How the fetus develops in the uterus. Pregnancy fetal development week by week, sensations. Changing the size of the child

02.05.2019

Probably every woman expecting the birth of her baby is ready to examine the transformation of a tiny lump into a cute baby body under a microscope. But, unfortunately, there is no such possibility yet.

Although modern medicine already provides many ways to study the development of a child in the womb. Of course, it is pleasant and interesting to learn that your future baby has a heart beat or all his fingers have formed.

However, this information is also necessary in order, even before birth, if necessary, to begin to influence his physical and mental development.

The main stages of intrauterine development

Many women, already at the planning stage of pregnancy, begin to take great care of their health. They are reviewing the diet, giving up bad habits, taking folic acid.

Traditionally, the stages of development of a child in the womb are divided into 3 trimesters, each of which lasts three months or 90 days and is characterized by significant changes in the life of the fetus.

The condition of a woman in the early and late stages of pregnancy is also usually not the same. Fluctuations in eating behavior and mood are observed.

Let's take a closer look at the development of a child in the womb by weeks.

First trimester of pregnancy

1 and 2 weeks of pregnancy can be called "conditional", since this is not yet the birth of a new life, but preparation for it. The hormonal background in the woman's body changes, the egg prepares for fertilization;
Week 3 is considered the period of conception and falls in the middle of the menstrual cycle. A woman usually does not yet feel any signs of pregnancy, although pulling pains in the lower abdomen may appear or eating behavior will begin to change (read on the topic: Pregnancy 3 weeks, stomach hurts >>>);
At 4 weeks, the embryo is already actively developing. It is not at all like the unborn child, but the formation of the head, brain, spine, muscles is already being laid. A heart appears and begins to beat;
By the end of 1 month of intrauterine development, the embryo has visible outlines of arms, legs, ears and eyes. He has already managed to grow ten thousand times!

That is why the first trimester is key in the development of the fetus.

At 5-6 weeks of development, the child continues to form internal organs (stomach, liver, kidneys, lungs), the circulatory system. Fingers become distinguishable. Usually a woman begins to notice the first signs of pregnancy, toxicosis may appear (actual: Nausea during pregnancy >>>);
7-8 weeks are characterized by the appearance of the vestibular apparatus, as the main sensory organ of the child. The baby already has eyelids, jaws. The skeleton develops, joints are formed. A child can react with facial expressions to external stimuli, touch;

At the same time, he begins to move, but the movements are not yet perceptible for the expectant mother, since the baby is still too small. Its weight is 2-4 g, and its length is 12-15 mm. With the help of a special device (stethoscope), you can already hear the baby's heartbeat.

At 9-10 weeks of age, the baby's fingers develop skin and nails. The genitals are forming. In the brain, the cerebellum is intensively developing, which is called upon to be responsible for the coordination of movements. Further formation of the bones of the skeleton and skull takes place;

Interesting! After 9 weeks of pregnancy, the embryonic period of intrauterine development ends and the fetal period begins. From week 10, the embryo becomes a fetus. Almost all organs are already laid in him. In the following weeks, they are actively maturing and developing.

At 11-13 weeks, a significant increase in the child's head occurs, due to the development of the brain. The first hairs begin to grow. The child can suck the thumb, bend and unbend the limbs.

His kidneys are already functioning, excreting urine. The roots of milk teeth are formed. The kid feels noise, reacts to sounds, warmth. He perceives the movements that are transmitted from the mother: if she is inactive, then he is calm, if she is active, then the child begins to move.

The first trimester ends and, from about 14 weeks, a quieter period begins for a woman, because the threat of miscarriage is significantly reduced.

In addition, usually, if in the early stages of pregnancy, the expectant mother was worried about toxicosis, then in the second trimester it recedes, the woman feels much better.

Second trimester of pregnancy

14-15 weeks;

The formation of the head, arms, legs is completed;
The child weighs about 110 g, and his height is 12 cm;
His movements become more coordinated;
The baby has a taste sensation, he can react to substances that get from the mother into the amniotic fluid;
The amount of urine excreted in the child becomes more.

At 16-17 weeks of intrauterine development, this is what happens:

The baby's skin turns pink;
He makes grasping movements, blinks, can open and close his mouth;
The kid grows up to 18 cm and weighs 150 g (weight can fluctuate up to 200 g);
He often swallows amniotic fluid;
The proportions of the head are greater than the proportions of the body;
Anyone who has not yet started talking with their child should start doing this during this period. This contributes to the establishment of better contact between the mother and the baby and, in the future, the development of speech.

18-19 weeks;

The movements of the fetus become felt (read: Stirring at the 18th week of pregnancy, wiggling >>>);
The child hears the mother's heartbeat and the flow of her blood through the vessels;
There is an active development of the lungs and bronchi;
The spleen begins to work.

From about 20-21 weeks, the child's activity increases markedly:

He moves in the uterus, pushes, moves his limbs, can play with the umbilical cord and even smile;
The kid begins to distinguish intonations more clearly. The more mom sings pleasant songs to him, the better for the development of his hearing;
The first feces, meconium, begin to form in the child's intestines;
The baby grows intensively (length about 30 cm) and gains weight (weighs 500-600 g).

At 22-23 weeks, the head-to-body ratio becomes more proportional. During this period, a new round in the development of nerve connections and the brain is noted. Accumulation of adipose tissue occurs. You can read more in the article 22 week of pregnancy >>>;
24-25 weeks;

The child has a connection between facial expressions and emotions;
He can smile if he is comfortable or angry, if he is dissatisfied and, at the same time, an appropriate expression on his face: the muscles around the eyes are tense, the lips are compressed. This is confirmed by photos of the development of the child in the womb;
Some studies indicate that the baby, during this period, is able to dream;
His skin is still very delicate and coated with a special lubricant;
A child born at this time is able to survive.

By 26-27 weeks of intrauterine development, all the baby's organs have formed;

Its weight ranges from 800 to 1200 g. Height: 32-35 cm;
With the beginning of the functioning of the endocrine system, there is an intensive production of its own hormones.

