The duration of pregnancy is 40 weeks. The process of fetal development is divided into weeks, months, and trimesters. For a more complete picture of bearing a child, a woman can read the description below.

Fetal development by week of pregnancy: 1st trimester 1-13 weeks of pregnancy

Obstetric and embryonic periods differ:

The beginning of the 9-month period is the time during which the fusion of male and female cells occurs, an embryo is formed, and internal organs and systems begin to develop.

1 Week

It is characterized by the process of the birth of a new life, the preparation of the cavity of the reproductive organ for the attachment of the embryo.

Happens:

1. Fusion of egg and sperm.
2. The beginning of the active process of cell division, the formation of a blastocyte - a hollow ball created from the resulting membranes.
3. Laying down genetic characteristics.
4. Starting the process of producing human chorionic gonadotropin, a pregnancy hormone, the concentration of which allows you to establish conception using test strips.
5. Development of a new layer of epithelium, preparation of the reproductive organ to receive an embryo.

In the 1st week, the expectant mother cannot notice signs of pregnancy and has no idea that conception has occurred.

2nd week

The fertilized egg attaches to the uterine cavity. An embryo is formed that receives nutrients from the mother's body. During ultrasound diagnostics, a specialist reliably diagnoses pregnancy.

Child development:

1. The fetus, which has reached a size of 2 mm, adheres to the reproductive organ.
2. A protective shell appears surrounding the embryo.
3. The process of formation of the brain, spinal cord, and circulatory system begins.

For a woman:

• Sudden mood swings occur, and a sudden onset of migraine may occur.
• Taste preferences change. An aversion to certain smells appears.
• Progesterone is intensively produced, leading to increased sensitivity and changes in the color of nipple halos.
• Periodically, spasms appear in the lower abdomen, clear, brown discharge from the vagina, without blood. This process accompanies the rupture of the follicle.

3rd week

There is a danger of fetal rejection caused by the rejection of a foreign body by leukocytes. Early toxicosis may occur due to the opposition of the body's protective bodies to the proteins of the embryo. Fruit size 2.5 mm.

Child development:

1. The circulatory system, brain and spinal cord are actively being formed.
2. The rudiments of the respiratory system appear. The facial features of the future baby are determined.
3. Establishes a connection between the child and the mother's body. The placenta appears.
4. A protective protein will be actively produced, designed to protect the fetus from the aggressive effects of the mother’s immune system.

The expectant mother is worried about:

• Sudden mood swings caused by hormonal imbalance.
• A constant feeling of drowsiness that does not go away after proper rest.
• 70% of women experience spotting from the genitals caused by embryo implantation, which is mistaken for the onset of menstrual bleeding.

4th week

Official confirmation of pregnancy by a doctor after no monthly bleeding.

In addition to the main symptom, the young mother feels:

• The first symptoms of toxicosis.
• Sudden mood swings.
• Changes in taste preferences. Intolerance to any odors, even faintly perceptible ones.
• Very thirsty.
• Constant lack of sleep.

At this stage the baby experiences:

1. Formation of germ layers: endoderm - the basis of future internal organs; ectoderm - soil for the development of the nervous system; mesoderm - the layer responsible for the cat's tissues and skeleton.
2. Development and formation of the respiratory, digestive system, brain bladders.
3. The appearance of a pulsating tube, which later degenerates into the heart muscle.
4. The emergence of limb buds.

5th week

It is characterized by the appearance of obvious signs of pregnancy, preparing the body to bear a baby. Test strips and an examination by a gynecologist will diagnose conception with 100% certainty.

Child characteristics:

1. The embryo reaches a size of 4-7 cm in length, 3.5 g. weight. It has a cylindrical shape, with the rudiments of limbs and fingers.
2. The first blood vessels are formed, and on the 22nd day from the moment of fertilization the heart contracts for the first time.
3. The foundations of the kidneys and abdominal organs are laid.
4. The fetus is separated from the chorion. The cells responsible for the growth of the genital organs appear in the yolk sac.

At the end of the first month of pregnancy, the young mother:

• He suffers from toxicosis, intolerance to smells and tastes.
• The uterus increases in size, causing frequent urination and pulling cramps in the lower abdomen.
• The body temperature of a pregnant woman rises to 37.3-37.5⁰C.
• There is a change in the amount of estrogen and progesterone in the blood.
• The amount of human chorionic gonadotropin increases.

6th week

At this time, registration at the antenatal clinic, clinical diagnostic testing of blood, urine, and bacterial tests take place. It is possible to conduct an ultrasound to confirm pregnancy and study the development of the baby.

Fetus:

1. The baby resembles a tadpole, with a large head and a long tail. Length – 4-6 mm. Constantly actively moving.
2. The heart muscle makes up to 120 beats per minute. (2 times more than an adult).
3. The neural tube closes.
4. The brain and cranium are actively developing.
5. The placenta reaches a weight of 800 g. The amount of amniotic fluid increases.
6. Facial features (chin, cheeks, lips, nose) are formed. The development of internal organs continues.

Feelings of a young mother:

• Toxicosis intensifies. Vomiting may occur at unspecified hours. Refusal to eat provokes weight loss.
• The woman is accompanied by a constant feeling of fatigue. The vessels of the brain become overstrained, causing migraines, dizziness, and loss of consciousness.
• Problems arise with the digestive system, constipation, diarrhea, and bloating.
• The growth of the reproductive organ is accompanied by cramps in the abdomen and lower back. Gradually decreasing pain, in the evening, and spotting may indicate a threat of spontaneous abortion.

7th week

Mid-first trimester of pregnancy.

