Development of the child for weeks of pregnancy. Norms of fetal development

When a woman receives a positive pregnancy test result, many questions appear in her head that need answers. So, the future mother worries about when her baby will be born, how it will develop in the womb and everything will go smoothly. This article will tell you about how the child develops during the weeks of pregnancy. Also you will find out how the baby grows and adds weight to the number. It should also be said about the delay in fetal development.

How is pregnancy calculated?

Physicians use two methods of calculating the gestational age: obstetric and fetal. Most often apply the first option. In this case, the first day of pregnancy is the onset of menstruation.

Normal intrauterine fetal development lasts about 40 weeks. At the same time an error of 14 days or less is allowed. If the birth of the baby occurred much earlier, then it may be a question of premature birth. The beginning of fights and the opening of the cervical canal in the first half of pregnancy leads to miscarriage. Determ

ine the period of development of the child in the womb of the mother can be by manual examination or ultrasound diagnosis. The second method is more reliable and reliable.

development of the child by weeks of pregnancy

How does a child develop for weeks of pregnancy?

In the period from the first to the forty second week there is a colossal transformation of the fetus. Of several cells that are not visible to the common eye, the embryo becomes a real small person, capable of living outside the mother's body. Doctors closely monitor the growth of the baby in the woman's belly. Regular inspections, measurements and weighing are carried out for this purpose. Based on this, doctors make a conclusion about whether the fetus is developing properly.

For weeks of pregnancy, the development of a baby can be tracked using ultrasound. In this case, doctors have certain norms with which the obtained data are compared. On the basis of this study, we can conclude whether there is a delay in the development of the fetus or whether the pregnancy is normal. Let's consider in detail how the baby grows and changes with each subsequent week.

First month of pregnancy

All stages of fetal development are divided into trimesters. There are three in total. The first trimester is already in full swing when a woman receives a positive pregnancy test result. The countdown begins long before that.

By the first month of pregnancy, the first, second, third and fourth weeks can be included. From the 1st to the 5th-7th day, the woman continues to have menstruation. However, during this period there is already an active production of hormones that affect the ovaries and provoke the growth of follicles. From the 8th to the 14th day, the dominant phyllocula is isolated and the endometrium is grown for implantation of the embryo. The third week is characterized by the release of the oocyte from the follicle and its fusion with the spermatozoon. The conception has already taken place, but the woman does not yet know about it. From the 22nd to the 28th day the fetal egg continues to actively divide and advance through the fallopian tubes to its goal. When the set of cells reaches the genital organ, a reliable attachment occurs. This is where pregnancy will progress.

With the onset of a delay in menstruation, a woman may suspect her new position. However, to confirm the guesswork, she needs to have a home test or a blood test.

First trimester

Every future mother should know everything about the development of the child on weeks of pregnancy. The first trimester lasts from the first to the thirteenth week. During this period the embryo from several cells will turn into a small semblance of a person. How does the child develop for weeks of pregnancy during this period?

Week 5

At this stage, the woman is most likely aware of her new position. The future baby actively forms vital sections: the respiratory tract, pancreas and liver. All this is rather difficult to consider with the help of an ultrasonic device, however, a competent specialist and good technique are capable of such.

Important cells are formed in the yolk sac - the sex cells. If you are expecting a girl, then this is an egg. The boys will have spermatozoa. The fetal egg increases in size and by the end of the week it takes about a fourth of the genital organ. The future baby looks like a small disk and has a size of not more than two millimeters.

weight of the child by weeks of pregnancy

Week 6

In this period, the child is more like a fish: he has a small tail and gills. Do not worry - by the time of delivery all this will disappear. The size of the crumb from the sacrum to the head is about four millimeters. He freely floats in his bubble and has no restrictions. With the mother the child is connected by a thin bundle, which later becomes the umbilical cord.

At the 6th week a very important event is happening: the child's heart starts beating. Outwardly, this is more like a rapid pulsation. However, with the help of a good ultrasound apparatus, it is possible to calculate muscle contractions. Their average number reaches 160 beats per minute.

This term actively transforms the baby's face. He already has lateral holes that will later become auricles, mouth and nose. In addition, the liver learns to secrete blood cells, and the rudiments of the brain follow the cardiac contractions.

Week 7

This week the kid adds strongly in growth. It is doubled and already equal to 10-12 millimeters. It is worth recalling that this measurement is made from the head to the sacrum.

The legs and toes of the toddler acquire a human outline. However, they are still more like flippers because of the presence of the membranes between the fingers. The size of the intestines increases. The brain is divided into two parts - the hemisphere. The heart of the unborn child strongly advances and already has several chambers. The fetus grows and develops actively.