If we take into account the development of the child in the womb by months, then this period marks the end of the sixth month of pregnancy.

Third trimester of pregnancy

28-29 weeks;

The child can breathe on its own;
He opens his eyes from time to time;
In the uterus, the baby becomes more and more cramped, he begins to take a normal position for childbirth: the head is located below;
The brain grows intensively, the number of convolutions increases;
The child is able to recognize the voice of the mother among others.

30-31 weeks;

During wakefulness, the child's eyes are open, and when asleep, it closes them. In bright light, he blinks;
The baby's skin thickens, acquires a bright pink color;
The digestive organs increase in size;
Muscle mass is growing.

32-33 weeks of intrauterine development;

During this and subsequent period, fetal growth and weight gain become very rapid. Its length is 40-45 cm, weight is 1500-2000 g;
Immunity is being formed;
The skin is smoothed, a fatty layer appears under it;
The child becomes more and more active and he is more and more closely in the uterus;
The development of nerve connections continues.

34-35 weeks;

During this period, the bones of the baby are strengthened, therefore, quite often, a woman needs an additional intake of calcium;
The development of muscle mass continues;
The nails are fully grown;
Fluff disappears from the skin;
The lungs are fully formed, ready to breathe;
The sucking reflex is actively developing, indicating that the child is preparing for the correct food intake required after birth;
The feces accumulated in the intestines will be released in the first hours of the baby's life;
These weeks for a woman can be marked by the appearance of the first training contractions.

36-37 weeks;

The genitals and heart are fully formed. The baby is ready for birth;
The movements become more and more tangible;
The baby's face is rounded due to the fat layer;
The cartilage becomes hardened;
Pregnancy over 37 weeks is full term. In the absence of pathologies and normal fetal weight (approximately 2500-2700 g), childbirth at this time, most often, is successful.

38-39 weeks;

Hair growth on the head occurs (they can be up to 2 cm);
The position of the baby in the womb is finally determined;
His liver accumulates iron, which is necessary for life after birth;
The development of a whole complex of reflex reactions comes to an end;
The cervix begins to open (on this issue, read the article: Preparing the cervix for childbirth >>>).

40-42 weeks pass while waiting for childbirth;

Completed all stages of the development of the child in the womb;
By this time, his weight is usually 3000-3500 g or more, height - from 49 to 55 cm (in rare cases - more);
In some cases, prolonged pregnancy leads to fetal postponement, then labor can be stimulated to avoid negative consequences for the baby and mother.

It would seem that for almost a whole year you will have to bear the baby, take care of him and your health, worry about ensuring that the pregnancy passes without prejudice to its development. But this period passes so rapidly that most women do not immediately realize that they have become young mothers.

And, the more attention was shown to the baby, communication with him during pregnancy, the stronger the connection between the woman and the child at the time of his birth and the easier the birth should take place.

And the main task of the mother during this period is to help the baby feel that life next to her and with other relatives is also safe and even more interesting and diverse than in her tummy.

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

Embryonic stage of development

First obstetric month

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

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

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

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

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

Second obstetric month

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

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

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

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

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

Fetal stage of development

Third obstetric month

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

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

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

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

Fourth obstetric month

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

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

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

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

Fifth obstetric month

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

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

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

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

Sixth obstetric month

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

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

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

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

Seventh obstetric month

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

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

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

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

Eighth obstetric month

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

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

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

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

Ninth obstetric month

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

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

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

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

Tenth obstetric month

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

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

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

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

The embryo (synonym for embryo) is an organism that develops within the egg membranes or in the body of the mother. Under embryonic, or embryonic, development in humans is understood the early period of development of the body (up to 8 weeks), during which a body is formed from a fertilized egg, which has the main morphological characteristics of a person. After 8 weeks, the developing human body is called a fetus (see).

Embryonic development is divided into a number of periods.
1. The period of the unicellular embryo, or zygote, is short-term, flowing from the moment of fertilization to the beginning of egg cleavage.

2. Period of crushing. During this period, cells occur. The cells obtained during cleavage are called blastomeres. First, a bunch of blastomeres is formed, resembling a raspberry berry in shape - a morula, then a spherical single-layer blastula; blastula wall - blastoderm, cavity - blastocele.

3. Gastrulation. A single-layer embryo turns into a two-layer one - a gastrula, consisting of an external germ layer - an ectoderm and an internal one - an endoderm. In vertebrates, already in the course of gastrulation, a third germ layer, the mesoderm, arises. In the course of evolution in chordates, the process of gastrulation was complicated by the emergence of an axial complex of primordia (anlage of the nervous system, axial and musculature) on the dorsal side of the embryo.

4. The period of isolation of the main rudiments of organs and tissues and their further development. Simultaneously with these processes, the unification of the parts into a single developing whole is intensified. From the ectoderm, the skin, the nervous system and partly, from the endoderm, the epithelium of the alimentary canal and its gland are formed; from the mesoderm - muscles, epithelium of the genitourinary system and serous membranes, from the mesenchyme - connective, cartilaginous and bone tissues, the vascular system and blood.

When conditions change, the course of development of individual parts of the embryo may change, and the germ layers may give rise to organs and tissues other than those that should have developed from them under normal conditions. The factors that change the conditions of development can be the environment (its chemistry, temperature, etc.), the interaction between the parts (cells, rudiments) of the embryo itself, as well as heredity. All these factors are closely related.

Rice. 1. Diagram of the early stages of development of the human embryo: a - the stage of the internal cell mass; b - an eight-day embryo; c - a twelve day old embryo; d - thirteen, fourteen-day-old embryo. 1 - trophoblast; 2 - blastocele; 3 - amnion cavity; 4 - endoderm cells; 5 - amnion; 6 - embryo; 7 - yolk sac; 8 - mesoderm cells; 9 - stalk; 10 - chorionic villus; 11 - extraembryonic whole.

