Changes in the body during pregnancy. General changes in the body during pregnancy

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.

There are changes in the functioning of the nervous system.

The consumption of various nutrients by cells and tissues of our body changes

Changes in the functioning of the immune system occur.

The load on the excretory system is increasing.

The volume of circulating blood almost doubles by the end of pregnancy.

The work of a woman's digestive system is changing.

The importance of the smooth functioning of the endocrine system is increasing.

The woman's respiratory system is under increasing stress.

There are changes in the load on the woman's musculoskeletal system.

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 the period of bearing a child, a woman changes dramatically in physiological and psychological terms. All organs and systems, appearance, well-being undergo changes. What do you need to know about the upcoming changes when pregnancy occurs?

When do changes begin in a woman's body during pregnancy

The expectant mother does not yet know about her interesting position, and her body is already rebuilding its work. Changes in the body begin from the first days after successful conception. This is fine. The expectant mother still does not feel toxicosis, and chorionic gonadotropin (hCG), a pregnancy hormone, is already beginning to increase in her blood. It is his doctors who call the main identification mark of a successful conception. HCG starts the process of carrying a baby, preparing the body for childbirth.

It is worth noting that internal changes are felt in different ways. Some already from the first weeks of bearing a child begin to vomit, constantly fall asleep. Others may not experience signs of either early or late toxicosis at all, despite the fact that everything inside the body is changing. There are women who, almost without feeling physiological changes, change greatly psychologically. They become touchy, whiny, angry, nervous. And these are also symptoms of hormonal changes.

How the body changes during pregnancy by month

If we talk about the first two months of gestation, then the external parameters of the female body have not yet changed. Weight gain is not felt in the early stages. More often the opposite. Toxicosis leads to the fact that the expectant mother loses a kilogram or two.

At the end of the second or third month, some pregnant women are worried about increased urination, which is caused by the pressure of the uterus on the bladder and a general increase in the volume of fluid in the body.

Also, in the first two months, a woman may feel swelling of the mammary glands. This is due to an increase in the level of estrogen and progesterone in the blood. Also, the area around the nipples darkens and increases. Breast sensitivity increases. In some women, the vascular network may even protrude. This is how the mammary glands prepare to supply the baby with milk.

In the first two months, women sometimes experience bleeding. Only a doctor can determine the degree of their danger.

By the end of the third month, the external parameters of the body hardly change. If a woman had early toxicosis, then her health improves. She continues to go to the toilet more often, but already due to the formation of the baby's excretory system.

The first constipation and heartburn may begin. As for the weight, the increase can be a kilogram and a half. Until 12 weeks of the term, many women notice from their clothes that their pelvis has expanded.

An inconvenience in the third month of carrying a baby can be caused by a lack or, on the contrary, an increase in appetite, headaches, pigmentation on the face.

From the fourth month of marriage between the fetus and the mother, it is time to think about looser clothes. The tummy begins to grow, but those around it do not yet notice. By the end of the fourth month, the fundus of the uterus is 17-18 centimeters above the pubic bone. It is during this period that a woman's gait begins to change. The upper torso is tilted back a little and the belly is tilted forward.

The inconveniences of this period are indigestion, bleeding gums, fainting and dizziness, nosebleeds, mild swelling of the feet and ankles.

In the fifth month of pregnancy, many women experience a lack of calcium in their bodies. This is manifested by dental problems. If a woman consumes little calcium-containing products, then fillings may fall out, teeth crumble.

Another symptom of calcium deficiency can be leg cramps.

The growth of the uterus is accompanied by pain in the lower abdomen, constipation, and increased urination at night. Gums may bleed, varicose veins of the legs or hemorrhoids appear.

Another thing that happens in a woman's body is skin pigmentation on the abdomen.

By the end of the fifth month of carrying a baby, a woman feels the first movements of her baby. Her growing tummy is visible to others. And she herself sees how the hips are rounded, fatty deposits appear on them.

At the sixth month of the term, there is a risk of compression of large veins. This is manifested by progressive varicose veins, pain in the legs, and their edema.

By the 24th week of intrauterine development, the baby has filled the entire uterine cavity. It increases, stretches, which is felt by all organs of the small pelvis. The woman becomes noticeably round.

During this period, many pregnant women can feel training contractions (or, as gynecologists also call them, Braxton Hicks contractions). They are neither painful nor dangerous.

Seventh month of pregnancy. The uterus rises high and already supports the diaphragm. The whole body feels the load and regular swelling appears. Many women complain of lower abdominal pain, increased vaginal discharge, ear congestion, itching of the abdominal skin, back pain. During this period, sleep problems usually begin, and colostrum may also appear. Most women notice stretch marks on their bodies by this time.

At the eighth month, the uterus is very sensitive to the baby's movements. The woman feels it by the tension of the muscles. Many develop late toxicosis. The amount of blood in a woman's body increases by approximately one liter.

By 36 weeks, the uterus moves away from the diaphragm, it moves forward, because the baby's head is pressed against the entrance to the pelvis.

The inconveniences of the eighth month are shortness of breath, increasing constipation, swelling of the face and hands, difficulty sleeping, heaviness when walking, fatigue. Visually, the woman becomes clumsy.

The ninth month is the period of maximum increase in the load on the body of a pregnant woman. The stomach goes down. The placenta has developed its resources, so the baby "insists" on life outside the womb.

The expectant mother is experiencing severe pain in her back, legs, and lower abdomen. To maintain balance, the pregnant woman is forced to walk, leaning back. She walks more slowly, more carefully.

The mammary glands are greatly enlarged, and the appearance of colostrum already portends childbirth.

The load on the woman's body during pregnancy

The cardiovascular system adapts to additional stress. It does this by increasing the mass of the heart muscle. By the seventh month of the term, the volume of blood in the body increases by one liter. In the last trimester, many women are worried about high blood pressure. The activity of the lungs also increases. The increased volume of air that is inhaled makes it easier for the fetus to move carbon dioxide out of the placenta. The respiratory rate slightly increases towards the end of the term.

The kidneys are extremely stressed during pregnancy. A pregnant woman excretes up to 1600 ml of urine per day, 1200 of which leaves during the day, the rest of the portion - at night. The tone of the bladder decreases, and this can lead to urinary stagnation and contributes to infection.

Under the influence of hormones, intestinal tone also decreases, which leads to frequent constipation. The stomach is compressed, some of its contents are sometimes thrown into the esophagus, which causes heartburn in the second half of pregnancy.

The main barrier organ, the liver, also works with a double load. It neutralizes the metabolic products of the expectant mother and the fetus.

The pressure on the joints increases. The joints of the pelvis become especially mobile under the influence of the growing body weight.

In the mammary glands, the number of lobules and the amount of adipose tissue increase. The breasts can double in size. The greatest changes are experienced by the uterus, which complicates the work of all organs of the small pelvis. The volume of her cavity for childbirth increases by about 500 times. It does this by increasing the size of the muscle fibers.

