The development of the human body begins from the very first day of fertilization of an egg with a sperm. The stages of embryogenesis are counted from the moment the cell begins to develop, which subsequently forms an embryo, and a full-fledged embryo appears from it.

The development of the embryo fully begins only from the second week after fertilization, and starting from the 10th week, the fetal period is already carried out in the mother's body.

The first stage of the zygote

Absolutely all somatic cells of the human body have a double set of chromosomes, and only sex gametes contain a single set. This leads to the fact that after fertilization and fusion of the male and female germ cells, the set of chromosomes is restored and becomes double again. The resulting cell is called a "zygote".

The characteristic of embryogenesis is such that the development of the zygote is also divided into several stages. Initially, the newly formed cell begins to divide into new cells of different sizes, called morula. The intercellular fluid is also unevenly distributed. A feature of this stage of embryogenesis is that morula formed as a result of division do not grow in size, but only increase in number.

Second phase

When cell division ends, a blastula is formed from them. It is a single-layered embryo the size of an egg. Blastula already carries all the necessary DNA information and contains cells of unequal size. This happens already on the 7th day after fertilization.

After this, the single-layer embryo passes through the stage of gastrulation, which is the movement of existing cells into several germ sheets - layers. At first, 2 of them are formed, and then a third appears between them. During this period, a new cavity is formed in the blastula, called the primary mouth. The previously existing cavity disappears completely. Gastrulation enables the future embryo to clearly distribute cells for the further formation of all organs and systems.

In the future, all skin, connective tissues and the nervous system are formed from the first formed outer layer. The lower, formed by the second, layer becomes the basis for the formation of the respiratory organs, excretory system. The last, middle cell layer is the basis for the skeleton, circulatory system, muscles and other internal organs.

The layers in the scientific environment are named accordingly:

• ectoderm;
• endoderm;
• mesoderm.

Third stage

After all the above stages of embryogenesis have passed, the embryo begins to grow in size. In a short time, it begins to represent a cylindrical organism with a clear distribution at the head and tail ends. The growth of the finished embryo continues until day 20 after fertilization. At this time, the plate formed earlier from cells, the precursor of the nervous system, is transformed into a tube, which later represents the spinal cord. From it, other nerve endings gradually grow, filling the entire embryo. Initially, the processes are divided into dorsal and abdominal. Also, at this time, cells are distributed for further division between muscle tissues, skin and internal organs, which are formed from all cell layers.

Extraembryonic development

All the initial stages of embryogenesis take place in parallel with the development of extraembryonic parts, which in the future will provide the embryo and fetus with nutrition and support life.

When the embryo is already fully formed and out of the tubes, the embryo is attached to the uterus. This process is very important, since the future activity of the fetus depends on the correct development of the placenta. It is at this stage that embryos are transferred during IVF.

The process begins with the formation of a nodule around the embryo, which is a double layer of cells:

• embryoplast;
• trophoblast.

The latter is the outer shell, therefore, is responsible for the effectiveness of the embryo's attachment to the walls of the uterus. With its help, the embryo penetrates into the mucous membranes of the female organ, implanting itself directly into their thickness. Only a secure attachment of the embryo to the uterus gives rise to the next stage of development - the formation of a child's place. The development of the placenta occurs in parallel with its separation from the droppings. The process is ensured by the presence of a trunk fold, which, as it were, pushes the walls away from the body of the embryo. At this stage of development of the embryo, the only connection with the placenta is the umbilical stalk, which later forms a cord and provides nutrition for the baby for the rest of the intrauterine period of his life.

Interestingly, the early stages of embryogenesis in the region of the umbilical peduncle also have a yolk duct and a yolk sac. In non-placental animals, birds and reptiles, this sac is the yolk of the egg, through which the embryo receives nutrients during its formation. In humans, this organ, although it is formed, has no effect on the further embryonic development of the organism, and over time it simply decreases.

The umbilical cord contains blood vessels that carry blood from the embryo to the placenta and back. Thus, the embryo receives nutrients from the mother and removes metabolic products. This part of the connection is formed from the allantois or part of the urinary sac.

The embryo developing inside the placenta is protected by two membranes. In the inner cavity there is a protein liquid, which is a water shell. The baby swims in it before its birth. This sac is called amnion, and its filling is amniotic fluid. All are enclosed in another shell - the chorion. It has a villous surface and provides respiration and protection to the embryo.

Step-by-step review

In order to analyze in more detail human embryogenesis in a language understandable to most, it is necessary to start with its definition.

So, this phenomenon represents the intrauterine development of the fetus from the day of its fertilization until birth. This process begins only after 1 week after fertilization, when the cells have already finished dividing and the finished embryo moves into the uterine cavity. It is at this time that the first critical period begins, since its implantation should be as comfortable as possible for the mother's body and for the embryo itself.

This process is carried out in 2 stages:

• tight attachment;
• penetration into the thickness of the uterus.

The embryo can be attached to any part of the uterus, except for the lower part. It is important to understand that this whole process is carried out for at least 40 hours, since only gradual actions can ensure complete safety and comfort for both organisms. The place of attachment of the embryo after attachment is gradually filled with blood and overgrown, after which the most important period of development of the future person begins - the embryonic one.

First organs

The embryo attached to the uterus already possesses organs that are somewhat reminiscent of the head and tail. The very first, after the successful attachment of the embryo, a protective organ develops - the chorion. To more accurately imagine what it is like, you can draw an analogy with a thin protective film of a chicken egg, which is located directly under the shell and separates it from the protein.

After this process, organs are formed that provide further nutrition for the crumb. Already after the second week of pregnancy, you can observe the appearance of allantois, or the umbilical cord.

Third week

The transfer of embryos to the stage of the fetus is carried out only after the completion of its formation, but already in the third week, you can notice the appearance of clear outlines of future limbs. It is during this period that the body of the embryo is isolated, the trunk fold becomes noticeable, the head stands out and, most importantly, the future baby's own heart begins to beat.

Power change

This period of development is marked by another important stage. Starting from the third week of life, the embryo ceases to receive nutrition according to the old system. The fact is that the reserves of the egg are depleted by this moment, and for further development the embryo needs to receive the substances necessary for further formation from the mother's blood. At this point, to ensure the efficiency of the entire process, allantois begins to transform into the umbilical cord and placenta. It is these organs that will provide the fetus with nutrition and release from waste products for the rest of the intrauterine period.

Fourth week

At this time, it is already possible to clearly determine the future limbs and even the places of the eye sockets. Outwardly, the embryo changes slightly, since the main emphasis of development is given to the formation of internal organs.

Sixth week of pregnancy

At this time, the expectant mother should pay special attention to her own health, since during this period the thymus gland of her future baby is being formed. It is this organ in the future that will be responsible for the performance of the immune system throughout its life. It is very important to understand that the mother's health will depend on the ability of her child to resist external stimuli throughout her independent life. You should not only pay attention to the prevention of infections, but also to warn yourself against nervous situations, to monitor the emotional state and the environment.

Eighth seven days

Only starting from this threshold of time, the expectant mother can find out the gender of her child. Exclusively at 8 weeks, the sexual characteristics of the fetus and the production of hormones begin to form. Of course, you can find out the gender if the child himself wants it and turns the right side on the ultrasound.

The final stage

Starting from the 9th week, the fetal ends and begins. By this time, a healthy baby should already have formed all the organs - they just have to grow. At this time, the child's body weight is actively gaining, his muscle tone increases, the organs of hematopoiesis are actively developing; the fetus begins to move erratically. Interestingly, the cerebellum by this time is usually not yet formed, so the coordination of fetal movements occurs over time.

Dangers during development

Different stages of embryogenesis have their weak points. To understand this, you need to consider them in more detail. So, in some periods, human embryogenesis is sensitive to infectious diseases of the mother, and in others - to chemical or radiation waves from the external environment. If problems arise during such a critical period, the risk of developing birth defects in the fetus will increase.

To avoid this phenomenon, you should know all the stages of embryo development and the dangers of each of them. So, a special sensitivity to all external and internal stimuli is the period of blastula. At this time, most of the fertilized cells die, but since this stage passes in the first 2, most women do not even know about it. The total number of embryos dying at this time is 40%. at the moment it is very dangerous, since there is a risk of rejection of the embryo by the mother's body. Therefore, during this period, you need to take care of yourself as much as possible.

The transfer of embryos into the uterine cavity marks the beginning of the period of the greatest vulnerability of the embryo. At this time, the risk of rejection is no longer so great, but from the 20th to the 70th days of pregnancy, all vital organs are laid, with any negative effects on the mother's body at this time, the likelihood of developing congenital health abnormalities in the future baby increases.

Usually, by the end of the 70th day, all organs have already been formed, but there are also cases of delayed development. In such situations, with the onset of the fetal period, there is a danger to these organs. Otherwise, the fetus is already fully formed and begins to actively increase in size.

If you want your unborn child to be born without any pathologies, then monitor your health both before and after the moment of conception. Lead the right lifestyle. And then no problems should arise.

Fetal development by week Photo

Future mothers are sensitive to the development of the baby, who is worn under the heart and want to learn as much as possible about the processes taking place with them. during pregnancy , study with interest the stages of intrauterine growth of the fetus, carefully examine the pictures that show in detail fetal development by week.

Gynecologists start counting the pregnancy from the first day of the last menstrual period. Basic unit of time for pregnancy- a week.
The first weeks for the unborn child - very important, at this moment the health of the body and its vitality are formed.
It's good if pregnancy will be planned , then the woman will begin to lead a correct lifestyle, will save the baby from many health problems. Below you will find detailed information on the formation embryo in the womb, you will be able to consider the development of the fetus by week - Pictures with all stages of intrauterine growth and development, as well as a description of the processes taking place at one stage or another of pregnancy.

Before referring to the photo with the stages of fetal development by week, we will briefly familiarize ourselves with the main periods of the formation of the organs of a little man during pregnancy. At 5-6 weeks, an embryo 6 millimeters in size (like a pear seed) lives in a bubble with a liquid. The nervous system is formed, the spine and the brain appear. Two pairs of dimples for the eyes and ears are visible on the head. Digestive tract arises already at this stage of fetal development.

It takes only 2 weeks and the main internal organs of the fetus are already formed. At the eighth week of fetal development, the face takes on the necessary shapes, nostrils, the tip of a small nose, mouth, tongue are visible. Begins to function inner ear ... The fingers of the developing baby are also looming.

12 weeks intrauterine fetal development- the age of a ten-centimeter embryo, in which the outlines of the human body are visible. Various systems and organs in the twelfth week of fetal development have already formed, and are developing safely. Upgraded ultrasound equipment allows you to find out the gender of the baby and see the features of the face at this stage of pregnancy.

The beginning of the second trimester of pregnancy is the period of fetal development, when all the baby's milk teeth are formed. The gastrointestinal tract also develops at 13 weeks, villi appear in the intestines that in the future they will accelerate the process of digestion of products.

Up to 21 weeks of fetal development, the size of the baby allows him to move in the womb in any direction. Fruit length - 26 centimeters, weight - 0.4 kilograms.