Rice. 2. The embryo and its membranes in the early stages of development (a - c - successive stages): 1 - chorion; 2 - allantois; 3 - yolk sac; 4- amnion; 5 - extraembryonic whole; 6 - umbilical cord; 7 - umbilical vessels; 8 - amnion cavity.

Rice. 3. Human embryo: a - by the end of the 4th week; b - by the end of the 5th week; c - by the end of the 7th week after fertilization.

In humans, fertilization takes place in the (oviduct). The cleavage process takes place within 3-4 days, when the embryo moves along the fallopian tube to the uterus. As a result of cleavage, a shell is formed from the surface blastomeres, which is involved in the nutrition of the embryo - the trophoblast. The central blastomeres form the embryoblast, from which the body of the embryo develops. Within 4-6 days, the embryo is in the uterine cavity. With the beginning of the second week, the embryo is immersed in the wall of the uterus (implantation). In a 7.5-day-old embryo, it forms an amniotic vesicle, a part of which, facing the endoderm, is the ectoderm of the embryo. During this period, the embryo has the form of a scutellum (disk). From it, cells of the extraembryonic mesenchyme move out into the blastocyst cavity and fill it (Fig. 1). Together with the trophoblast, it forms the villous membrane of the embryo - the chorion (see). By the end of the second week, it forms a yolk vesicle. As a result of overgrowth of the mesenchyme of the amniotic and yolk vesicles, the amnion and yolk sac are formed.

The "extraembryonic" parts play an important role in the development of the embryo. The yolk sac in the human embryo functions only in the early stages of development, participating in the nutrition of the embryo and performing a hematopoietic function. Allantois in oviparous higher vertebrates plays the role of a urinary sac, in humans it is a digital outgrowth of the hind intestine, along which they germinate to the chorion. The amnion - the water membrane - forms a closed sac around the embryo, filled with a liquid - amniotic fluid. It protects the embryo from harmful influences and creates favorable conditions for its development (Fig. 2).

At the 3rd week of development, on the dorsal side of the embryo, a dense strand of growing cells stands out - a primary strip, the head section of which thickens and forms a primary (Hensen's) nodule. The cells of the primary streak plunge into the primary groove, penetrate the space between the ectoderm and the endoderm, and give rise to the middle germ layer. In the 3rd week, the dorsal cord and neural tube are laid.

At the 4th week, the embryo separates from the extraembryonic parts and, as a result of increased growth, coagulates into a tube. At the same time, the mesoderm differentiates and body segments - somites - are formed (Fig. 3, a). In parallel with segmentation, the initial processes of organogenesis (see) and histogenesis occur. At the 5th week, the rudiments of the hands, and then the legs, appear, at the 6th week they are divided into main sections, at the 7th week the rudiments of the fingers appear (Fig. 3, b and 3, c). At the age of 8 weeks, the embryo acquires the main morphological features of a person in external appearance and in internal organization. Its length (from the crown to the coccyx) is 4 cm, weight is 4-5 g. By the end of the 8th week, the laying of the organs of the embryo ends.

Expectant mothers are always curious about how the development of the fetus is going at a time when it is awaited so impatiently. Let's talk and look at photos and pictures, how the fetus grows and develops week by week.

What does a belly stomach do for 9 months in a mom's tummy? What does he feel, see and hear?

Pregnancy: fetal development by week

Let's start the story about the development of the fetus week by week from the very beginning - from the moment of fertilization. A fetus up to 8 weeks of age is called embryo, this occurs before the formation of all organ systems.

Embryo development: 1st week

The egg cell is fertilized and begins to actively divide. The egg is sent to the uterus, freeing itself from the membrane along the way.

On the 6-8th days it is carried out implantation eggs - implantation into the uterus. The egg settles on the surface of the uterine lining and, using chorionic villi, attaches to the uterine lining.

Embryo development: 2-3 weeks

Picture of the development of the embryo at the 3rd week.

The embryo is actively developing, starting to detach from the membranes. At this stage, the rudiments of the muscular, bone and nervous systems are formed. Therefore, this period of pregnancy is considered important.

Embryo development: 4-7 weeks

Fetal development by week in pictures: week 4

week 4

Photo of the embryo before the 6th week of pregnancy.

The embryo forms a heart, head, arms, legs and tail... The branchial cleft is determined. The length of the embryo in the fifth week reaches 6 mm.

Fetal development by week photo: week 5

At the 7th week, the rudiments of the eyes, abdomen and chest are determined, and fingers appear on the handles. The baby already has a sense organ - the vestibular apparatus. Embryo length - up to 12 mm.

Fetal development: 8th week

Fetal development by week photo: week 7-8

The fetus has a face, you can distinguish between the mouth, nose, ears. The embryo's head is large and its length corresponds to the length of the body; the fetal body is formed. All significant, but not yet fully formed, elements of the baby's body already exist. The nervous system, muscles, skeleton continue to improve.

The development of the fetus in the photo is already sensitive arms and legs: week 8

The fetus has skin tenderness in the mouth (preparation for the sucking reflex), and later in the area of the face and palms.

At this stage of pregnancy, the genitals are already visible. The branchial slits die off. The fruit reaches 20 mm in length.

Fetal development: 9-10 weeks

Fetal development by week photo: week 9

Fingers and toes are already with marigolds. The fetus begins to move in the belly of the pregnant woman, but the mother does not yet feel it. With a special stethoscope, you can hear the baby's heartbeat. Muscles continue to develop.

Fetal development by week photo: week 10

The entire surface of the fetal body is sensitive and the baby is happy to develop tactile sensations, touching his own little body, the walls of the fetal bladder and the umbilical cord. It is very curious to observe this on an ultrasound scan. By the way, the baby first moves away from the ultrasound sensor (of course, because he is cold and unusual!), And then puts his palms and heels trying to touch the sensor.

It's amazing when a mother puts her hand to her belly, the baby tries to master the world and tries to touch his hand "on the back side".