The position of the uterus changes in parallel with the increase in its size. By the end of the first trimester, the organ “leaves” the pelvis. The uterus reaches the hypochondrium closer to childbirth. She stays in the correct position thanks to the ligaments that stretch and thicken. But the pains that pregnant women experience in the third trimester are just caused by the tension of these ligaments.

Since the blood supply to the genitals increases, varicose veins may appear on the labia. The growth of the fetus in the womb contributes to an increase in her body weight.

By the end of pregnancy, a healthy woman's weight increases by an average of 12 kilograms. But an increase from 8 to 18 is allowed. In the first half of the term, the weight may increase by 4-5 kilograms. In the second half of bearing a baby, this figure is twice as large. Usually, visually, weight gain in obese women is not visible, but thin women are noticeably rounded. They are more difficult to withstand the increasing load on the body.

Especially for - Diana Rudenko

Table of contents of the topic "Fetus in separate periods of development. Fetus as an object of childbirth. Changes in a woman's body during pregnancy.":
1. Fetus in certain periods of development. Two (II) month old fetus. Development level of two (II) month old fetuses.
2. The level of development of a three to six month old fetus. Signs of a three to six month old fetus.
3. The level of development of a seven to eight month old fetus. The maturity of the newborn. Signs of maturity in a newborn.
4. The fetus as an object of childbirth. Fetal skull. Fetal skull sutures. The fontanelles of the fetal skull.
5. The size of the fetal head. Small oblique size. Medium oblique size. Straight size. Large oblique size. Vertical dimension.
6. Changes in a woman's body during pregnancy. The mother-fetus system.
7. The endocrine system of a woman during pregnancy.
8. The nervous system of a woman during pregnancy. Gestational dominant.

10. Respiratory system of a woman during pregnancy. Respiratory volume of pregnant women.
11. The digestive system of a woman during pregnancy. Liver in pregnant women.

During pregnancy there are significant changes in activities cardiovascular system of the mother... These changes make it possible to provide the intensity of delivery of oxygen and a variety of nutrients necessary for the fetus and the removal of metabolic products.

The cardiovascular system functions during pregnancy with increased stress. This increase in load is due to increased metabolism, an increase in the mass of circulating blood, the development uteroplacental circulation, a progressive increase in the body weight of a pregnant woman and a number of other factors. As the size of the uterus increases, the mobility of the diaphragm is limited, intra-abdominal pressure increases, the position of the heart in the chest changes (it is located more horizontally), and some women experience a mild functional systolic murmur at the apex of the heart.

Among the many changes of cardio-vascular system, inherent in physiologically ongoing pregnancy, first of all, an increase in the volume of circulating blood (BCC) should be noted. An increase in this indicator is noted already in the first trimester of pregnancy and in the future it constantly increases, reaching a maximum by the 36th week. The increase in BCC is 30-50% of the initial level (before pregnancy).

Hypervolemia occurs mainly due to an increase in blood plasma volume (by 35-47%), although the volume of circulating erythrocytes also increases (by 11-30%). Since the percentage increase in plasma volume exceeds the increase in red blood cell volume, a so-called physiological anemia of pregnancy... It is characterized by a decrease in the hematocrit number (up to 30%) and hemoglobin concentration from 135-140 to 100-120 g / l. Since a decrease in the hematocrit number is observed during pregnancy, a decrease in blood viscosity occurs. All these changes, which have a pronounced adaptive character, ensure the maintenance during pregnancy and childbirth of optimal conditions for microcirculation (oxygen transport) in the placenta and in such vital organs of the mother as the central nervous system, heart and kidneys.

With a normal pregnancy, systolic and diastolic blood pressure decreases in the II trimester by 5-15 mm Hg. Peripheral vascular resistance is also usually reduced. This is mainly due to the formation of the uterine circle of blood circulation, which has a low vascular resistance, as well as to the effect on the vascular wall of estrogens and progesterone of the placenta. A decrease in peripheral vascular resistance, together with a decrease in blood viscosity, greatly facilitates hemocirculation.

Venous pressure measured on the hands of healthy pregnant women does not change significantly.

During pregnancy, there is physiological tachycardia... The heart rate reaches its maximum in the III trimester of pregnancy, when this indicator is 15-20 per minute higher than the initial data (before pregnancy). Thus, the normal heart rate in women in late pregnancy is 80-95 per minute.

The most significant hemodynamic shift in pregnancy is the increase in cardiac output. The maximum increase in this indicator at rest is 30-40% of its value before pregnancy. Cardiac output begins to increase from the earliest stages of pregnancy, while its maximum change is noted at 20-24 weeks. In the first half of pregnancy, an increase in cardiac output is mainly due to an increase in the stroke volume of the heart, later - a slight increase in the heart rate. The minute volume of the heart increases partly due to the effect on the myocardium of placental hormones (estrogens and progesterone), partly as a result of the formation of the uteroplacental circulation.

Electrocardiography, carried out in the dynamics of pregnancy, allows you to detect a persistent deviation of the electrical axis of the heart to the left, which reflects the displacement of the heart in this direction. According to echocardiography, there is an increase in the mass of the myocardium and the size of individual parts of the heart. X-ray examination finds changes in the contours of the heart, reminiscent of the mitral configuration.

The processes of hemodynamics during pregnancy are greatly influenced, as already noted, has a new uteroplacental circulation... Although the blood of the mother and the fetus does not mix with each other, changes in hemodynamics in the uterus are immediately reflected in blood circulation in the placenta and in the fetus and vice versa. Unlike the kidneys, central nervous system, myocardium and skeletal muscles, the uterus and placenta are not able to maintain their blood flow at a constant level with changes in systemic blood pressure. The vessels of the uterus and placenta have low resistance and blood flow in them is passively regulated mainly due to fluctuations in systemic arterial pressure. In the later stages of pregnancy, the vessels of the uterus are maximally expanded. The mechanism of neurogenic regulation of uterine blood flow is mainly associated with adrenergic influences. Stimulation of alpha-adrenergic receptors causes vasoconstriction and a decrease in uterine blood flow. A decrease in the volume of the uterine cavity (prenatal rupture of amniotic fluid, the appearance of contractions) is accompanied by a decrease in uterine blood flow.

Despite the existence separate circles of blood circulation in the uterus and placenta(the placental membrane is on the way of the two blood flows), the hemodynamics of the uterus is closely connected with the circulatory system of the fetus and the placenta. The participation of the capillary bed of the placenta in the blood circulation of the fetus consists in the rhythmic active pulsation of the chorionic capillaries, which are in constant peristaltic movement. These vessels with varying blood volume cause alternate lengthening and contraction of the villi and their branches. This movement of villi has a significant effect not only on the fetal blood circulation, but also on the circulation of maternal blood through the intervillous space. Therefore, the capillary bed of the placenta can rightly be considered as the "peripheral heart" of the fetus. All these features of the hemodynamics of the uterus and placenta are usually combined under the name "uteroplacental circulation".