Child development:

1. Fruit length is from 8-13 mm. The size of the head increases. The baby's brain is divided into 5 brain vesicles, the neural tube connects to the internal organs with the help of nerve fibers. The placenta thickens. Placental blood flow is completely improved.
2. The face takes on precise contours. The eyes are designated, and the formation of the optic nerves and retina begins.
3. The gastrointestinal tract consists of the stomach, pharynx, esophagus, rectum, and base of the bladder. The liver and pancreas are improved.
4. The respiratory organs are represented by the trachea, the rudiment of the bronchi.
5. The spinal column appears, the neck stretches, and the hands take on the appearance of shovels.

Woman's well-being:

• The week is characterized by increased hormonal changes, causing disruption in the process of biochemical reactions and exacerbation of chronic pathologies.
• Weight loss of 1-3 kg is possible, caused by refusal to eat due to toxicosis.
• Irritability increases, and taste preferences that are uncharacteristic of a normal state appear.
• The amount of creamy vaginal discharge increases. There is still a risk of miscarriage. It is necessary to monitor the shade of leucorrhoea and spasms.
• The skin becomes covered with acne, acne. There may be irritation, itching, and redness in the abdomen and chest caused by stretching of the skin tissue.

8th week

Pregnancy lasts about 2 months.

Baby changes:

1. The fruit takes on a human shape, 3-4 cm long. The back is straightened, the spine develops, and the tail disappears. Arms and legs appear, facial features are visible.
2. The heart and bronchi are fully formed, the trachea in the stomach produces gastric juice, and the intestines are enlarged.
3. The brain is growing. The foundation of lung tissue is laid.

For a pregnant woman:

• A small rounded tummy appears. The first weight gain is felt due to the growth of protective adipose tissue.
• The skin of the face is cleansed and the condition of the hair improves.
• I am worried about spasmodic pain in the lower abdomen and back. The discharge is white, the appearance of blood is dangerous and may indicate an incipient miscarriage.
• The uterus increases in size, and pressure is felt on the internal organs. Nausea is most common in the morning, and heartburn occurs in the evening.

9th week

Baby:

Future mom:

• Observes weight gain and increasing hunger. The daily food intake increases by ¼.
• Feels very tired and may have nightmares. There is heaviness in the legs, shortness of breath appears.
• Feels frequent vomiting and problems with teeth. The baby draws nutrients from the mother's body.

The uterine cavity grows rapidly, the walls of the organ thicken. Pressure on internal organs increases. Body temperature may rise to 37.5 degrees.

Week 10

New phase of pregnancy. By this period, the baby’s body is fully formed and has limbs. The fetus reaches a height of 8-9 cm, actively floats in the amniotic fluid, has a complete face, with the makings of auricles. Eyelashes and eyebrows begin to form. Reflexes develop.

The child constantly sucks his finger, reacts to changes in the environment, distinguishes between daytime and nighttime. Heart rate reaches 100 beats/min.

The young mother's condition worsens due to:

• Spasms in the lower abdomen, lower back.
• Shortness of breath, heartburn. Thrombocytosis and stretch marks on the chest, legs, and abdomen may occur.
• Insomnia, nightmares. There is a conscious fear of losing a child.
• Increased growth of the uterus, occupying the entire pelvic cavity. Disappearance of the waist, abdominal growth, pain, engorgement of the mammary glands.

Week 11

The beginning of the 2nd trimester is “fruit formation”.

Child's condition:

1. Height is 9-10 cm. The baby moves actively and feels comfortable in the uterine cavity. The head occupies ½ of the body, the eyes are open, the hands are moving, the fists are clenched.
2. Reflexes are improved.
3. The respiratory system develops fully and the intestines begin to function.

Maternal body:

• Gains weight. The stomach is clearly visible, changes in the figure begin.
• The breasts increase by 2 sizes, the nipples become very sensitive.
• Stretch marks appear and veins enlarge.
• The uterus compresses the blood arteries, causing a lack of oxygen, dizziness, and headaches.
• Toxicosis disappears.

12-week

Time of the 2nd planned ultrasound diagnostics, 1st screening for the amount of hCG in the blood. The fruit is in constant motion. Clearly distinguishes the time of day, feels cold and warm. Sucking thumb, drinking amniotic fluid.

Fully formed:

• the brain (will actively develop in the future);
• the thyroid gland works in full, launching metabolic processes;
• external shape of the genital organs;
• gastrointestinal system.

Nails and body hair appear, and bone tissue accumulates to form the skeleton. The mental state of the young woman is normalized. Weight is gaining and the belly is growing a little. There is a frequent urge to urinate. The amount of vaginal discharge increases. There is a high risk of bacterial candidiasis.

Week 13

The final stage of the first trimester. The body and vital organs of the child are completing their formation.

The baby during this period:

1. It measures up to 14 cm in length, weight 70-80 g. Swims, sucks his thumb. Reacts to external stimuli, the emotional state of the mother.
2. The skeleton and internal genital organs begin to appear.
3. The process of insulin production starts.

The young mother feels:

• Constant pain caused by a sharp enlargement of the uterus. There is a high probability of stretch marks developing.
• A burning sensation in the vagina is a symptom of a candidiasis infection.
• Shortness of breath, which occurs after physical exertion.
• Toothache caused by leaching of calcium from the body.

2nd trimester: 14 – 27 weeks of pregnancy

How the fetus develops over the weeks of pregnancy in the second trimester depends on the health status of the expectant mother. During this period, bone tissue is formed and the baby is nourished from the resources of the mother’s body.