Fetal development: 11-14 weeks

Development of the fetus in the photo of the leg: week 11

The baby has formed arms, legs and eyelids, and the genitals become distinguishable (you can find out the gender of the baby). The fetus begins to swallow, and if something is not to his taste, for example, if something bitter gets into the amniotic fluid (mother has eaten something), then the baby will frown and stick out his tongue, making fewer swallowing movements.

The skin of the fruit looks transparent.

Fetal development: week 12

Photo of the fetus 12 weeks on 3d ultrasound

Fetal development by week photo: week 14

The kidneys are responsible for the production of urine. Blood forms inside the bones. And hairs begin to grow on the head. The movement is already more coordinated.

Fetal development: 15-18 weeks

Fetal development by week photo: week 15

The skin turns pink, ears and other parts of the body, including the face, are already visible. Imagine that a child can already open his mouth and blink, as well as make grasping movements. The fetus begins to actively push in the mother's tummy. The sex of the fetus can be determined by ultrasound.

Fetal development: 19-23 weeks

Fetal development by week photo: week 19

The baby sucks his thumb, becomes more energetic. In the intestines of the fetus, pseudo-feces are formed - meconium, the kidneys begin to work. During this period, the brain is developing very actively.

Fetal development by week photo: week 20

The auditory bones are stiff and are now able to conduct sounds, the baby hears his mother - heartbeat, breathing, voice. The fruit is gaining weight intensively, and fatty deposits are formed. The weight of the fruit reaches 650 g, and the length is 300 mm.

The lungs at this stage of fetal development are so developed that the baby in the artificial conditions of the intensive care unit can survive.

Fetal development: 24-27 weeks

The lungs continue to develop. Now the baby is already falling asleep and waking up. The vellus hairs appear on the skin, the skin becomes wrinkled and covered with lubricant. The cartilage of the ears and nose is still soft.

Fetal development by week photo: week 27

The lips and mouth become more sensitive. The eyes develop, open slightly and can perceive light and squint from direct sunlight. In girls, the labia majora do not yet cover the small ones, and in boys, the testicles have not yet descended into the scrotum. The weight of the fruit reaches 900–1200 g, and the length is 350 mm.

9 out of 10 children born at this time survive.

Fetal development: 28-32 weeks

The lungs are now adapted to breathe normal air. Rhythmic breathing and body temperature are controlled by the central nervous system. The baby can cry and respond to external sounds.

The child opens his eyes while awake and closes during sleep.

The skin becomes thicker, smoother and more pinkish. Starting from this period, the fetus will actively gain weight and grow rapidly. Almost all babies born prematurely at this time are viable. The weight of the fruit reaches 2500 g, and the length is 450 mm.

Fetal development: 33-37 weeks

Fetal development by week photo: week 36

The fruit reacts to the light source. Muscle tone increases and the baby can turn and raise his head. On which, the hairs become silky. The child develops a grasping reflex. The lungs are fully developed.

Fetal development: 38-42 weeks

The fruit is quite developed, prepared for birth and is considered mature. The baby has perfected more than 70 different reflex movements. Due to the subcutaneous fatty tissue, the baby's skin is pale pink. The head is covered with hairs up to 3 cm.

Fetal development by week photo: week 40

The kid perfectly mastered the movements of the mother, knows when she is calm, excited, upset and reacts to it with her movements. During the prenatal period, the fetus gets used to moving in space, so babies love it so much when they are carried in their arms or rolled in a stroller. For a baby, this is a completely natural state, so he will calm down and fall asleep when he is rocked.

Nails protrude beyond the tips of the fingers, the cartilages of the ears and nose are elastic. In boys, the testicles descended into the scrotum, and in girls, the labia majora cover the small ones. The weight of the fruit reaches 3200-3600 g, and the length is 480-520 mm.

After the birth, the baby yearns for the touch of his little body, because at first he cannot feel himself - the arms and legs do not obey the child as confidently as they did in the amniotic fluid. Therefore, so that your baby does not feel lonely, it is advisable to carry him in your arms, press him to you, stroking his body.

And further, the baby remembers the rhythm and sound of your heart very well... Therefore, you can comfort the baby like this - take him in your arms, put him on the left side and your miracle will calm down, stop crying and fall asleep. And for you, at last, the time of bliss will come.

Forming a new life is a real sacrament. This period is happy and at the same time exciting, because a woman will have to face something new. From the moment of conception to the birth of the baby, a whole stage goes through, which entails many changes in the body of the expectant mother. To understand what is happening, consider each week of fetal development during pregnancy and the woman's feelings at this stage.

In medical practice, it is customary to use obstetric (calendar) and embryonic weekly gestational age. This is a simple math calculation. The obstetric period is calculated from the beginning of the last menstruation, taking into account the cycle. Fertilization does not always occur at this stage. It can happen in 14-18 days. It depends on the time of the onset of ovulation in the woman. You can find out about the onset of pregnancy by measuring the basal temperature. At the same time, tests and analysis of hCG will not show the onset of conception, since in the woman's body at this time only preparation for future pregnancy takes place.

A weekly pregnancy diary is kept from the conception process. The fusion of the sperm and the egg takes place in the fallopian tube. After the union of the male and female cells, a zygote is formed. It is the basis for the development of the baby, all his organs and systems. At the same time, the first changes begin in the woman's body. From 5-6 days of fertilization, the hormonal background changes. The woman begins to produce hCG. The immunity of the expectant mother is reduced, which is a normal reaction of the body to protect the fetus from rejection.

In the first week, the woman does not feel any major changes. Therefore, it is difficult to accurately calculate the date of conception. It is extremely rare for an expectant mother to feel signs of toxicosis, a change in taste and smell. Some mothers have breast swelling, nipple sensitivity increases, and pulling sensations in the lower abdomen are observed. A woman, as a rule, leads an active lifestyle, drowsiness and changes in the emotional background are still absent.

give up addictions;
switch to proper nutrition, give up junk food;
any medications or medical procedures should be performed only as directed by a doctor, informing him of the possible onset of conception;
take vitamins, eat a lot of vegetables and fruits;
maintain sufficient physical activity;
often in the fresh air.