All the metamorphoses that take place in the body of the expectant mother are due to one and only reason: her body is trying to provide the newly born life with all the necessary conditions for harmonious growth and development.

When do changes begin in a woman's body during pregnancy?

Changes in the body begin to occur from the very first day after conception. A woman may not be aware of her interesting position at all, since nothing changes except the level of hCG.

Reference! HCG (Chronological Gonadotropin) is a hormone that begins to be produced by the chorionic tissue on the 6-8th day after the cell is fertilized. This is one of the most important indicators of a successful conception.

The first weeks of pregnancy pass for each woman individually: some do not feel any changes at all, others suffer from drowsiness and apathy, while others, on the contrary, become too sensitive and receptive. All this speaks of the restructuring of the hormonal background.

In the first two months a pregnant woman may experience the following changes:

• Toxicosis - is expressed by bouts of nausea and increased susceptibility to odors. Sometimes, against the background of vomiting, a woman slightly loses weight.
• Frequent urination - the general level of fluid in the body rises, the uterus begins to press on the bladder.
• Swelling of the mammary glands - the level of estrogen and progesterone increases, the breasts become larger and more sensitive. The halo around the nipples also darkens and grows. Sometimes the vascular network becomes visible.

In the third month the external parameters of the body hardly change, with the exception of a slight increase in weight (1 - 1.5 kg). Toxicosis subsides, health improves. Frequent urge to go to the toilet for little need is now due not only to the pressure of the uterus on the bladder, but also to the formation of the excretory system in the embryo. Of the inconveniences in the third month, uncontrolled changes in appetite can be noted, from hunger to complete aversion to food. Headaches become more frequent.

In the fourth month the belly begins to round, and the expectant mother should think about purchasing looser and more comfortable clothes. The gait becomes more angular (the belly moves forward and the back bends back). The uterus begins to press on the intestines, which causes digestive disorders. The swelling becomes more noticeable, especially on the face and ankles.

Fifth month for many expectant mothers it is remembered as the time when the lack of calcium in the body is felt to the full. Teeth can begin to crumble, old fillings fall out, nails break and hair chops. In some cases, muscle cramps appear. Due to the increase in body weight, the veins in the legs (varicose veins) come out.

At the beginning of the sixth month the woman happily feels the first movements of the baby inside the womb. The way her thighs and belly are rounded is noticeable even to those around her.

Note! During this period, many pregnant women may begin to experience so-called training contractions (Braxton Hicks contractions). They are not painful or harmful.

In the seventh month the uterus rises so high that it begins to prop up the diaphragm. The whole body is under intense stress. Many women suffer from severe back pain and an increase in natural vaginal discharge. In some cases, stretch marks appear on the body.

At eight months the uterus becomes very sensitive to all movements of the child, and the woman feels this by the tension of the muscles. Many people develop “late toxicosis”. Of the inconveniences of this period, shortness of breath, swelling, sluggishness and chronic fatigue can be noted.

Ninth, final month- this is the period when the woman's body is experiencing colossal overload. Severe back pain and a large abdomen force the expectant mother to walk strongly backward. Colostrum begins to flow from the nipples.

What changes can be observed in the body during pregnancy:

To understand what changes occur in the body of a pregnant woman, it is worth breaking them down into points and considering each separately.

- body weight and metabolism

During the entire pregnancy, a woman gains weight by 8 - 18 kg. Do not be intimidated by this figure, because all the weight is dispersed according to the following principle:

• Fetus, amniotic fluid, placental membranes - from 4 to 4.5 kg.
• Uterus- the weight of the uterus increases from 50-100 grams to 1 kg.
• Blood- while carrying a child, about 1 liter of blood is added to the body of a pregnant woman.
• Adipose tissue and interstitial fluid - about 5 kg.

Reference! In the first half of pregnancy, the weight increases by about 4 kg, in the second - 2 times more.

The woman's metabolism is being rebuilt taking into account the fact that another small person grows and lives in the womb. The production of digestive enzymes is doubled. A woman should make such a menu for herself so that, together with food, a sufficient amount of nutrients, vitamins and microelements enter her body.

- nervous system

The first 4 months of pregnancy are accompanied by inhibition of the nervous system. In most cases, the expectant mother becomes lethargic, sleepy and lethargic. Thus, her body creates all the conditions for the ovum to be fixed, and the embryo began to develop.

After 4 months, the situation changes dramatically: abrupt mood swings appear, and the reaction to mental and physical stimuli is aggravated. In some cases, neuralgic back pain appears.

- respiratory system

In the last stages, the growing uterus shifts the diaphragm upward, however, this does not in any way affect the volume of inhaled and exhaled air. The respiration rate remains the same. Physiological changes are minimal.

- cardiovascular system, blood pressure

Unlike the respiratory system, the cardiovascular system undergoes significant changes:

• The volume of circulating blood increases: at about 32 weeks, it becomes 35% more than before pregnancy. This meets the increased requirements of the uterus and the fetus, protects against hypotension syndrome in the supine position and critical blood loss during childbirth.
• The composition of the blood changes. The number of erythrocytes slightly decreases, the level of folic acid in the plasma decreases, the concentration of hemoglobin and the value of hematocrit decrease. This increases the number of leukocytes, the erythrocyte sedimentation rate and the concentration of fibrinogen.
• Blood pressure changes. In the first half of pregnancy, blood pressure decreases, and in the second, on the contrary, it rises. It is important to ensure that pressure surges are not accompanied by a sharp deterioration in well-being.
• The venous pressure in the legs rises, and also compression of the central nerve highways occurs. This can provoke varicose veins, severe swelling of the extremities, and in some cases even hemorrhoids.

- organs of digestion and excretion

Many expectant mothers notice changes in the work of the digestive tract with the first signs of toxicosis - increased salivation, susceptibility to odors, nausea and vomiting. Unusual food addictions or aversions to familiar foods appear. Besides the obvious:

• metabolism accelerates;
• the liver begins to work in an enhanced mode, providing dehydration of decay products;
• there is a tendency to constipation or diarrhea, due to the fact that the growing uterus presses on the intestines.

- urinary organs

The urinary system works for two, which is why the expectant mother is forced to visit the ladies' room twice as often. In addition, as it grows, the uterus puts more pressure on the bladder, which also leads to frequent urination.

Reference! During pregnancy, the tone of the muscle layers of the urinary organs is significantly reduced.

- endocrine system

The endocrine system is a kind of "conductor" of the reproductive function. The normal functioning of the hypothalamus, pituitary and ovaries ensures the development of the egg and contributes to successful conception, and hormones produced by the endocrine gland are responsible for the formation of bone tissue and the brain of the embryo.

