Fetal development by week Photo

Future mothers are sensitive to the development of the baby they carry under their hearts and want to learn as much as possible about the processes happening to them during pregnancy , study with interest the stages of intrauterine growth of the fetus, carefully examine the pictures that depict in detail fetal development by week.

Gynecologists begin counting the pregnancy period from the first day of the last menstruation. Basic unit of time pregnancy- a week.
The first weeks for the unborn child - are 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 and will protect the baby from many health problems. Below you will find detailed information about the formation embryo in the womb, you can consider the development of the fetus week by week - Pictures with all stages of intrauterine growth and development, as well as a description of the processes occurring at one stage or another of pregnancy.

Before turning to the photo with the stages of fetal development by week, let’s briefly familiarize ourselves with the main periods of organ formation little man during pregnancy. At 5-6 weeks, an embryo measuring 6 millimeters in size (like a pear seed) lives in a bladder with liquid. The formation of the nervous system occurs, the spine and brain appear. Two pairs of dimples for the eyes and ears are visible on the head. Digestive tract begins already at this stage of fetal development.

Only 2 weeks pass and the main internal organs of the fetus are already formed. In the eighth week of fetal development, the face takes on the necessary shape, the nostrils, the tip of a small nose, mouth, and tongue are noticeable. Begins to function inner ear . The fingers of the developing baby are also emerging.

12 weeks fetal development- the age of a ten-centimeter embryo in which the outlines of a human body are visible. At the twelfth week of fetal development, various systems and organs have already formed and are developing safely. Modernized ultrasound equipment allows you to find out the sex of the baby and see facial features 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 week 13, villi appear in the intestines , which in the future will speed up the process of digesting foods.

Up to the 21st week of fetal development, the baby’s size allows him to move in the mother’s womb in any direction. The length of the fruit is 26 centimeters, weight is 0.4 kilograms.

The little 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, all that remains is to gain weight. The child is already able to feel, his condition can change depending on the mother’s mood. Hearing is developed enough to recognize voices. Vision and smell also function.

The baby is ready to be born at 37 weeks. Now the birth cannot be called premature. Of course, ideally you need to wait a little. But the baby can already absorb and digest mother’s milk , epithelium with villi appears on the mucous membrane of the stomach and intestines, through which Nutrients pass from food into the blood . Peristalsis is working, the first feces - meconium - have formed.

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

Even pictures with stages of intrauterine development of the fetus by week clearly demonstrate the importance of the ongoing formation processes internal organs baby. We hope that the information we post will help you better understand the processes what happens in your body during pregnancy and we want to wish you that the baby was born healthy and beautiful !
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A woman’s pregnancy is a unique natural process when, within 9 months, a full-fledged person appears in her stomach from several cells. Many expectant mothers are interested in how the fetus develops, because this miracle happens in their stomach and directly affects the entire body. Therefore, at present, monitoring the intrauterine development of a child week by week or day has become a very popular phenomenon.

Modern technologies allow you to monitor the development of the embryo week by week using photos. The development of the embryo week by week can also be observed on video.

However, despite the huge number of descriptions of the development of the baby in each trimester of pregnancy, every expectant mother will be interested in how exactly the intrauterine development of the child occurs in her, although in general terms the development of the embryo occurs in the same way for everyone. More details in the video.

Fetal development by week

1st week

Fetal development in the first week of pregnancy occurs literally day by day. The first day of pregnancy is considered the day when the egg is fertilized by a sperm. The new, formed single-celled organism is called a zygote and contains 46 chromosomes.

On the fourth day, the embryo, gradually moving along the fallopian tube, reaches the uterus. On the fifth day, the embryo is already a small lump of 12 cells. Every day, the fragmentation of the cells of the embryo occurs more and more quickly, and by the seventh day the embryo already consists of several hundred cells.

2nd week

During the 2nd week of pregnancy, the outer cells of the embryo are implanted into the lining of the uterus. The fetus, previously freely floating in the uterine cavity, attaches to its wall. At this point, the woman’s body is already completely ready for pregnancy, although she herself may not yet feel it.

At this stage, the rudiments of the muscular, skeletal and nervous systems are formed. Therefore, this period of pregnancy is considered important. The first two weeks of pregnancy in obstetric practice are not yet considered to be an actual pregnancy.

This is because at 2 weeks of pregnancy the follicle is still maturing, preparing for the possible successful fertilization of the intended egg.

In the future, upon the onset of ovulation and subject to successful fertilization, actual pregnancy will occur. In the meantime, in the first 2 weeks of pregnancy, the question of whether a real pregnancy will occur and whether the woman will be able to conceive a baby this time is still being decided. Thus, the first two weeks of pregnancy are still considered the follicular phase, that is, the woman is not actually pregnant yet.

3rd week

The development of the fetus in the third week of pregnancy is called the embryonic period of development and it lasts until the 12th week. During this period, the formation of the axial organs of the embryo occurs.

4th week

At week 4, the rudiments of the skeleton, brain, endocrine glands, kidneys, muscles, ears, and skin are formed.

At this point, the woman notices the absence of menstruation. Hormonal changes occur in her body, preparing her for further pregnancy and childbirth. Mild signs of pregnancy appear, such as drowsiness, loss of appetite, etc. A pregnancy test will 100% confirm it.

5th week

The fifth week of pregnancy is characterized by the formation of the placenta, which is a source of oxygen and nutrients for the future baby. The child’s ears and eyes begin to form, and finger shoots appear.

The length of the embryo at the end of the fifth week of pregnancy is 6.5 mm. Also this week, the rudiments of the baby’s cardiovascular system begin to form, which will complete their development for several more weeks.

6th week

At the 6th week of pregnancy, the development of the baby’s brain continues, the lungs, nose, jaws, and fingers are formed. An ultrasound will already determine the baby's heartbeat. Now you can take the first photos of your unborn child. The length of the embryo at the 6th week of pregnancy is about 1 cm.

7th week

Fetal development in the 7th week of pregnancy is characterized by the formation of all vital organs, hair follicles, eyelids, and tongue. The body grows, elbows and fingers acquire more distinct outlines. The intestines, liver, lungs, and kidneys are almost completely formed.

This week, the rudiments of the eyes, belly and chest are determined, and fingers appear on the arms. The baby has already developed a sense organ - the vestibular apparatus.

