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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 man from a fertilized egg goes through a rather difficult path. It will be very interesting for expectant mothers to know how the intrauterine development of the child takes place by week.

Initial development of pregnancy

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

So, fertilization took place: the sperm entered the egg and formed a single cell with two nuclei. These nuclei, moving towards each other, form a zygote. A zygote is a single-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 the following 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 increases intensively.

By the seventh day, the embryo already consists of hundreds of cells. On the eighth day, the embryo is attached 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 posterior part thickens, preparing for the formation of the main organs.

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

At the end of 4 weeks, the woman discovers 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 intervals: the 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 a high probability of miscarriage.

Embryonic development of a child in the womb

The development of the embryo is a key moment in pregnancy, since during this period all vital organs are laid, which will affect the health of the baby in the future.

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

By the end of 5 weeks, 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 into the gastrointestinal tract in the future. The mesoderm will turn into skeletal and muscle tissue, and will also form the basis of the circulatory, excretory and reproductive systems.

At 5 weeks, a certain heart tube is formed. It can be considered that from this moment the "heart" begins to beat in the embryo.

A groove forms 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 contributes to the full formation of the nervous system of the unborn child.

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

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

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

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

At 10 weeks, the membranes between the fingers disappear, the tail disappears. The sex of a child is still difficult to determine at this age, but testosterone production is already beginning in boys.

By 11 weeks, the embryo weighs 5 g with a size of 3 cm. This is the final stage of embryonic development, later the embryo will be called a fetus.

Intrauterine development of the child by weeks in the second trimester of pregnancy

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

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

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

It is also worth noting that the older the parents, the higher the risk of developing pathologies in the child. However, in this case, it may be the other way around: the percentage of the birth of talented children is higher in older parents.

At 13 weeks, the external genital organs are differentiated. However, they can be distinguished already at 14-15 weeks using ultrasound. At this stage, the formation of the intestine takes place. The baby is fed 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 proportion of the body, and the legs are formed with a certain delay. The baby knows how to yawn and suck a thumb. He perceives the vibrations of sounds, distinguishes well the mother's timbre of voice, music.

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

At 15 weeks, fetal blood vessels become visible, which are enlightened through the thin skin. The skeleton and bone marrow continue to form.

At 16 weeks, a planned ultrasound is performed, on which you can notice the movement of the baby's eye. 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 the primary fluff - lanugo. It is a primordial lubricant that protects the skin from the aquatic environment. During this period, fingerprints are laid, which are genetically predetermined.

The weight of the crumbs is 200 g with a height of 14 cm.

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. In a child, hairs on the head grow more actively, but their pigment is formed a little later.

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

From the 23rd week, the baby begins to gain weight. The child begins to see, he even dreams. There is an active development of the brain.

The muscular system and internal organs continue to be actively improved. The respiratory system is developing more and more. In the intestines of the baby, the first feces accumulate - meconium.

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 receptors have already formed in the tongue, due to which food addictions are formed in the child. It is important for mothers to understand this and try to avoid spicy and bitter foods, since the little baby prefers sweets more.

The beginning of the third and final trimester is 27 weeks. 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 the 29th week, the baby's immune system is formed. The heart rate reaches 120-130 beats per minute. The baby can hiccup, as evidenced by the mother's slight tremors.

A child born at a given time can survive with a certain amount of care. He is 37 cm tall and weighs 1150 g.

Prenatal development of a child in the last stages of pregnancy

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

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

On the surface of the small brain, convolutions appear. The pupils can already detect bright light. When carrying out an ultrasound scan at this time, you can see how the baby closes its eyes from bright light. For this reason, it is important to avoid ultraviolet rays and give up beach holidays.

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

If premature birth occurs at this stage, then the baby has every chance of survival. However, he will be considered premature and will require special hospital care.

The skin of the baby becomes pink and not so wrinkled, thanks to the 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 scratched.

From week 37, there has been an active improvement of the respiratory system. Babies born during this period can already cry. Fluffy hair on the body thinns, and on the head it grows intensively. The child is gaining 30 grams of fat every day.

By this time, the belly sinks, and it becomes easier for mom to breathe. This usually occurs two weeks before delivery.

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

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

Pregnancy is a magical time that precedes the birth of a new man. For parents, each child is extraordinary, individual.

Wise nature allotted its time and time to everything. Also, the development of the fetus in the mother's tummy occurs in accordance with her laws.

Each week of pregnancy is characterized by growth and the next stage, from the formation of the embryo to the formation of a newborn baby.

Knowing how the fetus is developing week by week will give future parents confidence and dispel fears.

From conception to the fourth week

The origin of life is a long process. Its countdown begins in the middle of the monthly female cycle.
Somewhere on the fourteenth day of the menstrual cycle, an egg ripens, which is transferred from the ovary to the fallopian tube. If, within the next day, she meets an active sperm and merges with it, then fertilization will occur. So, the formed unicellular embryo will become the beginning of a new life.

On about the fourth day, a multicellular fertilized egg enters the uterine cavity. By the end of the third week, it is firmly attached to the walls of the uterus. The onset of implantation speaks of the onset of conception. The villi of the outer cells of the embryo connect with blood vessels mother. This is the future placenta. Other cells will become the umbilical cord and the membrane that takes care of the fetus. The inner cells will subsequently split into 3 groups and become different organs and tissues.

5th to 6th

The embryo at this stage is in a bladder filled with liquid. Its length is only 6 mm. It resembles an apple seed in size.
Now the central nervous system is being formed, the brain and spine are being distinguished.
Four depressions are guessed on the head, which will become eyes and ears.
The mouth and digestive system are just beginning to develop.
The stomach and rib cage are forming. By the end of the period, the heart, which is a bulge on the chest, begins to beat. It has four departments.
A system of blood vessels is formed.
Four tiny rudiments have formed - these are the future legs, arms.

Embryo development at week seven

The size of the embryo is as small as a grape. The length of the unborn child is 13 mm.
A disproportionately large head has formed, pressed against the chest. The face is guessed. The eyes are tightly closed. Black pigment is visible through the skin.
The legs and arms end with finger buds.
The heart makes the blood circulate.
The central nervous system has formed.
Bone cells are created.
The embryo has incompletely formed lungs, intestines, liver, kidneys and internal genital organs.

Development in the eighth week

Now it is already a fetus, in which all the main internal organs have formed.
The face becomes embossed: the tip of the nose, nostrils, and mouth appear. Language appears.
The inner ear goes into action.
The fingers, tied with membranes, were well marked.
The limbs are longer. Shoulders, elbows, hips, knees stand out.
Fruit the size of a 2.5 cm strawberry is quite active.
The nervous system is improving.