Changes in the functioning of the organism of the expectant mother are caused by the influence of the endocrine glands. The ovaries are slightly enlarged, and one of them contains a functioning corpus luteum for up to 4 months.

Then, the placenta takes over the production of progesterone and estrogen. The number of blood vessels that expand and encircle the uterus gradually increases.

- skin, hair and nails

As much as the expectant mother wants to look perfect while carrying a child, this does not always work due to natural physiological changes.

Due to the hormonal surge, the skin on the face can become more oily and covered with small pimples, as a rule, this is a normal and reversible process.

Reference! There is a sign that damage to the skin on the face and deterioration of the condition of the hair are a sign of bearing a girl.

It is not only the face that is hit - the chest and abdomen can be covered with brown age spots. This is due to a change in the activity of the adrenal glands. If the skin is not elastic enough, stretch marks appear on the abdomen and hips.

As for hair and nails, their condition is strongly influenced by the level of calcium in the body. As mentioned earlier, its deficiency becomes especially noticeable in the fifth month of pregnancy. Hair can begin to fall out, split, and nails - break and exfoliate. The situation can be corrected by adding calcium-containing foods and vitamin-mineral complexes to the diet.

It is noteworthy, but the loss of hair on the head can be accompanied by hair growth in completely unexpected places: the chin, coccyx, "path" from the navel to the groin, etc.

- the immune system

For clarity, it can be imagined that the body of a pregnant woman works in a mode of saving resource consumption, so that its reserves are enough to ensure the life of both the mother and the embryo growing in her womb.

Specific (acquired immunity) decreases significantly, while nonspecific, on the contrary, increases. This process can be traced by the composition of blood cells and plasma proteins.

Important! It is twice as easy for a pregnant woman to catch a disease transmitted by airborne droplets. Therefore, wear a medical mask before going outside during cold season.

How does a past pregnancy affect a woman's health?

If a woman carefully monitors her own condition and timely eliminates existing ailments, then only frequent, multiple births, between which her body does not have time to recover, can cause significant harm to her. But, unfortunately, not all women in labor are in good health, and therefore, even at the planning stage, it is worth considering all the possible risks and consequences:

• Excess weight: during pregnancy, many women gain excess weight, which is quite difficult to eliminate without systematic exercise and diet correction. Not all young mothers have the time and energy for this. In addition, if a woman is genetically inclined to be overweight, pregnancy can be a trigger for the development of obesity.
• Breast shape changes. Breasts, especially large ones, may sag somewhat. In addition, there is a risk of nipple injury during feeding.
• Stretch marks. If the skin is not elastic enough, dark streaks of stretch marks can remain on the abdomen and thighs for life.
• Anemia as a result of large blood loss during childbirth.
• Postpartum depression. It occurs in women who have difficulty accepting their new status.

But, apart from the negative aspects, it is worth noting the positive ones. For example, a past pregnancy has a positive effect on the outcome of endometriosis and reduces the risk of ovarian cancer.

Conclusion

A woman who carries a child under her heart cautiously listens and looks closely at all the changes in her health and appearance, especially if the first pregnancy. We hope that our article helped you sort out your feelings.

Specially for- Elena Kichak

During development, the intrauterine fetus needs an increasing amount of oxygen, proteins, fats, carbohydrates, vitamins, minerals and other substances. All these substances are delivered to the fetus from the mother's body. The final metabolic products of the fetus enter the mother's blood, which are excreted by the excretory organs of the pregnant woman. Consequently, the body of a pregnant woman performs additional work that requires strengthening or restructuring the activity of the most important systems and organs.

Under the influence of new conditions associated with the development of the fetus, numerous and complex physiological, adaptive and protective changes occur in the body of a pregnant woman. They determine homeostasis and the normal functioning of organs and systems, contribute to the correct development of the fetus, prepare the woman's body for childbirth and feeding the newborn.

The restructuring of the body's activity associated with pregnancy is regulated by the central nervous system with the active participation of the endocrine glands. The growing fertilized egg is an irritant to the nerve endings of the uterus. These irritations are transmitted along the nerve pathways to the central nervous system, where in the cortex, subcortical regions, in particular in the hypothalamic region, corresponding reactions arise, under the influence of which changes in the activity of the endocrine glands and other organs and systems occur.

Changes in the central nervous system are carried out not only by reflex, but also under the influence of hormones. From the very beginning of pregnancy, the activity of a number of internal secretion organs changes. In this regard, the ratio in the blood of hormones circulating in the body changes. These hormonal shifts also have a significant effect on the activity of the nervous system and other organs.

Nervous system. During pregnancy, complex changes of a physiological nature occur in the nervous system. In the cerebral cortex, periodic fluctuations (increase and decrease) in the intensity of neurodynamic processes are observed.

In the first months of pregnancy and at the end of it, there is a decrease in the excitability of the cerebral cortex, which reaches its greatest extent by the time of the onset of childbirth. At the same time, the excitability of the reticular formation of the trunk and spinal cord increases. By the same period, the excitability of the subcortical spinal cord and receptors of the pregnant uterus sharply increases. these changes contribute to the onset of labor. During almost the entire pregnancy (up to 38-39 weeks), the excitability of the spinal cord and uterine receptors is reduced, which causes inertia ("rest") of the uterus and contributes to the correct course of pregnancy.

During pregnancy, changes in the tone of the autonomic nervous system are observed (at the beginning of pregnancy, an increase in the tone of the vagus nerve is observed), in connection with which various phenomena often occur: a change in taste and smell, nausea, increased salivation, constipation, and a tendency to dizziness.

Endocrine system. In the activity of the endocrine glands during pregnancy, significant changes occur, contributing to its onset, development and the correct course of childbirth.

In the ovary, a new endocrine gland develops - the corpus luteum of pregnancy, the hormone of which (progesterone) contributes to the implantation of the egg and the development of pregnancy. The corpus luteum of pregnancy from the III-IV month undergoes regression, and the placenta performs its functions. The follicles in the ovary do not mature, and ovulation stops. The process of follicular maturation is inhibited by the corpus luteum hormone and by a change in the gonadotropic function of the pituitary gland.

The hormones produced in the placenta are essential for the development of pregnancy. In the first weeks and months, there is an enhanced synthesis of chorionic gonadotropin. This hormone, entering the bloodstream, promotes the functioning of the corpus luteum, and, consequently, the physiological course of all processes that occur in the uterus in the early stages of pregnancy.

The placenta produces estrogenic hormones: estriol, estrone, estradiol. Especially a lot of estriol is formed, which plays an important role in pregnancy (hypertrophy and hyperplasia of the muscle fibers of the uterus, the synthesis of contractile protein, etc.). At the end of pregnancy, the formation of estrone and estradiol increases, which increase the excitability of the uterus and its sensitivity to oxytocin and other substances that cause muscle contraction. Other hormones are also produced in the placenta.