A small body is able to control its temperature from 29 weeks , the period of preparation for the birth of a baby and independent life begins.

At 31 weeks of development, the body is fully formed, it remains only to gain weight. The child is already able to feel, his condition can change depending on the mood of the mother. Hearing is developed enough to recognize voices. Sight and smell also function.

The baby is ready for birth at 37 weeks. Now childbirth cannot be called premature. Of course, ideally you need to wait a bit. But the child can already assimilate and digest mom's milk , an epithelium with villi appears on the mucous membrane of the stomach and intestines, through which nutrients enter the bloodstream from food ... Peristalsis is working, the first feces are formed - meconium.

Now let's take a closer look at fetal development by weeks of pregnancy, and also refer to the photo of the formation of the embryo in the womb with brief explanations. As you can see, already in the first weeks after conception, very important processes of formation of the structure of the fetus take place and the expectant mother needs to seriously change her lifestyle from the first days and adjust the diet. ... Visit your gynecologist regularly and go through all the necessary medical examinations.

Even pictures with the stages of intrauterine development of the fetus by week clearly demonstrate the importance of the ongoing processes of formation of the baby's internal organs. We hope that the information we have posted will help you better understand the processes, occurring in your body during pregnancy and we want to wish you that the baby was born healthy and beautiful !
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Every pregnancy for a woman is the same, but it feels differently. This is due to the state of her health and emotional and psychological state, social conditions of stay and the characteristics of the development of the fetus. Each stage of pregnancy is characterized by certain changes in the development of the fetus in the womb. What changes are we talking about, how the child grows and develops throughout pregnancy - we will talk about this in this article.

Pregnancy is an interesting and difficult period in a woman's life. At this time, the emergence and development of a new life takes place in her, her body is experiencing a great load, which gradually increases with each month of pregnancy. In a pregnant woman, changes in the physiological and psychoemotional order are noted, her tastes and preferences may also change. All this is closely related to the stages of intrauterine development of the fetus, which grows, develops and actively prepares for its birth.

Fetal development: stages and features

In the womb, the child develops over 9 months, or 280 days. The process of fetal development does not occur chaotically, but according to an algorithm written by nature itself and provided for by the peculiarities of human anatomy. Development of all organs and systems of the fetus occurs in a strict order and at a certain time.

Medicine divides pregnancy into three important stages - trimesters, each of which is characterized by the growth and development of certain systems / organs in the body of the unborn child. All stages are also subdivided into weeks, since the state of the fetus changes weekly. We'll look at the specifics of each trimester.

Trillions of new cells are formed from one cell in 38 weeks. There are more than 200 types of them, and they are the biological building material necessary for the growth and development of a child in the womb, his birth and full life on earth.

I trimester

In the first trimester, a woman shows the first signs of pregnancy, when the process of fertilization of the egg takes place, its movement and fixation in the uterine cavity. During this period, the vital systems of the unborn child are laid. This trimester is considered very important for the fetus and mother, so a woman needs to take care of herself and take care of the health of her unborn baby.

By obstetric terms
gestation, the development of the fetus in the trimesters in different women can proceed in different ways. This is due to many factors - hereditary, social, physiological, psychological and other circumstances that can affect the health of the mother, the course of pregnancy and the development of the fetus.

This is the period when a woman may suffer from early toxicosis, she may feel drowsiness, general malaise, dizziness, etc. What changes in the first trimester in the process of its development the fetus undergoes can be seen in table 1 below.

Table 1

A week	Fetal development
1	Egg development, ovulation, fertilization, blastocyst birth.
2	The movement of the blastocyst into the uterine cavity, where it will gain a foothold and continue its development.
3	The embryo takes on the shape of a human embryo. Nerve cells form the neural tube - the basis of the future spinal cord and brain of the embryo. The heart is forming, which until this moment resembled a clot of muscle cells. The size of the heart in the embryo does not exceed the size of a poppy seed. One cell suddenly contracts, propelling all the cells in the heart through a chain reaction. The heart of the embryo makes 20-25 beats per minute and is necessary for the embryo, since without it, full and correct distribution of oxygen and food is impossible. Blood cells are still primitive, but with each heartbeat, they circulate through the thinnest (thinner than a hair) blood vessels, delivering the necessary building material and oxygen to each cell of the embryo.
4	The period when a woman can feel pregnancy due to changes in her hormonal system. The embryo is no larger than a bean, but every day it grows by 1 mm. In the area of ​​his head, two black dots appear - these are future eyes. The embryo's heart is still single-chambered and miniature, but it already makes 80 beats per minute, accelerating the pace with each new day. “Kidneys” appear on the body of the embryo - in the future, arms and legs will form from them. From the neural tube of the embryo, areas of the spinal cord and brain are formed - the future central nervous system. The fabric growing on the four sides forms the face. Its upper part grows downward, forming an area for the formation of the nose and chin. The cheeks are formed by fabric on both sides, forming the upper lip. Its connection is called the "labial groove", and it remains - it can be seen on the face of an adult. Improper adhesion of this tissue contributes to a defect known as cleft lip. After birth, a baby with such a defect will need the help of a surgeon. The human embryo is not much different from the embryo of any other animal. Only 1.5% of genes indicate that this is a human embryo.
5	The first heartbeats of the embryo begin to be heard. Its size is only 3 mm, but it already shows signs of the formation of the lungs, heart and thyroid gland.
6	The spine, upper / lower extremities and two hemispheres of the brain are laid, and the intestines are formed. The embryo is stretched, its length is 20 mm, and its body takes on the appearance of a human embryo. Eyes are formed from black dots, they are widely spaced and not yet equipped with eyelashes. Head size is still dominant relative to body size. At the moment of birth, the baby's head will make up almost ¼ of its body, since the rest of the parts will not be able to keep up with the growth of the head.
7	The organs of vision develop, the organs of hearing are formed (on ultrasound, the appearance of auditory eminences, eye sockets, and nasal folds is observed). On ultrasound, it is already possible to clearly determine the presence of interdigital spaces, the formation of future fingers of the lower / upper extremities is taking place. The embryo length is 6 mm.
8	There is an active growth of the embryo, the formation of facial features, the nose and ears are clearly distinguishable, the neck is visible. It can already be called a fruit, and outwardly it looks more and more like a person. This is an important stage in the life of the fetus. Previously, he received nutrients through the yolk sac, a floating ball connected to the umbilical cord. Unlike chicken yolk, the human yolk sac lacks food reserves - in the early days of pregnancy, it produces blood cells necessary for nourishing the embryo. At this stage, he is unable to provide the fetus with the required amount of food, so the placenta becomes the source of nutrition for the fetus. It is connected to the umbilical cord and attached to the wall of the uterus. The placenta is a complex system that supports the intrauterine life of the fetus, consisting of an extensive network of the finest blood vessels. They are attached to the wall of the uterus and with their help the fetus draws out all the nutrients it needs from the mother's body through the umbilical cord: water, oxygen, proteins, etc. Through the placenta, the fetus also removes its waste products.
9	At the beginning of the week, the length of the fetus is 15 to 20 mm, the weight is 3-4 g, and at the end of the week these parameters almost double. The placenta controls the pregnancy process by producing essential hormones in the mother's body. The placenta acts as a filter, preventing harmful substances from reaching the fetus, but it is also unable to cope with some of their types. For example, alcohol, smoking products, and many drugs can easily cross the placenta to the fetus. In most cases, the mother's body tells her which foods her unborn child needs and which ones are dangerous for him. There is an active development of the nervous system of the embryo, when the body of the previously immobilized fetus begins to twitch as a result of the appearance of nerve impulses and reflex convulsions that are not yet controlled by the brain. The fetus needs movement to stimulate muscle growth and strengthen the ligaments. The brain is not yet able to control the work of the heart, which beats automatically. Its maximum speed is 157 beats per minute.
10	The brain begins to control all the vital systems of the fetus, slowing down its heartbeat. He also now controls the movement of the upper / lower limbs. The development of the sucking reflex is noted.
11	In the period from 6 to 11 weeks, the embryo undergoes important metamorphoses, its body grows almost 5 times. At the same time, more than 200 types of various cells are formed: nerve, muscle, liver, kidney, stomach and other cells that make up the human body. All parts of the body that are characteristic of a person are formed. The growth of the embryo is 7 cm. The development of the central nervous system of the fetus continues with the formation of its response to touch and breathing.
12	The size of the embryo is not larger than the mother's fist, but it is already more adapted to the environment in which it is located, and is less sensitive to various stimuli. The risk of his premature birth is reduced. The skeletal system is strengthened, further development of all systems and organs of the fetus occurs.

All the characteristic features of the human body (muscles, ribs, organs, heart, etc.) appear in the fetus within 9 weeks of the first trimester of intrauterine development.

For the development and health of the unborn baby, the first trimester is the most difficult and dangerous. Any a malfunction in the mother's body can affect the intrauterine development of the fetus. The most critical is the 3rd and 4th week of pregnancy - during this period, the process of implantation of the ovum in the uterine cavity and the laying of the central nervous system of the future fetus takes place. A common cold, infection, exacerbation of a chronic illness, nervous breakdown, stress, excessive physical or psychological stress - all this can cause a malfunction of a woman's hormonal system and provoke a miscarriage.

From the last week of the first trimester, the fetus is able to distinguish certain sounds. From now on, every week he will hear better, react more actively to the touch of his hands to his stomach, to the voice of his mother. In the second trimester, gynecologists and psychologists recommend that pregnant women talk with their unborn child, listen to calm and pleasant music, and the sounds of nature. It is believed that the baby in the mother’s tummy hears everything and feels her mood, feels the attitude towards himself both from the mother and those people who surrounds her.

II trimester

The second trimester covers the period from 13 to 27 weeks of pregnancy. In most pregnant women, toxicosis has passed by this time, the size of the tummy still allows you to move freely and wear ordinary clothes, which will soon have to be changed to dresses and sundresses for women in position. The well-being of a woman in the second trimester usually does not cause anxiety in the doctor, if the pregnancy is not burdened by any developmental pathology. From 20 or 22 weeks of gestation, some women are advised to wear a maternity band to maintain
growing tummy, reduce back and hip pain.