You can help ensure that the development of the fetus takes place in a favorable environment. Regular walks, balanced nutrition, good drinking will provide the baby with the necessary components for growth, improve digestion, and relieve you of a bad mood.

Ninth to Twelfth

The fruit already resembles a tiny little man 65 mm long. The baby weighs 18 grams.
The tail of the embryo disappears from the fetus.
The fingers have finally taken shape, marigolds grow on them.
Auricles with lobes were clearly visible.
Eyelids formed to cover the eyes.
Muscles develop - the fetus is actively moving. The thumbs are bent on the hands, the fists are compressed.
The kid knows how to wrinkle his lips, open and close his mouth, swallow the surrounding liquid, and urinate.

The doctor will help you navigate the intake of vitamins, so that the development of the fetus during the weeks of pregnancy is favorable.

Thirteenth to sixteenth

The kid is fully formed. Its length is 16 cm. It weighs 135 grams. From the fourteenth week, the fetus feeds through the placenta.
The head is disproportionately large. The neck showed.
The body is covered with lanugo - a gentle downy. Eyelashes and eyebrows have formed.
The baby's skin is so transparent that the blood vessels are visible.
The joints of the legs and arms have formed. The bones begin to harden.
Developing and strengthening muscles allow for more and more coordinated movements.
The sex of the baby can already be determined by the genitals.
The chest performs breathing movements.
The baby sucks a thumb.
The heart can be listened to with a special stethoscope. It beats twice as fast as that of an adult.

Consult in advance with your gynecologist how to act to avoid such pregnancy companions as bleeding gums, shortness of breath, constipation, cramps, weakness. Then and in the future, pregnancy and fetal development will be painless.

Seventeenth to twentieth

The child reaches 25 cm in length and weighs 340 g.
Hair appeared on the head.
The rudiments of the teeth are determined.
The surface of the baby is covered with original lubricant - a light fatty substance.
The formed internal organs begin a period of growth.
The arms and legs are well developed, they are in proportion to the rest of the body.
The fingers become more mobile.
The kidneys begin to work.
Mom can feel the activity of the baby.

The development of the fetus will be positively influenced by the skills of relaxation and breathing exercises.

Twenty-first to twenty-fourth

The kid reaches 33 cm and gains 570 grams.
The skin thickens, sweat glands are formed in it.
The arms and legs become strong. He knows how to push, roll over, squeeze a fist.
The child can cough, hiccup, frown, squint.
The eyes are still covered with plastic.
The auditory ossicles become stiff. The baby has developed hearing: the baby listens to the mother's heartbeat, breathing, and the sound of her voice.
The baby alternates between sleep and wakefulness.
Taste papillae are formed on the tongue.

You and your baby are getting ready for the meeting. The development of the fetus by weeks is "on schedule." It's time to take care of your breasts and purchase a special bra.

Twenty-fifth to twenty-eighth

The child grew up to 37 cm, gained almost 1 kg.
Fat cells form under the reddish skin.
The cerebral cortex has developed.
Taste buds allow you to recognize subtle shades of bitter, sweet and salty.
The lungs are not yet fully formed.
The eyes open and close.
The baby reacts to external sounds. Maybe cry.

Dear mommy, you should get enough sleep, then the development of the fetus will proceed in a calmer environment.

Twenty-ninth to thirty-second

The baby has reached 40.5 cm and weighs 1.6 kg.
For the baby, darkness and light are distinguishable. During sleep, the eyelids are closed, in moments of wakefulness - open.
The ears are finally taking shape.
He takes a prenatal position. By this time, most are head down.

You can see that pregnancy is going on as usual, and the development of the fetus by week is approaching its logical conclusion. Start attending parenting courses with your spouse.

Thirty-third to thirty-six

The child has grown. Its length is 46 cm.Weight is 2.5 kg.
The accumulated fatty tissue gives the baby a roundness.
The skin turned pink.
The nails on the legs and arms have grown back.
The grasp reflex develops.
Muscle tone increases. The child can lift and turn his head.
The lungs are developed.
The kid reacts to the light source.
The boy's testicles are clearly visible.

The development of the fetus by week shows that it is time to prepare for the trip to the hospital and collect the dowry for the baby.

Thirty-seventh to fortieth

The kid gained 3.4 kg and grew to 51 cm.
Lanugo disappeared from him. The shoulders, arms and legs may still be covered with a little bit of primary down.
The original lubricant in a child is distributed either throughout the body, or in the folds of the skin.
In the intestine, the primary feces are collected - meconium.
During the second and subsequent pregnancy, the head may sink into the pelvic region.

Dear future moms and daddies, the height and weight of the fetus and baby by week are given conditionally. This is not a strictly established norm. There are no correct standards for fetal development by weeks of pregnancy. The deviations up or down are individual.

The onset of pregnancy is the beginning of an amazing time for the expectant mother. Having seen two cherished stripes on the test, I can't wait to find out what awaits next on the upcoming path of bearing crumbs. Today we will tell you how the fetus develops by weeks of pregnancy, what the mother feels at the same time, and at what stages all organs and systems of the baby's body are formed.

Starting point: how to know when the pregnancy started

The obstetrician calculates the date of the beginning of waiting for the baby for the woman during the first visit to the antenatal clinic.

• The doctor conducts a manual examination to determine the size of the uterus. This will help him understand what period of pregnancy the uterus corresponds to.
• Also, the local doctor must specify the date of the first day of the last menstruation. This moment is taken into account, because the mucous membrane of the uterus begins to prepare for pregnancy from this particular period of time.
• You can find out the most reliable information about the duration of pregnancy using an ultrasound scan. An ultrasound study can tell up to the day when a small life was born. Examination even at the earliest stages (starting from 4-5 weeks) estimates the size of the embryo, which allows the obstetrician-gynecologist to calculate the exact date of the onset of pregnancy.

In the first week after conception, the embryo actively moves along the fallopian tube. After six days of active “travel” it enters the uterine cavity. Under the influence of progesterone (it is also called the pregnancy hormone), the future baby is attached to the mucous membrane of the uterus, this process is called implantation.

If the embryo is successfully attached, then the next menstruation will not happen - the pregnancy has begun.

Intrauterine development of the child

The development of an infant inside the womb, from the moment of conception to the moment of birth, is usually called a miracle, and there is every reason for this. Fortunately, medicine has studied quite well all the stages of the most important event in a woman's life - pregnancy. Each expectant mother can imagine exactly what will happen to her and her baby during all nine months.