Week 14

The woman's body has adapted to motherhood. Starts the process of protecting emerging life. The expectant mother feels an improvement in overall well-being, a normalization of her mental state, and a decrease in irritability. An increased feeling of hunger forces you to increase your daily diet by ½ part. The uterus extends beyond the pelvis. Shortness of breath and heaviness in the legs appear.

The child is up to 11-11.5 cm in size. He tries to smile, turns his head, clenches his hands, and moves his legs. Facial features are almost completely formed, clear reflexes.

The following are fully operational:

• spleen;
• liver;
• pancreas.

The respiratory system starts. Heartbeat up to 110 beats/min.

Week 15

The beginning of the 5th month of pregnancy is accompanied by a 3rd blood test to determine the amount of hormones estriol, AFP, and hCG. Based on the research results, it is concluded that the fetus is prone to DNA pathologies.

During this week, a woman:

Child development:

1. The fruit is covered with transparent skin of a reddish hue, height up to 18 cm, weight 200 g. Constantly swims, moves its limbs, and responds well to external stimuli. In addition to the placenta, the baby is protected by a lubricant that resembles melted margarine.
2. Skeletal development continues.
3. The immune system enters the formation stage, interferon and immunoglobulin begin to be produced.
4. The gastrointestinal tract functions in full, the genital organs develop.

Week 16

The baby's height is up to 19 cm, motor activity is increased, the child can yawn, tumble, and stretch. Reacts well to external stimuli, distinguishes voices and loud music. Heart rate from 120-140 beats/min. The intestines are capable of defecation. The endocrine system is fully formed and ready to begin work.

A young mother feels the baby's movement. During the daytime, small bumps on the abdomen are observed, caused by blows from small legs and arms. The uterus puts a lot of pressure on the bladder, causing frequent urination.

When holding back the urge to go to the toilet, the likelihood of developing cystitis increases. Hemoglobin level is low.

Fainting, headaches, and dizziness caused by a lack of oxygen in the vessels are dangerous.

Week 17

19th obstetric week, half of the 9 month period.

Characterized by:

A woman's condition is determined by:

• Weight gain.
• Changes in body structure. The pelvis increases in size, the stomach is quite large.
• Constant feeling of hunger.
• Lack of oxygen in the blood. An increase in the level of leukocytes.

Week 18

The baby's size is from 25 to 27 cm. The baby moves. The respiratory system is formed, but does not work. Nutrients are delivered through the umbilical cord. The ear bones begin to develop.

For a young mother, this period is accompanied by:

• Severe pain in the internal organs, caused by an enlarged uterus, displacement of the gastrointestinal tract. Heartburn appears.
• Increased hunger, thirst.
• Sleep comfortably in a side lying position.

Week 19

The expectant mother feels well. Weight increases by 4-7 kg from the original figures. The breasts swell and colostrum is released. The child reaches a height of 27 cm and a weight of 370 g. He gradually gains weight and improves his internal organs. Can detect taste and smell. The volume of bone and muscle tissue increases.

Week 20

A pregnant woman clearly feels the movement of the fetus. The enlarged uterus puts pressure on the respiratory system, causing shortness of breath and tachycardia. The navel begins to protrude.
The ratio of the sizes of the fetus and placenta changes in the direction of the child's growth. The cerebral cortex and nervous system are determined. The internal organs are formed.

21st week

The uterus compresses the diaphragm, making it difficult for the young mother to breathe. Gait changes due to a shift in the center of gravity. Leg cramps appear due to squeezing of the bloodstream.

The child's height is 30 cm, weight 500 g. The fetus moves, trying to find a comfortable position. The ears take on an anatomical shape. The baby reacts to the mother’s calm voice and recognizes it. Internal organs and systems are actively working. The formation of nervous tissue is completed.

Week 22

A young mother may begin to worry about late toxicosis. After eating, heartburn and pain in the abdominal area occur. The growth of the uterus slows down, the volume of the fetus increases. A strong sexual desire may occur.

The child is gaining weight (more than 500 g), moves actively, and is restless. Can sense all organs and parts of the body. The amount of hair on the head increases, eyebrows grow. Surfactant is produced, a substance that starts the respiratory system after birth.

22 week of pregnancy: what happens to the baby and mother:

Week 23

The woman's condition is satisfactory.

Characteristic features of the period:

• increased thrush;
• the appearance of false contractions;
• distinct movement of the baby;
• constant breaks caused by increased weight.

The baby is gaining subcutaneous fat. The skin becomes red and sags a little. The brain completes its formation and coordination of movements improves. The child is moving. Fetal height 34 cm, weight 1 kg.

Week 24

The pregnant woman's health is stable. Headaches, dizziness, and fatigue may bother you. The uterus is located 3-4 cm above the navel. The eyes become hypersensitive.

The child reaches a height of 34-35 cm and a weight of 1 kg. The accumulation of subcutaneous fat continues. Moves limbs, tugs on umbilical cord. He can no longer actively swim or tumble. The brain completes its development. The convolutions deepen, character traits and temperament are formed.

Week 25

A woman experiences increased heartburn, pain after eating, vaginal discharge, and uterine pressure. Hemoglobin levels decrease. False contractions appear at least once every 2-3 days

The child increases in size, cannot swim, tumble, and jerks his limbs. All organs and systems are formed. The gender of the baby is easily determined. This week, the testicles descend into the scrotum in boys, and the vagina appears in girls. Heart rate – 120 beats/min.

Week 26

The baby's organs are fully formed; in case of premature birth, the baby can survive if necessary care is provided. The brain improves and the immune system develops. Meconium is formed in the intestines - the first human stool. Fetal height 34 cm, weight 750 g.