By the beginning of the second trimester, the baby in the womb weighs on average no more than 30 g, its height is about 10 cm. By the beginning of the third trimester (at 27 weeks), the growth of the fetus will be almost 35 cm, and it will weigh about 1.2 kg. The fetal skeleton is already quite well formed, so in the second trimester its brain and muscular system will actively develop. There is a high mobility of the baby in the mother's womb, and in the period between 18 and 22 weeks, a woman can clearly feel the first movements and jolts of her unborn child. From table 2, you can see what changes occur in the fetus during the second trimester.

table 2

A week	Fetal development
13	The sex of the unborn child is still difficult to determine, but a competent ultrasound diagnostician will be able to recognize it. In boys and girls up to 13 weeks, instead of the genitals, a bulge is formed - the angle of inclination at which this bulge is located helps the doctor to reveal the secret of the sex of the embryo. It will be possible to recognize the sex more clearly at 15 weeks of gestation, but the formation of the genitals in the embryo has already begun. The formation of milk teeth and the development of muscles that provide the sucking reflex are also noted. The kid is already able to move his lips. In boys, on an ultrasound scan, the genital organ is clearly distinguishable, their body begins to produce testosterone (male hormone), the laying of the prostate gland (for boys) or the formation of an egg (in girls) begins. The first hairs appear on the skin of the fetus (just above the eyes and above the lip). There is a "drawing" of a unique pattern on the skin of the fingers of the future child.
14	The formation of sexual characteristics, intestines (with the presence of villi on its mucous membrane) continues. Male testes are already capable of producing testosterone, and female ovaries are capable of producing eggs. The pancreas begins to produce the hormone insulin, and the processes in which the blood cells of the unborn baby are formed take place in the liver and spleen.
15	The first hairline appears on the body of the fetus - fluff. The baby makes the first attempts at independent "inhalation": the embryo breathes with amniotic fluid. Now his gallbladder is starting to function. This week, a woman who has had pregnancies before can experience fetal movements for the first time. The weight of the unborn baby is already 130-160 g, his height is 12-14 cm.
16	Ossification of the skull and strengthening of the fetal muscular system is observed. An increase in his motor activity is noted (a woman may not yet feel the movements and shocks of the fetus). The sex of the unborn child is already easily determined by ultrasound. There are changes in the proportion of the fetus's body - the size of the head decreases, its lower / upper limbs lengthen, the fingers / toes are separated from each other, and the growth of nails begins. Hands develop faster than legs: perhaps because they act as important senses and develop at the same time as other organs. The distance between the eyes has decreased, giving the baby's face a human look. The central nervous system is functioning, it has expanded and controls all parts of the fetus's body, the movements of which have become more varied. The muscles acquired the necessary flexibility, the movements of the child in the womb became softer and smoother. The brain completely controls the baby's body, whose heart no longer beats spontaneously and convulsively - its work is controlled by the brain. The heart beats no more than 140-150 beats per minute. The weight of the fruit is 180 g, and its height is 14-16 cm.
17	Placenta formation is completed. The baby in the womb begins not only to hear, but also to distinguish between noises / sounds that surround him. His nervous system is improving, he becomes sensitive to touch, sounds, light. The fetus is too mobile, makes many complex movements and maneuvers, trying to find a comfortable position for itself. The joints of the fetus bend easily, opening up the space inside the mother's womb in a new way. By swimming and maneuvering, the baby learns to maintain balance and coordination. In the womb, the future person develops the ability to control the position and behavior of his own body in space. The fetus is in the process of forming subcutaneous fat, which is involved in the processes of heat exchange in the body.
18	This week the process of the formation of the child's immune system ends. His digestive system is already formed and developed so that it is ready to function. The baby makes swallowing movements, swallowing the amniotic fluid in which it swims. The kidneys and digestive organs are already working - some of the undigested particles will be deposited in the intestines, the rest of the processed products will be excreted in the form of urine into the amniotic fluid. Some babies at 18 weeks can already open their eyes, while others will be able to do this only at 24 weeks. This is how the blinking reflex develops. The kid learns about himself and the environment, actively moves. He feels himself with his fingers, touches the walls of the uterus, pushes off with his legs, jumps and turns over. These skills are necessary for him, since they are a kind of training before birth and passage through the birth canal. The grasping reflex develops well, although its meaning is not clear: it is hardly useful for the survival of the newborn.
19	The fetal movements are more conscious, since the connection between the muscular and nervous systems is almost completely formed. A woman may first feel the movement of the fetus at the end of 18 or at the beginning of 19 weeks. The baby has grown to 18 cm, his body is covered with soft hairs that will disappear by the time he is born. The molars are formed. They will begin to grow in the child during the replacement of his milk teeth with permanent ones. The fetus receives sugar and water from the mother's amniotic fluid; a small portion of hydrochloric acid and some digestive enzymes are already present in his stomach. Useful substances enter his body through "respiration" and through the placenta. He gets some of them by swallowing amniotic fluid.
20	This week, the body of the fetus reaches the proportions that are inherent in babies, the ratio of its head to the rest of the body is evened out. Since its body fat is not yet fully formed, the fetus's body appears thin, but the baby is active and feels normal. He is halfway to his birth. His height is already 19 cm, body weight - 300 g.
21	The baby grows and gains weight, accumulates subcutaneous fat, and his mother often feels hungry. A layer of special lubricant forms on the child's body, which protects his skin from the effects of amniotic fluid. His body weight this week reaches 350 g, and his height increases by 5-6 cm.
22	High motor activity of the fetus is noted: the baby can change its position in the mother's womb several times during one day. He eats, sleeps, moves - continues to study himself and the space around him, gain body weight and grow. The baby sucks his finger and can already turn his head to the side.
23	The weight of the fetus can reach 500 g. His heart sounds are well heard with an obstetric stethoscope. Twitching of the eyelids in a child, which is visible on an ultrasound scan, indicates that his brain is functioning correctly. The baby can be more awake if the mother is in motion, and when she is nervous, she behaves restlessly. The baby's hair begins to darken, since the production of a special pigment has already begun in his body. If the baby is born prematurely, he already has a chance of life, as well as the danger of problems with brain functions.
24	The child is still active, but his growth slows down a little at around 30 cm, and his body weight begins to increase and reaches 600-700 g. The kid opens his eyes for the first time and is able to distinguish between daylight and darkness. His eyebrows and cilia are already beginning to appear, and his face takes on the features of a newborn baby. His lungs are developing well, he is trying to "breathe". A baby born at 24 weeks has every chance of survival. At this stage, a woman needs to rest more and receive only positive emotions so as not to provoke premature birth. In case of premature birth, the baby has a chance to survive thanks to modern equipment and the experience of neonatologists.
25	All organs and systems of the baby are already functioning and at the same time continue to develop further. His heartbeat can be heard without a stethoscope by leaning his ear against the belly of a pregnant woman. The baby's skeleton becomes stronger, and the baby's pushes in the mother's stomach are more palpable for her.
26	The baby's lungs can barely cope with the task of supplying oxygen to his organs. With a lack of oxygen, the baby freezes, trying to move less, so the mother needs to walk more in the fresh air, not smoke, and ventilate the room more often. Almost half of children born before 26 weeks have brain malformations and problems in development and learning. Starting this week of pregnancy, the baby is actively developing all the senses: eyes, ears, taste buds on the tongue. The child learns to recognize the signals sent by the impulses of his central nervous system.
27	Hair begins to disappear from the skin of the child. The proportions of his body correspond to the proportions of a newborn baby, but the total mass is still not enough. His endocrine system begins to function, producing growth hormone. The baby's respiratory muscles develop. His height is 32-35 cm, body weight reaches 1000 g. If the mother has a premature birth, the baby has every chance to survive and grow up as a healthy, full-fledged person.

The second trimester is a period in which all systems / organs of the fetus are actively developing, the baby himself also grows and gains weight. He begins to actively move in the mother's stomach and declare himself. It has its own wakefulness and sleep patterns. He hears almost all the sounds going on around him, distinguishes between darkness and light.

To the woman abiding in the second trimester of pregnancy, you need to walk more often in the air, ventilate your room, eat more vegetables and fruits. She should diligently observe personal hygiene, not neglect morning exercises for pregnant women, try not to get nervous and not take negative events to heart.

During this period, a woman is advised to enroll in courses for a young mother, where she learns about the peculiarities of pregnancy in the last trimester, about the correct behavior of the mother during childbirth and caring for the child in the first days after birth. She also should not forget to visit her gynecologist and inform him about all the changes that occur in her body.

III trimester

The last trimester for the expectant mother will not be the easiest, since her tummy has already grown enough. It becomes difficult for her to move, sit down, bend over or roll over on her side in bed. It is impossible to sleep or rest on your back due to shortness of breath and a feeling of tightness in the internal organs. Many women are afraid of the onset of labor and in the last trimester, they begin to get nervous - these experiences can lead them to stress. At this time, advice and reassurance from those women who have already safely given birth are important for a pregnant woman.

As for the baby, he feels great. All his organs are already formed, he breathes on his own, hears perfectly, is able to distinguish tastes. The baby is actively twisting with his legs, turning over, spinning in the mother's womb in all directions. His head is already beginning to be covered with hairs, his body is covered with lubricant, which will facilitate his passage through the birth canal. The fetus is preparing for release, because soon it will be born. What changes occur with the baby in the third trimester of the mother's pregnancy can be seen in Table 3.