There are three periods of intrauterine development of a baby:

1. blastogenesis - starts with fertilization and lasts 15 days;
2. embryonic period - starts from the 16th day and ends by the 13th week of pregnancy;
3. fetal period - from 13 weeks and lasts until the very birth.

Each of the periods has its own chronology of events. The formation of the child's organs, systems of vital activity in his body and his direct growth naturally move in each period of intrauterine development. How this happens, find out what and when is formed, you can find out in the summary table. It will be informative for expectant mothers who are interested and important information about the development of the child at all stages of the pregnancy.

Pregnancy development by week

Waiting for the birth of a baby in obstetrics is usually divided into three conditional parts:

• I trimester - from the beginning of pregnancy until the 13th week;
• II trimester - from the 14th to the 26th week;
• III trimester - from the 27th to the 40th week.

These trimesters contain 10 obstetric months. Conditional split table:

Obstetric month	Weekly pregnancy period
First month	From the first to the fourth week of pregnancy (1-4)
Second month	From the fifth to the eighth week (5-8)
Third month	Week 9 to 12 (9-12)
Fourth month	Thirteenth to Sixteenth (13-16)
Fifth month	Seventeenth to Twentieth (17-20)
Sixth obstetric month	Twenty-first to twenty-fourth (21-24)
Seventh month	Twenty-fifth to twenty-eighth (25-28)
Eighth month	Twenty-ninth to thirty-second (29-32)
Ninth month	Thirty-third to thirty-six (33-36)
Tenth month	Thirty-seventh to fortieth (37-40)

Before a detailed study of the process of fetal development in the mother's abdomen, it is necessary to familiarize yourself with the table of changes in the height and weight of the future fetus:

Pregnancy week	Fruit size	Fruit weight
1	–	–
2	–	–
3	0.15-0.2mm	–
4	1 mm	–
5	1.25-1.5mm	–
6	2-4 mm	–
7	4-5 mm	–
8	1.6-2 cm.	1 g
9	2.3 cm.	3-4 g.
10	3-3.1 cm.	5 g
11	4.1 cm.	7 g
12	5.4-6.3 cm.	13-14 g.
13	7.4-8 cm.	20-23 g.
14	8.7 cm.	35-43 g.
15	10-11 cm.	50-60 g.
16	11.6 cm.	80-90 g.
17	12-13 cm.	100-110 g.
18	14.2 cm.	150 g
19	15.3 cm.	200-210 g.
20	16.4 cm.	260-270 g.
21	19-20 cm.	300-310 g.
22	21-22 cm.	350 BC
23	23 cm.	450 BC
24	24 cm.	550 BC
25	25-26 cm.	680-700 g.
26	33 cm.	800 BC
27	34 cm.	950 BC
28	36 cm.	1-1.3 kg.
29	37 cm.	1.4 kg.
30	38 cm.	1.5 kg.
31	39 cm.	1.6 kg.
32	42 cm.	1.7 kg.
33	43 cm.	1.9-2 kg.
34	44 cm.	2.2 kg.
35	45 cm.	2.4-2.5 kg.
36	47.5 cm.	2.6 kg.
37	48.5 cm.	2.9 kg
38	50 cm.	3.1 kg.
39	51 cm.	3.3 kg.
40	52 cm.	3.4 kg.

Now let's move on to describing the development of the baby in the womb at each week of a woman's pregnancy:

Week 1

The fetus as such is not yet in question, since pregnancy has not actually occurred yet. The main sign that fertilization has occurred is implantation bleeding. This phenomenon manifests itself as a slightly smearing spotting about 6-7 days from the moment of conception.

2 week

This week from the obstetric point of view is considered as possible for conception. The egg cell in the female body matures by the 14th day of the cycle and is theoretically ready for fertilization. If, according to your calculations, the moment of conception has already taken place, then the second week is marked by the attachment of the ovum to the uterus. This moment is important, since from the moment of attachment, the fetus begins its full development.

3 week

The embryo looks like a microscopic berry, in the third week it is still only a set of cells. The size of the embryo is negligible, the maximum diameter by this time is 0.2 mm. But just during this period, the formation of sexual characteristics begins at the cellular level. Having anchored in the uterus, the most important process of intrauterine development of the baby begins - the formation of the placenta. Very little is left before the formation and development of the basic systems of the organism of the unborn child.

4 week

Obstetric 4th week - the period during which the expectant mother discovers two cherished strips on the test. The functional distribution of cells is in full swing in the embryo. Its size can be compared with a poppy seed this week. The weight is still quite insignificant and does not exceed 0.5 g, but the process of cell division occurs every minute and the future baby is growing very quickly.

5 week

The embryo has already passed several stages of its development - zygote, morula and blastocyst. The cells continue to divide rapidly, and by the end of the fifth week the baby will weigh at least 1 g, and the size will reach as much as 1.5 mm. On the ovum, you can already make out the emerging sensory organs - eyes, ears and mouth gap. The blood group of the unborn child was formed just by the 5th week of intrauterine life. The formation of the thyroid gland, as well as the intestinal and urinary systems begins.

6 week

At this time, the unborn child clearly shows the largest parts of the body - the trunk and head. In the form of tiny processes, legs and arms are distinguishable, with tiny fingers appearing on them. The weight at the sixth week in the embryo is up to 2 g, and the average size is about 4 mm. Cartilage structures are actively developing, the thymus gland is formed. The main organs continue to develop: the heart, liver, lungs, stomach and pancreas. The baby is developing muscle tissue, the external genitals are outlined.

7 week

With the beginning of the seventh week, the embryonic period ends. The unborn baby is now called by another medical term - fetus. At this time, the facial features of the crumbs are already slightly distinguishable. The rudiments of the nose, eyelids are formed, the ears and upper lip are visible. Outwardly, there are still “unnecessary” organs - gills and a tail, which will disappear a little later. The cerebral hemispheres are formed, cartilage tissues develop continuously. The liver is already capable of producing blood cells at 7 weeks.

8 week

At 8 weeks, the weight of the fetus is 1 g, and the length reaches 20 mm. If you look at an ultrasound scan, the future baby will look proportionally like a grape. But every day the fruit looks more and more like a real man. The baby's face is already better defined, the nose has small nostrils, and the olfactory recipes are actively formed. His heart becomes four-chambered; ovaries are formed in future girls, testicles in boys; the arms and legs of the fetus at this time can already bend / unbend.

