-15.9 kg. Weight increases most rapidly at the end of pregnancy. If in the past 12 weeks you have gained between 1.8 and 3.6 kg, then this is quite normal.
By the end of week 12, your uterus becomes too large to fit in your hips. You can feel it over the pubic bone (pubic joint). The uterus has a remarkable stretch property during pregnancy. She will return to her previous size a few weeks after giving birth. And now it grows upward, filling with itself first the hip region, and then the abdominal.
Before pregnancy, the uterus is almost hard. Its volume is only 10 ml and even less. During pregnancy, it turns into a relatively thin-walled muscle sac that contains the fetus, placenta and amniotic fluid. By the end of pregnancy, its volume can reach 5-10 liters. Thus, its capacity increases 500 and even 1000 times!
The weight of the uterus also changes. If before pregnancy it is equal to about 70 g, then after childbirth - 1100 g.
The growth of the uterine wall in the first few months of pregnancy is stimulated by two hormones - estogen and progesterone. Later, the walls of the uterus stretch and become thin under the pressure of the growth of the baby and the placenta.
How your baby grows and develops
After the 12th week, new organs are no longer formed, but the existing ones continue to grow and develop.
At 12 weeks, you can hear your baby's heartbeat using a special device (not a stethoscope) called a doppler. It amplifies the sound of the heartbeat enough to be heard.
The child's skeleton, which began to develop earlier, is now in the phase of ossification - the formation of bone substance. The fingers and toes are parted and the nails continue to grow. Individual signs of hair appear on the body. The external genitals are of sufficient size to confidently determine the sex of the child.
The gastrointestinal system (small intestine) is already able to contract and push food through it. It can actively absorb glucose and sugar.
The pituitary gland at the base of the cranium begins to produce a variety of hormones. Hormones are biologically active chemicals produced in some parts of the body and affecting others. Hormones are classified into growth hormones, corticotropic hormones (ACTH), prolactin, luteinizing hormone (LH), and follicle stimulating hormone (FSH).
The nervous system continues to develop. Your baby starts to wiggle, but you may not feel it until after a month or two. Local stimulation of the fetus can cause it to squint, open its mouth, or wiggle fingers or toes.
The volume of amniotic fluid is steadily increasing. Now it is 50 ml. So far, this fluid resembles the plasma (the non-cellular portion) of your blood, except that it has a much lower protein content.
How do you change
You may be feeling much better. During this period, the nausea of pregnant women usually begins to pass. The belly is not too big and you probably feel quite comfortable.
You may or may not wear maternity clothing. If this is your first pregnancy, then you are still in regular clothes. If the pregnancy is not the first, then the belly usually appears earlier, and it's time for you to switch to looser clothes.
Not only the stomach becomes larger, but also the chest. It may be itchy for a while. You may have noticed that you have also put on weight in your legs and possibly your sides.
Some skin changes may also occur. In many women, the skin becomes noticeably darker in the middle of the abdomen, sometimes a longitudinal dark brown stripe appears.
13th week
How your baby's height and weight change
Your baby is growing very fast now! Its length from crown to tailbone lies within 6.5-7.8 cm, and its weight is 14-20 g. It resembles a peach in size.
How your body is changing
Your uterus has enlarged quite significantly. You can already feel it in the lower abdomen, about 10 cm below your belly button. At 12 and 13 weeks, the uterus fills the hip region and begins to grow upward into the abdominal region. It feels like a soft, smooth ball inside you.
Now, you are probably already gaining weight. If you were tormented by the morning sickness of pregnant women and made you averse to food, then the weight did not increase or even slightly decreased. But if you feel good, then as your child grows, your weight will inevitably increase.
How your baby grows and develops
Around this time, the embryonic period ends and the period of fetal development begins. It is characterized by the rapid growth of the baby's tissues and organs, which have already formed during the previous two weeks.
During this period, congenital defects, as a rule, are not formed. However, drugs and other harmful influences such as overvoltage or radiation can destroy some important cells in the fetus at any time during pregnancy. Avoid such influences.
The active growth of the fetus begins from this week, and ends with the 24th week of pregnancy. Compared to the 7th week, the length of the fetus has doubled. Changes in fetal weight are most significant between the 8th and 10th weeks of gestation.
An interesting feature is noted - there is a gradual slowdown in the growth rate of the child's head in comparison with the body. If during the 13th week the head is about half the length from the crown to the buttocks, then at the 21st week it will be only a third of this length. And by the time of birth, the baby's head is about a fifth of the body! Thus, the body begins to grow faster than the head.
The child's face begins to acquire familiar human features. The eyes, which appear first on the sides of the head, converge closer to each other on the face. The ears are in a normal position on the sides of the head.
The external genitals are already developed enough to distinguish a boy from a girl.
The intestine originally developed as a thickened umbilical cord outside the body. Now it begins to be drawn into the body of the fetus. If this does not happen, the intestines will remain outside the body until the very moment of childbirth, such an anomaly is called omphalocele (hernia of the umbilical cord). This is a very rare occurrence, it occurs in one case in ten thousand. The child undergoes surgery and subsequently becomes completely healthy.
How do you change
Your waist is missing! Regular clothes are tight - it's time to switch to loose-fitting clothes for pregnant women.
14th week
How your baby's height and weight change
Now the length of the fetus from the crown to the coccyx is 8-8.9 cm, and the weight is about 25 g. It is about the size of your fist.
How your body is changing
Loose clothes for pregnant women are now essential. Some women try to get out of a position by not buttoning or zipping their trousers, or by using elastic bands or pins instead. Others wear clothes one size larger, but this does not save them for long. You will be even bigger very soon. You will enjoy your pregnancy more and feel much more comfortable if you switch to loose-fitting clothing.
Usually women who have not had their first pregnancy complain that the belly appears earlier, is located lower and they become "even thicker than last time." Almost all women notice similar changes in themselves with each new pregnancy.
It really depends on how your previous pregnancy went. Remember what your belly was like. Your skin and muscles have been stretched to accommodate the uterus, placenta, and baby. The skin and muscles on the abdomen after childbirth never return to their previous state. The next time they become pregnant, they adapt more quickly to the stretching under the pressure of the uterus. This explains the fact that the belly appears earlier and becomes larger than the last time.
To see this, try standing up and looking down at your belly. Below the navel, you will notice a "drooping" fold of skin. She is not noticeable when you are lying down, but as soon as you get up, she is right there. And no tricks can get rid of it. This "extra" skin forces many women to undergo plastic surgery after childbirth to remove it.
How your baby grows and develops
By this week, your baby's ears have moved from the neck to their normal position on the sides of the head, the eyes have moved closer to the middle of the face, and the neck continues to stretch. The chin no longer rests on the chest.
Sexual differences are becoming more apparent. The external genitals continue to develop. It is now even easier to distinguish a boy from a girl by them.
15th week
How your baby's height and weight change
At the 15th week of pregnancy, the length of the fetus from the crown to the tailbone is 9.3-10.4 cm, and the weight is about 50 g. It is similar in size to a handball ball.
How your body is changing
Now you can already feel the uterus at the level of 7-10 cm below the navel. Your pregnancy is not yet so conspicuous for strangers if you wear your regular outdoor clothing. But it is no longer possible to hide it if you put on a swimsuit.
It's too early to feel the baby's movements, but after a week or two you will feel them!
How your baby grows and develops
Your baby's rapid growth continues. His skin is still very thin, through which you can see blood vessels. Thin hairs, the so-called lanugo hair, cover his entire body.
At this time, the baby can already suck on his thumb. This is usually clearly visible on an ultrasound examination. The eyes continue to move towards the middle of the face, but are still set wide apart.
The auricles continue to develop and look more like normal ears. In general, the child is acquiring more and more familiar human traits.
Bones are already formed and are getting stronger due to the accumulation of calcium (the process of bone formation is called ossification). If X-rays are taken now, you can see the skeleton of the child.
16th week
How your baby's height and weight change
This week, the length of the fetus reaches 11-11.5 cm, and the weight is about 80 g.
How your body is changing
Your baby grows, the uterus and placenta increase in size. Six weeks ago, the uterus weighed 140 g, and now its weight is about 250 g. The volume of amniotic fluid in which the baby is swimming increases to 250 ml. You can feel the uterus 7.5 cm below your belly button.
How your baby grows and develops
The baby has a nice fluff on the head. The umbilical cord leaves the abdomen. It is now attached lower on the fetal body than before. Marigolds are well formed. The legs are longer than the handles. The kid is already moving them. During ultrasound, fetal movements can be seen on the monitor screen. You may already be feeling them. And if not, don't be upset. Usually, the first movements, or movements, of the fetus occur between the 16th and 20th weeks of pregnancy: for all women in different ways. In addition, one child may be more active and the other less. Even in the same mother with different pregnancies, the timing of the first movements is different.
What are the first movements of a baby like? Many people compare these sensations to air bubbles or flutter. Often, you do not even immediately realize that it is a child moving. And only after a few days it dawns on you that your baby is making itself felt.
17th week
How your baby's height and weight change
By this week, the length of the baby from the top of the head to the tailbone is 11-12 cm. In two weeks its weight has doubled and is now about 100 g. Now the baby is the size of an open palm.
How your body is changing
The bottom of the uterus is located 4-5 cm below the navel. When your husband hugs you, he can feel your belly change. Pregnancy has already become visible to the "naked eye", and it's time for you to buy clothes for pregnant women - loose and elastic.
By this time, you have gained from 2.25 to 4.5 kg in weight.