Table 3

A week	Fetal development
28	The baby's weight is from 1000 to 1300 g, his body length is from 35 to 40 cm. The baby not only hears sounds, but also reacts to them, showing his mother with jerks what he likes and dislikes.
29	The kidneys of the baby begin to function, secreting up to 500 mg of urine per day. The adrenal glands are in the process of producing androgen-like substances, and in the baby's circulatory system, red blood cells are produced. The baby actively moves inside the uterus, where it becomes cramped for him. He gradually turns over, taking a position in which it will be easier for him to pass the birth canal. The fatty layer allows the baby's body to independently solve the problem of thermoregulation of the body. His skeleton has grown stronger, but the bones of the skull have not yet grown together to the end - this feature will allow his head to squeeze through the birth canal at the time of birth.
30	The baby begins to rapidly gain weight, his height reaches 35-37 cm with a body weight of 1000 to 1400 g. His brain has reached the stage of development when the baby is already able to analyze and memorize some information. At this stage, the baby's teeth are covered with a layer of enamel. His body is cleansed of a special lubricant that protects his skin from the effects of amniotic fluid. The baby swallows this liquid, and his digestive system processes the contents of the stomach. The undigested particles will form the newborn's first stool, meconium. At the end of 8 months, the baby's body weight reaches 1500 g, his growth is from 37 to 40 cm.
31	The baby continues to practice breathing exercises, preparing for its first breath outside the womb. His eyes are often open, he blinks, reacting to bright light. The eyes of all newborns are blue, only a few weeks after birth their color will begin to change. The pancreas continues to develop, the liver grows, muscle mass and blood volume in the child's body increase. The baby gets stronger, his skin becomes thicker, acquires elasticity and a characteristic bright pink hue, since there is already the necessary fatty layer under it. Subcutaneous fat is still insufficient, therefore, a network of capillaries and blood vessels is visible under the skin. The growth of the fetus reaches 40 cm with a body weight of about 1600 g.
32	Premature birth is no longer scary for a baby: he will be born with a body weight of 1500 to 2000 g and will be quite viable. True, his lungs are not yet well developed, and many of the reflexes necessary for his survival are absent. The baby's face is cleared of wrinkles, smoothed, and hairs grow on the head. He quickly gains body weight due to the production of immunoglobulins. During this period, some babies begin to gradually turn upside down - this is the position the fetus should take before the onset of childbirth. The baby moves more, disturbing the mother and causing her some inconvenience. To calm him down, a pregnant woman needs to lie down. A protruding navel should not bother the mother: this is the result of pressure and a heavy load on the mother's body. After giving birth, the navel will return to its previous appearance. The body weight of a child at 32 weeks is 2000 g, height is from 40 to 42 cm.
33	At 33 weeks, a woman is usually prescribed an ultrasound scan to determine how much the fetus is developed, whether its development corresponds to the gestational age, whether there are any pathologies in development. The baby's brain is already formed, the number of neurons is increasing, expanding the nerve connections. This week, the heart begins to gain mass, the subcutaneous fat layer grows. The baby needs more nutrients, and he insistently demands them from his mother.
34	· The sucking reflex is developed - the child sucks on his thumb, practicing to suck on the mother's breast. · His skeleton is getting stronger, and the body needs more and more calcium. The baby moves a lot: in the uterus it is already cramped, he tries to take a comfortable position, turns over and pushes. · The lungs are ready to receive oxygen, but are not yet 100% capable of independently and fully functioning. · The baby weighs up to 2400 g, and his body weight is 40-45 cm.
35	· The baby's skin acquires the required color and texture, is cleared of grease, becomes less transparent due to the accumulation of subcutaneous fat. The fluff on the baby's body is already invisible and has almost disappeared. The development of the adrenal glands continues, the growth of the nail plates is observed. · The baby's ears are already fully deployed and correctly positioned. · In the intestines of the fetus, there is already a little original feces - meconium, it will be the first bowel movement of the baby after birth. The baby weighs from 2000 to 2600 g, its body length can vary from 40 to 45 cm.
36	The baby's skin is smooth, vellus hair can remain in a small amount on his back and shoulders, but it will disappear in the first days after the birth of the baby. The presence of a sucking reflex indicates that the baby is ready to feed at the mother's breast. A fully formed baby's heart beats steadily, but there is still a small hole between the atria. When the baby breathes for the first time outside the womb, it will close. Usually this week, the baby is already positioned correctly - head down. He spins around inside his mom's belly, twists his legs and pushes, but by the time of delivery he must be in the correct position. The baby's body is getting rounded, its nervous, immune and endocrine systems continue to improve. In general, the baby is almost ready for its birth. His weight at this stage of development is from 2500 to 3000 g, height - from 43 to 47 cm.
37	The reproductive system of the child is established, the ovaries (in girls) and the testes (in boys) are functioning and producing the necessary hormones. The baby's body is covered with original lubricant, the accumulation of subcutaneous fat continues: on average, its increase per day is about 30 g per day. His skeleton has become stronger, the cartilages have become harder and denser, the ligaments are stronger. The baby continues to train on spontaneous breathing: after birth, he will have to breathe in air for the first time, and not amniotic fluid.
38	At 38 weeks, the baby is fully viable. A child born at this time may have some difficulty breathing, but in general he is absolutely healthy. If he is born this week, he will need medical attention and medication to help him breathe properly. His body weight is from 2700 to 3200 kg, his height can reach 45 cm.
39	· All organs of the baby are developed, all systems are functioning normally. If there are any minor flaws, then even with premature birth, they can be easily eliminated. This week, the child's body is completing the construction of its own body, and the brain is in full control of this process and the functionality of each system. The baby's hair on the head can grow from 1-3 to 7-9 cm by this time. It weighs over 3000g and is almost 50cm long.
40	· This last week of pregnancy for the baby is unchanged. He is ready for childbirth, for his first breath and meeting his mother. He tries to take the correct position (head down) and waits for the onset of labor. · The bones of the baby at the time of birth are not yet ossified and soft: this feature will help him to pass the birth canal more easily. Large amounts of norepinephrine and adrenaline can be found in his blood. These substances will support his body during childbirth, if this process is delayed and the baby experiences oxygen starvation. · There is a slight increase in blood sugar and an increase in heart rate. All this testifies to the closeness of childbirth. The body length of a child in the last week of pregnancy can be from 45 to 54 cm, body weight also varies between 3200-4100 g. · By the end of the week, the baby will turn his head down, press his knees to the body in readiness to leave the place where he is warm, cozy, nourishing and calm for all 9 months. · The intrauterine development of the fetus is now complete.

Pregnancy is a complex physiological process that takes place in a woman's body, during which the development of a fetus from an egg occurs, ending with the birth of a new person.

Very often during a woman's pregnancy, all the attention of close people is riveted to her. Everyone tries to help her in something, to fulfill her desire, to protect her from worries and illnesses. The main thing is that close people understand that the health and life of the future baby depends on the health and well-being of the mother.

Nature itself will cope with what is entrusted to it: the baby will grow and develop in the mother's womb. The task of a pregnant woman and her environment is not to harm the child even before he is born. And then after 9 months, to the delight of all family members, a strong and healthy baby will be born.

Pregnancy Is a physiological process in which a new organism develops in the uterus, which has arisen as a result of fertilization. Pregnancy lasts an average of 40 weeks (10 obstetric months).

In the intrauterine development of the child, two periods are distinguished.:

1. Embryonic(up to 8 weeks of pregnancy inclusive). At this time, the embryo is called an embryo and takes on the characteristics of a person;
2. Fetal(from 9 weeks to the very birth). At this time, the embryo is called the fetus.

The growth of the child, the formation of his organs and systems occurs naturally in different periods of intrauterine development, which is subordinated to the genetic code embedded in the germ cells and fixed in the process of human evolution.

Development of the embryo in the first obstetric month (1-4 weeks)

First week (1-7 days)

Pregnancy starts from the moment fertilization- the fusion of a mature male cell (sperm) and a female egg. This process usually takes place in the ampulla of the fallopian tube. After a few hours, the fertilized egg begins to divide exponentially and descends through the fallopian tube into the uterine cavity (this path takes up to five days).

As a result of division a multicellular organism is obtained, which looks like a blackberry (in Latin "morus"), which is why the embryo at this stage is called morula... Approximately on the 7th day, morula is introduced into the wall of the uterus (implantation). The villi of the outer cells of the embryo are connected to the blood vessels of the uterus, subsequently the placenta is formed from them. The other outer cells of the morula give rise to the development of the umbilical cord and membranes. After a while, various tissues and organs of the fetus will develop from the internal cells.

Information At the time of implantation, a woman may have small bleeding from the genital tract. Such discharge is physiological and does not require treatment.

Second week (8-14 days)

The outer cells of the morula grow tightly into the lining of the uterus. In the embryo the formation of the umbilical cord, placenta begins, and neural tube, from which the fetal nervous system subsequently develops.

Third week (15-21 days)

The third week of pregnancy is a difficult and important period.... At that time important organs and systems begin to form fetus: the rudiments of the respiratory, digestive, circulatory, nervous and excretory systems appear. In the place where the fetal head will soon appear, a wide plate is formed, which will give rise to the brain. On day 21, the child's heart begins to beat.

Fourth week (22-28 days)

This week the laying of fetal organs continues... The rudiments of the intestines, liver, kidneys and lungs are already present. The heart starts to work more intensively and pumps more blood through the circulatory system.

From the beginning of the fourth week in the embryo body folds appear, and appears spinal rudiment(chord).

By the 25th day ends neural tube formation.

By the end of the week (approximately 27-28 days) the muscular system, the spine are formed, which divides the embryo into two symmetrical halves, and the upper and lower limbs.

During this period begins formation of pits on the glans, which will later become the eyes of the fetus.

Development of the embryo in the second obstetric month (5-8 weeks)

Fifth week (29-35 days)

During this period, the embryo weighs about 0.4 grams, length 1.5-2.5 mm.

The formation of the following organs and systems begins:

1. Digestive system: liver and pancreas;
2. Respiratory system: larynx, trachea, lungs;
3. Circulatory system;
4. Reproductive system: precursors of germ cells are formed;
5. Sense organs: The formation of the eyes and inner ear continues;
6. Nervous system: the formation of brain regions begins.

At that time a subtle umbilical cord appears... The formation of limbs continues, the first rudiments of nails appear.

On the face upper lip and nasal cavities are formed.

Sixth week (36-42 days)

Length embryo during this period is about 4-5 mm.

The sixth week begins placenta formation... At this time, it is just beginning to function, blood circulation between it and the embryo has not yet been formed.

Continues the formation of the brain and its departments... At the sixth week, when performing an encephalogram, it is already possible to record signals from the fetal brain.

Begins the formation of facial muscles... The eyes of the fetus are already more pronounced and uncovered by the eyelids, which are just beginning to form.

In this period, begin change upper limbs: they lengthen and the rudiments of the hands and fingers appear. The lower limbs remain in their infancy for now.

Important organs are changing:

1. Heart... The division into chambers is completed: ventricles and atria;
2. Urinary system... Primary kidneys have formed, the development of the ureters begins;
3. Digestive system... The formation of parts of the gastrointestinal tract begins: the stomach, small and large intestines. By this period, the liver and pancreas had practically completed their development;

Seventh week (43-49 days)

The seventh week is significant in that the final the formation of the umbilical cord is completed and the uteroplacental circulation is established. Now respiration and nutrition of the fetus will be carried out due to the circulation of blood through the vessels of the umbilical cord and placenta.

The embryo is still bent arcuate, there is a small tail on the pelvic part of the body. The size of the head is not less than the entire half of the embryo. The length from the crown to the sacrum grows by the end of the week up to 13-15 mm.

Continues upper limb development... The fingers are visible quite clearly, but their separation has not yet occurred. The child begins to perform spontaneous movements with his hands in response to stimuli.

Good eyes are formed, already covered with eyelids, which protect them from drying out. The child can open his mouth.

The nasal folds and nose are laid, two paired elevations are formed on the sides of the head, from which they will begin to develop auricles.

Intense development of the brain and its departments.

Eighth week (50-56 days)

The body of the embryo begins to straighten length from the crown to the coccyx is 15 mm at the beginning of the week and 20-21 mm at 56 days.

Continues the formation of important organs and systems: Digestive system, heart, lungs, brain, urinary system, reproductive system (boys develop testicles). The organs of hearing are developing.

By the end of the eighth week a child's face becomes familiar to a person: well-defined eyes, covered with eyelids, nose, auricles, lip formation ends.

Intensive growth of the head, upper and lower horses is noted ossification of the long bones of the arms and legs and the skull develops. The fingers are clearly visible, there is no longer a skin membrane between them.

Additionally The eighth week ends with the embryonic period of development and the fetal period begins. The embryo from this time on is called the fetus.

Fetal development in the third obstetric month (9-12 weeks)

Ninth week (57-63 days)

At the beginning of the ninth week coccygeal-parietal size the fetus is about 22 mm, by the end of the week - 31 mm.

Is happening improvement of blood vessels of the placenta, which improves uteroplacental blood flow.

The development of the musculoskeletal system continues... The process of ossification begins, the joints of the toes and hands are formed. The fetus begins to make active movements, it can squeeze the fingers. The head is lowered, the chin is closely pressed to the chest.

Changes occur in the cardiovascular system... The heart beats up to 150 beats per minute and pumps blood through its blood vessels. The composition of blood is still very different from that of an adult: it consists only of red blood cells.