9 week

Many systems and organs are formed by the 9th week of pregnancy, but they are not yet fully functional, but continue to develop. The palms are formed, the membranes between the tiny fingers disappear. Lymph nodes are laid. The first reflex, the swallowing reflex, begins to develop. Your baby's eyelids are well-formed and can open and close involuntarily. The size of the fruit already resembles a large cherry berry - weight 4 g, height about 30 mm.

10 week

In the 10th week, the baby is actively moving and pushing. But these movements are so weightless that the expectant mother simply does not feel them. The muscles of the face, neck and pharynx begin to develop. The face has already been formed, and in a few weeks the appearance of the unborn child can be examined on an ultrasound scan. The rudiments of milk teeth develop. The cerebellum "acquires" neural connections, which are subsequently responsible for reflexes. A small heart makes at least 150 beats per minute. Now the fruit already weighs 5 g, has grown by about +12 mm and resembles a strawberry.

11 week

The organs and systems of the crumbs have already been formed by this time, some are working in full force, while others continue to ripen. Bronchi, lungs, trachea are actively developing; liver; intestinal tract; blood vessels; irises of the eyes. At 11 weeks on an ultrasound, you can see quite distinguishable outlines of the unborn baby.

12 week

The kid is already actively using some reflexes - he imitates breathing and swallowing movements, involuntarily clenches and unclenches his palms into fists. The first contractions of the intestinal muscles (perilstatic) appear. The pancreas is formed and is already “learning” to produce bile. A unique pattern appears on the fingertips. The baby develops facial expressions, he can smile or wrinkle his face. Weight - up to 13 g, and height - up to 62 mm.

13 week

A week of an active growth jump for the future baby. The brain is already able to give the first commands for the reflex movements of the fetus. The sense of smell develops, the vocal cords are formed. The body begins to grow faster, and the growth of the head, on the contrary, slows down. Digestive villi appear in the intestines of the crumbs. The baby's skin is still very thin and is riddled with blood vessels. The weight of the fetus increases to 20 g, and the growth to 80 mm.

14 week

At week 14, all organs and systems of the unborn baby are being improved and continue to grow actively. The ribcage can rise and fall as if breathing - this is how the lungs train. The process of hematopoiesis is formed, sweat glands, neck muscles become stronger every day. The baby's weight at this time is about 27 g, and his height is 110 mm. The lifestyle, nutrition and well-being of the mother are very important - if these indicators are in order, then the baby feels good and does not experience any discomfort.

15 week

This week, the fetus has already formed vision and the necessary nerve endings to be able to see after birth. From the 15th week, skeletal ossification gradually occurs - a long-term process that requires a large amount of calcium. In baby boys, the male hormone testosterone begins to be produced. The kidneys excrete the first amniotic fluid. The muscles of the child are improved and strengthened. Fruit weight - 50 g, height - up to 104 mm.

16 week

At 16 weeks, the future baby is actively growing up from the top of the head to the very heels. The weight is already about 80 g, and the height can reach 117 mm. The body's systems function to the best of their ability, some of them already “work” quite well. When the amniotic fluid is swallowed, it travels through the digestive tract and kidneys and becomes urine. The skeleton stiffens, the child's legs lengthen. The baby is actively moving in the uterus.

17 week

The auditory formation of the future baby is smoothly completed by 17 weeks. The weight is approaching the 100 g mark, and the height becomes about 12 cm. The blood vessel system develops and branches out. The most important components of its own immunity appear in the baby's blood - interferon and immunoglobulin. In female children, the uterus is formed in utero. The strength of the baby's pushes increases during this period, they become frequent and palpable.

18 week

The development of the fetus in this period of the second trimester is very intensive. The baby is growing so fast that it could already fit in the palm of your hand. The movements are palpable, the baby moves very actively at 18 weeks. Often swallows amniotic fluid, which can lead to hiccups - this moment the expectant mother can notice by a slight tremor of the abdomen. Gradually, a layer of subcutaneous fat forms in the fetus, muscles develop, and the mineralization of the skeleton continues. Weight - about 150 g, height does not exceed 14 cm.

19 week

The child inside the uterus is actively growing, improving and gaining weight. By the way, the baby weighs about 200 g by week 19, and his height is about 14-15 cm. The body focuses on the development of the brain, the improvement of the five basic senses. The amount of subcutaneous fat increases. The respiratory system continues to develop and strengthen. The period of wakefulness alternates with a period of activity, the baby can sleep up to 16-18 hours a day.

20 week

Outwardly, your baby has already become a real little man, and on an ultrasound scan you can already see the sex of the child, his facial features, observe facial expressions (which sometimes shows the character traits of the future child). The weight of the baby at the "equator" of pregnancy is about 250-270 g, and medium height is 16 cm. The child is active, turns his head, sucks his fingers, opens and closes his mouth.

21 week

At this time, you can already be sure that the child distinguishes sounds and hears what is happening outside the uterus. In terms of body proportions, the baby almost resembles a newborn. The weight of the fetus is about 300 g, the height is 19 cm. At this time, taste buds are actively formed, and the composition of the blood is improving.

22 week

The twenty-second week is the period when the unborn child prefers to spend most of the time sleeping. But, nevertheless, in a dream, the baby is actively turning over, the size of the uterus still allows you to change the position. The baby spins, pushes, pulls the umbilical cord. The weight at this stage is about 350 g, and the height is 20-21 cm.

23 week

The next week meets with the usual movements, although many babies prefer to “calm down” by 23-24 weeks and make their mothers worry about rare movements. The crumbs still have enough room in the uterus, so many of its tremors are simply not felt, so there is no need to worry. The weight is already moving towards the 450 g mark, and the height is more than 22 cm, although it is worth remembering: all the listed parameters are individual.

24 week

Under the mother's heart, the future baby grows and gains weight - the indicator for many future children at this time is at least 550 g. This week, the development of the infant's bronchi ends, which is very important for the child's respiratory system in general.

25 week

From the 25th week, the child in the womb begins to produce pigment in the hair, giving them the color that is due to heredity. It is this color that the mother will see in the baby at his birth. Weight reaches 700 g, height - 23-25 \u200b\u200bcm. Nerve connections and brain cells continue to form. Training breathing movements can be observed in the fetus.

26 week

Tremors at twenty-six weeks become strong, distinct, and many moms may even complain of their intensity. The child's weight is already at least 800-850 g, and his height is already more than 33 cm. The active strengthening of the bones of the skeleton is still continuing, the rudiments of milk teeth in the gums are mineralized. Marigolds and hairs begin to grow.