The length of the embryo is up to 12 mm. The fetus's face is already visible; one can even distinguish its mouth, nose and ears. The head of the embryo is large and its length this week already correlates with the length of the body. At this stage of development, the fetal body is almost completely formed.

8th week

At 8 weeks of pregnancy, the embryo finally turns into a baby. Bones and muscles are almost formed, facial features become even more distinct - the child’s eyes, ears, arms and legs are clearly visible.

The baby moves a lot. By the end of the 8th week of pregnancy, the length of the fetus reaches 3 cm, and it weighs 5 grams. From this moment on, the development of the human embryo by days turns into the development of the fetus by weeks. All important parts of the baby's body are present, although they are not yet fully formed. The nervous system is becoming more and more improved.

Third month of pregnancy, 9-12 weeks

During this period, the vestibular apparatus appears and begins to function in the fetus. The more the mother moves during this period, the more beneficial it is for the baby. The baby's skin is transparent, the arms grow faster than the legs. The head and neck of the fetus are straightened, a face has already formed. Muscles and bones are visible under the skin, which does not have a fat layer. The baby has a cartilaginous skeleton, the fetus begins to actively move.

A rapid fetal heartbeat can be heard. At the 10th week, you can already distinguish the sex of the baby. At the 12th week, the baby’s eyes become closer together, his mouth becomes smaller, vocal cords appear, and his nostrils spread wide.

The first hairs appear above the eyes and upper lip. Every day the baby grows by 1.8 mm and gains 1.4 grams in weight. By the end of the 12th week, the baby is 8-9 cm long and weighs about 30 grams. More details in the video.

Fourth month, 13-16 weeks

The development of the fetus at the 13th week of pregnancy enters a new stage. The baby already looks like a miniature copy of a person. All vital organs have already been formed, but are not yet fully functioning.

At the thirteenth week of pregnancy, the baby's first baby teeth form, hidden in the tissue of the jaws. The first hair appears on the head and body of the fetus.

At week 14, active growth of the baby’s brain occurs, as a result of which body growth slows down.

At the 15th week of fetal development, the hormone testosterone is produced in the body of the unborn baby. A little later, female hormones begin to be produced. During this period, the fetus's skin color changes.

At week 16, the baby’s body proportions change, the head becomes smaller in relation to the body. The kidneys, sweat and sebaceous glands begin to work. The liver is actively developing and is already able to accumulate bile and produce glycogen. The length of the four-month fetus is 16 cm, the hand size is 1.4 cm, and its weight is approximately 120 grams.

Fifth month, 17-20 weeks

From this moment, the development of the human embryo by week of pregnancy turns into the development of the child by week of pregnancy, since in the stomach of the expectant mother a full-fledged organism is already functioning, with all the internal and external organs formed.

The respiratory, digestive, nervous and circulatory systems are fully formed. At 17-20 weeks, a layer of subcutaneous fat forms on the baby’s entire body, with the exception of the face.

The face is very wrinkled, hairs grow on the head. Nails begin to grow on the baby’s fingers and a sucking reflex appears. The growth of the head slows down, and it already makes up a third of the body length. By the end of the fifth month, the baby's height is approximately 25 cm, and he weighs 300-400 grams.

By this time, mom has gained about 4 kg in weight.

Sixth month of pregnancy, 21-24 weeks

Fetal development at 21 weeks of pregnancy is characterized by active kidney function. They already secrete uric acid and urea into the amniotic fluid. At the 22nd week of pregnancy, aesthetic changes occur in the development of the child. The formation of the subcutaneous fat layer is completed, facial features become more defined.

At week 23, the baby’s neck lengthens, the ears become larger, and the line of the nose and eyebrows become clearer. The baby's body is covered with a thin layer of delicate hairs. The baby in the mother's belly is already waking up and falling asleep. The baby's length growth slows down, but weight gain increases. By the end of 24 weeks, the baby is about 30 cm long and weighs about 600-650 g. The length of the baby’s hand is 2 cm.

Seventh month, 25-28 weeks

In the seventh month of pregnancy, the baby's hair disappears on all parts of the body except the head. The development of the human embryo ends at the 28th week of pregnancy. From this moment on, the baby only gains strength and receives nutrients for further growth from the mother’s blood.

The baby's fully formed eyes open, he can already see, hear and suck his own finger. The baby freely changes its position in the uterus. The hair on the baby's head reaches a length of 50 mm. The baby gains weight on average 25 grams per day and by the end of the seventh month of pregnancy weighs about 1300 g and his height is 35 cm.

Eighth month, 29-32 weeks

Most likely, at the 29th week of pregnancy you will already notice that the fetal movements have changed their character: firstly, they have become more distinct, secondly, more noticeable, thirdly, now the baby will kick and push more and more, rather than roll over and much less tumble. And all because he has already grown enough for this - there is less and less room for activity.

In the eighth month of pregnancy, the baby's layer of subcutaneous fat thickens and the skin becomes lighter. The brain develops much faster than the body grows. The baby's entire body is covered with vernix, protecting it from amniotic fluid. The baby's eyelids have small eyelashes.

He distinguishes between light and darkness. The baby can already hear well and responds to screams, loud music and other sharp sounds with jerks. But quiet sweet words mothers are able to quickly calm him down.

At the 8th month of pregnancy, the baby gains approximately 190-200g in weight; the entire increase in the mother’s body weight is now due to the growth of the baby. At 32 weeks of pregnancy, the baby is 43 cm tall and weighs about two kilograms.

Ninth month, 33-36 weeks

36th week of pregnancy... Just a little more, and a long-awaited and unforgettable sacrament for a woman will take place - a meeting with her already beloved baby. “Just a little”... How much is just a little? – closer to the birth, a mother may ask a question, completely confused in the calculations. What happens to the fetus?

In the ninth month of pregnancy, the baby's down, which previously covered his entire body, disappears. The layer of subcutaneous fat grows, the skin color evens out, acquiring a beautiful pinkish tint.

By the end of the 36th week of pregnancy, the baby takes a permanent position in the ovum, usually head down. The baby's lungs and liver are maturing, and the heartbeat is 120-140 beats per minute. The baby weighs on average 2800 grams, and his height is about 46 cm. And although the baby’s development and strengthening of his body are still ongoing, he can already be born without any particular danger to life.