Continues further growth and development of the brain, structures of the cerebellum are formed.

The organs of the endocrine system are intensively developing in particular, the adrenal glands, which produce important hormones.

Cartilage tissue is being improved: auricles, laryngeal cartilage, vocal cords are being formed.

Tenth week (64-70 days)

By the end of the tenth week fruit length from the coccyx to the crown is 35-40 mm.

The buttocks begin to develop, the previously existing tail disappears. The fetus is in the uterus in a fairly free position in a bent state.

The development of the nervous system continues... Now the fetus performs not only chaotic movements, but also reflex movements in response to a stimulus. When accidentally touching the walls of the uterus, the child makes movements in response: turns his head, bends or unbends his arms and legs, pushes to the side. The size of the fetus is still very small, and the woman cannot yet feel these movements.

A sucking reflex is formed, the child begins to reflex lips movements.

The development of the diaphragm ends, which will take an active part in breathing.

Eleventh week (71-77 days)

By the end of this week coccygeal-parietal size the fetus increases to 4-5 cm.

The fetal body remains disproportionate: small torso, large head sizes, long arms and short legs, bent at all joints and pressed to the stomach.

The placenta has already reached sufficient development and copes with its functions: it provides oxygen and nutrients to the fetus and removes carbon dioxide and metabolic products.

Further formation of the fetal eyes occurs: at this time, the iris develops, which will further determine the color of the eyes. The eyes are well developed, half-closed for centuries or wide open.

Twelfth week (78-84 days)

Coccygeal-parietal size the fetus is 50-60 mm.

Goes distinctly the development of the genitals in a female or male pattern.

Is happening further improvement of the digestive system. The intestines are extended in length and fit in loops, like in an adult. Its periodic contractions begin - peristalsis. The fetus begins to swallow, swallowing amniotic fluid.

The development and improvement of the fetal nervous system continues... The brain is small in size, but it exactly repeats all the structures of the adult brain. The large hemispheres and other departments are well developed. Reflex movements are improved: the fetus can clench and unclench the fingers into a fist, grabs the thumb and actively sucks it.

In the blood of the fetus not only erythrocytes are already present, but the production of white blood cells - leukocytes - begins.

At this time, the child single respiratory movements begin to be recorded. Before birth, the fetus cannot breathe, its lungs do not function, but it makes rhythmic movements of the chest, imitating breathing.

By the end of the week, the fetus eyebrows and eyelashes appear, the neck is clearly visible.

Fetal development in the fourth obstetric month (13-16 weeks)

13 week (85-91 days)

Coccygeal-parietal size by the end of the week is 70-75 mm. The proportions of the body begin to change: the upper and lower limbs and the trunk are lengthened, the dimensions of the head are no longer so large in relation to the body.

The improvement of the digestive and nervous systems continues. The embryos of milk teeth begin to appear under the upper and lower jaws.

The face is fully formed, the ears, nose and eyes are clearly visible (completely closed by the eyelids).

14 week (92-98 days)

Coccygeal-parietal size by the end of the fourteenth week increases up to 8-9 cm... The proportions of the body continue to change to more familiar proportions. The forehead and nose are well defined on the face, cheeks and chin appear. The first hairs appear on the head (very thin and colorless). The surface of the body is covered with vellus hairs, which retain the lubrication of the skin and thereby perform protective functions.

Improves the musculoskeletal system of the fetus... Bones become stronger. Motor activity increases: the fetus can roll over, bend, make swimming movements.

The development of the kidneys, bladder and ureters ends... The kidneys begin to secrete urine, which mixes with the amniotic fluid.

: the cells of the pancreas begin to work, producing insulin, and the cells of the pituitary gland.

Changes in the genitals appear... In boys, the prostate gland is formed, in girls, the ovaries migrate into the pelvic cavity. At the fourteenth week, with a good sensitive ultrasound machine, it is already possible to determine the sex of the child.

Fifteenth week (99-105 days)

Coccygeal-parietal size of the fetus is about 10 cm, fetal weight - 70-75 grams. The head is still quite large, but the growth of arms, legs and trunk begins to outstrip it.

The circulatory system is improved... In a child in the fourth month, it is already possible to determine the blood group and Rh factor. Blood vessels (veins, arteries, capillaries) grow in length, their walls are strengthened.

The production of original feces (meconium) begins. This is due to the ingestion of amniotic fluid, which enters the stomach, then into the intestines and fills it.

Fingers and toes fully formed, an individual pattern appears on them.

Sixteenth week (106-112 days)

The weight of the fetus increases to 100 grams, the coccygeal-parietal size - up to 12 cm.

By the end of the sixteenth week, the fetus is already fully formed., he has all the organs and systems. The kidneys are actively working, every hour a small amount of urine is released into the amniotic fluid.

The skin of the fetus is very thin, subcutaneous adipose tissue is practically absent, therefore blood vessels are visible through the skin. The skin looks bright red, covered with vellus hairs and grease. Eyebrows and eyelashes are well defined. Nails are formed, but they cover only the edge of the nail phalanx.

Expression muscles are formed, and the fetus begins to "grimace": frowning of the eyebrows, a semblance of a smile, is observed.

Fetal development in the fifth obstetric month (17-20 weeks)

Seventeenth week (113-119 days)

The weight of the fetus is 120-150 grams, the coccygeal-parietal size is 14-15 cm.

The skin remains very thin, but subcutaneous fatty tissue begins to develop under it. The development of milk teeth, which are covered with dentin, continues. Under them, embryos of permanent teeth begin to form.

There is a reaction to sound stimuli... From this week on, we can say for sure that the child began to hear. When strong sharp sounds appear, the fetus begins to actively move.

The position of the fetus changes... The head is up and is in an almost vertical position. The arms are bent at the elbow joints, the fingers are clenched into a fist almost all the time. From time to time, the baby begins to suck on the thumb.

Heartbeat becomes distinct... From now on, the doctor can listen to him with a stethoscope.

Eighteenth week (120-126 days)

The child's weight is about 200 grams, the length is up to 20 cm.

The formation of a sleep and wakefulness regime begins... Most of the time, the fetus sleeps, movements stop at this time.

At this time, a woman may already begin to feel the movement of the child, especially with repeated pregnancies. The first movements are felt as gentle jolts. A woman can feel more active movements during excitement, stress, which affects the emotional state of the child. At this time, the norm is about ten episodes of fetal movement per day.

Nineteenth week (127-133 days)

The child's weight increases to 250-300 grams, body length - up to 22-23 cm. The proportions of the body change: the head lags behind in growth from the body, arms and legs begin to lengthen.

Movements become more frequent and palpable... They can be felt not only by the woman herself, but also by other people, putting their hand to the stomach. Primary pregnant women at this time can only begin to feel the movements.

The endocrine system is improving: the pancreas, pituitary gland, adrenal glands, gonads, thyroid and parathyroid glands are actively functioning.

The composition of the blood has changed: in addition to erythrocytes and leukocytes, there are monocytes and lymphocytes in the blood. The spleen begins to take part in hematopoiesis.

Twentieth week (134-140 days)

Body length increases to 23-25 ​​cm, weight - up to 340 grams.

The fetal skin is still thin, covered with protective grease and vellus hairs that can persist until the very birth. Subcutaneous adipose tissue develops intensively.

Well formed eyes, at twenty weeks, the blink reflex begins to appear.

Improved movement coordination: baby confidently brings a finger to his mouth and begins to suck. Facial expressions are expressed: the fetus can close its eyes, smile, frown.

By this week, all women are already feeling the movement., regardless of the number of pregnancies. The activity of movements changes during the day. When irritants appear (loud sounds, stuffy room), the child begins to move very violently and actively.

Fetal development in the sixth obstetric month (21-24 weeks)

Twenty-first week (141-147 days)

Body weight grows up to 380 grams, fetal length - up to 27 cm.

The subcutaneous tissue layer increases... The skin of the fetus is wrinkled, with many folds.

Fetal movements are becoming more active and tangible. The fetus moves freely in the uterine cavity: lies downside down or buttocks, across the uterus. Can pull the umbilical cord, push off with hands and feet from the walls of the uterus.

Sleep and wakefulness changes... Now the fetus spends less time in sleep (16-20 hours).

Twenty-second week (148-154 days)

At 22 weeks, the size of the fetus increases to 28 cm, weight - up to 450-500 grams. The dimensions of the head become proportional to the body and limbs. The legs are bent almost all the time.

The fetal spine is fully formed: it has all the vertebrae, ligaments and joints. The process of strengthening the bones continues.

Improves the nervous system of the fetus: the brain already contains all the nerve cells (neurons) and has a mass of about 100 grams. The child begins to take an interest in his body: he feels his face, arms, legs, tilts his head, brings his fingers to his mouth.

The size of the heart increases significantly, the functional capabilities of the cardiovascular system are being improved.

Twenty-third week (155-161 days)

The body length of the fetus is 28-30 cm, weight is about 500 grams... Pigment begins to synthesize in the skin, as a result, the skin acquires a bright red color. The subcutaneous adipose tissue is still quite thin, as a result, the child looks very thin and wrinkled. The lubricant covers the entire skin, and is more abundant in the folds of the body (elbow, axillary, inguinal, and other folds).

The development of internal genital organs continues: in boys - the scrotum, in girls - the ovaries.

Respiratory rate increases up to 50-60 times per minute.

Swallowing reflex is still well developed: the child constantly swallows amniotic fluid with particles of protective skin lubricant. The liquid part of the amniotic fluid is absorbed into the blood, a thick green-black substance (meconium) remains in the intestine. Normally, the intestines should not be emptied before the baby is born. Sometimes the swallowing of water causes hiccups in the fetus, the woman can feel it in the form of rhythmic movements for several minutes.

Twenty-fourth week (162-168 days)

By the end of this week, the weight of the fetus increases to 600 grams, body length - up to 30-32 cm.

The movements become stronger and more precise.... The fetus takes up almost all the space in the uterus, but it can still change position and turn over. Muscles grow vigorously.

By the end of the sixth month, the child has well-developed sense organs. Vision begins to function. If a bright light hits a woman's belly, the fetus begins to turn away, tightly squeezes the eyelids. Hearing is well developed. The fetus detects pleasant and unpleasant sounds for itself and reacts to them in different ways. With pleasant sounds, the child behaves calmly, his movements become calm and measured. With unpleasant sounds, it begins to freeze or, conversely, moves very actively.

An emotional bond is established between mother and child.... If a woman experiences negative emotions (fear, anxiety, melancholy), the child begins to experience similar feelings.

Fetal development in the seventh obstetric month (25-28 weeks)

Twenty-fifth week (169-175 days)

The length of the fetus is 30-34 cm, body weight increases to 650-700 grams. The skin becomes elastic, the number and severity of folds decreases due to the accumulation of subcutaneous fatty tissue. The skin remains thin with many capillaries giving it a red coloration.