The young mother's health is satisfactory. My weight is constantly increasing and I suffer from heartburn in the evenings. Headaches and dizziness became more frequent. The baby's movements can be clearly felt.

Week 27

The fruit reaches a size of 34-35 cm, weight 800 kg. Growth hormone will be produced. The baby's movements and gestures become more frequent. The immune system is being formed.
A woman's belly is getting bigger every week. Constantly accompanied by a feeling of fatigue. Swelling appears, possibly varicose veins.

3rd trimester: 28 – 36 weeks of pregnancy

How the fetus develops by week of pregnancy during the 3rd trimester is determined during a weekly visit to the gynecologist. By the beginning of this period, the baby is fully formed and is able to survive in the event of premature birth.

28 week

The weight of the fetus is 1.2-1.3 kg, and continues to gradually increase. The baby opens his eyes, turns his head toward the sound, and recognizes loved ones. Constantly hiccups. He can no longer swim freely; he now rests his head against the woman's ribs.

The young mother becomes clumsy, clumsy, and suffers from forgetfulness. The uterus grows (3-5 cm above the navel), strongly compresses the internal organs, causing pain and a feeling of heartburn. Swelling appears, especially in the hot season.

Week 29

For a woman, the time period begins with unpleasant sensations, concern:

• shortness of breath, lack of oxygen;
• swelling, heaviness in the legs;
• heartburn,
• chronic pathologies worsen;
• dizziness worsens in stuffy rooms.

The baby's movements can be clearly heard (up to 10 times per hour).

The child's skin smooths out and folds appear on the limbs. Begin to function:

• adrenal glands;
• body temperature regulator.

Hair growth grows, facial features become sharper. Height up to 40 cm, weight up to 1.5 g.

30th week

By this time, the woman should gain from 8 to 10 kg. The uterus is located 2-4 cm above the navel.
The child's movements can cause discomfort. The baby reached a height of 40-42 kg and weighs 1.7 kg. Tries to take the final position in which it will remain until the moment of birth. Constantly winces, expresses dissatisfaction and joy.

31st week

The child is fully formed, the skin is smoothed, and blood streaks disappear. The gallbladder produces bile, the liver purifies the blood. The lungs are closed, but spontaneous inhalation is attempted. The weight of the fetus is more than 2 kg, height is 40-42 cm.

The young mother feels strong tremors. She has difficulty climbing stairs. Tachycardia, varicose veins, constipation appear, and body temperature is poorly regulated. Shortness of breath, swelling, and heartburn increase. The baby's movement may be accompanied by pain in the internal organs.

Week 32

During this period, control ultrasound diagnostics with Doppler sonography is carried out.

The dangerous time for the child has passed. A baby born at this stage is fully viable. His internal organs and systems are formed. Only the lungs, which begin their start at birth, do not work.

Week 33

The child and the expectant mother rapidly gain weight. The woman is worried about shortness of breath and heartburn. It is difficult to walk (the uterus and fetus are compressed by the veins and arteries). The headache gets worse and it is difficult to sleep. The baby is almost ready for birth, the immune system is strengthened.

Week 34

The fruit weighs 2.5 kg, length 40-42 cm. The nervous, respiratory, and immune systems are improved.
The uterus is located 5-7 cm above the navel. The woman experiences false contractions and itchy skin in the abdominal area.

Week 35

During this time period, the baby’s movements are intensely felt, and the stomach takes on a variety of shapes.
The fetus takes its final position, head down towards the birth canal. The baby's height is 47-48 cm, weight 2.5 kg.

36 – 37 weeks of pregnancy

How the fetus develops over the weeks of pregnancy and in the last days before birth is examined during medical examinations of the expectant mother. At this stage, the child is completely ready for birth and is viable without the use of medical manipulation.

36th week. The fetus accumulates subcutaneous fat. Sucking reflexes are constantly improving. Hormonal changes occur in the mother's body - oxytocin and prostaglandins are produced. The woman's total weight has increased by 11-13 kg since registration.

37th week.A pregnant woman is worried about the warning signs of labor:

• the fundus of the uterus descends;
• preparatory contractions intensify;
• body weight decreases.

The child has grown to 46-47 cm, weight from 2.7 kg. Ready to be born. Improves finger coordination. The fluff covering the fetal body disappears.

38-40 weeks of pregnancy

Fetal development at 38-40 weeks of pregnancy consists of a constant accumulation of subcutaneous fat at the time of birth. At this stage, the pregnancy is considered fully term and the baby is fully formed.

The expectant mother will most likely experience symptoms that herald the onset of labor:

After birth, doctors clean the baby, measure, assess its condition and hand it over to the mother for the first feeding.

41-42 weeks of pregnancy

How the fetus develops over the weeks of pregnancy in the event of a delay in pregnancy is determined by a specialist during urgent ultrasound diagnostics and Doppler sonography.

A delay in labor up to 41-42 weeks is possible in case of incorrect obstetric calculations. The fetus is fully formed, viable, ready for birth. If the gestation period is exceeded (up to 42 weeks), the woman is injected with labor stimulants. Further delay is fraught with hardening of the skull and the risk of birth injuries.

How the fetus develops by week of pregnancy: critical periods.

Fetal development is a complex philological process that lasts for 40 weeks.

Pregnancy is a normal state of a woman, during which internal organs, systems, the body and skeleton of a small person are formed from a cluster of cells.

Article format: Svetlana Ovsyanikova

Video on the topic: how the fetus develops by week of pregnancy

How the fetus develops by week of pregnancy:

Fetal development at 11 weeks of gestation:

The ability to bear and give birth to a fetus is a real miracle that a woman performs. After all, at this time, it is a magical vessel in which a microscopic cell is transformed into a full-fledged human organism.