27 week

The child's height at this time is about 34 cm, and the weight is approaching 1 kg. The baby becomes cramped in the uterus, and the legs cannot be stretched out, so the baby takes an optimal position: pulls small crossed legs and arms to the chest. From the twenty-seventh week, the baby is already gradually taking the correct position in the uterus, but if he lies across or “sits on the bottom,” then there is still time to roll over.

28 week

With the beginning of the 28th week of pregnancy, the weight of the fetus is up to 1300 grams, and the height is up to 37 cm. The child's muscle tissue continues to develop intensively. New convolutions are formed in the cerebral cortex. Rh-conflict between mother and fetus is possible, and at this time the obstetrician-gynecologist must take special measures.

Week 29

The weight of the fetus is about 1500 kg, and the body length is at least 38 cm. It is time for the expectant mother to master the method of calculating movements.

30 week

The full growth of the fetus reaches 36-38 cm, the weight reaches 1.5 kg. The expectant mother may have several fears that are associated with future childbirth.

31 week

At the 31st week of pregnancy, the weight of the fetus will be about 1.6 kg, the full height is about 39 cm. The baby develops pain sensitivity. Possible disturbances in the night sleep of a pregnant woman due to active and strong tremors of the fetus. It's time to explore the issues of pain relief during childbirth.

32 week

The weight of the fetus is about 1.7 kg, the size from the crown to the heels is 40-42 cm. Abrupt movements can cause dizziness and nausea in a pregnant woman. It's time to think about the possible presence of someone close to you at birth.

33 week

The weight of the fetus by 33 weeks is about 2000 g, the height is 42-43 cm. The mineralization of the fetal bones is almost complete. The expectant mother should count the fetal movements from time to time.

34 week

The growth of the fetus is on average 43-44 cm, weight 2.2 kg. The baby becomes very cramped in the uterus, and motor activity decreases. It is time for the mother to discuss the method of delivery with the doctor: a natural birth or a cesarean section.

35 week

The growth of the fetus is 45-46 cm, weight is 2300-2500 grams. The fetus is almost completely ready for childbirth, but the lungs are not yet ready to perform the respiratory function. It's time to pack things for the hospital. If the baby in the uterus has not yet taken the correct position, special exercises will help.

Week 36

Fruit weight is approximately 2.5-2.7 kg. Full growth is about 45-47 cm. At this time, the indicators of each crumb can differ greatly from the average in a smaller or larger direction. It's time for parents to make a list of things to plan and complete before their baby is born.

37 week

The thirty-seventh obstetric week of pregnancy is the time when the mother must be mentally prepared for the birth of the child. This is especially true of multiple pregnancies and childbirth, starting with the second child. The weight of the child reaches 2.9 kg, and the height is within 50 cm.

38 week

Thirty-eighth week can be the last week of your pregnancy. The child gradually becomes heavier. The baby weighs about 3 kg, and the growth is already 48-50 centimeters. Childbirth can begin at any time, so loved ones should be within reach at all times.

39 week

At the 39th week, the mother is not only physically, but already mentally prepared for childbirth. The baby weighs about 3 kg, and its height is about 48-50 cm. In size, the child at this time is similar to a miniature watermelon.

40 week

At the end of this week, the estimated date of the baby's birth may come. The baby's weight is already about 3.5 kg, the height is about 51-55 cm. The baby is completely ready for birth. It remains to wait for the moment when he will make the newly-made parents happy with his birth.

Total.

This is how 40 weeks of pregnancy go. A happy start to a new life - watch the video of how the baby develops in the mother's belly:

Development of pregnancy by months: how the mother's body changes and the baby grows

1st month

Mum. The chest becomes sensitive and painful to touch. The uterus begins to grow gradually.

Child. So far, the future baby is called an embryo. For the first six days of pregnancy, he swims in amniotic fluid, lives "autonomously" and is not yet connected with his mother. Outwardly, the embryo resembles a tiny auricle 5 mm in size. By day 21, his heart starts to work; in parallel at the same time, important organs are formed: the spinal cord and the brain. By the end of the 1st month, the umbilical cord appears, connecting the baby to the future placenta.

2nd month

Mum. Pregnancy is not yet outwardly noticeable either to the expectant mother or to others - the uterus is in the small pelvis, and its size is small. Changes continue to occur in the breast, it swells and increases in size.

Child. This month, changes are coming in the appearance of the future baby - facial features appear, the outlines of the eye sockets appear; tiny arms, legs and even fingers are formed on them. The weight of the embryo at this time is up to 8 g, and the size is about 4 cm.

3rd month

Mum. Intensive growth takes place in the uterus, it develops, in size it already fills the small pelvis and almost reaches the bosom. Very soon everyone will see that you are in a position!

Child. By medical standards, your baby has already passed the embryonic stage and is now becoming a fetus. Its weight can reach 65 g, and its length varies from 10 to 12 cm. An important point in development - in the 2nd month, the child has an inner and outer ear. The baby is very active, moves his arms and legs, nods his head and clenches his fists. The growing child already has eyelids, and thanks to them, he can open and close his eyes.

4th month

Mum. A rounded tummy is already looming, the waist begins to gradually "blur". The mammary glands cause considerable discomfort due to their growth and sensitivity - you have to choose a suitable sleeping position for a long time.

Child. Your baby already has quite a tangible weight - up to 250 g. The child spends most of the time swimming in the amniotic fluid, their renewal occurs every 3-4 hours. A fluff appears on the baby's head, eyebrows and eyelashes on the face. In the intrauterine development process, the first feelings and sensations begin to form in the child. The baby reacts to loud sounds and a bright light source.

5th month

Mum. Almost every day the belly of the expectant mother becomes larger and clearly protrudes forward. The uterus is located about 8 cm below the navel. Starting from 17 weeks, most expectant mothers begin to feel new sensations in the stomach - while weak, but very pleasant jerks and movements of their baby.

Child. In the fifth month, the child's brain is actively growing, the nervous system develops. The heart beats twice as often as that of the mother. By this period, the weight of the crumbs can be up to 650 g, and the height is about 30 cm. By the 20th week, the baby is already able to suck his fingers on his hands, and at 24 weeks, he can open his eyes and react to light.

6th month

Mum. The waist of a pregnant woman by this time becomes 8-10 cm larger. The size of the uterus increases so much that now it reaches the navel. The state of health and mood is good, the weight has not grown too much and the activity of the expectant mother is not limited by anything.