During pregnancy, the anterior lobe of the pituitary gland increases 2-3 times, large cells with acidophilic granularity (pregnancy cells) are formed in it. Other cells (acidophiles, basophils) do not noticeably change.

During pregnancy, the production of gonadotronic hormones, especially luteinizing and luteotropic (prolactin), is significantly increased. These hormones enhance the development and endocrine function of the corpus luteum, and, together with estrogens and progesterone, help prepare the mammary glands for lactation.

The formation of thyroid-stimulating and adrenocorticotropic hormones, affecting the thyroid and adrenal glands, as well as growth hormone (somatotropic), which affects the growth of the uterus and other parts of the reproductive apparatus, increases; it is assumed that this hormone passes to the fetus and stimulates its growth.

The posterior lobe of the pituitary gland (neurohypophysis) does not increase during pregnancy. Oxytocin (pitocin) formed in the hypothalamus accumulates in the posterior lobe of the pituitary gland; the synthesis of this hormone increases at the end of pregnancy and it enters the bloodstream in significant quantities during childbirth. At the height of labor, there is more oxytocin in the blood than at the beginning of labor. Vasopressin (antidiuretic hormone) also accumulates in the posterior lobe of the pituitary gland.

The thyroid gland during pregnancy more or less noticeably increases in 35-40% of women. This is due to hyperemia and hyperplasia of the glandular elements, an increase in follicles and the content of colloid in them. In the first months of pregnancy, there is often a slight increase in the function of the thyroid gland, and in the second half, sometimes its hypofunction occurs. however, the content of protein-bound iodine in plasma does not decrease.

In the parathyroid glands, changes often occur, which are expressed in a tendency to hypofunction. In such cases, disturbances in calcium metabolism are possible, resulting in spastic phenomena (cramps in the calf muscles, etc.).

The adrenal glands undergo significant changes in connection with pregnancy. Their bark thickens due to hyperplasia of cellular elements and increased vascularization, increases the synthesis of steroid hormones and their release into the blood. The formation of glucocorticoids, which regulate carbohydrate and protein metabolism, as well as mineralocorticoids, which regulate mineral metabolism, is enhanced. There is evidence that during pregnancy, the synthesis of estrogens, progesterone and androgens increases in the adrenal cortex. The activity of the adrenal glands is associated with an increase in blood cholesterol and other lipids, as well as skin pigmentation during pregnancy. No morphological changes were found in the medulla. The cortex and medulla, when interacting with ACTH, contribute to the creation of a high tone of organs and tissues by the onset of labor.

The immune system. In the immune system, changes occur associated with the antigenic heterogeneity of the body of the mother and the fetus. Immune reactions occurring in the maternal body do not lead to rejection of the fetus and membranes (like reactions against allograft). This is explained by the immaturity of the antigenic system of the fetus, a decrease in the activity of the immune reactions of the pregnant woman, the presence of an immunological barrier, the role of which is played by the placenta, fetal membranes and amniotic fluid.

Metabolism. Metabolism during pregnancy changes significantly, this is due to the restructuring of the functions of the nervous system and endocrine glands. During pregnancy, the number of enzymes and the activity of enzyme systems increase, and assimilation processes prevail in metabolism. At the same time, the amount of metabolic products (carbon dioxide, nitrogenous compounds, etc.) to be excreted from the body increases.

BX. Basal metabolism and oxygen consumption during pregnancy increase, especially in the second half and during childbirth. an increase in oxygen demand is compensated by an increase in the respiratory rate, pulmonary ventilation, and bronchial patency.

Protein metabolism. Pregnant women accumulate nitrogen, the supply of which is necessary for the body of the mother and fetus. The accumulated proteins are spent on the growth of the uterus and mammary glands, the construction of organs and tissues of the growing fetus, and some of the proteins are stored as a reserve, which is spent after childbirth in connection with feeding the baby.

The content of proteins in blood serum during pregnancy decreases slightly due to amino acids and albumin (the globulin fraction increases). It is believed that this is due to the release of finely dispersed albumin through the vascular walls of the capillaries into the tissue (capillary permeability increases during pregnancy) or their increased consumption for the fetus.

The use of modern research methods made it possible to detect in the blood specific protein components characteristic of the pregnancy period (proteins of the pregnancy zone). They are synthesized in the placenta (in the chorion, amnion and in the decidua) and in the fetus (alpha and beta proteins) and enter the blood of a pregnant woman. The physiological significance of specific pregnancy proteins is being studied.

Carbohydrate metabolism. Carbohydrates, which are energy materials during pregnancy, are well absorbed; blood sugar concentration is usually normal. During childbirth, blood sugar levels rise moderately. carbohydrates in the form of glycogen are deposited not only in the liver and muscles of the body, but also in the placenta and muscles of the uterus. Carbohydrates from the body of a pregnant woman pass through the placenta to the fetus in the form of glucose. When the body is overloaded with carbohydrates in pregnant women, sugar sometimes appears in the urine, which is explained by an increase in the permeability of the renal epithelium, a change in the tone of the autonomic nervous system and an increase in the function of the adrenal glands. Such glucosuria quickly disappears with the establishment of the correct diet.

Lipid (fat) metabolism. In the blood of pregnant women, the amount of neutral fat, fatty acids, cholesterol, phospholipids and other lipids is increased. Lipid accumulation also occurs in the adrenal glands, placenta and mammary glands. Often during pregnancy, the subcutaneous fat layer increases. Lipids are spent on the construction of tissues of the body of the mother and fetus, neutral fat is an energetic material. A large amount of lipids in the blood explained the ease of onset of ether and other types of anesthesia in pregnant women. In the process of metabolism, fats are broken down into final products? carbon dioxide and water. In the event of a violation of the diet of a pregnant woman, especially with excessive introduction of fats, the process of their splitting may change. In such cases, harmful acidic products of incomplete combustion of fats accumulate in the body of a pregnant woman. Therefore, the amount of proteins and fats in the diet of pregnant women should be sufficient for the body of the mother and fetus, but not excessive.

Mineral and water exchange. During pregnancy, there is a delay in the body and the consumption of calcium salts for building the fetal skeletal system. The assimilation of phosphorus is enhanced, which is necessary for the development of the nervous system and the skeleton of the fetus, as well as for the synthesis of proteins in the mother's body.

Iron, which is an integral part of hemoglobin, passes from the mother to the fetus. During intrauterine development, the fetus accumulates iron in the liver and spleen. With insufficient intake of iron with food, pregnant women develop anemia, and the fetus has impaired development. There is a delay in the body of a pregnant woman of other inorganic substances: potassium, sodium, magnesium, chlorine, cobalt, copper and other microelements. These substances also pass to the fetus and determine the normal course of metabolic and growth processes. The retention of inorganic substances has biological significance for the mother's body, in particular for preparing it for childbirth and lactation.