How your baby grows and develops
From this week, the fetus begins to form a fatty layer, or subcutaneous fat, which is involved in the production of energy and the metabolic process.
At the 17th week of pregnancy, water is 89 g of the total weight of the fetus, fat - 0.5 g. In a full-term newborn, there are 2.4 kg of fat per 3.5 kg of the total weight.
This week you may already be able to feel your baby's movements, but if not, it will soon be. So far, he does not move every day, but with an increase in the period, the movements will be stronger and more frequent.
The first movements of a child are a great joy for a woman. It also indicates that the pregnancy is proceeding normally. And if you have had pain or bleeding before, then the baby's movements will make you doubly happy.
How do you change
With the development of pregnancy, the bottom of the uterus takes on a spherical shape. The uterus grows stronger in length - upward than in width, becoming oval in shape. It has already filled the small pelvis and is growing further, rising to the stomach, soon it will reach the liver. Increasing in size, the uterus shifts the internal organs up and to the sides.
The uterus is not fixed firmly in one place, but it does not float freely either. It is held in the pelvic cavity with the help of ligaments in the lower part and in the neck area.
When you stand, the uterus touches the front wall of the abdomen, in this position it can be easily felt. When you lie down, the uterus moves towards the spine and vena cava.
The round ligaments are attached to the sides of the uterus at the top of the uterus and extend to the side of the pelvis. During pregnancy, as the uterus enlarges, these ligaments stretch. They get longer and thicker. With your sudden movements, the ligaments are stretched, which causes discomfort or even pain. Moreover, the pain can appear both on one and on both sides, or on one side it will be stronger.
This pain is not terrible, it only indicates that the uterus is growing. If pain occurs, try to lie down. And some women just ignore the discomfort.
However, if other symptoms occur along with the pain, such as bleeding, fluid production, or the pain becomes very severe, see your doctor.
18th week
How your baby's height and weight change
The child grows, and its length from the crown to the coccyx by the 18th week averages from 12.5 to 14 cm.The weight of the fetus is now about 150 g.
How your body is changing
The uterus is already almost at the navel. You can measure it yourself. Place your hands on your waist and feel the fundus of the uterus. It is located two fingers thick below the navel, or about 2.5 cm.
Now the uterus is about the size of an average melon. From the beginning of pregnancy, you should gain between 4.5 and 5.8 kg in weight. If you have gained more, check with your doctor; you may need to see a dietitian. After all, you have more than half of your pregnancy ahead, and you will get better more and more.
Of course, it is foolish to go on a diet during pregnancy, but you must definitely control your calorie intake. After all, the baby receives food from your body, that is, from the food that you eat. And this food should be complete.
Weight gain during pregnancy can tell you how your baby is growing. Over the entire period, the increase should be from 11 to 15.5 kg. Gaining more can make pregnancy harder and more difficult to give birth. In addition, it will be very difficult for you to lose those extra pounds later.
How your baby grows and develops
The growth rate of the fetus slows down a little by this time. But it continues to grow and change.
How do you change
Back pain during pregnancy is experienced by almost every woman. You may have back pain as early as 18 weeks, although it is likely that it will also occur later when you are gaining weight.
Back pain is caused by the fact that as the uterus grows, the center of gravity of the body shifts and you have to bend a lot. This increases the load on the muscles of the sacrum. In addition, due to hormonal changes, the mobility of the joints increases. As a result, posture changes, which causes discomfort in the lower back. But this is typical mainly for late pregnancy.
How can you relieve back pain? First, warmth, secondly, rest, and thirdly, analgesics such as acetaminophen. You can purchase a special maternity bandage that supports your back muscles. Special exercises and weight control also help. In severe cases, you should contact your doctor, he can refer you to physiotherapy procedures or to a consultation with an orthopedist.
Now for a few tips.
Watch your weight, try not to gain too much.
- Keep doing exercise for pregnant women
- Develop the habit of sleeping on your side
- In the afternoon, whether you are at home or not, find half an hour to lie down. If you have young children, try to find a time to rest, such as when they have quiet hours.
Start following these tips now, don't postpone it. Believe me, the sooner you develop these healthy habits, the easier it will be for you to endure pregnancy in the future.
19th week
How your baby's height and weight change
By the 19th week, the length of the child from the head to the tailbone is 13-15 cm, and its weight is 200 g. It is difficult to even imagine that by the time the baby is born, the baby will have to gain 15 times in weight!
How your body is changing
The fundus of the uterus is now located 1.3 cm below the navel. During this period from the beginning of pregnancy, you have already gained 3.6-6.3 kg. How is this weight distributed? Only 200 g per child. The placenta weighs about 170 g, amniotic fluid - 320 g, the same - 320 g - the uterus weighs. Your breasts have also increased, each by 180 g. You seem very big to yourself, but it will still be.
20th week
How your baby's height and weight change
This week, the child's body length from crown to tailbone is on average 14-16 cm, weight is about 250 g.
How your body is changing
You can be congratulated - half of your pregnancy is over. As you remember, the entire pregnancy lasts 40 weeks from the day of the last menstrual period, so 20 weeks is a kind of milestone. The bottom of the uterus rose a little more and reached the navel. The belly continues to grow, you get more fat. Before 20 weeks you did not get too much fat, now everything is different - you will regularly gain weight and volume.
How your baby grows and develops
Your baby's skin develops from two layers: the outer layer of the epidermis and the inner layer of the dermis. At the very beginning, the embryo is covered with one layer of cells. Now, at the 20th week, there are already four of these layers in the epidermis. One of them has lines - in the future they will form a unique, genetically determined pattern on the palms, fingers and feet.
The dermis lies under the epidermis. It forms papillae that penetrate deep into the epidermis. They contain small blood vessels - capillaries and nerve endings. A layer of subcutaneous adipose tissue is located behind the dermis.
The skin of the newborn is covered with a white paste-like substance - original lubricant. This lubricant begins to be produced by the glands during the 20th week of pregnancy. It protects the skin of the fetus from the effects of amniotic fluid.
21st week
How your baby's height and weight change
During the first week of the second half of pregnancy, your baby has grown. Now it weighs 300 g, and its length from crown to tailbone is 18 cm. It is already the size of a large banana.
How your body is changing
You feel that the uterus has risen, it already rises 1 cm above the navel. The doctor will measure its height for you, it reaches 21 cm from the pubic symphysis. Weight gain ranges from 4.5 to 6.3 kg.
How your baby grows and develops
By this time, the growth rate of the fetus slows down, but it continues to grow and develop. Its systems are also developing.
By the 21st week of pregnancy, the fetal digestive system is already so developed that the fetus can swallow amniotic fluid. In the small intestine, water is extracted from this fluid, and the remainder is sent to the large intestine.
How do you change
Along with the enlargement of the uterus, other parts of your body also change and enlarge. You may notice that your legs are swollen, especially in the evening. If you spend all day on your feet, take a few free minutes during the day and give your feet a rest - they will swell much less.
22nd week
How your baby's height and weight change
Your baby weighs 350 g. It is 19 cm long from crown to tailbone.
How your body is changing
The uterus rose 2 cm above the navel and 22 cm above the pubic symphysis. This period can be called comfortable. The belly, of course, has increased, but not yet enough to bother you much. You can bend down, sit down as you like, you can easily walk on foot. Morning weakness no longer bothers you and you feel pretty good. Now pregnancy is a pleasure for you.
How your baby grows and develops
The baby in the womb continues to grow every day. He already has eyelids and cilia, on his fingers you can see tiny marigolds.
23rd week
How your baby's height and weight change
By this week, your baby weighs 450 g. Its length from head to tailbone is 20 cm. Now it is the size of a small doll.
How your body is changing
The uterus has risen 3.75 cm above the navel, its height above the pubic symphysis is 23 cm. And although your belly is growing a little, your figure has become noticeably rounded. Weight gain reaches from 5 to 6.7 kg.
How your baby grows and develops
Your baby continues to grow, his little body is rounded, but the skin is still wrinkled, since he does not yet have subcutaneous tissue. The fluff that covers the fruit begins to darken during this period.
How do you change
The uterus continues to grow, the placenta increases, the volume of amniotic fluid increases, as a result, you get more and more fat. Some acquaintances note that your belly has grown too much and you probably carry twins. Or, on the contrary, that the belly is too small for your term. Don't panic: all women are different, and all children develop in different ways: some more, some less. Most likely, you are all right. But if you are still worried, see your doctor: he monitors the development of the fetus from the very beginning and is better than others aware of whether your pregnancy is going well.
24th week
How your baby's height and weight change
This week, the baby weighs about 530 g and is 21 cm long from crown to tailbone.
How your body is changing
The uterus has risen 3.8-5.1 cm above the navel and 24 cm above the pubic symphysis. You have already noticeably plump, and your belly has grown a lot.
How your baby grows and develops
Your baby has also noticeably recovered, and now he clearly looks like a newborn. But although it already weighs more than half a kilogram, it is still very small.
25th week
How your baby's height and weight change
Your baby already weighs 700 g, the length of his body from crown to tailbone is 22 cm. These are average data, and they can vary greatly: after all, all children are different, just like mothers.
How your body is changing
The distance from the uterus to the pubis is 25 cm. Over the past month, her height was 4 cm, and she is now the size of a soccer ball. The bottom of the uterus is now halfway between the navel and the sternum, a bone located in the middle of the chest at the junction of the ribs.