The face looks familiar to humans: well-defined eyes, eyelids, eyebrows, eyelashes, cheeks, auricles. The cartilage of the ears is still thin and soft, their curves and curls are not fully formed.

Bone marrow develops intensively, which takes on a major role in hematopoiesis. The strengthening of the bones of the fetus continues.

Important processes take place in the maturation of the lungs: small elements of lung tissue (alveoli) are formed. Before the baby is born, they are without air and resemble deflated balls, which unfold only after the first cry of the newborn. From the 25th week, the alveoli begin to produce a special substance (surfactant) necessary to maintain their shape.

Twenty-sixth week (176-182 days)

Fruit length is about 35 cm, weight increases to 750-760 grams. The growth of muscle tissue and subcutaneous adipose tissue continues. Bones are strengthened and permanent teeth continue to develop.

The formation of genitals continues... In boys, the testicles begin to descend into the scrotum (the process lasts 3-4 weeks). In girls, the formation of the external genital organs and the vagina is completed.

The senses are improved... The child develops a sense of odors (sense of smell).

Twenty-seventh week (183-189 days)

Weight increases to 850 grams, body length - up to 37 cm.

The organs of the endocrine system are actively functioning in particular the pancreas, pituitary gland and thyroid gland.

The fetus is active enough, makes various movements freely inside the uterus.

From the twenty-seventh week of the child an individual metabolism begins to form.

Twenty-eighth week (190-196 days)

The child's weight increases to 950 grams, body length - 38 cm.

By this age the fetus becomes practically viable... In the absence of organ pathology, a child with good care and treatment can survive.

Subcutaneous fat continues to accumulate... The skin is still red in color, vellus hair begins to gradually fall out, remaining only on the back and shoulders. Eyebrows, eyelashes, hair on the head become darker. The child begins to open his eyes often. The cartilage of the nose and ears remains soft. The nails have not yet reached the edge of the nail phalanx.

This week starts over to actively function one of the cerebral hemispheres. If the right hemisphere becomes active, then the child becomes left-handed, if the left, then right-handedness develops.

Fetal development in the eighth month (29-32 weeks)

Twenty-ninth week (197-203 days)

The weight of the fetus is about 1200 grams, the growth increases to 39 cm.

The child has already grown up enough and takes up almost all the place in the uterus. Movements become less chaotic. The movements are manifested in the form of periodic jolts with the legs and arms. The fetus begins to occupy a definite position in the uterus: with the head or buttocks down.

All organ systems continue to improve... The kidneys excrete up to 500 ml of urine per day. The load of the cardiovascular system increases. Fetal circulation is still significantly different from that of a newborn.

Thirty week (204-210 days)

Body weight increases to 1300-1350 grams, growth remains about the same - about 38-39 cm.

Subcutaneous fatty tissue constantly accumulates, the skin folds are straightened. The child adapts to the lack of space and takes a certain position: folds, arms and legs crossed. The skin is still brightly colored, the amount of lubricant and vellus hair is decreasing.

Alveoli development and surfactant production continues... The lungs prepare for the birth of the baby and the beginning of breathing.

The development of the head brain, the number of convolutions and the area of ​​the cortex increases.

Thirty-first week (211-217 days)

The child's weight is about 1500-1700 grams, the height increases to 40 cm.

The child's sleep and wakefulness patterns change... Sleep still takes a long time, at this time there is no fetal motor activity. During wakefulness, the child actively moves and pushes.

Eyes fully formed... During sleep, the child closes his eyes, while awake, the eyes are open, and occasionally the child blinks. The color of the iris in all children is the same (blue), then after birth it begins to change. The fetus reacts to bright light by constricting or dilating the pupil.

The size of the brain increases... Now its volume is about 25% of the brain volume of an adult.

Thirty-second week (218-224 days)

The child is about 42 cm tall and weighs 1700-1800 grams.

The accumulation of subcutaneous fat continues, in this connection, the skin becomes lighter, almost no folds remain on it.

Internal organs are improved: organs of the endocrine system intensively secrete hormones, surfactant accumulates in the lungs.

The fetus produces a special hormone, which promotes the formation of estrogen in the mother's body, as a result, the mammary glands begin to prepare for milk production.

Fetal development in the ninth month (33-36 weeks)

Thirty third week (225-231 days)

The weight of the fetus increases to 1900-2000 grams, the growth is about 43-44 cm.

The skin becomes lighter and smoother, the layer of adipose tissue increases. Fluffy hair is increasingly wiped off, the layer of protective lubricant, on the contrary, increases. Nails grow to the edge of the nail phalanx.

The child becomes more and more cramped in the uterine cavity, so his movements become more rare, but strong. The position of the fetus is fixed (with the head or buttocks down), the likelihood that the child will turn over after this period is extremely small.

The work of internal organs is being improved more and more.: the mass of the heart increases, the formation of alveoli is almost completed, the tone of the blood vessels increases, the brain is fully formed.

Thirty-fourth week (232-238 days)

Child's weight ranges from 2000 to 2500 grams, height is about 44-45 cm.

The child now takes a stable position in the uterus.... The bones of the skull are soft and mobile thanks to the fontanelles, which can close only a few months after birth.

Head hair grows intensively and take on a certain color. However, hair color may change after childbirth.

Intensive strengthening of bones is noted, in this regard, the fetus begins to take calcium from the mother's body (a woman at this time may notice the appearance of seizures).

The baby constantly swallows amniotic fluid, thereby stimulating the gastrointestinal tract and kidney function, which secrete at least 600 ml of clear urine per day.

Thirty-fifth week (239-245 days)

Every day the child adds 25-35 grams. Weight in this period can vary greatly and by the end of the week it is 2200-2700 grams. Growth increases to 46 cm.

All internal organs of the child continue to improve, preparing the body for the upcoming extrauterine existence.

Fatty tissue is intensively deposited, the child becomes more plump. The amount of vellus hair is greatly reduced. The nails have already reached the tips of the nail phalanges.

A sufficient amount of meconium has already accumulated in the intestines of the fetus., which should normally leave within 6-7 hours after childbirth.

Thirty-sixth week (246-252 days)

The weight of a child is very different and can be from 2000 to 3000 grams, height - within 46-48 cm

The fetus already has a well-developed subcutaneous fatty tissue, the skin color becomes light, wrinkles and folds disappear completely.

The baby takes a certain position in the uterus: more often it lies upside down (less often, legs or buttocks, in some cases, transversely), the head is bent, the chin is pressed to the chest, arms and legs are pressed to the body.

Skull bones, unlike other bones, remain soft, with cracks (fontanelles), which will allow the baby's head to be more pliable when passing through the birth canal.

All organs and systems are fully developed for the existence of a child outside the womb.

Fetal development in the tenth obstetric month

Thirty-seventh week (254-259 days)

The child's height increases to 48-49 cm, the weight can fluctuate significantly. The skin has become lighter and thicker, the fat layer increases by 14-15 grams per day every day.

Cartilage of the nose and auricles become denser and more elastic.

Fully lungs are formed and mature, the alveoli contain the necessary amount of surfactant for the breathing of the newborn.

The maturation of the digestive system has ended: contractions occur in the stomach and intestines necessary to push food (peristalsis).

Thirty-eighth week (260-266 days)

Child's weight and height vary greatly.

The fetus is fully ripe and ready for birth.... Outwardly, the baby looks like a full-term newborn. The skin is light, the fatty tissue is quite developed, and vellus hair is practically absent.

Thirty-ninth week (267-273 days)

Typically two weeks before delivery the fruit starts to sink pressing against the bones of the pelvis. The child has already reached full maturity. The placenta begins to age gradually and metabolic processes deteriorate in it.

The weight of the fetus increases significantly (30-35 grams per day). The proportions of the body completely change: the chest and shoulder girdle are well developed, the rounded abdomen, long limbs.

The senses are well developed: the child catches all sounds, sees bright colors, can focus vision, taste buds are developed.

Fortieth week (274-280 days)

All indicators of fetal development correspond to the new expected. The baby is completely ready for childbirth. The mass can vary significantly: from 250 to 4000 and more grams.

The uterus begins to contract periodically(), which is manifested by aching pains in the lower abdomen. The cervix opens slightly, and the fetal head is pressed closer to the pelvic cavity.

Skull bones are still soft and pliable, which allows the baby's head to change shape and easier to pass through the birth canal.

Fetal development by weeks of pregnancy - Video

After the successful fertilization of an egg with a sperm, a new organism begins to form in the uterus, which after 40 weeks becomes a viable child, ready to be born. Pregnancy, as a physiological process, normally lasts 10 obstetric months, and the entire intrauterine period of fetal development is usually divided into two stages: embryonic and fetal. At the stage of embryonic development - up to 8 weeks of the term inclusive, the fertilized egg is considered an embryo and gradually begins to take on human forms and features. From the 9th week until the baby is born, doctors distinguish the fetal period of pregnancy, during which the embryo already becomes a fetus and the process of forming its own systems and organs goes through. The development of all vital internal organs of a child occurs at a specific time, which is subordinated to the genetic code laid down in the process of human evolution into sex cells.

Embryonic stage of development

First obstetric month

From the moment of the union of healthy male and female cells - the sperm and the egg, fertilization takes place in the ampullary section of the fallopian tube. Over the next few hours, an active process of division of a fertilized egg begins, during which it begins to gradually move into the uterine cavity down the fallopian tube. On average, a fertilized egg - a fertilized and multiplied egg cell reaches the uterine cavity in 5 days. After dividing the egg cell exponentially, it begins to look like a blackberry. It is worth noting that in Latin this berry is called "morus", from which a multicellular organism formed after cell division is called morula in medicine.

Morula by the end of the week should join one of the walls of the uterus - to undergo the implantation process, in which the outer cells of the embryo with their villi are introduced into the blood vessels of the organ. After the fusion of the morula with the female body, placental tissues begin to form, which, subsequently, form a protective shell for the fetus, providing it with nutrition until the very birth. The cells of the embryo, not taking part in the formation of cells for the placenta, give impetus to the development of other membranes and the umbilical cord. The internal cells of the embryo, thanks to reunification with the mother's body, after a while begin to lay the foundation for their own internal organs and systems.

After successful fusion with the mother's body and the beginning of the formation of placental tissue, umbilical cord and other membranes, the embryo is even more intensively implanted into the uterine mucosa. Over the next seven days, the cells for the umbilical cord and placenta are actively developing, in addition, the foundation is laid for an important system of the unborn child - the neural tube, from which the brain and the entire nervous system of the new organism will then begin to form.

15-21 days of pregnancy is considered the most dangerous period - a complex process of laying all important systems and organs of the unborn child takes place. The digestive, respiratory, circulatory, nervous and excretory systems "lay" the first rudiments in the embryo, and a wide plate appears in the place where its head will be formed. On the basis of this element and the neural tube, the brain is later formed. By the 21st day of the term, the heart tissue is so developed that it is able to provide a heartbeat.