A pregnant woman should try not to be nervous, stress negatively affects the unborn child. You can read more about the first week.

Starting from the second week, it is already possible to conduct tests and donate blood for hCG. At this stage, in most cases, it is possible to confirm the pregnancy.

2 week

If we take obstetric terms, then the second week of pregnancy is the period of conception. It is at this time that a woman ovulates. The ovary releases a female cell that travels to the fallopian tube. There she waits for fertilization within 24 hours. Male cells - sperm, live longer. They remain active for up to five days. When they meet, conception occurs. If fertilization has not occurred, after 2 weeks the unfertilized egg is excreted from the body with menstruation.

From the second week of pregnancy, many girls feel some changes in their bodies. Pregnancy proceeds with the following sensations:

the emergence of sensitivity to various odors. Habitual aromas can be aggravated so much that it greatly annoys the expectant mother;
mood swings. Emotional "swing" is explained by changes in hormonal levels;
in the lower abdomen and back area, pulling, even quite painful feelings may occur. This is due to the contraction of the genital organ, because the uterus is trying to get rid of the endometrium;
some women develop increased sexuality during pregnancy. This is due to a change in hormonal levels.

The description of these symptoms does not apply to all women. Sometimes moms don't feel any changes, especially when it comes to their first pregnancy. Read more about the second week.

You can find out about the onset of ovulation by measuring the basal temperature, using special pharmacy tests, or by a simple calculation if the menstrual cycle is regular.

3 week

It is the third week of pregnancy in obstetric terms that is considered the time of the birth of a small organism. At this stage, a complex process takes place, giving rise to a new life. After the strongest and most active sperm reach the female cell, one of them enters the egg. Here a fusion takes place, accompanied by the formation of a set of chromosomes of the unborn child. Surprisingly, already at this stage, the baby's gender is laid. Spermatozoa that have not reached the ovum die.

A fertilized female cell is called a zygote. Immediately after fusion, it moves up the fallopian tube into the uterus. During this period, the ovum feeds on various protein compounds. After attachment in the uterus, a long and difficult path of fetal development begins. Often at this time, a woman may notice minor spotting, but often this symptom goes unnoticed.

A photo of the ultrasound of the fetus can be found below.

After fertilization, the egg begins to actively divide into blastomeres. At the next stage, the morula is formed. Around the fifth day, a hollow ball is formed, which is called a blastocyst. After it reaches a significant size and breaks the wall due to stretching, the process of hatching (hatching) of the embryo from the shell takes place. Immediately after this, the blastocyst is attached to the uterine wall. As a rule, implantation occurs on the seventh day after fertilization.

In the third week, the woman feels some changes. These include:

drowsiness, weakness, dizziness;
changes in the emotional background, frequent mood swings;
many mothers experience nausea, a change in taste preferences;
breasts are poured, the shade of the nipples may change (they become darker).

Most young mothers already know about the onset of pregnancy or are beginning to guess about it. During this period, it is very important to take care of your health, because immunity is reduced, a woman is more susceptible to various diseases. For the normal development of the embryo, doctors advise to rest more and eat right. In this case, it is necessary to consume a sufficient amount of vitamins and minerals. It will be useful to take folic acid and other vitamins, for example, such as Vitrum for pregnant women, Elevit pronatal and others. You can learn more about the development of pregnancy at 3 weeks.

4 week

In the fourth week, the active process of formation of the placenta begins. In addition, amniotic fluid appears. They are necessary for the normal functioning of the unborn child. During this period, the head and three main layers appear. In the future, all organs and tissues will be formed from these sheets.

At this stage, the embryo consists of the following parts:

ectoderm (the tissue from which the brain is formed);
endoderm (the organs of the digestive system, liver, thyroid gland and pancreas will later be formed from it);
mesoderm (this is the rudiment of the skeleton and circulatory system).

So far, the embryo is very similar to a tadpole, has no human outlines. Every day the future baby is actively growing and developing.

Mom's condition in the fourth week remains unstable. A woman often experiences mood swings. Drowsiness can be replaced by arousal of consciousness and vice versa. Tastes and smells continue to be annoying. For some pregnant women, even routine food preparation becomes unbearable. Many women suffer from morning sickness and malaise.

The tummy still remains the same, but due to the increased appetite, some girls may gain weight. The chest increases slightly in size. Sometimes the sensitivity and appearance of the nipples increases.

Toxicosis is not observed in all women. Many lucky women are lucky enough to avoid these sensations altogether.

In the fourth week, you can easily determine the onset of pregnancy. HCG is already produced in large quantities, so the test in 99% of cases will show two strips.

If a happy event happened, you should not delay a visit to the gynecologist. At this stage, it will be necessary to pass all the tests, undergo an examination on the gynecological chair. This will help to timely identify certain diseases, to carry out their treatment. In addition, we must not forget about what sometimes happens. This dangerous condition should be diagnosed and treated as early as possible. Read more about the fourth week at.

5 week

In the fifth week, many women who do not know about pregnancy begin to suspect their delicate situation. Menstruation is absent, which most often acts as a signal of the onset of conception. In addition to frequent mood swings, there are other changes.

Physiological signs:

dizziness and fainting. These conditions are explained by a sharp change in blood glucose levels. To avoid such phenomena, a pregnant woman should revise her diet, eat fractionally 4-5 times a day;
increased vaginal discharge. Many moms notice that the amount of mucus becomes large. This is due to the process of cork formation, which will further protect the fetus from various infections;
pulling sensations and pain in the lower abdomen can indicate both a natural contraction of the uterus and the threat of miscarriage. If you experience such sensations, you should consult your doctor.

On the part of the psycho-emotional state, a woman may experience fear, panic, and anxiety. This is quite normal, because now mommy is responsible for her own life and for the life of the baby.

In the fifth week of development, the embryo reaches a size of up to 2 cm.At the same time, its body is disproportionate. The head is large, and the body, in comparison, is small. This stage of development is very important. Right now, a neural tube is being laid, which will later form the spinal cord.