Week 8

The growth of the embryo at this stage is from one and a half to two centimeters. The sexual organs are actively formed. During this period, they are the same for girls and boys, but soon the sexual lump will turn into a penis or clitoris.

Fingers grows in size and become like human. The stomach passes into the peritoneum and acquires nerve endings there. These structures will be needed in the future for normal digestion. At this stage, the heart is almost formed. It has a connection with large vessels and veins.

Week 9

In this period the size of the crumb is about three centimeters. You can already see during ultrasound that the tail has disappeared. The mass of the embryo at this moment is about one gram( the weight of the child on week of pregnancy will actively increase).

The heart muscle is divided into four parts and already functions quite well. During this period, the germs of future teeth are laid. That's why a future mother can suffer from a lack of calcium. However, it should be used only if the doctor recommends it.

fetal arrest

Week 10

During this period, the crumb has a length of three to four centimeters. Its average mass is equal to four grams. The period of the formation of all important organs came to an end.

The baby's arms and legs begin to move. They actively bend and unbend. All this can be seen during the ultrasound. The liver continues to actively select blood cells, the heart contracts, the brain functions. The child's body acquires a new covering - fluff. It will disappear shortly before birth. On the fingers are formed marigolds and pads.

Week 11

The baby weighs about 7 grams. He is already making active movements, although the woman still does not feel it at all. The basic parts of the trunk, including the neck, are strengthened.

The peculiarity of this period is that a child can begin to hiccup. This is a consequence of the formation of the diaphragm. In the blood of the baby there are still no leukocytes, this substance has only red blood cells. The legs and arms of the baby are becoming more proportional, but the upper limbs are somewhat longer.

Week 12

At this time the length of the child from the buttocks to the head is about 6 centimeters. All previously formed bodies continue to grow and develop. The child learns to carry out new movements. He opens his mouth wide and tries to grab the liquid. Eyes can be screwed up. The facial expressions of the child are formed.

Week 13

At this time, the first trimester ends. The development of the fetus continues to progress. Weight is about 25-30 grams, and the growth from the crown to the buttocks - about 6-8 centimeters. On the pads of the fingers an image was drawn. It is individual for every person.

If you are expecting a girl, this week her ovaries develop. They are still very small, although they contain more than two million sex gametes. It should be noted that only a few hundred thousand will remain for their birth.

Second trimester

During this period, the weight of the child is actively increased by weeks of pregnancy. During ultrasound, the body length from the coccyx to the top of the head is no longer measured. Specialists often deduce formula calculations and announce the approximate growth of an infant. How does the child grow in the second trimester? Consider the intrauterine development of the fetus for weeks.

intrauterine fetal development

Week 14

The length of the baby is about 9 centimeters. The kidneys acquire a new function - the production of urine. The bowel becomes even longer and performs the first contractions.

White blood cells are produced in the blood, which will protect the baby after birth. The process of formation of vocal cords begins. The first sounds, issued crumbs, you hear immediately after his birth. Nerve endings are formed. The baby can already react to external stimuli and feel the touch of the mother to the stomach.

Week 15

The growth of the baby by this time is from 9 to 10 centimeters. His eyes are still closed, but the crumbs are good at distinguishing light stimuli. The child is actively moving, and the expectant mother at this time can already feel slight tremors.

The legs have grown and become longer than the upper limbs. The child actively develops the respiratory system. He forcefully pushes out of the lungs amniotic fluid. You can not worry, this substance is absolutely sterile and can be updated more than 10 times in 24 hours.

Week 16

The weight of the child at this moment is about 70-80 grams. The bladder is active, releasing the fluid approximately once per hour. The bowel is gradually filled with contents that will be released in the first day after birth.

The stomach with the gallbladder is actively starting to function. The child already has his own blood type and Rh factor.

Week 17

The baby weighs about 100 grams. At this time, the subcutaneous fatty tissue is formed. It will play an important role in the metabolism.

A crumb can control its movements. He brings the handles to his face and sucks his finger. With his hands the child closes his eyes when he does not like something. Most of the processed substances are released through the placenta, despite the fact that the kidneys can already quite well cope with their work.

fetal development 8 weeks

Week 18

A child weighs approximately 150 grams. The mothers already had ovaries and ovaries. These organs occupy the right place in the peritoneum. The boy's testicles have not yet descended into the scrotum. This can happen only after birth.

The endocrine system of the child begins to work actively. It is worth noting that if the mother has some problems, then the baby can help her body. However, such a replacement is fraught with violations in the body of the child. That is why it is so important for mom to monitor her hormonal background.