The accumulation of inorganic substances affects water metabolism, which is characterized by a tendency to water retention in the body during pregnancy. Water retention, associated mainly with a slowdown in the excretion of sodium chloride, causes tissue juiciness during pregnancy. It depends mainly on the increase in interstitial fluid. The juiciness of tissues inherent in pregnancy determines their easy extensibility, which is essential for the passage of the fetus through the birth canal.

The hormones of the adrenal cortex (mineralocorticoids), aldosterone, progesterone, sodium diuretic factor play an important role in the regulation of water metabolism during pregnancy; water retention is possibly dependent on the action of antidiuretic hormone. During the normal course of pregnancy, there is no significant retention of water and chlorides, the liquid is quickly excreted from the body.

In the pathological course of pregnancy (late toxicosis), fluid secretion slows down, the accumulation of chlorides and water increases, and edema occurs.

Vitamins. In the general metabolism during pregnancy, vitamins are of paramount importance. The need for them by the pregnant woman's body increases due to the need to supply the fetus with vitamins and maintain its own metabolism at the physiological level. Increased need for vitamins A, B 1, D, E, K, PP and especially C. The daily requirement for vitamin C increases 2-3 times; it is of great importance, in particular, for the development of the fetus, the embryonic membranes and the placenta. The role of vitamin A in the process of fetal growth is great, vitamin B 1 - in the regulation of the functions of the nervous, enzyme and other systems. Vitamin D is necessary for the full development of the fetal skeleton, vitamin E contributes to the proper development of pregnancy (with a lack of it, a miscarriage occurs); its action is associated with hormones of the anterior pituitary gland.

With an irrational diet of a pregnant woman, a lack of vitamins easily arises, which can lead to a disruption of the physiological processes inherent in a properly developing pregnancy. With hypovitaminosis, the development of the placenta is disrupted.

The prophylactic use of vitamins (especially in winter and spring) contributes to the normal course of pregnancy, the correct development of the fetus.

The cardiovascular system. During pregnancy, increased requirements are imposed on the cardiovascular system due to an increase in the vasculature of the uterus and other parts of the reproductive system, an increase in blood mass, and the emergence of a new placental circulation.

The heart of a pregnant woman gradually adapts to the load. Physiological hypertrophy of the left ventricle, an increase in the functional capacity of the heart, an increase in minute volume, a slight increase in vascular tone and an increase in heart rate occur. Due to the high standing of the diaphragm in the last months of pregnancy, the heart is located more horizontally and closer to the chest; at the same time, its borders expand and the cardiac impulse is shifted outward. Kinks of large vessels can cause the appearance of vague systolic murmurs. These changes are functional and disappear completely after childbirth.

During pregnancy, the network of vessels of the uterus, vagina, and mammary glands increases sharply. On the external organs, in the vagina and on the lower extremities, some expansion of the veins is often observed, sometimes the formation of varicose veins.

The permeability of the capillaries increases, which facilitates the transfer of water, salts, albumin and other substances into the tissues. There are observations indicating the expansion of the capillaries and a slight slowdown in the blood flow in them during pregnancy. Blood pressure during physiological pregnancy does not change or there is some decrease in it in the first half. In the second half of pregnancy, there is a tendency to hypertension, which is associated with an increase in vascular tone.

It is generally accepted that the rise in blood pressure above 120-130 mm Hg. and lowering to 100 mm Hg. and less signal about the occurrence of complications of pregnancy. It is important to have data on baseline blood pressure levels. An increase in this indicator (especially stable) is taken into account as the beginning of a pathological process.

The heart rate increases moderately in the second half of pregnancy (75-80).

Blood. During pregnancy, hematopoiesis increases, the number of erythrocytes, hemoglobin, blood plasma and the total volume of circulating blood increase.

An increase in the mass of blood, erythrocytes and hemoglobin begins in the first months of pregnancy and continues until the 7th-8th month; before childbirth, the intensity of hematopoiesis decreases. The volume of circulating blood by the end of pregnancy increases by 35-40%, and circulating erythrocytes by 15-20%. The increase in plasma volume surpasses the process of increasing the mass of erythrocytes, therefore, with active erythropoiesis and an increase in the number of erythrocytes, their content in 1 liter of blood in pregnant women may be lower than in non-pregnant women. Most healthy pregnant women often have a slight leukocytosis (due to neutrophils), the content of monocytes, eosinophils and platelets does not change. The erythrocyte sedimentation rate (ESR) during pregnancy increases to 20-30 mm / h.

An increase in blood mass, the number of red blood cells and hemoglobin is important in relation to the delivery of nutrients and oxygen to the fetus and tissues of the pregnant woman.

In the blood coagulation system, changes occur that are of an adaptive nature. Most researchers point to an increase in clotting potential, especially in the last months of pregnancy. Starting from IV-V months, the content of fibrinogen, prothrombin, factors V, VII, VIII, X gradually increases; the content of fibrin-stabilizing factor decreases, especially towards the end of pregnancy. The adhesion of platelets slightly increases. The anticoagulant potential decreases, fibrinolysis is inhibited. In this case, intravascular coagulation does not occur. These changes contribute to hemostasis and the prevention of significant blood loss during childbirth (with placental abruption) and in the early postpartum period.

Respiratory system. During pregnancy, the activity of the lungs increases due to the increased demand for oxygen. Despite the fact that the uterus pushes the diaphragm upward at the end of pregnancy, the respiratory surface and vital capacity of the lungs do not decrease due to the expansion of the chest. Bronchial patency increases, oxygen use increases. Breathing in the last months of pregnancy becomes somewhat more frequent and deeper, gas exchange increases. Sometimes congestion in the larynx and bronchial mucosa is noted. This increases the sensitivity of pregnant women to the flu and other common infectious diseases.

The digestive system. In many women, at the beginning of pregnancy, changes in taste are noted, the appearance of whims (gravitation to sour, salty, etc.), aversion to certain types of food (for example, to meat, fats, etc.); some pregnant women have a significantly increased appetite, which is associated with changes in the functions of the nervous (diencephalic region) and digestive systems. The secretion of the glands of the stomach and intestines does not change, however, sometimes there is a decrease in the acidity of gastric juice. The stomach is displaced by the growing uterus upward and posteriorly. The intestine is pushed back from the anterior abdominal wall; some pregnant women have lower intestinal hypotension.

The liver is involved in the regulation of all types of metabolism and neutralizes toxic metabolic products. In the last months of pregnancy, the liver shifts upward and posteriorly, its blood supply increases, the structure does not change. In connection with changes in metabolism and the need to neutralize metabolic products not only of the mother, but also of the fetus, the load on the liver during pregnancy increases. Some researchers have noted a decrease in the antitoxic and instability of the carbohydrate functions of the liver. In healthy women, during the physiological course of pregnancy, the liver copes with the increased load and its functions are not disturbed.