How do you change
Starting from the 20th or 21st week, the doctor will measure your belly at each visit. Now not only the belly protrudes forward, but also the sides are heard. And for all this happens in different ways: someone grows more fat in the sides and their stomach looks smaller, while in others the stomach protrudes far forward and seems very large. Therefore, you may look completely different than your girlfriend at the same stage of pregnancy. Don't worry, these are natural differences.
26th week
How your baby's height and weight change
Your baby now weighs about 900 g. By this week, his length from crown to coccyx has reached 23 cm.
How your body is changing
During the second half of your pregnancy, your uterus will rise 1 cm every week. Now it rises 6 cm above the navel, and 26 cm above the pubic symphysis.
If you followed a rational, balanced diet, then the total weight gain was 7.2-9.9 kg.
How do you change
You get fat more and more - after all, the child grows, the uterus and placenta increase. Therefore, such ailments as back pain, pressure on the bladder, leg cramps, occur more and more often. Do not be discouraged, the matter is moving to an end. You have already departed two-thirds of the term, there is only a third left - and the long-awaited hour of meeting will come
27th week
How your baby's height and weight change
This week begins the third trimester of your pregnancy. Now, along with the length of the fetus from crown to tailbone, we will also monitor its full growth - from crown to heels. This will make it easier for you to imagine how your baby is growing.
So, the child has now reached a kilogram. Its length from head to coccyx is 24 cm, and its total length is 34 cm.
How your body is changing
The uterus has risen 7 cm above the navel, and it is already 27 cm away from the pubic symphysis.
How your baby grows and develops
By this time, the baby's eyelids will rise.
How do you change
Your breasts also change as pregnancy progresses. The mammary glands are enlarged and engorged.
28th week
How your baby's height and weight change
This week, the baby weighs 1.1 kg, is 25 cm long from crown to coccyx, and its total length is 35 cm.
How your body is changing
The uterus rose high above the navel. It continues to grow, and the belly continues to grow. Sometimes this growth happens gradually, but it happens that the change happens suddenly. The uterus is now located 8 cm above the navel, and from the pubic symphysis it has risen 28 cm.
By this time, you have probably gained 7.5-10.5 kg in weight.
How your baby grows and develops
Until this time, the fetal brain was smooth. By the 28th week, characteristic grooves and convolutions begin to appear on it. The brain mass has also increased.
The baby already has eyebrows and eyelashes. The head is covered with small hairs.
Until that time, the baby was thin. Now the baby's body is filling up, he is recovering. This is due to an increase in the volume of subcutaneous tissue.
The baby already weighs more than a kilogram. It is interesting to compare his weight now with what it was only 11 weeks ago: then, at the 17th week of pregnancy, the fetus weighed only 100 g. And in just over two months it became 10 times heavier! And over the past four weeks (from the 24th week of pregnancy), his weight has doubled. How fast your baby is growing!
29th week
How your baby's height and weight change
This week, the child weighs 1.25 kg, its length from crown to coccyx is 26 cm, and at full height is 37 cm.
How your body is changing
The uterus rose above the navel by 7.5-10.2 cm, above the pubic symphysis - by 29 cm. Four weeks ago, at the 25th week, the distance from the pubic symphysis to the bottom of the uterus was 25 cm, that is, for this time the uterus rose by 4 cm.
Weight gain since the beginning of pregnancy - from 8.5 to 11.25 kg.
30th week
How your baby's height and weight change
At this point, your baby already weighs about 1,360 kg. Its length from crown to coccyx is a little more than 27 cm, and at full height - 38 cm.
How your body is changing
The uterus rose above the navel by 10 cm, and from the pubic symphysis by 30 cm.
It's hard to believe that you have to carry your baby for another 10 weeks! It even seems to you that soon you will not be able to crawl through the door. However, the fetus, placenta and uterus, along with the amniotic fluid, are still growing.
On average, weight gain during pregnancy ranges from 11.4 to 15.9 kg. About half of this weight is made up of the uterus, placenta and amniotic fluid. The growing fetus puts pressure on the stomach and pelvis, which is very noticeable. The feeling of discomfort increases noticeably, it becomes more and more difficult to carry the baby every week.
31st week
How your baby's height and weight change
Your baby-to-be continues to grow. It weighs approximately 1.6 kg. Its length from crown to tailbone is 28 cm, and at full height - 40 cm.
How your body is changing
The uterus has risen above the pubic symphysis by 31 cm or slightly more. It is 11 cm above the navel.
By the 12th week of pregnancy, the uterus has filled only the pelvic region, and by the 31st week, it has already filled most of the abdomen.
Weight gain ranges from 9.45 to 12.15 kg.
32nd week
How your baby's height and weight change
Your baby already weighs 1.8 kg. Its length from crown to coccyx is 29 cm, and from crown to heels - 42 cm.
How your body is changing
The apex of the uterus rose 32 cm from the pubic symphysis. It is 12 cm removed from the navel.
How do you change
Until this week, you saw your doctor about once a month if there were no complications. From the 32nd week, the doctor usually prescribes to visit him twice a month. And this will continue until the last month of pregnancy. You will then see your doctor on a weekly basis.
33rd week
How your baby's height and weight change
Your baby continues to grow. His weight reached 2 kg by this week. Its length from crown to tailbone is about 30 cm, and at full height - 43 cm.
How your body is changing
From the pubic symphysis, the apex of the uterus is 33 cm. From the navel, it rises by 13 cm. You have already put on weight from 9.9 to 12.6 kg.
34th week
How your baby's height and weight change
Your baby weighs almost 2.3 kg. Its length from crown to coccyx is 32 cm.And at full height it is 44 cm.
How your body is changing
The upper point of the uterus rises 14 cm above the navel.And from the pubic symphysis, it has grown by as much as 34 cm.
It doesn't matter if your friends tell you that their results were different for the same period. What's really important is that your body and your uterus grow properly. All pregnancies develop differently. If the doctor believes that the growth of the uterus is normal, then you should not worry and worry about trifles.
35th week
How your baby's height and weight change
Your baby weighs approximately 2.5 kg. Its length from crown to coccyx is about 33 cm, and at full height - 45 cm.
How your body is changing
The height of the uterus above the navel is 15 cm.From the pubic symphysis to the apex of the uterus, this distance is about 35 cm.
You should have gained between 10.3 and 13 kg by this week. Is it worth crying for a thin waist now?
How do you change
As the day of birth approaches, you and your partner become more concerned about the outcome of your pregnancy and childbirth. You may have sudden mood swings for which there seems to be no reason. It is often heard from expectant mothers and even dads that the feeling of their own helplessness and uncertainty is intensifying, which is very depressing these days. You may even get depressed and incomprehensible sullenness. However, this is a temporary phenomenon.
You will be preoccupied with various little things, you will become anxious about completely unnecessary things. The fear of health, of your own and of the child, increases, all the time it seems that something is wrong with you, therefore, you will probably be upset over trifles. Very often women are afraid that they will not be able to withstand childbirth. They are afraid that they will not be able to become a good mother. And in general, they are afraid of everything.
Among other things, you also get fat, and it is already difficult to do everyday activities. Sleep can be restless and wakefulness uncomfortable. And all this together plunges you into the abyss of fears, irritation and a state close to hysterics.
All these changes are normal. This happens to all pregnant women, so you are not alone.
Pregnancy happens only a few times in your life, and often even once, so enjoy this state, get joy from it. After all, you and your partner are discovering a small and very important miracle - the miracle of a new life.
36th week
How your baby's height and weight change
By this week, the baby already weighs 2.75 kg. Its length from crown to tailbone is 34 cm, and at full height - 46 cm. Your baby is growing by leaps and bounds.
How your body is changing
From the pubic symphysis to the apex of the uterus about 36 cm, from the navel to it 14 cm.
You may get the feeling that you not only can't get through the door, but the room is not enough for you. This is how quickly you have grown in size in the last few weeks. Now the uterus has risen to the ribs, and it seems that there is not enough air.
How do you change
You have already gained from 11 to 13.5 kg, and there is still a month before giving birth. It will not be unusual that your weight will no longer change until the very birth.
Now your baby is surrounded by the maximum amount of amniotic fluid. The baby will continue to grow in the coming weeks. At the same time, your body will absorb some of the amniotic fluid, thereby reducing its volume around your baby and making him less able to move. You will notice that the baby has begun to move less and less actively. Some women fear that he has completely stopped moving or that he is not moving as usual.
37th week
How your baby's height and weight change
The baby weighs approximately 2.95 kg this week. He is gaining weight quickly. Its length from crown to coccyx is 35 cm, and from crown to heels - 47 cm, that is, it grows by 1 cm every week.
How your body is changing
The height of the uterus may remain at the same level as the last week or two. From the pubic symphysis, the apex is 37 cm, and from the navel - 16-17 cm.By this week, you have gained from 11.2 to 13.5 kg.
38th week
How your baby's height and weight change
By this time, your baby weighs approximately 3.1 kg. Its length has not changed significantly - 35 cm.In full growth, the baby is already more than 47 cm.
How your body is changing
Despite the fact that the pregnancy is already coming to an end, you continue to grow in size. True, it also happens that in the last weeks of pregnancy, the belly stops growing, and the woman no longer gains weight. But, regardless of whether you are getting fat or not, the feeling of discomfort these days intensifies in all expectant mothers.
The height of the standing of the uterus now from the pubic symphysis is from 36 to 38 cm, and from the navel - 16-18 cm.
39th week
How your baby's height and weight change
Your baby weighs a little over 3.2 kg. Its length from crown to coccyx is about 36 cm, and at full height - 48 cm.
How your body is changing
From the pubic symphysis, the uterus rises by 36-40 cm.From the navel, this distance is 16-20 cm.