37-40 week

At 37-40 weeks the baby is almost ready to be born. He reaches the size he will be at birth. The fingernails are longer than the fingertips. The weight of a full-term baby is 2700 - 3500 g, and its height is about 50 cm.

During this period, pregnant women usually feel some relief. Food is digested better, shortness of breath disappears. The baby’s nervous system is strengthened, and the development of the lungs allows him to breathe oxygen freely. Learn more about this period of pregnancy in the video.

Video and ultrasound

Of course, expectant mothers are interested not only in knowing how their baby is developing, but also in observing the process. Modern technologies allow pregnant women to watch the entire process on video. However, doctors do not recommend doing ultrasound examinations too often.

The problem is solved with the help of numerous ready-made videos. This is due to the fact that the development of the embryo occurs to a greater or lesser extent in the same way, which means that in the video, almost everyone has the same pictures.

Details about ultrasound and pregnancy on video.

The most dangerous weeks

The most dangerous of the entire pregnancy period are:

• 2-3 weeks, the period when the fertilized egg moves towards the uterus;
• 8-12 weeks when it occurs hormonal disbalance body;
• 18-22 weeks, when the risk of infection increases;
• From the 28th week there is a risk of placental abruption or placental insufficiency.

These periods are characterized by an increased risk of losing a child. To avoid this, you need to register with the antenatal clinic, take all tests and undergo examination on time. When found dangerous symptoms qualified doctors will take the necessary measures to preserve the pregnancy and the life of the child.

Observation of the development of the embryo is not carried out out of idle curiosity. Knowledge of the processes occurring in the body of a pregnant woman and her baby will allow the expectant mother to understand what her actions will bring greatest benefit for the baby, which will be useful for his development.

Observing how the baby develops, young mothers realize that the life of a little man begins from the first day of fertilization of the egg, and not from the moment the child is born, as was previously believed.

Read in this article:

The birth of a new life is the most beautiful secret of nature. What could be more mysterious than the development of a child in the womb? The formation of a little person from a fertilized egg goes through a rather complicated path. Expectant mothers will be very interested to know how the child’s intrauterine development occurs week by week.

Initial development of pregnancy

Pregnancy lasts 40 weeks or 10 obstetric months. The term “obstetric month” implies 28 calendar days. But the first day is considered the beginning of pregnancy itself. menstrual cycle. Thus, according to medical calculations, pregnancy lasts not 40, but 38 weeks.

So, fertilization occurred: the sperm penetrated the egg and formed a single cell with two nuclei. These nuclei, moving towards each other, form a zygote. A zygote is a one-celled embryo. This fact is the beginning of the development of a new life.

The zygote lives for 30 hours, after which its first division occurs. In subsequent days, cell division is repeated. On the fourth day of life, the embryo consists of 8-12 cells. By this time, this small lump reaches the uterine cavity, where the process of cell division intensively increases.

By the seventh day, the embryo already consists of hundreds of cells. On the eighth day, the embryo attaches to the wall of the uterus, where its walls have acquired a loose and thickened structure. The implantation process takes about 40 hours.

On the 14th day of the embryo's life, its back part thickens, preparing for the formation of the main organs.

Already in the second week after fertilization, pregnancy can be determined using tests. Already on the 3rd day of its life, a small embryo begins to produce a hormone - gonadoprin. All pregnancy tests are sensitive to this hormone.

At the end of the 4th week, a woman notices the absence of menstruation. The first symptoms of pregnancy will appear: nausea, dizziness, drowsiness.

During this period, the embryo is already called an embryo, the size of which is about 1 mm.

The development of a child in the womb can be divided into three main periods:

• Blastogenesis - the first 15 days.
• Organogenesis is the development of the embryo from 15 days to 10 weeks of pregnancy.
• The fetal period is the development of the fetus in the womb.

If we divide the entire pregnancy into 3 equal periods, we get the following time periods: first, second and third trimesters. Each trimester lasts 3 months.

If a woman is not yet aware of her “ interesting position” and continues to lead an inappropriate lifestyle, then the embryo will most likely die at the stage of blastogenesis. If the mother's destructive lifestyle does not change during the first 12 weeks, there is Great chance miscarriage.

Embryonic development of a child in the womb

Embryo development is a key moment of pregnancy, since during this period all vital organs are formed, which will affect the baby’s health in the future.

Mommy should never be nervous: only peace and positive emotions!

By the end of week 5, the embryo consists of three cell layers: ectoderm, endoderm and mesoderm. Ectoderm is the basis of the nervous system, hair and skin. The endoderm will develop in the future into the gastrointestinal tract. The mesoderm will turn into skeletal and muscle tissue, and will also form the basis of the circulatory, excretory and reproductive systems.

At week 5, a kind of heart tube is formed. We can assume that from this moment the embryo’s “heart” begins to beat.

A groove is formed on the back of the embryo, which is the basis of the spinal cord and the entire nervous system. It is very important for the expectant mother to take enough folic acid during this period. This substance promotes the full formation of the nervous system of the unborn child.

At week 6, the embryo takes on a C-shape. During this period, the formation of the primary intestine, skeletal cartilage, liver, kidneys, and thyroid gland occurs. The small embryo reaches 4 mm.

At the 7th week of pregnancy, women experience toxicosis. This period is characterized by intensive development of the brain. The mouth and eye sockets begin to form. The respiratory system actively develops, the heart begins to divide into chambers and arteries, and the spleen and gall bladder are formed.

At week 8, ultrasound can record the first movements of the embryo.

At week 9, the fingers on the upper and lower extremities are visible, although they are still webbed. This period is characterized by the fact that the placenta begins to supply the embryo with nutrients and take away waste products. The embryo already has taste sensations.

At week 10, the membranes between the toes disappear and the tail disappears. The gender of the child is still difficult to determine at this age, but boys are already beginning to produce testosterone.

By the 11th week, the embryo weighs 5 g and measures 3 cm. This is the final stage of embryonic development; the embryo will subsequently be called a fetus.

Intrauterine development of a child by week in the second trimester of pregnancy

At 12 weeks, almost all organs of the fetus have formed and the child begins to actively move inside the uterus.

This is the beginning of the third period of fetal development. At this time, as a rule, an ultrasound is performed, which determines the quality of the child’s development and genetic abnormalities.