Until the 28th day of pregnancy, inclusive, the formation of the foundations for all internal organs of the unborn child continues. It is quite natural when by this time the embryo has the rudiments of the intestines, liver, lungs and kidneys. Its small heart gradually increases the intensity of its work, due to which more and more blood volume of the embryo is pumped through its circulatory system. It is worth noting that it is at the 4th week of development that the embryo acquires clearer outlines, reminiscent of the human body, since its spine has already begun to form. The neural tube completes the developmental stage before day 25, and on the 28th day after conception, muscles develop, forming the future muscular system. During this period, the spine of the embryo is so strong that it divides its body into two identical parts, and also gives an impetus to the formation of the lower and upper limbs. In the area of ​​the head of the unborn child, pits are formed, which will form the basis of the eyes of the fetus.

Second obstetric month

By the 35th day of development, the embryo grows to 1.5-2.5 millimeters in length and weighs about 0.4 grams. This week, the constituent elements of such systems as the respiratory, digestive, reproductive and nervous systems are actively being formed. The embryo develops the rudiments of the liver, pancreas, larynx, trachea and lungs. Special cells are formed, a kind of precursors of germ cells. In the fossae on the head, the formation of the eyeballs and the inner ear begins, and most of the parts of the future brain are actively formed. In the second month of pregnancy, the formation of the umbilical cord is more active, and it can already be distinguished. In general, the limbs of the embryo become more pronounced and acquire the foundations of future nails. In the area of ​​the child's face, the outline of the upper lip differs, and nasal cavities are formed.

From the 36th day of pregnancy, the embryo already has a body length of 4-5 millimeters. During this period, the tissues of the future placenta already form a pronounced shell for the child. At this stage of fetal development, the placenta is gradually fusing with the blood vessels of the female body, but the blood circulation between the embryo and the mother is not yet functioning. The parts of the brain continue to acquire clear forms, and when an encephalogram is taken at a routine examination, the child's brain signals are already clearly recorded by the device.

The face of the unborn child is gradually acquiring the first features, since the facial muscles are already being formed. On the upper limbs, which are noticeably extended in length, the outlines of the fingers and hands are laid. It is worth noting that the lower limbs are still in their infancy at this time. The heart of the embryo acquires a clearer shape, is divided into chambers (atria and ventricles), and the baby's “primary” kidneys also finish forming, on the basis of which the ureters begin to grow. In the digestive system, the foundation is laid for the stomach, large and small intestines, and other important digestive organs - the liver and pancreas, gradually complete their formation.

At this stage, the uteroplacental communication between the embryo and the mother becomes possible due to the final formation of the umbilical cord. At this stage of development, the life support of the fetus is provided by the placenta and the umbilical cord, oxygen and nutrients enter the body of the unborn child through the blood vessels. The location of the body of the embryo in the uterus has an arched shape, and a small tail can be seen in the lower part of the pelvis. The head of the unborn child corresponds in size to half of the entire size of the embryo. Normally, it should grow to 13-15 millimeters. The active growth of the upper limbs continues, the fingers have a clear shape, but are still connected. At this stage of his development, the child can make uncontrolled movements of the limbs, especially under the influence of external stimuli. His eyelids are already formed and protect the eyes from drying out, in addition, the baby periodically opens the mouth cavity. A nasal fold and nose begin to form on the head, and two small elevations are visible on the sides - the rudiments of future ears. The brain continues to actively form.

From 50 to 56 days of pregnancy, the future baby grows from 15 to 21 millimeters in length. Internal organs and systems continue to develop actively, the heart grows, the lungs enlarge, the urinary system appears, the embryo acquires characteristic genitals - the boy's testicles are formed. The auricles are actively developing. By the end of the 8th week, the baby's face becomes more and more human-like - the eyes cover the eyelids, the nose and ears are visible, besides, both lips have finally formed. The active growth of the entire head begins, and the arms and legs go through the stage of ossification, and the bones of the skull are formed. The membrane from the skin disappears between the fingers. This week, the embryonic stage of development of the unborn child is over, the embryo becomes a fetus and begins the fetal period of its development.

Fetal stage of development

Third obstetric month

On the 57th day of development, the fetus reaches 22 millimeters in length, by the 63rd day, growth increases to 31 millimeters. At this time, the condition of the placental vessels improves, due to which the metabolic processes between the fetus and the mother become more intense. The bones and muscles of the unborn child are actively developing - the process of ossification occurs, the development of joints on the fingers and toes. From this point on, frequent body movements can be observed in the fetus, which can clench and unclench the fingers. He lowers his head and presses his chin tightly against his chest. The cardiovascular system becomes more powerful - the heart beats at a speed of 150 beats per minute, intensively pumping blood, which so far consists only of red blood cells. In the brain of the unborn child, the sections become larger and the basis for the future cerebellum begins to develop. In the endocrine system of the fetus, the adrenal glands begin to produce the first important hormones. The cartilaginous tissues of the auricles and larynx are actively formed, and the vocal cords also develop.

On the 64th day of pregnancy, the fetus grows to 40 millimeters, the outlines of the buttocks are formed, a small tail disappears. There is still a lot of space for him in the uterine cavity, so he takes a free half-bent position. The nervous system continues to form intensively, and the fetus often makes reflex movements. For example, in contact with the uterine wall, he turns his head, unbends or bends his legs and arms to push to the side. The woman does not yet feel these movements, since the size of the fetus is too small. This week, the sucking reflex appears, and the diaphragm finishes its development.

The length of the child from the crown to the coccyx by the end of this stage already reaches 5 centimeters. Its torso is still out of proportion due to its large head size, long arms and short legs. The fetus bends its limbs in all joints and presses it to the stomach. The development of the placenta is finally completed and the membrane fully performs all its functions, bringing the necessary volume of oxygen and nutrients to the child, while the vessels also remove metabolic products and carbon dioxide. An iris is formed in the eyes, which affects their color, the eyeball is able to rotate and the eyelid can open and close.

From 78 to 85 days of pregnancy, the fetus grows to 50-60 millimeters. The sex becomes clearly visible, since the genitals are actively developing only in the male or female type. The digestive organs are improved: the intestines are lengthened by twisting into loops. In addition, the intestines periodically begin to contract - peristalsis is formed. Now the baby in the womb can swallow amniotic fluid, thereby developing the swallowing reflex. His brain already exactly repeats the shape of an adult organ, has all sections and both hemispheres, but is still very small in size. The fetus's behavior is now more varied - by sucking on the fist, the baby satisfies his sucking reflex. White blood cells are formed in the blood, and the chest makes breathing movements. By the end of 12 weeks, eyelashes and eyebrows appear on the face, and the neck becomes noticeable.

Fourth obstetric month

At the end of this week, the fetus already reaches 75 millimeters, the outlines of its body are changing, now you can see a small person in it. The limbs are getting longer, the body is larger, and the head is more proportional - now it no longer looks so big. The digestive organs are actively improving - the rudiments of milk teeth are formed under the upper and lower jaw. The facial features are almost formed - the nose, eyes and ears are clear, and the eyelids are completely closed.

From 92-98 days, the unborn child grows to 9 centimeters. His torso continues to improve and the proportions become more familiar to the human eye. The forehead, nose, cheeks and chin are clearly visible on the face. The first hairs appear on the head, the body is also covered with fine hairs. These hairs are fluff, retain oil, and perform a range of protective functions. During this period, bones are actively compacted and muscle tissue grows, the fetus becomes more mobile - it periodically bends, turns over and tries to make the first swimming movements. The organs of the genitourinary system finish forming - the kidneys begin to release liquid (the baby pisses), which gets into the fetal waters. The endocrine system of the fetus is actively completing its formation, after which the pancreas will begin to secrete insulin. The pituitary cells in the brain gradually begin to function. The reproductive organs of the fetus acquire a perfect appearance: the prostate gland of boys ends up forming, and in girls, the ovaries migrate into the pelvic cavity. As a result, with the help of ultrasound, it becomes possible to determine the sex of the unborn child.

By the end of the week, on the 105th day of pregnancy, the unborn child weighs about 75 grams and reaches a length of ≈ 10 centimeters. The growth process of the limbs of the fetus becomes more intense than the head, so the body is already relatively proportional. By the end of the fourth month of pregnancy, the unborn child already has its own blood group and Rh factor, its blood vessels lengthen and tighten their walls. Meconium (the original feces of the fetus) begins to be periodically produced by the intestines and enter the fetal waters. This process provokes the ingress of fetal waters into the body of the unborn child, while he makes reflex swallowing movements. The fingers and toes are finished forming, the skin at the tips takes on a special pattern.

The fruit already weighs about 100 grams, grows up to 12 centimeters and has all the organs and systems. The genitourinary system works regularly, the kidneys produce a certain amount of urine (urine) every hour. The blood vessels are visible through the skin because the subcutaneous fat has not yet formed. The skin has a bright red hue, covered with vellus hairs and grease. Eyelashes and eyebrows become thicker, nails are actively forming and already cover the edge of the nail phalanx. The fetus has facial expressions - the facial muscles finish developing, so it periodically frowns and even smiles.

Fifth obstetric month

By the 119th day of pregnancy, the fetus gains a mass of ≈ 120-150 grams, and reaches 15 centimeters in length. The skin is still quite thin, but subcutaneous fatty tissue is already beginning to form. Dentin forms on the rudiments of milk teeth, and permanent teeth are formed under them. The fetus can already react to the sound with active movements, and some women, especially very sensitive women, can feel these movements. The position of the unborn child in the uterus changes - it becomes vertical, the baby bends his arms at the elbow joints, and squeezes his fingers into fists almost all the time. Unclenching his fists, the baby straightens his fingers and even sucks, often large. The heartbeat is already clearly audible when examined by a gynecologist with a stethoscope.

The body weight of the fetus reaches 200 grams, and the length from the crown to the coccyx is 20 centimeters. This week, you can fix the semblance of the sleep and wakefulness regime of the unborn child, who sleeps most of the time, and makes active movements during the waking period. Most pregnant women at the 18th week of the term begin to clearly feel the movements and movements of the fetus. As a rule, you can feel the gentle jolts of the unborn child when he pushes off the wall of the uterus, or reacts to sounds. The mother's stress also encourages the fetus to move. Normally, at this time, the unborn child should do up to 10 episodes of movements during the day.

On the 127-133 day of pregnancy, the fetus weighs up to 300 grams, while growing up to 22-23 centimeters. Its proportions change - the head grows much slower than the body, and the limbs continue to actively lengthen. The fetus often moves, its mother feels it, and others can even feel it, touching the stomach. It is worth noting that at this time during the first pregnancy, the woman may not yet recognize the fetal movement, in contrast to the more experienced mother. The organs of the endocrine system of the unborn child work very actively, and the blood gradually acquires a new composition - monocytes with lymphocytes are added to the erythrocytes and leukocytes. The spleen begins to take part in the formation of fetal blood cells.