You are almost on the cusp of the main event. The pregnancy is already coming to an end. And if you are tired of gaining weight, then rejoice - you will not get fat anymore before giving birth. During these 39 weeks, you have put on weight by 11.4-15.9 kg!
How your baby grows and develops
But your child, unlike you, continues to gain weight in recent weeks. And he has less and less room to push and toss and turn in the womb.
By this time, all the organs and systems of the baby have already developed and are in their places. Last but not least, the baby's lungs and respiratory system develop.
40th week
How your baby's height and weight change
Your baby weighs 3.4 kg. Its length from crown to tailbone is 37-38 cm, and in full height - 48 cm. The baby is now about the same size as it will be at birth. It has filled the entire uterus with itself, and there is no more room to move.
How your body is changing
You don't grow in size anymore. From the pubic symphysis, the uterus rises by 36-40 cm, everyone has it differently. From the navel, this distance is 16-20 cm.
Now, most likely, you no longer care how much you weigh. It's just that the feeling that there is simply nowhere to grow further does not leave you. The birth is very soon, so if you suddenly recover a little more, do not worry.
41st week
You are anxiously awaiting the birth of your baby and literally counting the days until the birth.
42nd week
Pregnancy is considered post-term if more than 42 weeks or 294 days have passed since the last menstrual period.
Most doctors agree that labor should be induced if the cervix is ajar and stretched, and the position of the baby is upside down. Before this, the condition of the child and the placenta is assessed. Whether to have a cesarean section, to induce childbirth or continue to monitor the child - the doctor decides on the basis of the examinations performed.
Changes in a woman's body during pregnancy are of an adaptive and adaptive nature and are aimed at creating optimal conditions for the growth and development of the fetus. Let's consider what these changes are in various organs and systems.
NERVOUS SYSTEM
The concept of the dominant of pregnancy (gestational dominant) was put forward: a corresponding focus of excitation appears in the central nervous system after fertilization of the egg and its implantation into the mucous membrane of the uterus; in this case, a constant source of afferent impulses is formed from the interoreceptors of the uterus.
In the first months of pregnancy, a decrease in the excitability of the cerebral cortex is observed, which leads to an increase in the reflex activity of the subcortical centers, as well as the spinal cord. Subsequently, the excitability of the cerebral cortex increases and remains elevated until the end of pregnancy. By the time of childbirth, the excitability of the cerebral cortex sharply decreases, accompanied by an increase in the excitability of the spinal cord, which leads to an increase in spinal reflexes, an increase in neuroreflex and muscle excitability of the uterus, which is necessary for the onset of labor.
The tone of the autonomic nervous system changes, and therefore, pregnant women often experience drowsiness, tearfulness, increased irritability, sometimes dizziness and other disorders. These disorders are usually inherent in the early period of pregnancy and then gradually disappear.
ENDOCRINE GLANDS. ENDOCRINE CHANGES
Understanding the complex endocrine changes during pregnancy remains sketchy and incomplete. Many of the peptide and steroid hormones that are produced by the endocrine glands outside of pregnancy can be synthesized by the tissues found in the uterus during pregnancy.
With the onset of pregnancy, the ovaries increase slightly, ovulation in them stops; in one of the ovaries, the corpus luteum functions. The hormones secreted by it (progesterone; to a lesser extent - estrogens; relaxin) contribute to the creation of conditions for the development of pregnancy. The corpus luteum undergoes reverse development after 3-4 months of pregnancy in connection with the formation of the hormonal function of the placenta; further, the function of the corpus luteum is insignificant. In vivo surgical removal of the corpus luteum before 7 weeks of pregnancy leads to a rapid decrease in progesterone levels and miscarriage; if removed later, pregnancy may persist. The corpus luteum also produces the polypeptide hormone relaxin, which inhibits the activity of the myometrium; after the termination of the function of the corpus luteum, relaxin is synthesized in the placenta.
Placenta is the organ that unites the functional systems of the mother and the fetus. It performs the following main functions.
The respiratory function provides transport from the mother to the fetus of oxygen and the release of carbon dioxide in the opposite direction. The exchange of gases takes place according to the laws of simple diffusion. The placenta contains enzymes involved in oxidation-reduction processes, the breakdown and synthesis of proteins, fats and carbohydrates necessary for the development of the fetus.
With limited permeability, the placenta is able to protect the fetus from a number of damaging factors that have entered the mother's body (toxic products, microorganisms, medicinal substances, etc.), but not all, and many of them have a direct effect on the embryo and fetus.
The excretory function of the placenta is to remove metabolic products from the fetus.
The placenta is a powerful endocrine gland, in which the processes of synthesis, secretion and transformation of a number of hormones (Fig. 20), both steroid (gestagens and estrogens) and protein (CG, PL), are intensively occurring.
Hormones produced in the uterus during pregnancy.
Pregnancy-specific hormones.
Hypothalamic hormones.
Corticoliberin. Pituitary hormones.
Prolactin.
Growth hormone.
Other peptide hormones.
Insulin-like growth factor I and II.
Parathyroid-like peptide.
Angiotensin II.
Steroid hormones (estrogens, progesterone).
1,25-dihydroxycholecalciferol.
There is a functional relationship between the placenta and the fetus, which is considered as a single endocrine system - the "fetoplacental system", which has, to a certain extent, some autonomy. The fetus, placenta and mother are involved in steroidogenesis.
rin organism, which complement each other in such a way that the fetoplacental system is able to maintain the synthesis of all biologically active steroid hormones.
The main hormone of the fetoplacental system is estriol, called a pregnancy protector. It accounts for 85% of all estrogen during pregnancy. Its main role is the regulation of the uteroplacental circulation, i.e. supplying the fetus with all vital substances necessary for normal growth and development.
Synthesis and metabolism of estrogen
Estriol is synthesized in the placenta from dehydroepiandrosterone sulfate, which is formed in the adrenal cortex of the fetus and, to a lesser extent, in the adrenal cortex of the pregnant woman. 90% of estriol in the blood of a pregnant woman is of fetal origin and only 10% is of maternal origin. Part of estriol is in a free state in the blood of the pregnant woman and the fetus, performing its protective function, part enters the liver of the pregnant woman, where, combining with glucuronic acid, it is inactivated. Inactivated estriol is excreted in the urine of a pregnant woman. With a complicated course of pregnancy, the secretion of estriol in the urine may decrease, which was previously used as a diagnosis
a logical sign of fetal developmental disorders (with the advent of more specific biophysical methods, this is not necessary).
In a much smaller amount than estriol, other estrogens are formed in the fetoplacental system - estrone and estradiol. They have a diverse effect on the body of a pregnant woman: they regulate water-electrolyte metabolism, cause sodium retention, an increase in the volume of circulating blood (BCC), vasodilation and an increase in the formation of steroid-binding plasma proteins. Estrogens cause the growth of the pregnant uterus, cervix, vagina, promote the growth of mammary glands, change the sensitivity of the uterus to progesterone, which plays an important role in the development of labor.
Rice. twenty. The content of hormones in the blood at different stages of pregnancy
The mechanism of interaction between the mother's body, placenta and fetus is described as the "theory of the placental clock". Starting from the middle of pregnancy, trophoblast is able to synthesize corticoliberin, which stimulates the fetal pituitary gland to increase the level of ACTH, thereby increasing the synthesis of dehydroepiandrosterone, the main precursor of placental estrogens, by the adrenal glands of the fetus. A high level of estrogen by the end of pregnancy stimulates the formation of gap junctions between the cells of the myometrium, contributing to arousal and labor. Synthesis of corticol-
berina regulates estrogen content according to the principle of positive feedback.
This mechanism by which the placenta regulates its own metabolism, influencing the fetus, which in turn, acting on the function of the uterus, possibly triggers labor, is called the placental clock. We sometimes break this delicate mechanism by untimely induction of labor.
Hormonal changes during pregnancy are reflected in table. 3.
Table 3
Hormonal changes during pregnancy
The second important steroid hormone for pregnancy is progesterone. The concentration of progesterone in the blood increases significantly with the progression of pregnancy. The hormonal function of the corpus luteum, which synthesizes progesterone in the first trimester of pregnancy, gradually passes to the placenta, already from 10 weeks the maximum amount of progesterone is produced by trophoblast. The fetus receives 50% of progesterone, where it is metabolized and used for the synthesis of corticosteroids in the adrenal glands of the fetus. The rest passes through a series of transformations into estriol. Progesterone causes changes in the mother's body, contributing to the emergence and development of pregnancy
ness. Under its influence, secretory processes occur, which are necessary for the implantation and development of the ovum. Progesterone also promotes the growth of the genitals of the pregnant woman, the growth and preparation of the mammary glands for lactation, is the main hormone that reduces the contractility of the myometrium, reduces the tone of the intestines and ureters, has an inhibitory effect on the central nervous system, causing drowsiness, fatigue, impaired concentration, and in addition, it helps to increase the amount of adipose tissue due to hypertrophy of fat cells (adipocytes). The metabolite of progesterone, pregnandiol, is excreted in the urine.
The main protein hormones of pregnancy are chorionic gonadotropin (HCG) and placental lactogen (PL). HCG is a glycoprotein produced by the chorion even before the formation of the placenta. In terms of its biological properties, it is similar to the LH of the pituitary gland, contributes to the preservation of the function of the corpus luteum of the ovary, affects the development of the adrenal glands and fetal gonads, affects the exchange of steroids in the placenta. CG is detected in urine already on the 9th day after fertilization, reaches a peak concentration by 10-11 weeks of pregnancy (about 100,000 units), and then its level remains constantly low (10,000-20,000 units). Currently, the definition of hCG is used to diagnose early pregnancy and its disorders, as well as to diagnose trophoblast diseases.