If intrauterine abnormalities are detected in the fetus, the woman is recommended to undergo additional tests. But final conclusions about chromosomal abnormalities can be made at 20 weeks with a control ultrasound. If serious pathologies are confirmed, doctors recommend terminating the pregnancy.

It is also worth noting that what older parents, the higher the risk of developing pathologies in a child. However, in this case, the opposite may be true: the percentage of talented children born is higher among older parents.

At week 13, the external genitalia differentiate. However, they can be distinguished already at 14-15 weeks using ultrasound. At this stage, the formation of the intestines occurs. The baby receives nutrition through the umbilical cord.

From the 14th week, the baby’s skeleton begins to form, which was previously represented by cartilage. The length of the arms corresponds to the proportions of the body, and the legs are formed with some delay. The baby can yawn and suck his thumb. He perceives the vibrations of sounds, distinguishes well the timbre of his mother’s voice and music.

That is why it is important for expectant mothers to listen to beautiful classical music, thus instilling in the baby good taste.

At week 15, the blood vessels of the fetus become noticeable, visible through the thin skin. The skeleton and bone marrow continue to form.

At 16 weeks, a routine ultrasound is performed, where you can notice the movement of the baby's eyes. The legs have become proportional to the length of the body and small marigolds begin to grow.

At 17-18 weeks, the small body is covered with primary fluff - lanugo. This is a natural lubricant that protects the skin from the aquatic environment. During this period, fingerprints are laid, which are genetically predetermined.

The baby weighs 200 g and is 14 cm tall.

At 19-20 weeks, fetal growth begins to slow down somewhat. At this stage, subcutaneous fat is deposited, which keeps the small body warm. The respiratory system is improving more and more, but it is not yet able to function independently.

Mid-pregnancy: intensive fetal development

Starting from the 20th week, the baby's teeth begin to form. The baby's hairs on his head grow more actively, but their pigment is formed a little later.

From the 22nd week, mothers begin to feel the baby pushing. His weight at this stage is 450 g, and his height is 19-20 cm.

From 23 weeks the baby begins to gain weight. The child begins to see, he even dreams. The brain is actively developing.

The muscular system and internal organs continue to actively improve. The respiratory system is becoming increasingly developed. The first stool, meconium, accumulates in the baby’s intestines.

The baby's skin is red and wrinkled. The child actively reacts to the position of the mother’s body and to external sounds. Taste buds have already formed on the tongue, thanks to which the child develops food preferences. It is important for mothers to understand this and try to avoid spicy and bitter foods, since the little one prefers sweets.

The beginning of the third and final trimester is week 27. By this time, all the organs of the fetus have already formed, and in the future they will be improved, as well as the development of the brain.

At week 29 it is formed the immune system baby. The heart rate reaches 120-130 beats per minute. The baby may hiccup, as evidenced by slight tremors to the mother.

A child born at this stage can survive with certain care. His height is 37 cm and weight is 1150 g.

Prenatal development of the child in the last stages of pregnancy

For women who are preparing to become mothers of a healthy baby, it will, of course, be superfluous to talk about the right lifestyle. Alcohol, cigarettes, lack of routine, sleep and rest have a very detrimental effect on the health of the unborn child.

At 30-32 weeks, the baby’s subcutaneous fat layer becomes thicker. Some babies are already turning head down at this stage.

Convolutions appear on the surface of the small brain. The pupils can already detect bright light. When performing an ultrasound at this stage, you can notice how the baby closes its eyes from bright light. For this reason it is important to avoid ultraviolet rays and give up a beach holiday.

From the 33rd week, the little man already becomes cramped in his mother’s tummy. At this stage, the fetus turns head down, preparing for birth.

If at this stage there are premature birth, then the baby has every chance to survive. However, he will be considered premature and will need special care in the hospital.

The baby's skin becomes pink and not so wrinkled, thanks to subcutaneous fat. It makes up 8% of the total body weight.

Thanks to the appearance of marigolds, the baby can scratch himself. Some newborns are born scratched.

From the 37th week there is an active improvement of the respiratory system. Babies born during this period can already scream. The vellus hair on the body thins, and on the head it grows rapidly. The child gains 30 grams of fat every day.

By this time, the stomach drops, and it becomes easier for mom to breathe. This usually happens two weeks before birth.

By this time the baby is ready to see the light. He is very cramped inside his mother: his knees are pressed tightly to his chin.

At week 39, the body becomes clean: the fluff remains only on the shoulders. The baby's intestinal system is filled with meconium and amniotic fluid.

At 40 weeks, prenatal development ends and the baby is born. new person! Photos of newborns become almost the most important photo in the house. After all, what could be more exciting and beautiful than the birth of a small miracle!

Today we will discuss and show the intrauterine development of the fetus by week of pregnancy in photos and videos, we will analyze everything step by step and in great detail.

Pregnancy is a wonderful physiological process in the female body, which can be characterized by the development of an egg fertilized by a sperm into an embryo, and then a fetus.

How long does the average pregnancy last? healthy woman– approximately 9 calendar months or 10 obstetric months. The development of any pregnancy is easier to view and track by trimester.

But it is no less interesting to consider in more detail and with photos the intrauterine development of the fetus week by week.

Embryo or fetus?

In obstetric practice, two concepts are often encountered that refer to the stages of bearing an unborn child - “embryo” and “fetus”. How are they different and what is the difference between them?

Intrauterine development The fetus is divided into stages:

1. Embryonic– which lasts for the first 8 weeks of pregnancy. Due to its small size and relatively different appearance from a fully formed human, the fetus in the womb is called an embryo.
2. Fetal- lasts from the 9th week of pregnancy until the very moment of birth. The baby is already more formed and looks like a little man; it is called a fetus.

The genetic material that the father and mother put into the unborn child will directly influence the development of the embryo, and the first trimester of pregnancy and the condition of the mother will have a subsequent impact on the fetus.

1-10 weeks

1 Week

If we talk about the first week of pregnancy, we need to clarify what is taken as the main starting point. In gynecology, however, they often focus on obstetric timing.

The first few days after conception, even with multiple pregnancy, future mom doesn't feel any characteristic features. This is the time when the menstrual cycle should begin.

The hCG level is within the normal range (5 IU/ml for non-pregnant women). In the first week, pregnancy tests are unlikely to show the coveted 2 stripes. Since precisely focusing on hCG level pharmacy tests react.