Urinary organs. During pregnancy, the kidneys function with great stress, because they remove from the body the metabolic products of the woman's body and the growing fetus. Despite this, during physiological pregnancy, neither morphological nor functional changes occur in the kidneys. In the last months of pregnancy, traces of protein may appear in the urine. This indicates the possibility of a serious pathological condition - toxicosis of pregnant women. The previous understanding of the physiological nature of mild proteinuria is currently not supported. Even traces of protein in the urine should be considered a signal of a premorbid state. Sometimes pregnant women experience transient glucosuria, especially with an excess of carbohydrates in food. When glucosuria appears in a pregnant woman, it is necessary to carefully examine it.

In the first months of pregnancy, some women notice an increased urge to urinate due to the fact that the uterus presses on the bladder. In the following months of pregnancy, the bladder stretches, shifts upward, the urethra stretches and straightens; the tone of the ureters decreases, their lumen becomes wider. At the end of pregnancy, the fetal head is pressed against the entrance to the small pelvis, which may cause pressure on the bladder and increased urge to urinate.

System of the musculoskeletal organs. During pregnancy, serous impregnation and loosening of the articular ligaments, cartilage and synovial membranes of the pubic and sacroiliac joints occurs. These physiological changes occur under the influence of relaxin formed in the placenta, they are most pronounced in the pubic junction and to a lesser extent in the sacroiliac junction.

As a result of the appearance of changes, the discrepancy of the pubic branches to the sides by 0.5-0.6 cm occurs. A more significant discrepancy (1-2 cm or more) is considered pathological, especially when pain occurs.

Physiological changes in the joints of the pelvis give a slight increase in the direct size of the entrance to the pelvis, which contributes to the normal course of labor (adaptive factor). During pregnancy, the ribcage expands, the costal arches rise, the lower end of the sternum moves away from the spine. The posture of the pregnant woman changes: as the uterus grows and the abdomen grows, the spine straightens, the shoulders and the back of the head are reclined backward, the bending of the back in the spine increases (“proud gait” of the pregnant woman).

Leather. During pregnancy, the skin undergoes peculiar changes. quite often there is a deposition of brown or coffee-colored pigment in certain areas: along the white line of the abdomen, on the nipples and areola, as well as on the face. Pigment spots (chloasma uterinum) are especially often formed on the forehead, nose bridge, and upper lip. Pigmentation is more pronounced in brunettes. The origin of the pigment is associated with a change in the activity of the adrenal cortex, in particular with an increase in the formation of brown pigment in the reticular zone.

The abdominal wall gradually stretches due to the enlargement of the pregnant uterus. This is especially pronounced with a large fetus, polyhydramnios and multiple pregnancies. With significant stretching of the abdominal walls in women with insufficiently elastic skin, pregnancy scars appear - striae gravidarum. Pregnancy scars are formed due to the divergence of the connective tissue and elastic elements of the skin.

Pregnancy scars appear as pink, reddish, or bluish-purple arcuate stripes. They are usually located on the skin of the abdomen, less often on the skin of the mammary glands and thighs. After childbirth, pregnancy scars take on the appearance of white shiny stripes.

In subsequent pregnancies, fresh, reddish-bluish pregnancy scars may develop if old, faded scars are present. During pregnancy, changes occur in the navel area. In the second half of pregnancy, it smoothes out, bulges out in the X month. In women with multiple births, with multiple pregnancies and excessive accumulation of amniotic fluid, divergence of the rectus abdominis muscles often occurs.

Some pregnant women develop hair growth on the face, legs, and the lateral line of the abdomen (hypertrichosis). This hair growth in unusual places is associated with a change in the activity of the endocrine glands and the endocrine function of the placenta. Hypertrichosis usually resolves within a few months after delivery.

Body mass. An increase in body weight during pregnancy is associated with the growth of the fetus and uterus, an increase in the amount of amniotic fluid, and the total mass of blood. The increase in body weight is also associated with the deposition of fat and serous saturation of the tissues of the pregnant woman; the enlargement of the mammary glands is of some importance.

During the first months, body weight gain is hardly noticeable or absent. After the third month, body weight gradually increases, this is especially noticeable in the second half of pregnancy. The body weight of a woman in the second half of pregnancy normally increases by 300-350 g per week (fluctuations from 250 to 400 g are possible). A more significant increase in body weight usually indicates excessive water retention in the body, which is observed with toxicosis. During pregnancy, a woman's body weight usually increases by 10-12 kg.

Mammary gland. During pregnancy, the mammary glands undergo significant changes, which result in preparation for lactation. The glandular lobules increase in volume, their number increases. epithelial cells in the glandular lobules increase, fat droplets form in their protoplasm; In the first months, droplets of colostrums (colostrums) appear on the surface of the nipples; in the second half of pregnancy, colostrum can be excreted on its own. The blood supply to the mammary glands increases, the saphenous veins expand in volume and become tense, and tingling is often felt in them. The nipples are enlarged, pigmented together with the areola, the rudimentary glands of the areola (Montgomery) are more pronounced. The excitability of the smooth muscles embedded in the nipple increases; with mechanical irritation of the nipple, the muscles contract, the areola decreases, the nipple protrudes sharper.

The growth of the mammary glands and their preparation for lactation occur under the influence of hormones produced in the placenta (estrogens, progesterone); secretion is activated by the growth hormone of the placenta (placental lactogen).

The genitals. Pregnancy causes changes in the entire body of a woman, but they are most significant in the uterus. During pregnancy, the size, shape, position, consistency and reactivity (excitability) of the uterus change.

The uterus grows in size throughout the pregnancy. At the end of her uterus occupies almost the entire abdominal cavity. The length of the non-pregnant uterus is 7-8 cm, and by the end of pregnancy - 37-38 cm.The diameter increases from 4-5 to 25-26 cm, the anteroposterior size - up to 24 cm.The weight of the non-pregnant uterus is 50 g (in those who have given birth up to 100 g ), at the end of pregnancy - 1000-1200 g (without the ovum). The volume of the uterine cavity by the end of pregnancy increases 500 times. The enlargement of the uterus occurs mainly due to the hypertrophy of its muscle fibers. Each muscle fiber lengthens 10-12 times and thickens 4-5 times; at the same time, the multiplication of muscle fibers, the growth of newly formed muscle elements, the reticular-fibrous and agrophilic "frame" of the uterus, which is inextricably linked with its muscles, take place.