PL is a polypeptide hormone, in its chemical and immunological properties close to the growth hormone of the anterior pituitary gland and prolactin. It is synthesized in the trophoblast syncytium. 90% of the hormone enters the blood of the pregnant woman, and 10% - into the blood of the fetus and amniotic fluid. PL can be detected in blood from 5 weeks of gestation. Long-term low levels of prolactin or a sharp drop in the level of the hormone indicate a violation of the condition of the fetus up to its antenatal death.
PL affects metabolic processes that are aimed at ensuring the growth and development of the fetus. PL gives an anabolic effect, retains nitrogen, potassium, phosphorus, calcium in the body; has a diabetogenic effect. Due to its anti-insulin action, PL leads to an increase in glyconeogenesis in the liver, a decrease in the body's tolerance to glucose, and an increase in lipolysis.
The placenta produces a number of other protein-peptide hormones such as melanocyte-stimulating hormone, relaxin, vasopressin,
oxytocin. Similar to insulin and insulin-like growth factor, relaxin is secreted by the corpus luteum of pregnancy, the placenta and deciidua parietalis. In the first trimester, it stimulates the synthesis of hCG. In addition, relaxin performs the following functions: relaxation of the uterus, shortening and softening of the cervix, regulation of uteroplacental blood flow, softening of the pelvic joints.
Methods for studying specific proteins of pregnancy have found clinical application, because they are produced directly in the placental trophoblast and reflect the functional state of the fetoplacental system. Embryospecific protein is α -fetoprotein (AFP), which is synthesized mainly by embryonic cells and in the yolk sac. In embryos, AFP synthesis begins simultaneously with embryonic hematopoiesis, and its concentration in blood plasma increases from 6-7 weeks of gestation, reaching a peak at 14 weeks. In clinical practice, the determination of AFP is carried out for prenatal diagnosis of anomalies in the development of the nervous system and gastrointestinal tract in the fetus.
The placenta performs important functions of the immunological protection of the fetus. One of the components of this system is a layer of fibrinoid located on the surface of the villi and preventing direct contact between the tissues of the fetus and the mother. Immunosuppressive action is possessed by some substances located on the surface of the placenta in high concentrations (hCG, progesterone, steroid hormones), as well as some proteins of the fetus and placenta (AFP, trophoblastic R 1-glycoprotein, etc.).
The placenta plays an important role in the transport of immunoglobulins. Of the immunoglobulins of the five classes, only IgG is capable of transplacental transition. The transfer of immunoglobulins in the motherfetus system begins only after 12 weeks of pregnancy and has important biological significance.
Pituitary. The anterior lobe of the pituitary gland during pregnancy increases in size by 2-3 times due to the multiplication and hypertrophy of cells that produce hormones:
Prolactin, which helps prepare the mammary glands for lactation, by the end of pregnancy, its concentration increases 10 times or more, it is also synthesized by the placenta and is found in amniotic fluid (the function of prolactin in the amniotic fluid is not yet precisely known, it has been shown that it promotes fetal lung maturation);
Thyroid stimulating hormone (TSH), leading to an increase in thyroxine production and an increase in the activity of the thyroid gland, which is necessary for the proper development of the fetus;
Adrenocorticotropic hormone (ACTH) promotes an increase in the hormonal activity of the adrenal glands;
Growth hormone (GH), which affects the growth of the uterus and other organs of the reproductive system, and can also cause transient acromegaloid features (enlargement of the limbs, lower jaw, brow ridges) in some pregnant women, disappearing after childbirth.
The formation and release of gonadotropic hormones of the pituitary gland (luteinizing and follicle-stimulating) sharply decreases, which causes a decrease in hormone production in the ovaries and the cessation of the growth and development of follicles.
During pregnancy, the formation of oxytocin and vasopressin by the supraoptic and paraventricular nuclei of the hypothalamus is enhanced. Oxytocin has a specific tonomotor effect on the myometrium. The accumulation and effect of oxytocin are in direct proportion to the accumulation of estrogen and serotonin in the placenta, which block oxytocinase, an enzyme that inactivates oxytocin in the blood of a pregnant woman.
Adrenal glands during pregnancy, they undergo significant changes. Education is strengthening:
Glucocorticoids, which regulate carbohydrate and protein metabolism;
Mineralocorticoids, which regulate mineral metabolism;
Estrogens, progesterone and androgens in the adrenal cortex. An increase in the concentration of corticosteroids during pregnancy is not
causes pronounced clinical manifestations of hypercortisolism, which is explained by a simultaneous increase in the concentration in the plasma of binding globulin - transcortin.
The increased function of the mother's adrenal cortex contributes to the delivery of the necessary amounts of nutrients, salts and hormones to the growing fetus, which the embryo itself is not yet able to produce.
An increase in blood cholesterol and other lipids is associated with the activity of the adrenal glands.
During pregnancy, insulin secretion increases, which is determined by the physiological needs of the body, as well as the influence of placental lactogen.
Thyroid during pregnancy, it increases in 35-40% of women due to hyperemia, an increase in the number of follicles and the content of colloid in them. CG has an effect on the thyroid gland similar to that of TSH. In the first months of pregnancy, there is often a slight increase in the function of the thyroid gland (Fig. 21), an increase in the content of iodine in the blood associated with protein, but there are no hyperthyroidism phenomena. In the second half of pregnancy, there are no signs of increased thyroid function.
In the parathyroid glands, there is often a tendency to hypofunction. In such cases, disturbances in calcium metabolism are possible, leading to spastic phenomena (cramps in the calf muscles, etc.).
Rice. 21. Changes in thyroid function during pregnancy
THE IMMUNE SYSTEM
During normal pregnancy, the maternal immune system (Table 4) does not reject the fetoplacental complex, although it has alloantigens of paternal origin, which are immunologically different from maternal antigens. The existence of an allogeneic fetus is ensured by the development of metabolic immunosuppression in the body of a pregnant woman, suppression of cellular and, to a lesser extent, humoral immunity is noted. During pregnancy, a unique new
balance between the specific and nonspecific immunity of the mother, in which the central cell of the immunological adaptation of the mother becomes not a lymphocyte, but a monocyte. It is the factors of natural immunity that direct the specific immune response along the Th1 (cellular, inflammatory) or Th2 (humoral, immune) pathways.
From the early stages of pregnancy, there is an increase in the number of monocytes and granulocytes in the mother's blood, and the absorption activity of macrophages increases. These monocytes secrete a large number of cytokines, including interleukins - IL-12. The concentration of complement proteins in the blood serum also increases.
Table 4
The immune system during pregnancy
There is a hypothesis that the activation of innate immunity in pregnant women occurs due to the entry into the bloodstream of a number of soluble placental products (Table 5), which have a suppressive effect on lymphocytes and an activating effect on monocytes.
Table 5
Influence of placental factors on the activity of cells of the immune system
During normal pregnancy, the mechanisms of systemic immunosuppression are activated. The negative side of immunosuppression in pregnant women is an increased susceptibility to infectious diseases.
METABOLISM
Metabolism during pregnancy is characterized by the following.
1. The number of enzymes (phosphatases, histaminases, cholinesterase) increases and the activity of enzyme systems increases.
2. Protein metabolism: the content of proteins in blood serum is slightly reduced due to amino acids and albumin; specific proteins of pregnancy appear in the blood.
3. Carbohydrate metabolism: there is an accumulation of glycogen in the cells of the liver, muscle tissue, uterus and placenta. Carbohydrates are transferred to the fruit mainly in the form of glucose, which it needs as a high-energy material and as a substance that provides the processes of anaerobic glycolysis. An increase in the level of cortisol, growth hormone and PL in the blood causes a compensatory increase in the insulin content. Pregnancy is a diabetogenic factor, with a hidden inferiority of the insular apparatus of the pancreas or a hereditary predisposition to diabetes mellitus, glucose tolerance decreases.
4. Lipid metabolism (Fig. 22): the amount of free fatty acids, cholesterol, triglycerides, lipoproteins, mainly atherogenic (low and very low density lipoproteins), increases in the blood. Fats are transferred to the fruit in the form of glycerin and fatty acids. In the fetus, these compounds are consumed in the construction of tissues;
the role of fatty substances as an energetic material is great. Lipid accumulation also occurs in the adrenal glands, placenta and mammary glands.
Rice. 22. Lipid metabolism during pregnancy
5. Mineral and water exchange:
The assimilation of phosphorus, calcium salts, necessary for the development of the nervous system and the skeleton of the fetus, as well as for the synthesis of proteins in the body of a pregnant woman, is enhanced;
The consumption of iron increases (a pregnant woman should receive 4-5 mg of iron per day) and other inorganic substances: potassium, sodium, magnesium, chlorine, cobalt, copper, etc.;
In pregnant women, the release of sodium chloride from the body slows down, which leads to water retention in the body, which is necessary for the physiological hydration of the tissues and joints of the pelvic bones; in the regulation of water metabolism during pregnancy, estrogens, progesterone, natriuretic factor play an important role (contributes to an increase in renal blood flow, glomerular filtration rate, as well as a decrease in renin secretion), adrenal cortex hormones (mineralocorticoids), in particular aldosterone, deoxycorticosterone;
The need for vitamins increases due to the need to supply the fetus with them and maintain an intensive metabolism; hypovitaminosis during pregnancy causes many forms of pathology in both the mother and the fetus.