Child. It's time for the baby's respiratory system to mature. The lungs begin to mature after 24-25 weeks of gestation. The child has already formed sensations of light and noise - when he hears a sharp sound, the baby can shudder. The first reflexes (hiccups, swallowing and sucking reflexes) also appear and actively develop.

7th month

Mum. The size of the uterus by the seventh month of pregnancy reaches 24-28 cm in height, it continues to grow and grows with the baby.

Child. The baby is already less active than in earlier periods. In most cases, the baby settles down in the uterus, head down, and sleeps for a long time. The baby's weight is already 1-1.2 kg, and the height is up to 37 cm. He is already learning to breathe, but the lungs are not yet mature enough - they will finally be ready for the breathing process at about 34 weeks, which is important in case of premature birth. By this time, the baby has already learned to recognize the mother's voice, and recognizes it when he hears it.

8th month

Mum. The body of the expectant mother continues to change - the uterus rises up already by 30 cm, from time to time contracting, as if “rehearsing” the upcoming contractions. Colostrum appears in the breast. In the third trimester, the load on the female body increases many times over, and existing chronic diseases may worsen.

Child. The kid is growing and gaining strength. For bone mineralization, the baby needs a large number of calcium, which comes to him from mom. The baby's skin becomes pink, smoother. From time to time, a mother can observe protrusions and “bumps” on her stomach at those moments when the baby is tossing and turning.

9th month

Mum. The body of a pregnant woman begins to actively prepare for childbirth. The uterus, together with the baby, weighs about 6-7 kg at this time, and its height is measured within 33 cm. In the third trimester, pain in the pubic joint, edema and increased blood pressure are frequent.

Child. After 38 weeks of pregnancy, the development of the intrauterine development of the baby can be considered complete. The baby is ready to be born. In the last month, the baby is gaining 10-15 g daily. Amniotic fluid becomes less and less, the baby grows by leaps and bounds, and it becomes cramped in the uterus. In girls, the labia majora cover the small ones; in boys, the testicles descend into the scrotum. The fluff on the body completely disappears, and only a little primordial grease remains. At the time of birth, the child weighs approximately 3-3.5 kg, and the height varies from 50 to 55 cm.

And finally, photos and recommendations from a young mother. Look at the photo of the growth of the belly during forty weeks of pregnancy. Have you photographed your belly week by week?

The Swedish photographer Lennart Nilsson back in 1965 for the first time using a powerful macro lens captured the stages of embryo development. And since then, as it turned out, nothing new has been invented. Nielson's photographs are ingenious - he placed a microscopic macro lens of a camera and an illuminator on the tip of a cystoscope tube (a device with which the bladder is examined) and filmed a unique 40-week "reportage" about how a new life begins and develops.

Lennart Nilsson was born in 1922 on August 24 and is still alive, which is good news. In 2006, he released his last book, Life. It will be still interesting to understand his books and photographs, but it will be ahead.

Now let's look at the stages of fetal development by week. After all, pregnant women always want to know how the life that is nascent in them is developing. What the future man sees, hears, feels.

7-8 hours passed ...

The sperm practically digs into the egg.

Up to eight weeks, the fetus is called an embryo.

Week 1

For the birth of a new life in the female body, ovulation occurs. At the same time, the temperature rises, the amount of vaginal mucus increases, and there may be slight pains in the ovarian region. Hormones are active in the body, causing the desire for intimacy. Fertilization of the egg with the sperm takes place.

2 week

The fertilized egg divides. The child inherits half of the parental chromosomes. The sex of the unborn child depends on the sperm that fertilized the cell. After that, the embryo enters the uterus through the fallopian tube. At the end of the second week, it attaches to the uterine lining. This insertion sometimes causes minor bleeding.

3 week

On the 18th day, the heart of the embryo begins to pulsate. The embryo is detached from the membranes, actively developing. Nervous, skeletal, and muscular systems are born.

4 week

Often it is during this period that a woman learns about hers. Appear, there is no menstruation.

5 week

The embryo is 6-9 mm long. The brain and spinal cord develop, the central nervous system is formed. The heart, head, arms, legs, tail, gill slit appear. You can see a face with holes for future eyes, mouth, nostrils.

A pregnant woman should use enough folic acid to prevent baby's neural tube defects. By the end of this week, the heart begins to beat.

6 week

The placenta is formed, which is for the fetus its lungs, liver, stomach, kidneys. The placenta is also called a children's place.

7 week

The expectant mother's breasts are significantly enlarged. The length of the fetus reaches 12 mm, weight - 1 g. The fetus already has a vestibular apparatus, rudiments of the abdomen, chest, eyes. The brain develops, fingers on the handles. The fruit starts to move.

8 week

The embryo length reaches 20 mm. The body of the fetus is formed. The face, nose, ears, mouth are different. The skeleton continues to grow, the nervous system improves.

In the area of \u200b\u200bthe mouth, face, palms, skin sensitivity appears. The gill slits die off, the rudiments of the genital organs appear.

9 week

All fetal muscles develop. On the hands and feet, the fingers already have marigolds. Sensitivity has the entire body of the baby. He touches his body, the umbilical cord, the walls of the fetal bladder. Thus, the tactile sensations of the fetus are developed.

10 week

This is one of the most important stages in a baby's development. The nervous system and almost all organs develop. His eyelids are half open and will fully form over the next few days.

It is very important for the mother not to consume alcohol and other toxic substances during this period. The placenta does not yet fully protect the baby, so significant harm can be done to his health.

11 week

The amount of blood in the body rises. The hormones produced during this period affect the body's thermoregulation. Therefore, a woman increasingly feels changes in blood pressure, dizziness, weakness, stuffiness.

The fetus has formed eyelids, arms, legs. He is already making swallowing movements.

12 week

The baby's blood already contains red blood cells, and the production of white blood cells begins, which will be responsible for protecting the body. In the meantime, antibodies protect the baby from infection. They come from the mother through the blood and are passive immunity.

13 week

The expectant mother is already proudly wearing her protruding tummy. The fetus is actively developing skeleton and growth. This causes increased calcium intake. Therefore, a pregnant woman should take special medications to replenish this trace element.

The baby begins to hear, thanks to special vibration receptors that are on the skin. The fetal vocal cords begin to form. The baby's pancreas begins to produce insulin, the liver - bile. Villi are formed in the intestines, which have great importance for digestion.

14 week

The fetus develops training movements that are very important for the development of the lungs - inhalation and exhalation. The kidneys, bladder, urethra begin to function. Excreted urine is excreted by the placenta. The baby's body begins to cover the lanugo. This is a fluff that performs a thermoregulatory and protective function of the fetus's body.