In the fifth week, it is very important to continue eating right, getting adequate rest, and avoiding stressful situations. A woman should take vitamins and folic acid. Trace elements are essential for the proper formation of the fetal nervous system. If pregnancy occurs in the winter, you should try to be in crowded places as little as possible. The transfer of viral and bacterial diseases during this period can lead to serious consequences, up to a miscarriage. You can learn more about the fifth week from.

6 week

At this stage, on the ultrasound, you can already see the head of the fetus, the tubercles of the arms and legs. Fingers will begin to form very soon. Already, the baby's cheeks, chin, and mouth are looming. At the sixth week of development, a change in appetite occurs. A woman may feel constant hunger, or, conversely, she is sick of any food. The weight gain of the pregnant woman is also associated with this. Some mothers are losing weight due to severe toxicosis, while others are getting better. In addition, some girls have a slightly increased area in the lower abdomen. This happens more often with repeated pregnancies or with a reduced uterine tone.

In the picture you can see the embryo at 6 weeks of gestation.

A girl should take care of her health and the health of her baby. In addition to proper nutrition, good rest and hygiene, she should try to avoid contact with various chemicals. This even applies to ordinary household chemicals. It is recommended that a woman often walk on the street, listen to calm music. All information about the sixth week.

If you find a discharge with a foreign odor or color, you should tell your doctor about it. Such signs may indicate the presence of a fungal infection.

7 week

This period of pregnancy is accompanied by an important event. The corpus luteum is replaced by the placenta. By this time, it should be fully formed, it is good to perform the protection of the fetus. If a woman has suffered various infectious diseases, the functions of the placenta may be impaired.

The kid is developing rapidly. The weight is already 2 grams, and the size is about 2 centimeters. The fetus is actively continuing the formation of the nervous system. The placenta provides the fetus with oxygen and essential nutrients. In addition, it protects against pathogenic microorganisms.

Physiological changes in the child:

toes and toes appear;
bone tissue is formed;
the embryo is already bending the knees, elbows;
the heart has 4 chambers, due to which the blood moves throughout the baby's body;
the rudiments of teeth are laid;
a nose, lips appear;
the genitals are formed, but so far it is impossible to determine the sex of the child.

A young mother, in addition to toxicosis, at this stage may face edema, frequent urination, and indigestion. Due to the rapid development of the fetus, a woman often feels pressure in the lower abdomen. In the seventh week, the uterus reaches the size of a large apple. A dark line begins to appear from the navel to the pubis, the nipples also darken. Detailed description .

8 week

If we consider pregnancy by months, then 8 weeks is 2 months. At this time, the woman already clearly understands her condition. Outward signs of an interesting position become noticeable:

the figure is rounded, the gait becomes smoother;
the condition of the skin changes. It is worth noting that for some ladies it becomes cleaner, smoother. Other girls have to deal with the appearance of acne and age spots;
the desire to eat something incongruous is becoming more and more pronounced.

The first trimester of pregnancy becomes a real challenge for many mothers. Don't worry. More often, toxicosis passes by the end of the third month.

The weight of the crumbs is already up to 3 grams. At this stage, almost all systems have already been established and continue to actively form. The tail, which was present in the coccyx region, disappears, the embryo moves its arms and legs. While these movements are unconscious, chaotic. Bones are getting stronger every day. For more information on week 8, see.

Photo of the fetus on ultrasound

In the eighth week, the visual system of the fetus is effectively formed. The eyes are located closer to each other, the embryo takes on a human form. During an ultrasound examination, the auditory canal can be seen, facial features are barely visible. Surprisingly, during this period, the child already reacts to touch.

9 week

At this stage, the growth of the baby continues, he passes from the embryo to the fetus. The head is still large, the limbs are well formed. The child moves freely in the amniotic fluid. Its size does not exceed three centimeters. The genitals are forming, but at the ninth week it is still impossible to determine the sex of the crumbs.

A woman should also be attentive to her health. If any discharge of an uncharacteristic type appears, you should immediately contact your gynecologist. You also need to be careful about painful or cramping sensations in the lower abdomen. This often requires consultation with a geneticist and other specialists. The doctor may order a chorionic biopsy test to identify possible malformations. All about the ninth week.

10 week

The woman transfers this stage more calmly. Mom gradually gets used to her new position, fears and anxiety calm down. The crumbs have already formed the main internal organs and systems, the brain is actively developing. The baby's weight is about 7 grams. The head gradually rises from the chest, becomes more proportional to the body.

In the fetal brain, new chains of neurons are formed every moment. The fingers and toes are lengthening, but there is still a septum between them. Internal organs are located in their places, they continue to improve every day. In boys, testosterone is already beginning to be synthesized, and in girls the hormone estrogen.

In a young mother, the mammary glands are noticeably enlarged, veins and capillaries become visible on them. The lower abdomen is rounded. During this period, it is necessary to revise the wardrobe, put aside tight things. Clothes should not constrain the stomach and chest. Due to the rapid growth of the uterus, the girl feels pressure on the internal organs, and urination becomes noticeably more frequent. You have to get up to the toilet even at night.

Don't worry about the changed body shapes. A woman should enjoy her position, have a positive attitude. Read more about week 10 in this one.

11 week

At this stage of development, the crumb already weighs about 11 grams, and its size is up to 6 cm. With the help of ultrasound, it is possible to consider whether the fetus is developing normally. The heart rate is around 140 beats per minute. The third month of pregnancy is accompanied by the formation of auricles and hair follicles. The crumb requires more and more nutrients, because its growth is now very rapid.

Most mothers with toxicosis feel relief. By this age, morning sickness and malaise gradually disappear. By the end of the third month, the girls are literally “blooming”. The state of health is improving.

If there is no threat of miscarriage, it is allowed to walk a lot, do gymnastics for pregnant women. To prevent stretch marks on the body, you can use special creams or natural oils. Olive, almond, apricot and peach oils soften the dermis well. Find out about this period.