2 week

The period is characterized by the maturation of the zygote in the uterus or fallopian tube. And if everything goes well, the pregnancy will take place.

After conception, the fertilized egg attaches to the wall of the uterus.

If attachment has passed, then there may be discharge indicating this event and the appearance of the embryo. They are similar in consistency to egg white, and sometimes can be bloody.

If the discharge at week 3 is similar in color and consistency to menstruation, then this is not normal and you should consult a doctor.

3 week

The third week is the starting point in a woman’s pregnancy; it is after it that one can say whether conception has occurred. The embryo is so small that its size does not exceed 0.15-0.2 mm in length and weighs 2-3 μg.

If the sperm does not fertilize the egg, your period may begin in a couple of days ahead of schedule. This will be easy to notice if you keep a calendar.

Heavy discharge in the third week can cause a miscarriage.

4 week

The embryo at 4 weeks of pregnancy is actively developing and a pregnant woman can feel changes in her body. Many people note severe swelling of the breasts, the nipples become bright and become especially sensitive. Menstruation does not occur, but sometimes some pregnant women may experience scanty discharge, which should not worry her.

This time of fetal development is especially dangerous if there is excessive physical activity, lifting weights. There is also a risk of complications for the embryo when infectious diseases, which are most often accompanied high temperature. Alcohol and cigarette abuse are also dangerous. It's better to exclude them completely.

So far, the level of hCG increases only in the blood. And on an ultrasound, you will most likely notice a yellow jelly-like body that provides nutrition to the embryo until the placenta begins to fully perform its protective functions. Progesterone, the pregnancy hormone, is actively produced.

The size of the embryo is about 2-3 mm in length.

5 week

During this stage of pregnancy, the size of the uterus changes. At the ultrasound examination stage, a qualified specialist can tell about the presence or absence of a multiple pregnancy.

Changes in the body of the expectant mother become noticeable and even more tangible. Many women notice a slight increase in temperature and weakness. But if your condition resembles cold-like symptoms, consult a doctor immediately.

week 6

At this stage, the pregnant woman begins to actively show signs of future motherhood. The uterus of a pregnant woman at 6 weeks is the size of a plum. If you contact a gynecologist, he will already be able to feel it.

If you are pregnant with twins, then an ultrasound at this stage will show the presence of two fetal sacs and a yolk sac. At the 6th week of pregnancy, an examination will show small tubercles on the embryo - this is the site of development of future limbs. You can already listen to the heartbeat of the embryo using a special device. The embryo is no more than 4-9 mm in length and weighs no more than 0.2 - 0.8 grams.

week 7

There are important changes happening this week. The embryo's heart becomes four-chambered, and the main large blood vessels are formed.

The first trimester can be characterized by the continued development of vital internal organs and other body systems of the embryo. It weighs about 1 g, and the size from the tailbone to the crown is no more than 13 mm.

The unborn child, although slowly, begins to straighten up. His brain begins to develop very rapidly.

The baby's face is being improved and the upper limbs are being developed. The umbilical cord of the embryo completes its formation and a mucous plug is formed.

8 week

The fruit begins to move and increase significantly. Its length is 14-20 mm. Every day the baby’s face acquires more and more familiar human features.

The formation of the main vital organs and systems is gradually being completed. And some are already actively functioning. The embryo gradually develops an optic nerve, and the appearance of the rudiments of future genital organs can also be observed.

Week 9

The embryo reaches a length of no more than 22-30 mm, and its weight is still so small, about 2 g. At this stage, the cerebellum and pituitary gland are actively forming, the middle layer of the adrenal glands is formed, lymph nodes are born, as well as future genital organs.

The formed limbs begin to slowly move, learn to bend, and the first muscle fibers appear. The fetus develops the ability to subsequently urinate.

10 week

The embryo weighs about 5 g and its length is approximately 30-40 mm. The heart of a nascent man beats at a speed of 150 beats per minute. The baby’s limbs are formed, and sometimes you can already see your fingers in ultrasound images. In the baby, most of the gastrointestinal tract organs have already formed.

At week 10, the foundation is laid for the formation of subsequent baby teeth. This obliges the expectant mother to keep her food calendar and also mark each consumption of a dairy product in it.

11-20 weeks

11 week

At week 11, the fetus weighs about 8 g, and its “height” is approximately 5 cm. From this moment, the former embryo gradually grows and enters the fetal stage.

His small heart It is already functioning fully, the vessels and circulatory system are completing their formation. The placenta around the fetus becomes very strong and dense. The baby's liver takes up about 10% of his body. The intestines are already trying to make the first movements reminiscent of peristalsis.

the genitals are formed. The color of the fetus's eyes is determined and the sense of smell already appears. The baby's fingers and palms become sensitive.

12 week

The most important stage in fetal development. Critical moments largely depend on the lifestyle of the expectant mother and her health and eating behavior. The baby's body is no more than 6-9 cm in length.

But at the same time, the unborn baby already has all the fingers and toes, and the organs of the gastrointestinal tract are actively forming. The immune system improves and begins to function.

Week 13

The critical cycle is ending and things will become easier for the expectant mother. Her baby's future baby teeth are embedded. All systems are developing and continue to improve. Muscle and bone tissue are slowly growing.

The genital organs are already differentiated. The length of the fetus at week 13 reaches 8 cm, and the weight is still very small - 15-25 g.

Week 14

At this wonderful stage, it is already possible to determine the sex of the child. The baby is actively developing and has already grown from about 8 to 10 cm, and weighs about 30-40 g. Every day the fruit looks more and more like a little man.

The bones of the fetus become stronger, the skeleton gradually grows, and ribs are already beginning to form. The movements of the baby's diaphragm are increasingly reminiscent of breathing. The baby already has a Rh factor and a blood type, as its composition is gradually stabilizing.

Week 15

At this stage, the fetus begins to form the cerebral cortex. This is a long process that will take most of the entire second trimester. The endocrine system of the small organism comes into operation. The sebaceous and sweat glands begin their activity.

At week 15, the fetus has already formed taste buds, but the respiratory system is still improving.

The baby weighs approximately 70 g, height is about 10 cm. At this stage, even if you have a multiple pregnancy, their size does not interfere with free movements for you or the babies.

Week 16

During this period, the baby is no more than 11 cm tall, and weighs about 120 g. The baby’s neck has already taken a stable, even position, the head rotates freely.