The average duration of pregnancy is 280 days, that is, 10 obstetric (28 days) or 9 calendar months, counting from the first day to the last menstrual cycle. During this period, the tiny egg in the uterus will have time to develop to the stage of a mature fetus - a small person prepared for extrauterine existence. Are you interested in tracking your baby's development from month to month? Then use our flow calendar pregnancy.

Stages of pregnancy by month

1 month (1-4 week of pregnancy)
After fertilization of the egg has occurred, the fallopian tube starts the process of cell division. All processes are carried out at such a rapid speed that it is just right to say that “the child grows by leaps and bounds.”

• Already three days after conception, the fetus begins to produce the hormone hCG, due to which the female body undergoes some changes.
• During the first three weeks, the fertilized cell becomes an embryo.
• The baby's organs are developing.
• By the end of the 4th week, blood circulation starts in the embryo, and an umbilical cord is formed as a connection with the placenta.
• The embryo is implanted into the uterus.
• The first month of pregnancy ends with the formation of the eye sockets, the buds of the legs and arms.
• By the end of 4 weeks, the appearance of the embryo is comparable to the shell of the ear and is the size of a grain of sand - about 1 mm.

2 month (5-8 a week)
The fetus stops receiving nutrition from the fertilized egg and immediately after its attachment to the inner walls of the uterus receives nutrition from the woman. From this moment on, its development accelerates significantly.

• In the first month, two layers are distinguished in the fetus - endoderm and mesoderm, in the 5th week a third appears - ectoderm, from which the nervous system, skin, hair, and tooth enamel are built. In addition, the embryo exhibits the formation of a groove that consistently folds. It transforms into the neural tube - later - into the notochord, central and peripheral system. A primitive heart tube is formed in the chest.
• At week 6, your baby undergoes active organogenesis - the process of formation of the most key systems in the body: arms, legs, head.
• Week 7 is marked by rapid head growth, as the brain is actively developing. In the rounded head one can already distinguish the eye sockets. The formation of the nose and mouth begins. Two bronchial branches are already present in the area of ​​the future respiratory system. The heart is divided into chambers and arteries. The appearance of veins is also accompanied by the conception of organs such as the liver, spleen and gall bladder.
• At week 8, an ultrasound will show a picture of the baby’s first unconscious movements. It will be possible to observe the outlines of the arms and fingers, upper lip, nose and ears. At 2 months of development, the child is 13 mm tall.

3 month of development (9-12 a week)
During the third month, your baby will have to move from the status of “embryo” to the so-called “status” of a fetus by obstetricians.

• The 9th week is notable for changes associated with the baby’s skeleton. The transformation of hand cartilage into bones, bending of arms and legs, and the final formation of the neck begin. Eyelids will appear, although fused to each other at this stage of development.
• Week 10 - the fetus completes a stage called embryonic development. The fingers and toes are separated. It is not yet possible to identify the external genitalia, but the boy will already begin to produce testosterone.
• At 11, the tail completely disappears. The child can already be compared to a small person, but his body has not yet assumed the proportions characteristic of a newborn. At this stage, 10% of its weight is occupied by the liver. The kidneys are already working in the body - the amniotic fluid is replenished with the urine produced.
• Week 12 – complete completion of organogenesis. The complete formation of all systems ends and at subsequent stages of the baby’s development they simply continue their development.

By the end of 3 months, the fetus reaches 61 mm in height and 14 g in weight.

4 month (13 - 16 weeks)

• Week 14 - the entire system of cartilage from which the fetal skeleton was built becomes bones. Genitals can already be assigned to a specific gender, but ultrasound cannot yet show them.
• Week 15 – appearance of hair on the head, formation of eyebrows. At this stage, the formation of the gallbladder begins.
• Week 16 - the eyes and ears take their final form. Solid lengthening of the legs - in relation to the body they will become proportional. At this stage, the child develops fully formed nails.

The baby's weight at 4 months is 130 g, height - 12 cm.

5 month (17-20 week)

• The final formation of grooves on the palms and heels, which will form the basis for prints in the future.
• The size of the baby is equal to the size of the placenta.
• Week 18 - the baby begins to perceive external sounds and respond to them.
• Week 19 – the baby’s rapid growth slows down, from this moment subcutaneous fat begins to form. Bronchioles form in the lungs. The baby's reaction to light is noted.
• By week 20, the girl will have a fully formed uterus, but the vagina is still missing.

By the end of the 5th month, the child will reach 16 cm in height and 320 g in weight.

6 month (21-24 a week)

• A striking example of a leap in the development of the nervous system is the baby’s ability to swallow amniotic fluid.
• Milk and permanent teeth in their rudimentary state can be seen on ultrasound.
• Hair growth on the head continues, but its color cannot yet be determined, since the time for the appearance of pigment has not yet come.
• Week 23 - ultrasound can monitor rapid eye movements while the baby is sleeping, which confirms high brain activity.
• 24 weeks - the child’s vitality at a qualitatively different level begins precisely at this period. In the lungs, the formation of terminal sacs is noted at the ends of the capillaries, separated from the alveoli by a thin film. The lungs begin to produce surfactant, a surface substance that prevents the capillary sacs from closing during breathing.

By the end of 6 months, the fruit grows to 21 cm in length and up to 630 g in weight.