Nutrition should be complete. The diet should include cereals, soups, lean meat and fish, vegetables, fruits. It is important to eliminate caffeinated drinks and alcohol altogether. It is also not recommended to eat large amounts of salty foods. This can lead to swelling. The list of restrictions includes sweet pastries and pastries in large quantities, sparkling water.

12 week

It is believed that the threat of termination of pregnancy is highest in the first trimester. At the twelfth week, the expectant mother feels more relaxed, anxiety and fears go away. Often girls in a position hear that pregnancy suits them. Many ladies do bloom during this period. Hair becomes shiny and thick, the skin is firm, elastic, smoother.

Due to the fact that toxicosis by this time ceases to torment the pregnant woman, many forget about the need for a healthy diet. This is wrong, because healthy food and adherence to the daily routine are the key to the development of a healthy baby.

How much does the fetus weigh? At 12 weeks, the fetus already weighs up to 14 grams. Its growth is about 5-6 cm. Here the further development of the respiratory system takes place, the functioning of the digestive system is getting better. The baby is already raising its head, taking a finger in its mouth.

In addition, a small organism already reacts well to sounds and bright light. More details.

13 week

Thirteenth week is the beginning of the second trimester. During this period, doctors recommend that a woman observe proper nutrition, rest a lot, and often be in the fresh air. The tummy becomes more and more rounded, the waist increases in volume. If a woman is carrying twins or triplets, the tummy is large enough. Often multiple pregnancies occur with IVF (artificial insemination). At this stage, Mom should already be thinking about changing her bra. The breasts are quite large, so the usual underwear can squeeze it.

Toilet trips become less frequent in the thirteenth week. This is explained by the raising of the uterus. If you find painful sensations, you should immediately contact a gynecologist. We must not forget that the threat of miscarriage persists at any time. Vaginal discharge should normally remain free of unpleasant odor and pathological color.

The baby is actively developing inside the mother's womb, its weight is about 20 grams, and its height is up to 7 cm. A small body reacts to music, touch, bright light, voices. At this stage, the following physiological changes occur:

the eyes move more and more to the bridge of the nose;
muscles develop, bones become stronger;
the auricle takes on a normal shape;
the baby is already sleeping for several minutes;
the child is chaotically moving the arms and legs, but the knees still do not bend.

The size of the fetus is still so small that the woman does not feel its movements. It is not yet possible to determine the sex of the child. Read about this term.

14 week

19 week

weight at 25 weeks about 700 gr., while the growth is about 35 cm;
strengthening of the skeletal system;
improving muscle tissue;
the baby constantly moves its limbs, turns its head;
the grasping reflex develops;
the leading hand is determined - right or left.

Due to the fact that the child has already formed an inner ear, he orients himself well in space, takes a comfortable body position for himself.

26 week

With each day of pregnancy, the tummy becomes larger, the load on the legs and spine increases. During this period, you should already think about maternity leave. The gait of the future mother is more and more like a pendulum. The total weight gain ranges from 8-9 kilograms. If an increased uterine tone has been diagnosed, the pregnant woman can be put on hold.

The growth of the baby is about 35 cm, and the weight is up to one kilogram. Due to the accumulation of subcutaneous fat, the baby becomes lighter, the skin is smoothed. A small body is improving every day. Jerks with arms and legs become more palpable and even painful for the mother.

At this time, you need to continue to eat right, watch beautiful films, listen to calm classical music. This will help improve the emotional state of the mother and baby.

27 week

It becomes more and more difficult for a woman to do the usual things. Difficulties can arise during this period of pregnancy when shoeing, tying shoelaces, undressing. Many moms go on maternity leave at this time. This time can be devoted to your favorite activities, hobbies, walks, watching films about the development and upbringing of children.

In the seventh month, the changes in the fetus are as follows:

the laying of such important processes as memory, thinking occurs;
at this stage, the temperament of a little man is formed;
bone tissue continues to strengthen, so a woman should not reduce the amount of calcium consumed;
further growth of adipose tissue occurs.

In the formation of primary immunity occurs. In the future, he will protect the baby from various diseases.

Many mothers gain quite a lot of weight at this stage of pregnancy. This makes them clumsy, clumsy. In addition, excess body weight provokes drowsiness and fatigue. It is very important to monitor your diet, eat a lot of vegetables, herbs, fruits and cereals.

Discomfort in the lumbar region becomes frequent companions of a young mother. To relieve them, doctors recommend doing special gymnastics, wearing a bandage.

The following happens on development:

the thickening of the layer of subcutaneous fat continues in the baby;
the rudiments of intelligence appear in the brain, convolutions are formed;
to any stimuli, the baby frowns, grimaces, wiggles his legs, turns his head.

In case of Rh-conflict, the introduction of immunoglobulin is necessary. This helps to avoid many serious complications.

Week 29

The child continues to grow, and in the womb he becomes uncomfortable, because there is not enough space for him. The growth of the crumbs at the 29th week of pregnancy reaches approximately 40 cm, and the weight is 1.5 kg. The optic nerves are well developed, which allows the baby to better distinguish the light, squints with bright glare. Many mothers feel the hiccups of the baby, his movements. The organs are well formed, the muscles and respiratory organs are being improved.

Most girls are not forced to change their wardrobe, since the tummy no longer fits into old clothes. Do not be upset, because soon you will be able to bring yourself back to normal.

Changes in a pregnant woman:

the skin becomes drier, pigmentation is noticeable;
pulling pains are increasingly felt in the back area, the woman quickly gets tired;
the mom-to-be often feels annoyed. Due to the fact that during sleep she can only lie on her side, fatigue accumulates.

Despite fatigue and mood swings, mommy should remember the need to continue eating right, monitor body weight gain, you can keep a personal detailed nutrition diary, and attend scheduled check-ups. An experienced doctor should be involved in pregnancy management. If you do not visit the hospital, the outcome can be the most negative.

30 week

Is seven and a half obstetric months. By this time, the woman is gaining about 10 kg, some mothers are even more. At this stage, the baby is fully formed, continues to train breathing. It draws in and out fluid, thereby preparing its lungs to draw in air.