Week 19

The crumb weighs about 200 grams. On his body appear the first real hairs, which are very different from the gun. The brain actively transforms and acquires new functions. The baby can hear, taste the amniotic fluid, acquire sight and touch.

A grease is formed on the body of the baby. It protects the baby from bacteria and helps it to easily pass through the birth canal.

Week 20

Weight of crumbs is from 250 to 300 grams. The height is 23-27 centimeters. The child's heart becomes bigger and knocks harder. From this time, many doctors begin to measure the contractions of this muscle with a special tube.

The excretory system is still active. In the intestine there is already a certain amount of stool - meconium. It is worth noting that it will be released only after the birth. Preliminary excretion speaks about oxygen starvation of the child and requires urgent medical help.

Fetus of 23 weeks of pregnancy

Week 21

The crumb weight is approximately 320-400 grams. From the body of the expectant mother through the placenta, he begins to receive immune cells. The vestibular apparatus actively develops and trains during movements.

Week 22

The growth of the future baby is about 28 centimeters. Weight crumbs - about 450 grams. The cilia begin to grow and the eyebrow arches. The baby moves and pushes more and more.

Week 23

What characteristics during this period has a fruit?23 weeks of pregnancy is the time when a child weighs about 500 grams. After overcoming this boundary, he has every chance to survive with preterm labor. However, this will require some hardware.

Week 24

During this period the weight of the child has already exceeded half a kilogram and is about 600 grams. The height of the baby is 28-32 centimeters. Most often the baby is in a state of sleep. At this time, it is actively growing.

Week 25

The weight of the baby is about 700 grams, and the height is over 30 centimeters. Bones and cartilages are strengthened with every minute, but they are still very fragile and delicate.

Week 26

Weight crumbs - about 750 grams, and the growth exceeds 32 centimeters. During this period, the pituitary gland of the child assumes responsibility for the growth of the baby. Earlier it directly depended on the maternal organism.

Third trimester

stages of fetal development

This period is characterized by strong growth of the baby. All organs and systems are already formed and function as it should be. Fetal development rates in the third trimester are as follows:

  • week 27: 34 centimeters and 900 grams;
  • week 28: 34.5 centimeters and 1050 grams;
  • week 29: 36 centimeters and 1150 grams;
  • week 30: 40 centimeters and 1300 grams;
  • week 31: 41 centimeter and 1550 grams;
  • week 32: 42 centimeters and 1700 grams;
  • week 33: 43 centimeters and 1950 grams;
  • week 34: 44 centimeters and 2200 grams;
  • week 35: 45 centimeters and 2.5 kilograms;
  • week 36: 46 centimeters and 2.6 kilograms;
  • week 37: 49 centimeters and 3 kilograms;
  • week 38: 49.5 centimeters and 3.03 kilograms;
  • week 39: 50 centimeters and 3.2 kilograms;
  • week 40: 53 centimeters and 3.5 kilograms.

Important dates in diagnosing a child's condition

An important role is played by 32 weeks of pregnancy. The weight of the child and his height allow us to conclude on what size the baby will reach by the time of delivery. During this period, the final ultrasound is performed.

Also considered the timing of fetal development for the appointment of the first ultrasound. More often physicians choose the period from 11 to 13 weeks. At this time, you can identify the presence of some congenital diseases and syndromes.

Despite the fact that 32 weeks of pregnancy is very important, the weight of the child plays a big role in 20 weeks. During this period, doctors can find out whether there is a delay in intrauterine development.

Possible deviations

In some cases, during ultrasound, it turns out that the baby is very small or large. Often this is a consequence of an incorrectly fixed term, but it can also be a sign of some diseases. Do not panic ahead of time. Physicians in this case prescribe correction for some drugs and recommend repeating the test in a few weeks.

A small child can have such dimensions because of a genetic predisposition. The same can be said about the fruit of large sizes.

first trimester fetal development

Summing up

So, now you know how the correct development of the fetus takes place. The organism of every woman is individual and full of mysteries and mysteries. Any pregnancy can take place in different ways. Consider this and do not compare yourself with other future moms. However, to monitor the condition of the fetus should always be. In time, visit the doctor and go through all the prescribed examinations. Only in this case, you will be sure that your baby is developing in accordance with the deadline.


Use during pregnancy prescribed vitamins and preparations. If you have problems with hormones, it is worth constantly maintaining their level and, if necessary, adjusting. Walk more often outdoors and eat well. Easy to you bearing of the kid and successful sorts!

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