Hyperplasia of muscle fibers occurs mainly in the first half of pregnancy (during the first 18-20 weeks). The walls of the uterus reach their maximum thickness (3-4 cm) by the end of the first half of pregnancy. At a later date, the uterus increases mainly due to the stretching of its walls by the growing fetus, its membranes and waters. The increase in the uterine cavity is facilitated by the vertical extension of the spiraling muscle fibers of the uterus. By the end of pregnancy, the walls of the uterus become thinner to 0.5-1 cm.

The connective tissue of the uterus grows and loosens. The number of elastic fibers increases. All this leads to a softening of the uterus, an increase in its plasticity and elasticity. The uterus acquires the ability to change its shape, size, capacity, tone, excitability and contractile function. The mucous membrane of the uterus undergoes significant changes, turning into a decidual (falling off) membrane.

The vasculature of the uterus increases significantly. The arteries and veins of the uterus lengthen and dilate; especially the veins are lengthened and their lumen increases. The course of the vessels becomes tortuous, spur-like, which allows them to adapt to changes in the size of the uterus during its contractions. The uterine vasculature is enlarged not only by lengthening the arteries and veins, but also by the formation of new vessels. The lymphatic vessels also dilate and lengthen.

During pregnancy, the blood supply to the uterus increases dramatically, the amount of blood flowing through its vessels increases many times. A relatively constant and optimal blood supply is maintained in the uterus, which does not undergo special changes when processes occur, accompanied by blood redistribution (shock, blood loss, etc.). There is an opinion that a kind of blood depot is formed in the pregnant uterus. These changes in the vascular system and blood supply to the uterus are important in relation to the delivery of nutrients and oxygen to the fetus, not only in the myometrium, but also in the maternal part of the placenta (deciduas basalis). Nerve elements of the uterus are hypertrophied in number, the number of sensitive receptors increases sharply. These receptors are essential in the transmission of impulses from the fetus to the central system of the mother.

In the wall of the pregnant uterus, the content of calcium, trace elements, glycogen and phosphocreatinine increases, which are necessary for its contractile activity during childbirth. The presence in the uterus of biologically active substances - serotonin and catecholamines - was noted.

There are fewer muscle elements in the cervix than in her body; the process of hypertrophy in them is not very pronounced, the number of elastic fibers increases, the connective tissue is loosened, the vascular network (mainly venous) develops so strongly that the cervix resembles cavernous (spongy) tissue. In the cervix, congestion gradually develops, it becomes cyanotic, edematous, softened, the cervical canal is filled with thick mucus (mucous plug).

Until the 4th month of pregnancy, the ovum is in the uterine cavity. From the 4th month of pregnancy, the lower pole of the growing ovum stretches the isthmus of the uterus and is placed in it. From this point on, the isthmus is part of the fetus and turns into the lower segment of the uterus.

During childbirth, the isthmus, together with the cervix, turns into an exit tube. The cervix at the end of pregnancy seems to be shortened due to the fact that the head of the fetus descends into the entrance of the small pelvis (in primiparous) and shortens the vaginal vaults. The length of the cervical canal does not change. The serous cover of the uterus is stretched, but at the same time it does not become thinner.

The external and internal pharynx of the uterus in primipregnant women remains closed during childbirth; in re-pregnant women, the cervical canal expands in the last months of pregnancy and often misses a finger.

The shape of the pregnant uterus also changes. In early pregnancy, there is a protrusion of the corner of the uterus where the egg implantation took place. From the third month of pregnancy, the uterus becomes round, becomes spherical, and later ovoid. The position of the uterus changes in accordance with its growth. At the very beginning of pregnancy, the anterior bend of the uterus increases, and later the angle between the body and the cervix disappears, the uterus straightens, often tilts to the right and turns slightly with the left edge anteriorly, and the right edge posteriorly. After the second month of pregnancy, the bottom of the uterus rises above the plane of the entrance to the small pelvis, at the end of the ninth month it reaches the hypochondrium.

The excitability of the uterus in the first months of pregnancy is reduced; with an increase in the duration of pregnancy, it increases, reaching its highest degree before childbirth. According to some authors, an increase in the excitability of the uterus is observed in the first months of pregnancy and at the end of it. During pregnancy, irregular, weak, painless contractions of the uterus occur, which promote blood circulation in the intervillous spaces and in the uterus. Women hardly feel these contractions. From the VIII-IX months of pregnancy, the contractile activity of the uterus increases, and by the end of pregnancy the contractions become more frequent and stronger.

During pregnancy, the fallopian tubes thicken, become juicy due to hyperemia and serous tissue impregnation. As the uterus grows, the position of the tubes becomes more and more vertical; towards the end of pregnancy, they hang down the ribs of the uterus.

The ovaries increase slightly, become softer; ovulation stops in them; in one of the ovaries is the corpus luteum of pregnancy. Due to the growth of the uterus, the ovaries rise from the pelvis and are located in the abdominal cavity.

The uterine ligaments lengthen and thicken. The round and sacro-uterine ligaments are especially significantly hypertrophied, which helps to keep the uterus in the correct position during childbirth. The round ligaments of the uterus are felt through the abdominal walls in the form of cords. By the location of the round ligaments, one can judge the place of attachment of the placenta. If the placenta is located on the anterior wall, then the round ligaments run parallel or diverge downward. If the placenta is attached to the back of the uterus, the round ligaments go down in a converging direction.

During pregnancy, the pelvic tissue becomes loose, juicy, and easily extensible.

The vagina undergoes significant changes in connection with pregnancy. The blood supply to its walls increases sharply, serous impregnation of all its layers occurs. The walls of the vagina are loosened, becoming juicy and easily stretchable. The mucous membrane of the vagina becomes bluish in color.

During pregnancy, hyperplasia and hypertrophy of the muscle and connective tissue elements of the vagina occur; in this regard, the vagina lengthens, expands, the folds of the mucous membrane appear sharper. Due to loosening, the absorption capacity of the vaginal mucosa increases. Therefore, during pregnancy, douching with solutions of toxic substances (for example, mercuric chloride) is dangerous. During pregnancy, the contents of the vagina increase due to hyperemia and increased extravasation. The secretion of the glands of the cervix, rejected cells of the integumentary epithelium of the vagina, leukocytes and microorganisms are mixed with the transudate.

During pregnancy, the external genitals are loosened, the mucous membrane of the entrance to the vagina becomes cyanotic. In re-pregnant women, sometimes varicose nodes form on the external genital organs, the secretion of the sebaceous glands of the vulva increases.

The above basic data on the changes occurring in the body of a pregnant woman show their complexity and versatility. All the most important systems of the woman's body take part in preparing for pregnancy and in ensuring its correct development. All the changes that arise are of an adaptive nature, their totality determines the process of procreation.

It is believed that during pregnancy a dominant focus of excitation arises in the central nervous system (pregnancy dominant, gestational dominant), which ensures the normal course of physiological changes in the mother's body necessary for the development of the fetus.