The body weight of the fetus on the 134-140 day of the term reaches 340 grams, and in length it grows up to 25 centimeters. The skin is still very thin, but the subcutaneous tissue is practically formed, and the vellus hairs and lubricant protect the fetus. The eyes are already so formed that the baby has a blinking reflex. The coordination of movements of the unborn child becomes more pronounced and active: the thumb of the hand is brought to the mouth with a conscious movement, the eyes can be closed, the lips stretch in a smile and the eyebrows frown. Without exception, all expectant mothers already clearly feel the movements of the baby in the womb, noting changes in his movements during the day. The fetus becomes especially active under the influence of stimuli - loud sounds or stuffiness.

Sixth obstetric month

On the 141-147th day of pregnancy, the fetus already reaches 27 centimeters in length and weighs about 380 grams. His skin acquires folds, becomes wrinkled due to the dense layer of subcutaneous tissue. The fetus moves more and more often, moves freely in the uterus, can sit upside down or pelvis, sometimes lies across the uterus. Thanks to the developed arms, the unborn child periodically grabs the umbilical cord, and with its legs can decisively push off the uterine wall. His sleep and wake patterns change - less time is devoted to sleep.

During 148-154 days of pregnancy, the fetus grows in size up to 28 centimeters and weighs about 500 grams. The body of the unborn child becomes more proportional - the head is no longer so large in relation to the whole body. His legs are bent almost all the time at the hip and knee joints. The bones continue to actively strengthen. The spine is almost completely formed and has all the joints, vertebrae and ligaments. All nerve cells - neurons - appeared in the brain, and the organ weighs about 100 grams. The fetus becomes more conscious - it is interested in its own body, touching its face, arms and legs, while it deliberately tilts its head and brings its hands to its face. His heart grows and improves his work.

At this stage of fetal development, the body reaches 30 centimeters in length and weighs 500 grams. At 23 weeks, the skin already acquires a bright color - red, due to the synthesis of a special pigment, but the subcutaneous fatty tissue is still thin, so the body of the fetus looks thin and wrinkled. The entire skin of the unborn child is covered with a thick layer of lubricant that gets into the folds of the body. The genitals continue to develop, and the activity of the movements of the diaphragm increases. The fetus can breathe 50-60 times a minute and constantly swallows the fetal water along with the protective lubricant of the skin. As a result, these substances enter the intestines and turn into meconium, which normally should not be excreted from the intestine before childbirth. The swallowing reflex and the ingress of liquid into the child's intestines provokes hiccups, it is easily felt by the expectant mother.

On the 168th day of its development, the fetus reaches 32 centimeters in length and weighs about 600 grams. He begins to move even more actively in the womb and gradually occupies almost the entire uterine cavity. At the same time, the baby sometimes changes its position and even turns over, which is facilitated by active muscle growth. It can be noted that at the 24th week of pregnancy, the unborn child already has developed sense organs: the eyes begin to function fully, therefore, when a bright light hits the pregnant woman's belly, the fetus turns away from it or closes its eyelids. The hearing organs are also well developed and functioning, so the fetus can distinguish the voice of its mother and actively respond to unpleasant or loud sounds. At this stage, a strong emotional connection is established between the fetus and the woman, therefore, the child also begins to experience any negative emotions of the mother with her.

Seventh obstetric month

By the 175th day of the term, the weight of the fetus is approximately 650-700 grams, and the length is 30-34 centimeters. The skin of the child acquires elasticity, the folds become less noticeable, as the layer of fatty tissue increases. In the still thin skin, a large number of capillaries are formed, giving it a bright red hue. The facial part of the head becomes more like the face of an adult: the eyes are clearly defined, framed by eyelashes and eyebrows, the ultrasound scan shows the cheeks of the unborn child and the outlines of the auricles. The curves and curls of the ears are not yet fully formed, the cartilage has a soft and thin structure. There is an active development of the bone marrow, due to which the process of hematopoiesis is enhanced, and the bones are strengthened. Tissues ripen in the lungs - alveoli are formed, but until the baby is born, the organ will be without air. In their shape, the alveoli still resemble deflated balloons, which will straighten out after the child's first breath. At the 25th week of the term, the alveoli already produce a special element - a surfactant, which ensures their shape.

This week, the unborn child grows up to 35 centimeters in length, gaining a mass of 750-760 grams. Its adipose tissue and muscle tissue are actively gaining volume, and the main teeth also continue to form. The genitals in boys are already beginning to descend into the scrotum, and this process will last about 4 weeks, while in girls at this time the outlines of the external genitalia are formed. The sense organs are more and more improved, so the fruit sometimes distinguishes smells.

On the 183-189 day of pregnancy, the weight of the unborn child increases to 850 grams with an increase of 37 centimeters. An active process of the fetal endocrine system begins - the pituitary gland, pancreas and thyroid gland perform the necessary functions. The unborn child often makes movements of the limbs and head, freely changing the location in the uterine cavity. From this moment, the process of forming his personal metabolism begins.

The body weight of the unborn child reaches 950 grams, and the length is 38 centimeters. At this stage of formation, the fetus can be considered viable, but only in the absence of pathologies of internal organs. The fatty tissue continues to increase in volume, but the skin is still red in color. The skin gradually gets rid of the vellus hairs, which are partially retained on the shoulders and back. The hairs of the eyebrows and eyelashes acquire a more intense shade, and the amount of dark hair on the head also increases. Periodically, the unborn child opens the eyelids, his nose and ears remain soft, but the nails already cover half of the phalanx of the fingers. From this moment, one of the cerebral hemispheres can actively begin to work.

Eighth obstetric month

From 197 to 203 days of pregnancy, the unborn child is actively gaining body weight and weighs about 1200 grams with a height of 39 centimeters. The body of the fetus has grown so much that it occupies almost the entire uterine cavity, therefore, chaotic and frequent body movements are already excluded. The fetus occasionally moves gently, making points with its arms or legs to take a specific position in the uterus for future childbirth. Normally, he should descend to the pharynx with his head or pelvis. In general, all internal organs and systems continue to develop in him, for example, the kidneys already excrete 500 milliliters of urine during the day. The cardiovascular system increases the load, but its circulation is still different from that of an adult.

From 204 to 210 days of pregnancy, the unborn child gains weight up to 1300-1350 grams with an increase of 39 centimeters. A layer of subcutaneous fat is actively accumulated by straightening the folds, and the child himself begins to gradually adapt to a limited place in the uterus. As a rule, he already takes a certain and comfortable position for himself - he folds and crosses his limbs. Despite the fact that the vellus hairs and grease gradually disappear from his skin, it (the skin) still remains a red tint. In the lungs, alveoli are actively formed and a surfactant is produced, thereby preparing the respiratory organs for childbirth. The brain is enlarged due to the formation of new convolutions and expansion of the area of ​​\ u200b \ u200bthe cortex.

211-217 days of pregnancy is characterized by a gain in fetal body weight up to 1500-1700 grams with an increase of 40 centimeters. In the mode of sleep and rest, changes occur: sleep takes most of the time of the day, but while awake, the child actively moves and pushes the mother's stomach with his legs. Frequent blinking of the eyelids and a change in the color of the iris to blue can be noted. The pupils of the unborn child are already fully formed and react by constriction to bright light. The volume of the brain reaches 25% of the size of an adult's brain.

At this stage of the term, the fetus is gaining weight in 1700-1800 grams and grows to 42 centimeters. The skin gradually lightens and gets rid of folds by increasing the fatty tissue. Internal organs are actively improving, the endocrine system produces hormones, and the lungs accumulate a sufficient amount of surfactant. Thanks to a special hormone, in the woman's body this week, the mammary glands begin to prepare for the production of milk for the baby.

Ninth obstetric month

On days 225-231, the fetus weighs about 2 kilograms with an increase of 43-44 centimeters. The skin becomes lighter and smoother under the influence of fatty tissue. The vellus hairs almost completely disappear, but the layer of protective grease is compacted. The nail plate is strengthened and covers the entire phalanx of the toe. The unborn child moves very rarely, but at the same time makes strong shocks, since he no longer has enough space for free movement. Finally, its location is fixed in relation to the pharynx of the womb, and from that moment, the chances that it will change its position decrease. The internal organs increase the intensity of work, the heart becomes larger, the alveoli have finished forming and the vascular tone has appeared. The brain has formed all the departments and the cortex.

From 232 to 238 days of pregnancy, the weight of the unborn child increases to 2500 grams with an increase of 45 centimeters. At this stage of development, the fetus has soft bones in the skull due to the mobility of the fontanelles, which is necessary for delivery. The bones on the head will strengthen only a few months after the baby is born. The active growth of hair on the head continues, while they acquire a certain color, which may change after childbirth. The bones of the body are actively enlarged and strengthened, for which the child's body takes calcium and other substances from the mother's body. The fetus continues to actively swallow the waters of the fetus, which stimulates the production of up to 600 milliliters of urine per day.

On the 245th day of the term, the unborn child gains about 35 grams in weight every day, so the weight of the fetus can change greatly, and by the end of the week it will be 2200-2700 grams with a height of ≈ 46 centimeters. The body of the unborn child is actively preparing for childbirth, strengthening the internal organs, increasing the amount of fatty tissue and getting rid of vellus hairs. The fingernails are fully formed, and a large amount of meconium has accumulated in the intestines.

From 246 to 252 days of the term, the child gains from 2 to 3 kilograms of mass with an increase of 46-48 centimeters. The skin acquires a light color, the fatty tissue has formed and the folds have completely disappeared. Often, the fetus in the womb is positioned upside down, bending and leaning against the chest, and the limbs are crossed and pressed against the body. Almost all bones, except for the skull, are already strong, and the internal organs are ready for extrauterine life.

Tenth obstetric month

By the 259th day of pregnancy, the unborn child can gain different body weights, depending on the genetic disposition, but his height should be about 49 centimeters. The skin is actively denser, and the fatty tissue acquires up to 14-15 grams of volume per day. Also, the cartilages of the nose and auricles are actively compacted, the lungs are already mature, and a sufficient amount of surfactant has accumulated in the alveoli. The digestive organs have finished forming, and the stomach and intestines can periodically contract to push food.

Day 260-266 is characterized by fetal weight gain, which often varies. At the same time, the unborn child is already completely ready for childbirth and life outside the womb. His appearance is completely consistent with the appearance of a normal child: the skin is of a natural color, fatty tissue is available in sufficient volume, and the vellus hair has completely disappeared.

On the 267-273 day of pregnancy, the fetus should begin to gradually descend to the pharynx of the uterus - to the birth canal. Usually it is pressed against the mother's pelvic bones, and the placenta is gradually aging, no longer ensuring the normal course of all metabolic processes between the child and the mother. Normally, the fetus should reach absolute maturity, but at the same time it is still gaining 35 grams of mass per day. The proportions of his body are completely modified: the chest and shoulder girdle are well developed, the abdomen has become rounded, and the limbs have lengthened.

On the 274-280th day of the term, the child should be born, since it has already reached compliance with the forms and condition of the newborn. His body weight can vary from 2.5 to 4 kilograms. Starting this week, the expectant mother should expect the appearance of uterine contractions - the onset of labor. In this case, the head of the child, with the soft bones of the skull, should closely press against the pelvic cavity and prepare for the passage through the birth canal.