In girls, the ovaries move to the pelvic region. In boys, the prostate gland is forming. Blood forms inside the baby's bones. Hair growth begins on the head.

15 week

The baby's hematopoietic system is actively developing. Veins and arteries supply all organs and systems with blood. The heart of the fetus beats twice as fast as mother's, while passing about 23 liters of blood per day. The first foci of hematopoiesis appear in the walls of the gallbladder. You can find out the blood type and Rh factor of the child.

16 week

There is great physical activity of the baby. The child's eyes open. There is still no subcutaneous fat layer at all. The baby's skin is very thin, with blood vessels visible through it. The fetal skeleton consists of a flexible rod and a network of blood vessels.

17 week

During this period, the fetus experiences rapid eye movement. In this regard, scientists argue that a child can dream. They are associated with his physical activity during the day.

18 week

The length of the fetus reaches 14 cm. The kid blinks, opens his mouth, makes grasping movements. He moves a lot in mom's belly. All parts of the body are clearly visible, the face, the skin of the calf turns pink.

19 week

Mom can feel the baby moving. Later, the movement turns into jolts. The strength of the jolts is different. It depends on the mood, activity of the mother, on the time of day. On average, in half an hour, the baby makes 20-60 pushes. The baby's brain is actively developing. He begins to suck his thumb.

20 week

At this time, expectant mothers are seriously thinking about childbirth. It is good to choose courses for expectant mothers.

21 week

The length of the fruit already reaches 20 centimeters. The kidneys work in the fetus, meconium is produced in the intestines - pseudo-feces.

22 week

The weight of the fetus increases, fatty deposits accumulate.

23 week

The length of the fruit reaches 30 cm, and the weight is 650 g. The lungs are quite developed. In the event of premature birth during this period, the baby will be able to survive in the intensive care unit.

24 week

You can hear the baby's heartbeat by putting your ear to the mother's belly. During this period, the placental circulation of the child is of primary importance. The dimensions of the child's pelvis and lower limbs are relatively smaller than the upper part. This is due to the fact that the upper body is better supplied with lower arterial blood. At the same time, the lungs receive very little of the blood.

25 week

Still soft cartilage of the nose and ears. The skin of the fetus is wrinkled, covered with lubricant, and vellus hair is formed on it. The child is already falling asleep and waking up.

26 week

The baby has a well-formed sucking reflex. He often sucks his thumb. This activity calms him down, strengthens the muscles of the jaws and cheeks. Depending on which finger of which hand the child is sucking, it can be assumed that he will be right-handed or left-handed.

The kid pushes, explores the space that surrounds him. During this time, the child's normal number of pushes is 10 times per hour.

The mother's uterus quadrupled in size. She expands the lower ribs, resting on the hypochondrium.

27 week

The length of the fetus reaches 350 mm, weight -900-1200 g. The child's eyes open slightly, perceive light. The mouth and lips become even more sensitive.

The boys' testicles have not yet descended into the scrotum. In girls, the labia minora are not yet covered by the large ones.

28 week

On the head, the hair becomes thicker. Although some children are born almost bald. All these are variants of the norm. Lanugo practically disappears. Although in some places on the body fluff may still remain, which will disappear in the first weeks after birth.

Week 29

The baby has eyelashes. His eyelids are already closing and opening. Nails grow on the feet.

30 week

The child reacts to the sounds of the external environment, may cry. The central nervous system controls body temperature and breathing rhythm. The lungs can already breathe normal air.

31 week

While awake, the child opens his eyes. Closes them during sleep.

32 week

The length of the fetus reaches 450 mm, its weight is about 2500 g. From this period, the baby is actively growing and gaining weight. His skin becomes thicker, pinkish, smoother.

33 week

During this period, brain mass, depth and number of convolutions significantly increase. The most important vital functions of the fetus are controlled by the spinal cord, parts of the central nervous system. After birth, the functions of the cerebral cortex will develop.

34 week

The child can raise and turn his head, thanks to the increase in muscle tone. Actively reacts to light, can squint from the direct rays of the sun.

35 week

The baby's lungs are fully developed. The fetus quickly develops a grasping reflex.

Week 36

The first harbingers of future childbirth may appear. There is a "ptosis" of the abdomen when the height of the uterine fundus decreases. The mucous plug from the cervix may come off. During this period, frequent urination and defecation are characteristic. Not only does the uterus press on the intestines and bladder. Also, simple strokes (hormones produced at that time) periodically cause the desire to empty.

The child pushes and moves less. The cervix is \u200b\u200bshortened and softened. Sometimes the external os of the uterus can open 1-2 cm.

37 week

The child's length reaches 47 cm, weight - 2600 g.

38 week

The fruit is already quite viable, ready to be born. On the head there can be hairs up to three cm. Its skin is pale pink, has a layer of subcutaneous fatty tissue. The child performs about 70 reflex movements.

39 week

The baby is very sensitive to all the movements and condition of the mother. He responds with his movements to her anxiety, joy, fear.

40 week

The length of the child reaches 480-520 mm, weight - from 3200 to 3600 g. In girls, the labia minora are covered with large ones. The boys' testicles descended into the scrotum. The cartilages of the nose and ears are elastic, there are nails on the fingers. The baby is ready for birth.

In the first weeks after the birth of a baby, it is very important to stroke his little body, gently press it to you. The child cannot yet feel himself and misses touch very much.

The baby's memory very well preserves the sound and rhythm of the mother's heart. To calm the baby, it is sometimes sufficient to place the baby on the mother's left side.

- and here is the book itself by Lennart Nilsson "The child is born! The miracle of the birth of a new life. "

Even Lennart Nilsson filmed short videos about the development of the embryo, I found them when I studied information from his official website.

A selection of books on pregnancy and childbirth:
- Mommy is Me, or the Diary of a pregnant woman about the most intimate. L. Lomanskaya

- Big book about pregnancy. McCarthy Jenny

On average, pregnancy lasts about forty weeks or ten obstetric months. The intrauterine development of a child can be divided into 2 periods.

1. Embryonic (from the moment of conception to the eighth week inclusive). During this period, the embryo is called an embryo, it begins to acquire characteristic human features.

2. Fetal (from the ninth week until delivery). During this period, the embryo is called the fetus.

Let's consider in detail how the fetus develops by week.