The ears and eyes are still in an unusual place, but are gradually starting to rise up. The baby's liver begins to take over its functions.

In case of multiple pregnancy, the expectant mother can feel the movements of the children, who are becoming more and more active.

Week 17

IN active work The baby’s immune system turns on, interferon and immunoglobulin begin to be produced. The baby himself is already able to provide protection against various infections coming from outside. But still, microbes can be critical for such a fragile organism.

At the 17th week, the baby develops a fat layer, albeit not large. The girl has a uterus. The length of the fruit is no more than 13 cm and weighs about 140 grams.

The baby is already able to catch sounds and feel emotions. Therefore, be sure to establish contact with the baby. Talk to him, stroke his belly, sing songs. This is extremely important for establishing a bond between the expectant mother and the baby.

Week 18

At this stage, the immune system and brain are actively developing, and adipose tissue continues to accumulate. In the fetus, you can notice the formation of the rudiments of molar teeth. Height is approximately 14 cm, weight - 200 grams, like a stick of butter.

The baby has a clear reaction to light, and hearing is noticeably enhanced.

Week 19

At this stage, there is a sharp and significant jump in the formation of the fetus and its development. His movements can be called more meaningful and orderly. The respiratory organs are improving and developing. The tiny baby's body is covered with the so-called vernix lubrication.

The baby's head begins to rotate freely, he can hold it in a fixed position. The fetus weighs about 250 g at week 19, and its height does not exceed 15 centimeters.

Week 20

The fetal heartbeat can already be heard with an ordinary stethoscope. The baby's limbs are fully formed and visible on ultrasound. For the baby, sounds become more audible. The length of the fruit is approximately 25 cm, and the weight is about 300 grams. Movements are already felt in the tummy.

21-30 weeks

21 weeks

The height of the fetus at this stage does not exceed 26 cm, and its weight is 360 grams. The tiny human's digestive system is much more active than before. He often swallows amniotic fluid. Muscle and bone tissue gradually grows and strengthens. The spleen is connected to organs that work independently.

Week 22

This week the baby weighs about 400 grams. Height can reach up to 28 cm. The fetus is already quite viable, even if it is born prematurely.

His brain and spinal skeleton are already fully formed. Reflexes continue to develop. The baby's heart increases significantly in size.

Week 23

By this period, the fetus is already quite well formed, its digestive organs work independently. So far, slowly, but fatty tissue is accumulating. The genitals can be easily distinguished.

The baby's height can reach 28 cm, and weight - 500 g. The spleen becomes more active.

Week 24

Outwardly, your fetus is already quite similar to a newborn baby. Due to lack large quantity fat layer, the baby weighs only about 400 - 600 g with a height of 23-30 cm. But from the 24th week, your fetus will begin to independently produce growth hormone, which will allow you to gain weight faster.

The respiratory organs are entering their final stage of development. Reflexes develop very quickly, all senses improve. The baby is already developing a sleep-wake pattern. He begins to sense and respond to his mother's emotions. Fetal movements become more sensitive for the expectant mother.

Week 25

Your fetus this week weighs about 700 g, and the tiny man is approximately 34 cm tall. Every day he becomes more and more like a newborn.

Your baby's lungs are preparing to take their first breath.

The sense of smell at this stage is very well developed, and the baby also senses even minor mood swings of the mother and can react to them. The bone skeleton develops and begins to become more and more actively overgrown with muscles. Boys develop testicles, and girls develop a vagina.

Week 26

An unusually wonderful week of pregnancy. Your baby, being in your tummy, already acquires its own individual characteristics and is even able to recognize the voices of its parents. Therefore, try to talk to your baby more often and read to him.

The eyes gradually open. The baby's skeleton is noticeably strengthened. His lungs are not yet fully formed, but are already taking on their final shape.

The baby's brain begins to produce various hormones. Weight is approximately 750 g, but height reaches approximately 36 cm. During this period, the baby sleeps a lot, 16-20 hours. His movements can be noticed.

Week 27

The baby weighs about 900 g. Every week there is active growth and build-up of muscle mass and subcutaneous fat. The endocrine system of a tiny human begins a new phase of its activity.

At this stage, the stability of his pancreas is important. After all, it is she who influences the development of all metabolic processes, as well as its mental abilities. Surfactant production in the lungs gradually stabilizes.

Mom feels the baby’s development more and more every day.

Week 28

The baby's bones are still getting stronger. Alveoli gradually appear in the baby's lungs. The weight of the baby can reach 1 kg. And the height is already at around 38 cm. Having become so large, he begins to realize his cramped position in the mother’s uterus, but no significant activity appears.

Week 29

At this stage, the baby can already do a lot. If you shine a flashlight through the belly, it will notice the light and follow it, this indicates that the eyes are gradually acquiring the ability to focus. He has already established heat exchange and regulation, and the functioning of the immune system is being adjusted.

The baby's skin becomes lighter, the folds gradually smooth out due to the fact that there is more subcutaneous fat. Muscles are actively growing.

Week 30

At this stage, the tiny baby weighs no more than 1.3 - 1.5 kg. His nervous system begins to activate. The liver is preparing to carry out its functions. A girl's heart will beat faster than a boy's.

At this time, the baby’s eyes are open, and his movements become calmer and more meaningful. Most often, at week 30, the fetus occupies the position from which it will subsequently be born. Therefore, it is worth monitoring his movements so that he takes the correct position.

31-40 weeks

31 weeks

At this stage, the baby reaches a weight of no more than 1.5 kg. His internal organs are actively learning to work independently. The liver can already cleanse the blood on its own.

Surfactant, that is, a mixture of surfactants that lines the pulmonary alveoli from the inside, is still being produced. Gradually, a connection between the brain and peripheral nerve cells is established. If the baby decides to touch his eye, he will definitely close his eyes.

Week 32

This is the phase when the baby is actively growing and continuing its development. The organs and systems of his body are establishing their full functioning. The baby is becoming more and more like a normal newborn.

During this period the baby finally occupies cephalic presentation. His Skull is still soft.

Week 33

During this period, the baby weighs up to 2 kg. He continues to build up his muscles, gets stronger and forms a fat layer. His body becomes more proportional, his limbs lengthen slightly.

The baby is already able to express his emotions, and many systems of his body are fully functioning. The child is able to express emotions. The kidneys are still only preparing for their main function in the future - the ability to filter.