This is where the active interaction of the tiny man with his mother begins. He worries if a woman raises her voice, calms down when stroking her tummy. The weight of the fruit is approximately 1.5-1.6 kg. Before giving birth, he will need to gain about two more kilograms. The hairs covering the baby's body begin to fade away, but sometimes they remain for some time after the baby is born.

The grooves of the brain, which have formed by this time of development, become deeper. Mom feels that the baby does not just move chaotically, but can consciously react to various types of stimuli.

At 30 weeks of gestation, the baby is increasingly lacking in space. He now and then tries to straighten the arms and legs, which is clearly felt by the pregnant woman.

31 weeks

The fatigue and discomfort of the young mother is increasing more and more. The uterus grows and puts pressure on the internal organs. Back pain occurs while sitting, walking, even lying becomes uncomfortable. Convulsions often occur at night. To alleviate your condition, you should do yoga, a relaxing massage helps a lot. At this stage, doctors recommend reducing the amount of fluid consumed, adhering to a proper diet, and limiting the amount of salt.

The physiological changes in the child are as follows:

weight is approximately 1.7 kg;
growth reaches 40-45 cm;
the crumbs improve their basic senses (hearing, sight, smell);
more and more neural connections are developing;
the waking period becomes longer.

The closer the due date of the upcoming birth, the stronger the anxiety of the pregnant woman grows. Fears and worries are quite normal feelings, and relatives and friends should help to cope with them.

32 week

At this stage of pregnancy, the baby is up to 47 cm tall and weighs approximately 1.8 kg. Many babies are still in the feet-down position, but they soon turn over into the correct position. The coordination of movements is improving, the brain is developing better and better. In the last stages of pregnancy, many doctors advise mothers to read books, listen to calm music, and recite poetry to the child. It is believed that this helps to improve the development of the baby, to make his psyche more stable.

Feelings of a woman at this stage of pregnancy can hardly be called pleasant. The uterus enlarges, presses on the stomach, heart, diaphragm. It becomes harder to breathe, a woman is tormented by belching, heartburn, finding a comfortable body position is becoming more and more difficult.

Many women can feel contractions, but more often they are false. They are called Braxton-Higgs contractions. This is a kind of training before the upcoming birth.

33 week

The weight gain of a pregnant woman at this time is approximately up to 12-14 kg. Because of the fear of the upcoming birth, the irritability of the young mother increases. To avoid various problems, the girl is advised to remain calm, communicate more with loved ones, watch films about the birth and raising of children.

The child often turns head down. If this did not happen, do not be upset. Doctors will help control the birth process. The crumb is rounded, cheeks, skin folds appear, the skin brightens.

In the last trimester of pregnancy, the musculoskeletal system is actively formed. A woman should not forget about sufficient calcium intake during this period.

34 week

Thoughts about having a baby at this stage of pregnancy are becoming more and more frequent. The meeting with the baby is more and more desirable. The body weight of a girl, as a rule, increases by 10-15 kg, her breasts are poured and continues to grow. Areolas take on a darker shade.

The crumb weighs up to 2.5 kg. The growth of the fetus is up to 49 cm. The baby's skin becomes lighter, smoother, but still covered with protective lubricant. It is designed to facilitate its passage through the birth canal, protect against pathogenic microorganisms. If a child is born prematurely, he will be able to breathe on his own without a special camera and rehabilitation.

35 week

At this stage of pregnancy, mothers should take special courses where they will tell you about how to behave during childbirth. In addition, it is important to think about choosing a maternity hospital and a doctor who will control the birth process. Many women decide to have a partner birth. At the same time, a husband or another close person can stick in the delivery room.

When walking, there is fatigue and shortness of breath due to the rather large abdomen. Doctors recommend not to overeat during this period. If the fetus is too large, the birth will be quite difficult.

At the 35th week of pregnancy, all reflexes of a small person are improved (sucking, swallowing, grasping). The amount of amniotic fluid becomes less, which causes discomfort to the baby. This becomes one of the first signals for the onset of labor. In the third trimester, the development of the respiratory, nervous, endocrine and other systems improves.

The fruit sinks. In this case, the woman feels pulling pains in the back and lower abdomen. Soon after, breathing is relieved and back discomfort is reduced.

36-39 weeks

At this stage, the child is fully formed. All organs and systems function in the right order. The body of a pregnant woman at this time is already completely ready for the birth of a new life. At this time, a woman should be able to distinguish false contractions from true ones. The following signs indicate the onset of labor:

increased appetite;
contractions are of a regulatory nature;
often there is vomiting, diarrhea;
amniotic fluid leaves;
the cork comes off (mucus that covered the uterus).

If a pregnant woman develops such signs, she needs urgent hospitalization. The baby at that stage of pregnancy weighs from 3 to 3.5 kg. The growth of the baby is up to 55 cm.

The baby is formed and ready to be born. It is definitely impossible to calculate the date of birth and the gender of the child. The date of birth of a baby can be calculated by knowing the first day of the last period. This is the so-called obstetric term.

40 weeks

At this time, most mothers expect a long-awaited acquaintance with their baby. All organs and systems of the crumbs are fully formed, a meeting with the outside world awaits him. The further growth and development of the child will completely depend on the care of the parents for the little man.

On many sites and forums about pregnancy, you can find a variety of charts for the development and weight gain of a baby in the womb. We propose to consider one of these lines of development.

The data in the table are approximate, may vary depending on the characteristics of the development of the fetus.

Correspondence of weeks and months of pregnancy: table

The ratio of weeks and months of pregnancy in the table.

Trimester	Month	A week
First	1	1-4
	2	5-8
	3	9-13
Second	4	14-17
	5	18-21
	6	22-26
The third	7	27-30
	8	31-35
	9	36-40

The start date of labor is calculated by the doctor. The date of the baby's birth can be determined with an error of 2-3 weeks according to the obstetric time. In addition, there are special calculators with which you can approximately calculate the baby's birth date.

Intrauterine development video

This video will help you learn more about fetal development.