7 month (25 - 28 week)

• Subcutaneous fat is actively being formed, but the child is still thin and has red and wrinkled skin.
• The appearance of taste buds on the tongue.
• The normal functioning of all organs is noted, but their development is still ongoing.
• In the last three months, brain growth is especially enhanced.
• Week 28 – the baby will open his eyes. At this time, the boy's testicles will descend into the scrotum.

By the 6th month of pregnancy, the baby will grow to 35 cm in length and weigh approximately 1 kg.

8 month (29 - 32 weeks)

• White subcutaneous fat continues to form - an important source of energy nutrition for the child.
• The immune system begins to work, however, the baby's blood is also replenished with the mother's antibodies.
• The teeth in the gums are covered with enamel.
• Already in the uterine cavity, the child is preparing for independent existence: he breathes amniotic fluid (an analogue of respiratory exercises, which allows the lungs to expand), and one can observe the sucking of a fist or finger (the development of the sucking reflex).
• The baby is plump, the subcutaneous vessels are no longer visible.

By the end of this period of pregnancy, the fetus will reach 40-41 cm in height and 1600 g in weight.

9 month (33 - 36 week)

• The child's activity increases, his water room becomes more and more cramped for him.
• The ratio of white subcutaneous fat is 8% of its weight.
• The baby's lungs secrete more and more sulfactant.

By the 10th month, the fetus grows to 45 cm and weighs approximately 2500 g.

10 month (37 - 40 weeks)

• Loss of lanugo - hair covering the surface of the child's head and body.
• The original lubricant is reduced in volume.
• The baby takes the position in which he is born (knees tightly closed with chin).
• His preparation for independent life is completely completed.

Typically, full-term babies are 51 cm tall and weigh 3400 g.
The final stage of the baby's intrauterine development is behind you, and you have to cope with a serious test - childbirth, after which you will finally get to know your long-awaited treasure.

See what fetal growth looks like from start to finish.

Even if you are in the early stages, very soon you will need special underwear for expectant mothers, and cosmetics for stretch marks and pigmentation on the skin will also come in handy.

Closer to the expected date of birth, mothers begin to prepare a trousseau for the baby. In the Lapsi online children's goods store you can buy everything you need for babies:

Read in this article:

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

Initial development of pregnancy

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

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

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

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

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

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

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

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

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

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

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

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

Embryonic development of a child in the womb

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

The baby weighs 200 g and is 14 cm tall.

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

Mid-pregnancy: intensive fetal development

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

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

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

The muscular system and internal organs continue to actively improve. The respiratory system is becoming increasingly developed. The first feces - meconium - accumulate in the baby's intestines.

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

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

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

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

Prenatal development of the child in the last stages of pregnancy

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

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

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

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

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

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

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

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

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

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

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

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

Childbirth can occur between the 37th and 42nd weeks of pregnancy. It is believed that giving birth two weeks earlier or one week later than expected is normal. In the medical literature, during the intrauterine development of a child up to 11 weeks, it is usually called an embryo, and from the 11th week - a fetus. Next, I will describe the weekly intrauterine development of a child.

The first beats of a child’s heart differ already on the 21st-22nd day, that is, already in the 4th week intrauterine development. At this time, not every woman knows that she is pregnant, but the baby’s heart is already beating.

At 5th and 6th weeks The main parts of the brain are formed, the umbilical cord is formed, through which the baby will receive the nutrients necessary for its growth and development from the placenta. During this period, internal organs also begin to develop: intestines, liver, kidneys, stomach, the thymus develops - the gland responsible for the immune system, the thyroid gland is formed, the formation of the placenta and hematopoiesis begins. During this period, it is especially important that the expectant mother leads a healthy lifestyle.

At 7-8 weeks It is already possible to distinguish the child’s fingers and toes, fragments of the face, segments of various organs; at this time, all four ventricles of the heart are already formed, the rudiments of teeth are formed, the outlines of the genital organs are formed, the respiratory, muscular, nervous systems and bone marrow are developing. Starting from the eighth week of intrauterine development, the child develops tactile sensitivity (reaction to touch), ears form and hearing begins to appear.

At 9-10 weeks The child’s liver grows, the kidneys finally form, the blood type is determined and a swallowing reflex appears. During this period, the appearance is already clearly visible, the child’s face is also practically formed.

On the 11th-12th Within weeks, the first bones have already formed, facial expressions have appeared, and the child has learned to clench and unclench his fists. During the third month of intrauterine development, the child's gender is revealed and the external genitalia are formed, but they cannot yet be seen with ultrasound. During this period, the liver begins to produce bile and intestinal peristalsis appears.

On the 13th-16th During the week, the child’s brain actively develops, the organs of touch are formed, and the organs of taste function well. From this time on, the child begins to distinguish the taste of the amniotic fluid that surrounds him. The main organs and systems of the child’s body are almost completely formed and functioning normally.

At 16 weeks the child begins to open his eyes.

From 17-20 weeks(if the child is the first-born) the expectant mother begins to feel his movements. If the child is the second, the mother will feel his movements earlier. The baby already perceives a lot, he hears well, and the mother can begin to actively communicate with him (read fairy tales to him, sing lullabies, talk). From this time on, the child already recognizes his mother’s voice and the beat of his mother’s heart. Upon contact with his hand, the child opens his mouth and puts his finger there - this is how he begins to develop a sucking reflex. At this time, the rudiments of molars are formed. The process of formation of the child’s main organs and systems is almost complete, but he continues to grow and develop.

At 21-24 weeks The child continues to develop the respiratory apparatus, and the genital organs are finally formed.

Beginning from 22-24 weeks In life, he already recognizes sounds from the outside very well and reacts to them. Having been born, he immediately recognizes his native voices.