34 week

These days, the baby's development is almost completely completed. The baby's facial features acquire individual characteristics and become clearer. The baby's gastrointestinal functions are actively developing and improving.

Week 35

This week is characterized by activity in the growth of both muscle and fat tissue by the baby. Every week, the baby continues to gain approximately 220 g. His skin is completely freed from lanugo, and his shoulders are rounded.

36 week

The baby’s body, which is growing stronger every day, continues on the path of improvement. In his already formed liver the process is underway accumulation of iron. All body systems continue to be fine-tuned for flawless operation. The baby is actively moving in the womb, sucking his finger, preparing to kiss for the first time. mother's breast. By 36 weeks, most expecting babies are lying head down.

Week 37

The baby in the womb has formed, as all vital organs are ready for independent work. The stomach is ready to accept food, the heat exchange process is well established. The lungs are ready to take their first breath outside the mother’s body. The baby continues to grow stronger and gain weight.

Week 38

The baby is formed and ready to be born. In boys, the testicles gradually descend into the scrotum at this time. At 38 weeks, babies' skin takes on a pleasant pink tone.

Week 39

Your baby is already fully developed and is often born at 39 weeks, without waiting for the due date. All the baby’s organs are fully capable of independent functioning. The baby responds to light stimuli and is very sensitive to sounds. The skin is completely cleansed of vernix.

40 week

In the fortieth, final week, the baby is fully formed and ready to be born. His height is already approximately 49-55 cm, and his weight is from 2.5 to 4 kg. Everything will depend not only on how you ate during pregnancy, but also on genetics.

41-42 weeks

Sometimes pregnancy lasts more than 40 weeks, the baby is already post-term. At this time, they resort to artificial stimulation of labor.

All stages of pregnancy and fetal development from conception to birth video

Knowing how your baby is developing in your tummy is simply necessary. This way you can protect yourself from possible complications. Don’t forget to also regularly visit your gynecologist. An experienced doctor will help determine possible deviations during pregnancy and prevent complications.

With the onset of the first day of pregnancy, hormonal and structural changes occur in the body of the expectant mother, which are aimed at maintaining intrauterine fertility. However, the most incredible changes occur in the child’s body, which goes through several stages of transformation - from ovum to the embryo, from the embryo to the fetus. As a result, it is born small man with fully formed organs and systems. Subsequent development and maturation occurs in childhood. Information about changes in the fetus during each week of pregnancy is of interest to every woman in an interesting position. With this knowledge, the expectant mother will better understand the cause of changes in her body and respond correctly to each stage of the baby’s development.

Now let's look at this in more detail.

Periods of intrauterine development

Pregnancy is a physiological process in a woman’s body that begins with the fertilization of an egg by a sperm and ends with the birth of a child. The gestation period lasts 9 calendar (36 weeks) or 10 obstetric months (40 weeks or 280 days). You should know that the obstetric month lasts 28 days.

The intrauterine development of a child takes place in 3 periods:

• the period of the fertilized egg - from the moment of fusion of the egg and sperm (conception) until the moment of implantation into the endometrium of the uterus, lasts 3-10 days;
• embryonic period - begins from the moment of implantation of the fertilized egg into the endometrium of the uterus, lasts 8 weeks, at this stage the formation of all organs and systems of the unborn child occurs, the embryo is usually called an embryo;
• fetal period - starts from the 9th week and ends with the moment of birth, at this stage the embryo grows and gains weight, organs and systems are improved, the body is prepared for life outside the womb, the embryo is usually called a fetus.

At each week of pregnancy, changes naturally occur in the body of the fetus, which contain the laws of evolution. Individual characteristics the fetus depends on the genetic code that the child receives from the chromosome set of the reproductive cell of the father (sperm) and mother (egg).

Fetal development by week of pregnancy

Pregnancy is divided into 3 periods (trimesters), each of which is characterized by characteristics and changes in the woman’s body. Next we will consider the actual, not obstetric weeks the period of gestation, which begins from the moment of conception. Obstetric weeks are counted from the first day of the last menstruation. Thus, in 1-3 obstetric weeks the woman is not actually pregnant.

– 1-13 weeks of pregnancy

In the 1st trimester, the implantation of the egg in the uterine cavity, the formation of organs and systems of the embryo, the beginning of the development of functional systems, and the rapid growth of the embryo occur.

In the first week of pregnancy, fertilization of the egg by the sperm takes place in the ampulla. fallopian tube. After this, a fertilized egg is formed, the cells of which immediately begin to divide. A multicellular organism develops, which in obstetric practice is called morula (from the Latin word “morus” - blackberry). Within 3-10 days, the fertilized egg enters the uterine cavity, where it attaches to the mucous inner layer - the endometrium. This process is called implantation. The villi of the cells of the outer layer of the morula penetrate the endometrium, connect with the blood vessels of the uterine mucosa, and in the future form the placenta. The villi of the outer layer of the other side of the fertilized egg are involved in the formation of the umbilical cord and membranes of the embryo. The cells of the inner layer become building material for the child’s organs and systems.

Starting at 2 weeks, the morula becomes an embryo. The formation of vital organs and systems begins in the embryo’s body. The rudiments of the umbilical cord, amniotic membranes, and placenta continue to develop. First of all, the neural tube is laid - the predecessor of the fetal nervous system.

Over the course of 3 weeks, the remaining functional systems of the body are formed - digestive, respiratory, circulatory, excretory. The nervous system continues to develop. In place of the head of the unborn child, a wide plate is formed, which is the rudiment of the brain. At the end of the 3rd week, the fetal heart begins to beat, which is not yet detected by medical diagnostic equipment.

The process of laying down internal organs, such as the liver, kidneys, lungs, and intestines, continues. The heart and large blood vessels develop rapidly. The rudiment of the spine (chord) is formed, which divides the body into right and left halves. Folds of the body and processes of future limbs appear. The development of the neural tube is completed. The muscular system is formed. Indentations appear on the head - the rudiments of the organ of vision.

At week 5, the embryo measures 2 mm and weighs 0.5 grams. It cannot yet be determined using ultrasound diagnostics. The formation of limbs with rudiments continues nail plates. Nasal cavities and rudiments form on the face upper lip. Functional systems organisms continue to develop rapidly.