1-4 weeks. First obstetric month

Week 1

The moment of fertilization of the egg is the beginning of pregnancy. In the middle of the monthly female cycle, a mature egg enters the fallopian tube from the ovary. During the day, if it meets with an active sperm, fertilization occurs. A single-celled embryo is formed, it is he who, having undergone various transformations and changes, will become a new person. The photo shows the phased development of the fetus.

In the next five days, the fertilized egg divides exponentially, descending into the uterine cavity through the fallopian tube. A multicellular organism resulting from the division of an egg is called a morula.

Somewhere on the seventh day, the morula is implanted into the wall of the uterus. By the way: the implantation process is sometimes accompanied by small bloody discharge from the genital tract in women, they do not require treatment, since this is physiological discharge. It connects with the blood vessels of the uterus through the villi of the outer cells, and later the placenta will be formed from them. The umbilical cord and membranes will be formed from the other part of the outer cells of the morula. The inner cells will develop over time into organs and tissues of the fetus.

There are many factors to consider when determining the day of conception. Several lessons are devoted to this issue. You can thoroughly prepare for the meeting with your baby if you join the Club and indicate the date of the expected birth.

2 week

The outer cells have firmly grown into the wall of the uterus, and the placenta, umbilical cord and neural tube, which will later become the fetal nervous system, begin to form in the embryo.

3 week

It is a very difficult and responsible period, because it is at this time that the digestive, respiratory, nervous, excretory and circulatory systems of the embryo begin to form. Formed, in place of the future head of the fetus, a wide plate, this is the future brain. Finally, the child's heart begins to beat.

4 week

At the beginning of the fourth week, the notochord forms in the embryo, which is the rudiment of the spine, while the spine itself will be formed on days 27-28. Also, the first folds are formed on the trunk. The organs of the future man are still being formed, such as the liver, intestines, kidneys, and lungs. The heart pumps blood more and more actively. On the 25th day, the neural tube is finally formed.

By the end of the week, along with the formation of the muscular system, pits begin to appear on the head of the fetus, these are the future eyes of the child.

5-8 weeks. Second obstetric month

5 week

The embryo weighs about 0.4 g and is only 2.5 millimeters long (from crown to tailbone). The main organs and systems are formed: the nervous system, sensory organs (eyes and inner ear), reproductive, circulatory, digestive and respiratory systems. A slightly visible umbilical cord appears. Limbs are forming. The nasal cavities and upper lip are formed on the face of the embryo.

Download the checklist "Calendar of pregnancy by weeks", and follow the development of your baby!

6 week

The embryo is already about 5 millimeters long. The placenta begins to form. The brain of the embryo is actively developing, the enzifologram can already record its signals, and the muscles of the face. The upper limbs are lengthened, hands and fingers begin to form.

Important changes are taking place in the developing organs:

The heart is divided into ventricles and atria;

The urinary system already includes the primary kidneys, the ureters are developing;

The digestive system forms the stomach and intestines.

7 week

The length of the embryo reaches 13-15 mm. The umbilical cord is formed and the blood circulation between the uterus and the placenta is established. The child's eyes are covered with formed eyelids. The child can already open his mouth, make uncontrolled movements with his hands under the influence of external stimuli. The fingers on the upper limbs become visible. The brain is still developing dynamically.

8 obstetric week of pregnancy

By the end of the week, the body of the fetus can reach 20 mm, it begins to gradually straighten. The upper and lower extremities grow intensively, the ossification of the long bones of the legs and arms, and the skull actively occurs. Fingers are clearly visible. The main organs and systems continue to form. It is the eighth week that the first period of development ends - the embryonic one. The human embryo is now called the fetus and the fetal period of development begins.

9-12 weeks. Third obstetric month

9 week

The length of the fetus by the end of the week is about 30 mm. The musculoskeletal system develops. The fetus is able to actively move the limbs and even squeeze the fingers. The heart works at a speed of 150 beats per minute, although blood, in contrast to the blood of an adult, consists only of erythrocytes. Cartilaginous tissues (ears, larynx) develop, vocal cords are formed. Vital systems and organs continue to develop, as well as the brain.

10 week

By the end of the week, the length of the fetus becomes 35-40 mm. The tail disappears, the buttocks develop. The position of the fetus in the uterus is quite free, it is in a bent state. The development of the fetus is active, but it is still very small, so a woman may not have any sensations. But the child is already capable of making reflex movements in response to a stimulus. The child begins to move his lips, this forms a sucking reflex. The fetus already has a diaphragm that it needs to breathe.

11 week

By the end of the week, the length from the crown to the coccyx of the child can reach 50 millimeters. Nutrients and oxygen enter through the placenta, it also ensures the removal of metabolic products and carbon dioxide. The fetus looks like this, the head is large, the body is disproportionately small, the arms are long, while the legs, on the contrary, are very short, bent at the joints and pressed to the stomach. The eyes of the fetus can be open or half closed.

It is impossible to tell in one article about all the features of the development of a future man, because more than a dozen books have been written about this. Of course, you are already full of worries, and there is no time to shovel a mountain of reference books. Make it easier - join and complete special training programs for pregnant women.

12 week of pregnancy, photo of the fetus

The length of the child is now about 6 cm. The genitals are clearly developing in the male or female pattern. The child's digestive system continues to improve. The intestines, like in an adult, are stretched in length and fit in loops. It begins to contract periodically. The fetus can now swallow amniotic fluid, making swallowing movements.
The nervous system is improving. The brain differs from the adult brain only in size, but its structure is identical. The cerebral hemispheres and other sections are well developed. The child sometimes sucks on the fist, which indicates the improvement of reflex movements. The composition of the blood changes, in addition to erythrocytes, white blood cells-leukocytes appear in it.

At the end of this week, the fetus's neck becomes noticeable, eyelashes and eyebrows appear. The child begins to perform, albeit isolated, but respiratory movements. Of course, the child will not be able to breathe before birth, the lungs will not work until the baby is born, but he is already capable of imitating breathing by making movements of the chest.

The first stage of pregnancy ends in the twelfth week. This is an important period in the development of the fetus, as the basic systems and organs of the baby are laid. Right now, mom needs to concentrate all attention on her own health: eat right, get more rest and be as little nervous as possible. Indeed, the successful development of the child at the next stage, when the fetus begins to acquire the features of a newborn child, largely depends on how a woman spends the first weeks of pregnancy. For a detailed description of the next stage of pregnancy, from 24 to 24, read our next article.

Download the checklist "Calendar of pregnancy by week"

As soon as a woman finds out about pregnancy, she becomes interested in everything related to the development of the child. So that you do not have unnecessary fears, it will be useful to know how the fetus develops by weeks of pregnancy.