At 25-28 weeks During intrauterine development, the baby's movements become more and more confident, his bone marrow is intensively developing, his stomach and intestines are working, his kidneys and lungs are quite ready to perform their functions after birth. The child can suck his thumb, hiccup and cry, and reacts to pain and light.

At 29-32 weeks it grows very quickly, accumulates subcutaneous fat, and has the ability to control body temperature.

At 33-36 weeks the child takes up all the space available to him, moves less due to the cramped space, but his kicks become stronger and more confident. By the end of pregnancy, the child weighs more than 3 kg, height - 50 cm or more. At this time, the baby moves little, as he no longer has enough space and is ready to be born!

Before you start counting the term of the expected pregnancy, you need to get acquainted with two concepts - real and obstetric term. The actual gestational age is counted from the moment of fertilization. Obstetric - from the first day of the last menstruation. The difference between them is on average about 2 weeks. The obstetric gestational age is indicated on the sick leave certificate. Therefore, fetal development begins at 3 weeks.

1st week

During this period, fertilization occurred. The fetus is very tiny and it is almost impossible to detect it on an ultrasound. Embryo implantation occurs. The body begins to undergo restructuring and the production of a hormone that is responsible for protecting the fetus during pregnancy. The formation of the placenta and umbilical cord also occurs.

There are no signs of pregnancy in the first week. However, some women already feel drowsiness, weakness, and heaviness in the lower abdomen. The same symptoms occur with premenstrual syndrome. A distinctive feature may be implantation bleeding - small pink or brown discharge.

2nd week

The differences from the first week are minor. In the second week, the fetus increases by 1/10 of its total size. The placenta continues to form and begins to function.

There is a nagging pain in the lower abdomen, and pink discharge may appear. It is important to note that heavy brown discharge may indicate a miscarriage. They are often confused with menstruation.

3rd week

The fetus looks like a small cellular condensation, which can already be detected on ultrasound. Its diameter varies from 0.1 to 0.2 mm, weight - 2-3 μg.

In some women, the urge to urinate becomes more frequent and toxicosis appears. The amount of discharge may sharply increase or decrease. It is important to pay attention to their color and smell. Any deviations from the norm may indicate the presence of an infection.

4th week

The size of the fruit is 5 mm, weight is 0.5 mcg. Externally, the fruit resembles a three-layer disk. Subsequently, each layer (ectoderm, mesoderm, endoderm) will be responsible for the formation of certain organs. Extraembryonic organs develop - chorion, amnion, yolk sac.

The woman's appetite increases noticeably. The belly is slightly rounded, the waist changes shape. The gag reflex increases, and odor intolerance occurs. There is a sharp change in mood, irritability, and emotional instability. The mammary glands gain volume and nipple sensitivity increases.

5th week

The size of the fruit is 4-7 mm, weight - up to 1 gram. The dorsal chord with the neural tube is formed. They then form the center of the nervous system. The organs of the digestive system (liver, pancreas, kidneys, adrenal glands) begin to form. The thyroid gland and heart are formed. Forming blood vessels have already begun to join it.

Nausea worries a woman at any time of the day. The likelihood of miscarriage increases, especially with increased levels of male hormones. An unusual smell and color of discharge, and aching pain in the lower abdomen indicate problems.

6th week

The size of the fruit is 4-9 mm, weight is 0.9-1.3 grams. The fruit begins to move. The fetal nervous system is formed. The brain begins to develop, grooves and convolutions form, and the skull forms. The rudiments of arms and legs appear. The cartilage system develops.

A woman experiences tingling in her chest. There is bloating due to intestinal changes. The rest of the sensations are the same as in previous weeks. Toxicosis continues, and you should be wary if it suddenly stops. Such changes occur when pregnancy fades.

7th week

The size of the fruit is 13 mm, weight is 1.1-1.3 grams. Fingers, neck, ears, and face begin to form. The eyes are still placed far from each other. The heart is fully formed, 2 atria and 2 ventricles have emerged. Red blood cells appear and the Rh factor of the fetus is determined. The fetal intestine grows in length, the appendix and large intestine have formed. The pancreas begins to produce insulin. Bile ducts have formed in the liver. The kidneys and reproductive system develop.

The mother has headaches. Blood pressure may drop, leading to dizziness and fainting. The sensitivity of the nipples increases significantly. They get darker. The breasts are enlarged. Constipation, bloating and heartburn occur. Swelling of the limbs appears.

8th week

The fruit is 14-20 mm in size, weighing 1.5 grams. Many organs have already formed and even begun to function. The heart became four-chambered, vessels and valves formed. Facial features become clearer. Taste buds develop on the tongue.

Sweat and salivary glands are formed, the digestive and excretory systems begin to work. Ovaries are formed in girls and testicles in boys. The diaphragm and bronchial tree begin to form. Joints and muscles, phalanges of the fingers develop. The arms, legs and skull become ossified.

The uterus grows and pain appears in the bladder area. Due to irritation of the sciatic nerve, burning pain occurs in the pelvis and thighs. Eating habits change. The condition of the skin worsens. Varicose veins occur. It is worth considering that nausea during this period should not occur more than 2 times a day.

9th week

The size of the fruit is 22-30 mm, weight is 2 grams. The brain and nervous system are already formed. The cerebellum, pituitary gland, middle layer of the adrenal glands, lymph nodes, mammary glands, and genitals are formed. Cranial, intervertebral and spinal nerves appear. The excretory system is functioning.

The mother's belly becomes rounded, the breasts grow, and varicose veins appear on them. The urge to urinate doubles. Despite the tired state and loss of strength, insomnia appears.