The formation of the placenta begins and the formation of the umbilical cord continues. The upper limbs are stretched, the makings of hands appear. The lower limbs are not yet developed. Parts of the brain and facial muscles are formed, the heart becomes 4-chambered. The kidneys, liver, and pancreas are fully formed, the stomach, intestines and ureters begin to develop.

The growth of the embryo is 13-15 mm. The fetus can be tracked in the uterus using modern ultrasound equipment. Rapid brain development continues. The eyes are formed, the rudiments of the nose and ears are formed. You can track fingers on hands that are not yet separated from each other. The lower limbs are forming. The main event of the week is the completion of the formation of the placenta and umbilical cord, the beginning of the uteroplacental circulation.

Intensive growth of the head, trunk and limbs continues. The fingers are fully formed without any bridges between them. The face takes on a human appearance - eyes, nose, lips, ears. The development of the hearing organ ends. The body of the embryo gradually straightens. The functional systems of the body are improved, including the reproductive system. Testicles are formed from the germ cells in boys.

From the beginning of the 9th week, the fetal period begins. The musculoskeletal system is rapidly developing, joints are being formed. The fetus can move its limbs, the head is pressed with the chin to the body. Placental vessels develop, which improves uteroplacental blood flow. The endocrine system is improved, the adrenal glands begin to synthesize hormones. Cartilage tissue develops - the cartilages of the auricles, larynx, and vocal cords are formed. The brain continues to improve and the cerebellum is formed.

Fruit length 35-40 mm. Reflexes to stimuli begin to form, including the sucking reflex. Fetal movements become more active, but due to large sizes The woman is not yet able to feel the baby move. The diaphragm is finally formed.

The placenta is well formed. The development of the organ of vision continues. The fetal body is not proportional - large head, short legs and Long hands, which are bent at the joints and pressed against the body (fetal position).

Fetal brain small size, the structure completely replicates the brain of an adult. Reflex movements occur more often. The fetus imitates breathing - this is the baby's preparation for the first breath outside the mother's womb. The baby begins to swallow amniotic fluid, and digestive system ready to digest them and form original feces (meconium).

The fruit size is now 70-75 mm. The proportions of the body change, becoming similar to the proportions of a newborn child. The neck is clearly visible. The face is fully formed - lips, closed eyes, nose, eyelashes and eyebrows are growing.

As the functional systems of the body develop and improve, the appearance of the fetus takes on the appearance of a newborn child.

The formation of the urinary system is completed - Bladder, urethra, ureters. The kidneys begin to filter urine, which is released from the fetus and mixed with amniotic fluid. The pancreas produces insulin, and pituitary hormones are synthesized. Bones and joints are strengthened, which allows the fetus to expand its motor activity (somersault, bend, turn from side to side). The genital organs are developing rapidly. In girls, the ovaries descend into the pelvis; in boys, the prostate forms. At this time, it is possible to determine the sex of the unborn child using a modern ultrasound machine.

The circulatory system is improved. Blood consists not only of red blood cells, but also leukocytes. The blood group and Rh factor are formed. An individual pattern (fingerprints) is laid on fully formed fingers of the limbs. Meconium continues to form from ingested amniotic fluid, the original feces pass after the birth of the child.

The length of the fruit reaches 12 cm, weight – 100 grams. All functional systems of the body are formed. Facial muscles develop, the fetus can grimace, thus expressing its emotions. The skin is thin, covered with vernix and vellus hair (latugo). There is no fat layer under the skin. Skin have a dark red color due to translucent blood vessels. There is already scant hair on the head. The hair is devoid of melanin pigment, so all children have a white color.

The fetal heartbeat can be heard with a stethoscope. Milk teeth are formed and developed in the upper and lower jaws. The child begins to hear and can respond to sound stimuli. The fetal head is extended.

The length of the fruit reaches 20 cm, weight – 200 grams

Some women already feel fetal movements. The child develops biorhythms - periods of sleep and wakefulness change cyclically.

Organs continue to form endocrine system– gonads, adrenal glands, pituitary gland, pancreas, thyroid and parathyroid glands. The work of an important hematopoietic organ, the spleen, starts. Monocytes and lymphocytes appear in the blood.

All pregnant women should feel fetal movement.

The subcutaneous fat layer and the volume of visceral fat begin to rapidly increase.

The average length of the fruit is 28 cm, weight – 450 grams. The formation of the spine is completed. The brain contains all the neurons. The child begins to take an interest in his body - he feels the body, face, limbs.

The fat layer continues to develop. The skin is still wrinkled and red. The fetus's face resembles an old man.

The sense organs are well developed - the fetus reacts to sound and light stimuli. The movements are frequent and more sensitive for women. An emotional contact is established between the expectant mother and the child.

The bone marrow, which performs the function of hematopoiesis, is finally formed. The skin is smoothed due to an increase in the volume of subcutaneous fat. An important event weeks - the full development of the alveoli of the lungs, which begin to produce surfactant.

The fetus develops a sense of smell. In boys, the testicles begin to descend into the scrotum; in girls, the formation of the vagina and external genitalia is completed.

The length of the fruit reaches 37 cm, weight – 800 grams. All parts of metabolism are formed.

The body of the mother and child prepares for childbirth. The functional systems of the fetus are improving every day and are able to work outside the womb. The baby is viable if born prematurely.

The development of alveoli and surfactant in the lungs continues. One hemisphere of the brain is active, which determines whether the child will be right-handed or left-handed. The fat layer under the skin rapidly accumulates. Fetal height is 40-44 cm, weight is 1500-2000 grams. The skin becomes pink, smooth, the fetal face no longer resembles the appearance of an old man. All organs and systems are improved. Brain mass increases.

The fetus in the uterus assumes a cephalic presentation, which is optimal for physiological labor. The appearance of the fruit is fully consistent appearance newborn baby. The eyes are often open, movements are rare due to the large size of the fetus compared to the size of the uterus. Moving the hearth is painful for a woman.

The height of the fetus is 46-50 cm, weight – 2500-4000 grams. The child is preparing for childbirth. All organs are sufficiently formed for efficient work outside the mother's body. Hair color depends on heredity. Correct body proportions. The woman feels contractions of the uterus, the cervix opens slightly, and the mucus plug leaves the cervical canal. The bones of the skull are soft, which allows the fetus to pass through the mother's birth canal. A woman is waiting for her baby to be born.