Body weight (Table 6) increases over the entire period of pregnancy by 12-14%, ie. on average 12 kg. Normally, weight gain in the second half of pregnancy should not exceed 300-350 g per week. The increase in body weight is due to:
Conception products (fetus, placenta and amniotic fluid);
Maternal factors (uterus, mammary glands, increased BCC, increased body fat, fluid retention).
In the first 20 weeks of pregnancy, the contribution of the fetus to the weight gain is insignificant, but in the second half, the fetal weight grows faster. The mass of the placenta increases in accordance with the growth of the fetus, which is reflected in the graph (Fig. 23). The volume of amniotic fluid rapidly increases from 10 weeks of gestation, amounting to 300 ml at 20 weeks, 600 ml at 30 weeks, reaching a peak of 1000 ml by 35 weeks. After that, the amount of amniotic fluid decreases slightly.
Rice. 23. Dynamics of the weight of the fetus and placenta
Table 6
Distribution of weight gain during pregnancy
The mass of the uterus during pregnancy increases from 50 to 1000 g, and the mammary glands also increase due to the growth of glandular elements, fat deposition and fluid retention. BCC increases, as well as the amount of body fat. During normal pregnancy, the total amount of fluid increases by 6-8 liters, of which 2-4 liters are extracellular. Most of the fluid is retained for up to 30 weeks, however, even in women without clinically pronounced edema, 2-3 liters of extracellular fluid are retained in the last 10 weeks of pregnancy.
THE CARDIOVASCULAR SYSTEM
During pregnancy, significant changes occur in the cardiovascular system, which create the possibility of fetal development and functionally provide the process of childbirth.
The increase in stress on the cardiovascular system of a pregnant woman's body depends on the following factors.
Mechanical factors - high standing of the diaphragm, restriction of respiratory movements, transverse position of the heart axis, changes in the shape of the chest, increased intra-abdominal pressure, general weight gain;
Hemodynamic factors - an increase in the capacity of the vascular system, the emergence of the uteroplacental circle of blood circulation, an increase in the BCC, pulse rate and cardiac output, changes in arterial and venous pressure.
Rice. 24. Change in BCC during pregnancy
During pregnancy, the BCC increases (Fig. 24), which causes physiological hypervolemia of pregnant women, aimed at maintaining optimal conditions for microcirculation in the placenta and other vital organs of the mother during pregnancy and childbirth. The protective effect of hypervolemia allows some pregnant women to lose 20-25% of their blood volume without developing severe hypotension.
The volume of blood plasma begins to increase from the 10th week of pregnancy and progressively increases until the 34th week, after which the intensity of the increase decreases. In general, the volume of circulating plasma (VCP) during pregnancy increases by 35-50%, and in multiparous women, VCP exceeds that in primiparas by about 10%. With twin pregnancy, the increase in VCP is even more significant. Increased plasma volume (total body water)
due to endocrine changes in a pregnant woman, an increase in the secretion of aldosterone and the activity of the renin-angiotensin system, the secretion of placental hormones, leading to sodium and water retention. An increase in albumin synthesis also leads to an increase in VCP.
During pregnancy, an increase in the volume of circulating erythrocytes by 11-40% occurs, but the intensity of the increase in erythrocytes is less pronounced compared to that of the plasma volume. This causes the occurrence of physiological hemodilution of pregnant women and is characterized by a decrease in hematocrit to 0.32-0.36 and hemoglobin concentration to 110-120 g / l.
During pregnancy, the capacity of the vascular system increases. With a normal pregnancy, there is a decrease in the total peripheral blood resistance, which is caused by physiological hemodilution, a decrease in blood viscosity and the vasodilating effect of estrogens and progesterone. With a normal pregnancy in the first and second trimesters, there is a tendency to a decrease in diastolic blood pressure and, to a lesser extent, systolic (Fig. 25), resulting in an increase in pulse pressure. In the third trimester, blood pressure in pregnant women returns to normal levels. If the blood pressure in a pregnant woman is higher than it was in the period preceding pregnancy, then this indicates either complications (gestosis), or the body's response to stress.
Rice. 25. Dynamics of systolic and diastolic blood pressure during pregnancy
The individual level of blood pressure is determined by the interaction of the following main factors: a decrease in the total peripheral vascular resistance and blood viscosity, which contributes to a decrease in blood pressure, and an increase in blood volume and cardiac output, which contributes to an increase in blood pressure. With inadequate compensatory mechanisms, for example arteriolospasm and hypovolemia, an increase in blood pressure is observed. For a correct judgment about the level and dynamics of blood pressure, it is necessary to know the initial value of blood pressure before pregnancy (for example, for pregnant women with an initial blood pressure of 90/60, a pressure of 120/80 means undoubted hypertension). An increase in systolic pressure by 30% relative to the baseline should be regarded as a pathological symptom. With a normal pregnancy, the diastolic pressure should be no more than 75-80 mm Hg, and the pulse pressure should not be less than 40 mm Hg.
Rice. 26. Dynamics of venous pressure in the ulnar and femoral veins during pregnancy and the postpartum period
Venous pressure (Fig. 26) in the lower extremities increases from the 5-6th month of pregnancy (it is especially high in the position of the pregnant woman on her back) and by the end of it exceeds the venous pressure in the upper extremities by a factor of two. This is due to the compression of the inferior vena cava by the pregnant uterus, which relatively often causes swelling of the legs and varicose veins of the legs and external genitalia.
The most significant hemodynamic shift is considered to be an increase in cardiac output (Fig. 27) in the early stages of pregnancy: at 4-8 weeks it can exceed its average value in healthy non-pregnant women by 15%, the maximum increase is up to 40%.
Rice. 27. Changes in cardiac output during pregnancy
In the first half of pregnancy, the increase in cardiac output is mainly due to an increase in the stroke volume of the heart by 30%. Later, there is a slight increase in the heart rate (HR), which reaches a maximum in the third trimester of pregnancy, when the heart rate is 15-20 beats per minute higher than that of a non-pregnant woman (i.e., by 15%). With multiple pregnancies, the increase in heart rate reaches 20-30 beats per minute. It is believed that tachycardia is caused by a number of factors, including increased secretion of progesterone, starting in the first trimester of pregnancy.
In addition, during pregnancy, there is a regional redistribution of blood. Its inflow to the uterus by 16 weeks is 400 ml / min higher than that of non-pregnant women and remains at this level until the due date.
What are the main hemodynamic parameters during pregnancy is shown in Fig. 28.
Rice. 28. The main hemodynamic parameters during pregnancy
The blood flow through the capillaries of the skin and mucous membranes also increases, reaching a maximum of 500 ml / min - by 36 weeks. The increase in cutaneous blood flow is associated with peripheral vascular dilatation. This explains the frequent occurrence of a feeling of heat in pregnant women, increased sweating, some pregnant women may complain of nasal congestion.
RESPIRATORY SYSTEM
During pregnancy, a number of adaptive reactions occur, aimed at satisfying the increased metabolic activity. The development of compensatory reactions (they are similar to the mechanisms that contribute to the adaptation of the body to hypoxia) is primarily associated with the activity of the lungs (hyperventilation, respiratory alkalosis), the cardiovascular system (hemodynamic shifts, increased cardiovascular output) and the red blood system (activation of erythropoiesis, an increase in the volume of circulating erythrocytes).
With an increase in the uterus, there is a gradual displacement of the abdominal organs and a decrease in the vertical size of the chest, which is compensated by the expansion of its circumference, increased excursion of the diaphragm. During pregnancy, the frequency of respiratory movements increases by 10%. All these factors lead to
a gradual increase in tidal volume by the end of pregnancy by 30-40%.
Oxygen consumption by the end of pregnancy increases by 30-40%, and during attempts - by 150-250% of the original. Due to the fact that the need for oxygen during pregnancy increases, it is more difficult for a pregnant woman than for a non-pregnant woman to tolerate hypoxia of any genesis and severity. Physiological decrease in the level of pO 2 in the mother's blood does not affect the saturation of fetal blood with oxygen. This is due to the higher concentration of hemoglobin in the fetal blood and the higher affinity of fetal hemoglobin for oxygen.
The main changes in the respiratory system during pregnancy are shown in table. 7.
Table 7
The main changes in the respiratory system during pregnancy
ORGANS OF HEMOPOTIOLOGY
Hemopoiesis increases; increase: the number of erythrocytes, the amount of hemoglobin, leukocytes and blood plasma. ESR during pregnancy increases slightly - up to 20-30 mm / h, which is mainly associated with an increase in the concentration of fibrinogen.
During normal pregnancy, changes in the acid-base state of the blood are observed, which is expressed in the accumulation of acidic
exchange products. As the gestational age increases, the phenomena of metabolic acidosis and respiratory alkalosis increase. It is believed that maternal acidosis may be a consequence of the primary acidosis of the fetus due to the predominance of anaerobic glycolysis in its body. In most pregnant women, these changes are compensated, and there is no pH shift, which indicates a sufficient capacity of the body's buffer systems during physiological pregnancy.
SYSTEM OF HEMOSTASIS
Under normal conditions, hemostasis depends on the state of the vascular wall, platelets, coagulation factors and fibrinolysis. During pregnancy, significant changes occur in the coagulation system and fibrinolysis. The hemostasiological status is characterized by an increase in blood coagulation potential, an increase in the structural properties of a clot, and inhibition of enzymatic fibrinolytic activity. These changes, together with an increase in BCC, prevent bleeding during placenta separation, the formation of an intravascular thrombus, and play an important role in the prevention of pregnancy complications such as thromboembolism, bleeding after the development of disseminated intravascular coagulation. In normal pregnancy, there is an increase in the level of VII (proconvertin), VIII (antihemophilic globulin), X (Stewart factor) coagulation factors (from 50 to 100%), the level of prothrombin and factor IX (Christmas factor by 20-40% and especially the level of plasma fibrinogen The concentration of fibrinogen increases by 50%, which is the main reason for a significant increase in ESR during pregnancy.By 38-40 weeks of pregnancy, the prothrombin index also significantly increases. The number of platelets decreases slightly due to their increased consumption.
Fibrinolytic activity of plasma decreases during pregnancy, becomes the lowest during childbirth and returns to the initial level 1 hour after the birth of the placenta.
Changes in the hemostatic system are a unique feature of the gestational process, they are supported by the existence of the fetoplacental complex and, after the end of pregnancy, undergo
regression. However, in the case of the development of pathological conditions during pregnancy, the hemostatic system universally and nonspecifically reacts to them in the form of the formation of a blood ICS syndrome, the trigger points of which lie in physiological hemostatic reactions.
DIGESTIVE ORGANS
Many women in the early stages of pregnancy experience nausea, vomiting in the morning, taste sensations change, these phenomena gradually disappear. Progesterone helps to reduce the tone of smooth muscles. Due to the relaxation of the lower esophageal sphincter, intraesophageal pressure also decreases, with increased intra-abdominal and intragastric pressure, heartburn appears. The listed factors determine the danger of endotracheal anesthesia in pregnant women and women in labor - regurgitation and aspiration of gastric contents (Mendelssohn's syndrome) occur with a frequency of 1: 3000. Mechanical compression of the large intestine by the growing uterus leads to congestion and deterioration of peristalsis, constipation. Pregnant women often develop hemorrhoids due to constipation and an increase in venous pressure below the level of the growing uterus. There is an upward displacement of the anatomical structures, making it difficult to diagnose diseases of the abdominal cavity.
During pregnancy, liver function changes. Laboratory tests give results that are sometimes similar to those in liver pathology:
Alkaline phosphatase activity doubles (placental alkaline phosphatase isoenzyme);
The level of albumin and the albumin-globulin coefficient decrease.
The amount of glycogen in the liver decreases slightly, because a lot of glucose is transferred from the mother to the fetus. The intensity of fat metabolism changes (increased lipemia, high cholesterol content, increased fat deposition in hepatocytes). The protein-forming function of the liver also changes, aimed at providing the fetus with the necessary amount of amino acids. The synthesis of fibrinogen in the liver increases, the processes of inactivation of estrogens and other steroid hormones produced by the placenta are enhanced. Some
women with normal pregnancies have skin changes such as palmar erythema and petechial hemorrhages. They are considered not a manifestation of liver disease, but only a sign of an increase in the concentration of estrogen, and completely disappear by the 5-6th week after childbirth. The detoxification function of the organ is somewhat reduced. In addition, one should take into account the progesterone effect on the tone and motility of the biliary tract, which contributes to the occurrence of cholelithiasis and cholestasis even in healthy women.
ORGANS OF URINARY
The main changes in kidney function during pregnancy are as follows:
Increase in renal blood flow by 60-75%;
Increase in glomerular filtration by 50%;
Acceleration of the clearance of most substances;
Decrease in the level of creatinine, urea and urate in the blood plasma;
Possible glucosuria.
The urinary function of the kidneys is based on three main processes:
Glomerular filtration;
Tubular reabsorption;
Tubular secretion.
The kidneys function with increased stress, removing from the mother's body not only the products of her metabolism, but also the metabolic products of the fetus. Glomerular filtration increases by 30-50%. Typical for physiological pregnancy, compared with the norm for non-pregnant values of the concentration of creatinine and urea in the blood plasma.
An increase in glomerular filtration with a decrease in tubular reabsorption of filtered glucose may be accompanied by the development of glucosuria even in the physiological course of the gestational process, which is more often observed in the third trimester of pregnancy.
One of the main tests for diagnosing kidney pathology during pregnancy is proteinuria. It should be noted that during physiological pregnancy, the amount of protein excreted in daily urine is increased to 0.05 g / day, and therefore the diagnostic value of this test decreases.
Changes in the concentration and clearance indicators of renal function are accompanied by an increase in the indicators of the sodium / potassium ratio of urine, the clearance of endogenous creatinine, and osmotically free water.
The tone of the urinary tract decreases mainly as a result of the influence of placental progesterone, the capacity of the bladder increases slightly. Atony and expansion of the lumen of the ureters disrupt the passage of urine and can cause the onset or exacerbation of infectious diseases. Mechanical pressure in combination with the action of progesterone sometimes contributes to hydronephrosis, expansion of the lumen of the ureter (86% on the right).
BONE-MUSCULAR SYSTEM
The load on the spine of the pregnant woman increases, the gait changes ("proud step" of the pregnant woman). Progressive lordosis with an enlarging uterus shifts the center of gravity to the lower extremities. Changes during pregnancy are characterized by serous impregnation and loosening of the articular ligaments, symphyseal cartilage and synovial membranes of the pubic and sacroiliac joints, due to the effects of relaxin produced in the placenta. In this regard, there is a slight increase in mobility in the joints of the pelvis and the possibility of a slight increase in the capacity of the pelvis during childbirth, including due to the divergence of the pubic bones (normally, no more than 1 cm).
LEATHER
Deposition of brown pigment is often observed in the skin of the face, the white line of the abdomen, nipples and areola (pregnancy mask - chloasma or melasma gravidarum). The pigmentation is caused by melanocyte-stimulating hormone, a polypeptide similar to corticotropin, under its action in zona reticularis the adrenal glands synthesize a pigment similar to melanin. Estrogens and progesterone
also give a melanocyte-stimulating effect. In the same women, hormonal contraceptives can cause similar changes.
Under the influence of mechanical stretching and under the influence of hypercortisolism, pregnancy stripes appear (striae gravidarum) blue-purple in color, localized around the navel, in the lower abdomen, often on the thighs and on the mammary glands. These scars (a consequence of the divergence of connective tissue fibers) do not disappear after childbirth, but take on the appearance of whitish scars.
In 2/3 of pregnant women angiomas, telangiectasias, nevi appear, and in 2/3 - palmar erythema. They have no clinical significance and in most women disappear immediately after childbirth, as a result of hyperestrogenism.
MAMMARY GLAND
During pregnancy, the mammary glands reach full morphological maturity, their size increases due to the growth of glandular tissue. The number of alveoli, lobules, ducts increases. In the epithelium lining the alveoli, the secretion of colostrum begins. These changes occur under the influence of estrogens, progesterone, PL and prolactin. The nipples also grow, the areola circles are intensely pigmented. Montgomery's glands - hypertrophied sebaceous glands - appear on the areoles.
GENITAL ORGANS
The genitals undergo significant changes, especially in the uterus.
The size, shape, position, consistency and excitability of the uterus change. Its mass, equal to 50-100 g before pregnancy, increases to 1000 g (without the ovum) at the end of pregnancy. The volume of the uterine cavity increases by the end of pregnancy 500 times. The dynamics of the increase in the height of the fundus of the uterus is shown in the illustration (see below). After 12 weeks, the uterus extends beyond the pelvis. Physiological dextrorotation of the uterus is due to the presence of the sigmoid colon in the left side of the pelvis.
The mucous membrane of the uterus, which was in the secretion phase before the start of implantation, from the moment of attachment of the blastocyst undergoes a complex of complex morphological and biochemical changes and is called decidual - falling away.
Hypertrophy of the nerve elements of the uterus, an increase in the number of receptors, and growth of the vasculature are observed.
The amount of actomyosin (a complex compound of contractile proteins - actin and myosin) increases, which reduces the motor function of the uterus.
The amount of phosphorus compounds increases, as well as the energetically important creatine phosphate and glycogen.
By the time of delivery, there is an accumulation of serotonin, catecholamines. Serotonin is a progesterone antagonist and a synergist of estrogen hormones, contributes to the contractile activity of the uterus. Irregular, sporadic contractions of the uterus are called Braxton-Hyx contractions (described in 1872).
There is a hypertrophy of the ligamentous apparatus of the uterus, especially the round and sacro-uterine ligaments.
In the cervix, the processes of hypertrophy and hyperplasia are less pronounced. Due to the significant development of the venous network, the neck resembles spongy tissue, becomes cyanotic, edematous, softened. The cervical canal is filled with thick mucus (mucous plug), discharge of the mucous plug is a harbinger of childbirth. The external and internal os of the cervix in primipregnant women is closed before delivery, in re-pregnant women -
external pharynx in the last months of pregnancy with a vaginal examination misses a finger. From 4 months of pregnancy, the lower pole of the ovum stretches the isthmus of the uterus and occupies it, the isthmus becomes part of the fetus and is called the lower segment of the uterus. The lower segment is limited by the line of attachment of the peritoneum of the vesicouterine fold from above and by the level of the internal os of the cervix from below. This volume of the uterus contains fewer muscles and blood vessels, is thinner, and is usually the incision site for a caesarean section.
"RATE OF PREGNANCY"
In view of the above, in recent years in obstetric practice, the concept of "pregnancy rate" has begun to be used. Under the "norm of pregnancy" should be understood the average indicators of homeostasis and functional tests, characteristic of the uncomplicated development of pregnancy in a practically healthy woman at different stages of gestation.
To identify pathological disorders during pregnancy, it is necessary to clearly understand the permissible fluctuations of certain parameters. Previously, the main indicators of homeostasis of pregnant and non-pregnant women were compared, which does not seem entirely legitimate, since it does not reflect the functional changes inherent in the gestational process.
Knowledge of physiological changes in the body during normal pregnancy is necessary for a doctor of any specialty, since it allows you to quickly identify pathology that precedes complications of childbirth and the postpartum period or determines them. If the doctor ignores the above changes, it can lead to both an underestimation of the severity of the condition and an iatrogenic overcorrection in the treatment of complications or critical conditions.
Pregnancy this is a normal (physiological) process that takes place in a woman's body during the intrauterine development of the fetus. During pregnancy, a woman's body undergoes profound transformations. With the normal development of pregnancy, all changes that take place in a woman's body are aimed at creating a harmonious relationship between the mother's body and the developing fetus. Also, from the very first days of pregnancy, the preparation of the body of a pregnant woman for future childbirth and breastfeeding begins.
Below we will consider in more detail the most important changes in a woman's body during pregnancy, as well as their significance for normal evolution of pregnancy itself, childbirth and lactation period.
Body systems that undergo changes during pregnancy
From the very first days of pregnancy, the body of a pregnant woman undergoes profound transformations. These transformations are the result of the coordinated work of almost all body systems, as well as the result of the interaction of the mother's body with the child's body.
Nervous and endocrine system changes
The main roles in the implementation of the transformations of the female body during pregnancy are played by the nervous and endocrine systems.
At the level central nervous system(brain and spinal cord), complex nervous mechanisms are triggered, aimed at maintaining the constancy of substances in the body of a pregnant woman, which is necessary for the normal development of the fetus. For example, it was noted that up to the 39th week of pregnancy, impulses coming from the sensitive receptors of the uterus are blocked at the level of the spinal cord, which allows the preservation of pregnancy and prevents premature birth. Changes in the central nervous system lead to some changes in the mood and behavior of the pregnant woman. Especially in the first weeks of pregnancy, a woman may notice increased irritability, fatigue, drowsiness - all these are defense mechanisms developed by the central nervous system to prevent excessive fatigue of a pregnant woman. Changes in smell (intolerance to some odors), taste and gastronomic preferences, as well as incoming nausea, vomiting and dizziness are associated with a change in the tone of the vagus nerve (the nerve that regulates the work of most of the internal organs).
It is well known that the nervous and endocrine systems are in close interaction. This interaction is especially clearly manifested during pregnancy, the normal course of which is the result of the interaction of these two systems. The inclusion of the endocrine system in the development of pregnancy takes place even before fertilization. The normal functioning of the hypothalamus (the center of the brain responsible for the transmission of nerve signals from the nervous system to the endocrine system), the pituitary gland (the central human endocrine gland) and the ovaries (the sex glands of the woman's body) make possible the development of the egg and prepare the female reproductive system for fertilization. From the first days of pregnancy until the 10th week, the development of pregnancy is supported by hormones secreted by the ovaries. During this period, there is an intensive growth of the fetal placenta. The placenta, as you know, in addition to the role of nutrition for the fetus, also synthesizes hormones necessary for the normal development of pregnancy. The main hormone in the placenta is estriol (it is also called the protector of pregnancy). This hormone stimulates the development of blood vessels and improves the supply of oxygen and nutrients to the fetus.
In smaller quantities, the placenta synthesizes estrone and estradiol. Under the influence of these hormones, the reproductive organs of a pregnant woman grow: the uterus, vagina, mammary glands, an increase in the volume of circulating blood in the mother's body (to improve the nutrition of the fetus). If the functioning of the placenta is impaired (during various diseases of the mother or fetus), abortion or impaired fetal development (underdevelopment).
Also, the placenta synthesizes progesterone, which stimulates the development of the mammary glands and prepares them for lactation. Under the influence of progesterone, the muscles of the uterus and intestines relax. Progesterone has an inhibitory effect on the nervous system, determining the sleepiness and fatigue described above. The effect of progesterone on the development of adipose tissue in a pregnant woman is important. The storage of nutrients in adipose tissue during pregnancy is necessary for the nutrition of the fetus and the formation of milk in the postpartum period.
In addition to hormones synthesized in the placenta, various hormones produced by the endocrine system of the mother's body play an important role. It should be noted that at the initial stages of development, the body of the fetus is not able to synthesize many hormones, but they come to it from the mother's body. For example, thyroid hormones are an extremely important factor in fetal development. These hormones stimulate bone formation, brain growth and development, and energy production. To meet the needs of the fetus, the mother's body synthesizes large amounts of hormones.
Various incoming changes, such as skin pigmentation and an increase in the width of the bones and facial outlines, arise due to the action of the pituitary gland of a pregnant woman, which synthesizes melanotropin (a hormone that stimulates the production of skin pigment) and growth hormone (a hormone that stimulates the growth of the body).
Metabolic changes
Metabolic changes during pregnancy are aimed at meeting the needs of the developing fetus. It is clear that for the normal course of metabolism, and, consequently, the development of the fetus, the normal functioning of metabolic processes in the mother's body is necessary.
To increase the amount of assimilated food, the mother's body produces more digestive enzymes. At the level of the lungs, blood oxygen saturation increases. This is done mainly due to an increase in the number of erythrocytes, and an increase in the content of hemoglobin in them.
In the blood of a pregnant woman, there is an increase in the concentration of glucose and insulin, as well as fatty acids, proteins and amino acids. All of these nutrients cross the placenta into the blood of the fetus, thereby providing the developing body with material for growth and development.
It is important to change the metabolism of minerals in the body of a pregnant woman. An increase in the concentration of many minerals in the blood is observed: iron, calcium, phosphorus, copper, cobalt, magnesium. Like nutrients, these elements enter the fetal bloodstream through the placenta and are used by the growing body for development.
During pregnancy, the woman's body needs more vitamins. This is due to an increase in metabolic processes, both in the body of a pregnant woman, and with the fact that part of the vitamins from the mother's body passes into the body of the heart and is used by him for his own development.
Internal organ changes during pregnancy
During pregnancy, many internal organs undergo significant restructuring. These changes are adaptive in nature, and, in most cases, are short-lived and completely disappear after childbirth.
The cardiovascular system mothers have to pump more blood during pregnancy to ensure an adequate supply of nutrients and oxygen to the fetus. In this regard, during pregnancy, the thickness and strength of the heart muscles increases, the pulse and the amount of blood pumped by the heart in one minute become more frequent. In addition, the volume of circulating blood increases. In some cases, blood pressure rises. The tone of blood vessels decreases during pregnancy, which creates favorable conditions for an increased supply of nutrients and oxygen to tissues.
All of the above changes in the cardiovascular system completely disappear after childbirth.
Respiratory system works hard during pregnancy. The breathing rate increases. This is due to an increase in the need for the body of the mother and fetus for oxygen, as well as in the limitation of respiratory movements of the diaphragm due to an increase in the size of the uterus, which occupies a significant space of the abdominal cavity.
The most significant changes, however, occur in the genitals of a pregnant woman. These changes prepare a woman's reproductive system for childbirth and breastfeeding.
Uterus the pregnant woman increases significantly in size. Its mass increases from 50 g - at the beginning of pregnancy to 1200 - at the end of pregnancy. The volume of the uterine cavity by the end of pregnancy increases more than 500 times! The blood supply to the uterus is significantly increased. In the walls of the uterus, the number of muscle fibers increases. Cervix filled with thick mucus, clogging the cavity of the cervical canal. Fallopian tubes and ovaries also increase in size. In one of the ovaries, there is a "yellow body of pregnancy" - the place of synthesis of hormones that support pregnancy.
The walls of the vagina are loosened and become more elastic.
External genital organs(small and large labia), also increase in size and become more elastic. The tissues of the perineum are loosened. In addition, there is an increase in mobility in the joints of the pelvis and a divergence of the pubic bones. The changes in the genital tract described above are of extremely important physiological significance for childbirth. Loosening the walls, increasing the mobility and elasticity of the genital tract increases their throughput and facilitates the movement of the fetus along them during childbirth.
Leather in the genital area and along the midline of the abdomen, it usually becomes darker in color. Sometimes “stretch marks” (striae gravidarum) form on the skin of the lateral parts of the abdomen, which after childbirth turn into whitish stripes.
Mammary gland increase in size, become more elastic, tense. When pressing on the nipple, colostrum (first milk) is excreted.
The body weight of a pregnant woman increases in size. Normal weight gain at the end of pregnancy is 10-12 kg. Or 12-14% of the body weight of a pregnant woman.
All the changes described above that occur during pregnancy should be distinguished from the signs of the so-called "imaginary" or "false pregnancy". A false pregnancy occurs when a non-pregnant woman is convinced that she is pregnant. This situation is observed in a number of cases in patients with mental or endocrine disorders. At the same time, the power of a woman's self-hypnosis is so great that some physiological changes characteristic of a real pregnancy occur: an increase in the mammary glands, the appearance of colostrum, the disappearance of menstruation. Examination of the patient helps to establish a diagnosis and recognize a false pregnancy. It is also important to recognize a false pregnancy from a simulated pregnancy, in which a woman knows that she is not pregnant, but, based on some considerations, tries to convince others otherwise.
Bibliography:
- Kokhanevich E.V. Topical issues of obstetrics, gynecology and reproductology, M Triada-X, 2006
- Savelyeva G.M. Obstetrics, Medicine, M., 2000
- Karr F. Obstetrics, gynecology and women's health, MEDpress-inform 2005