Week 10

The size of the fruit is 3-4 cm, weight is 4-5 grams. The nervous system was formed and divided into central and peripheral. The brain produces neurons and controls all systems of the fetus. The immune and lymphatic systems are formed, and the diaphragm is formed.

Teeth appear. The muscular and skeletal system develops. The arms and legs are fully formed, and the fetus actively moves them. Marigolds began to form on my fingers. Taste and olfactory receptors have developed. The face is fully formed. The fetus opens and closes its mouth.

Toxicosis begins to disappear, but the pain and dizziness do not stop. Appetite increases noticeably. Some women experience constipation and heartburn. A pigmented stripe forms on the abdomen due to the synthesis of melanin.

Week 11

The size of the fruit is 5 cm, weight is 7-8 grams. The placenta is becoming stronger every day. The intestines are temporarily united with the umbilical cord. The brain and nervous system conductivity increases. The sense of smell, genitals, digestive tract, teeth, joints, vocal cords, taste, olfactory and tactile receptors are formed. Reflexes develop, especially sucking and grasping. The fetus begins to react to external stimuli.

The woman feels the baby's movement. Reduces sensitivity to odors, sensitivity and soreness of the breast. The general condition is normalizing.

Week 12

The size of the fruit is 6-9 cm, weight - 14 grams. Thanks to the development of the nervous system, a connection arises between the hemispheres and the spinal cord. All body systems are formed and began to function. The heart supplies them with blood. In addition to erythrocytes, leukocytes were formed in it. The liver began to produce bile, and now the fetus absorbs fats. The sucking reflex develops. Down appears on the head, chin, area above the lip, in place of eyebrows and eyelashes.

The sudden mood swings, nausea, drowsiness, and loss of strength are gone. The urge to go to the toilet becomes less frequent. Skin sensitivity increases and itching occurs.

Week 13

The size of the fruit is 7-10 cm, weight is 15-25 grams. The heart actively pumps blood. The formation of the reproductive system is completed. The baby teeth are completely enclosed. The body develops faster than the head. The skeletal system is being formed. Limbs lengthen. The fingers bend, a prototype of fingerprints appears on them.

The woman is no longer bothered by pregnancy symptoms. The abdomen rounds and begins to protrude. The waist is almost invisible. There is a feeling of tension in the legs, and the risk of varicose veins increases.

Week 14

The size of the fruit is 9-11 cm, weight - 30-40 grams. The chest, diaphragm, intercostal muscles, and muscles develop. The fetus swallows the amniotic fluid and tastes it by sucking its finger. The bridge of the nose and cheeks have formed. The fetus uses facial muscles.

Temporary pain in the groin and sides is normal, provided that they are not cramping in nature. Brittle hair and nails, peeling and dry skin appear. The skin stretches and thins, and stretch marks form. Bleeding gums appear.

Week 15

The size of the fruit is already more than 10 cm, weight - about 70 grams. Blood vessels develop. Blood flows to the organs through the arteries. The skeleton begins to stiffen. The child can bend his elbows and clench his fingers. The face changes. The eyes become closer and take a natural position. The skin is so thin that blood vessels can be seen through it.

Some women feel uplifted, others feel down. Rhinitis, nosebleeds, and night suffocation may occur. The belly increases noticeably compared to week 14.

Week 16

The size of the fruit is 11-13 cm, weight is about 100-120 grams. An ultrasound can determine the sex of the child. The girls have formed a set of eggs. The composition of the blood is fully formed. Nerve cells - neurons - are formed. Nerves intertwine organs. The convolutions and furrows of the brain increase in size. The body becomes proportional, the neck becomes stronger, the fetus holds and turns its head.

The woman is not bothered by frequent urges to go to the toilet. But heartburn and constipation do not go away. Shortness of breath and a feeling of lack of air may occur.

Week 17

The size of the fruit is 13 cm, weight is 140 grams. Ultrasound shows all organs of the fetus. Subcutaneous fat tissue is formed. The bronchi and alveoli developed. Sweat glands, joints, almost the entire muscular system and auditory organ were formed. The muscles contract, so the fetal head straightens.

The woman feels movement. The volume of circulating blood increases, so urination becomes more frequent. Cramps may cramp the calf muscles.

Week 18

The size of the fruit is 14 cm, weight is 190-200 grams. The endocrine and nervous systems develop. Interferon and immunoglobulin are released. The thymus is formed and secretes lymphocytes. The vocal cords and hearing organ are formed. The size of the brain and head increases.

The fetus releases more metabolic products, and this, in turn, affects the emotional state of the mother. Nervousness appears. The woman feels the pressure of the uterus on the abdominal wall and neighboring organs.

Week 19

The size of the fruit is 15.3 cm, weight is about 250 grams. The parts responsible for hearing, vision, taste, smell, and touch are formed in the brain. The connection between the brain and spinal cord and systems is established. The lungs are developing, the bronchial tree is almost formed. The spleen begins to function.

A woman experiences heartburn and bloating, and intestinal motility is impaired due to the displacement of organs by the growing uterus. Sweating increases due to increased activity of the thyroid gland. The belly is large, so it is more difficult to choose a comfortable sleeping position.

Week 20

The size of the fruit is 16 cm, weight is about 300 grams. The organs are formed, but are not ready to function outside the mother’s body. The fetus reacts to light stimuli. He turns and grabs the umbilical cord. Can yawn, frown, smile, hiccup.

The center of gravity shifts due to the growing belly, and the woman’s back begins to hurt. The bandage relieves stress and reduces discomfort. Swelling on the legs, ankles and fingers increases.

21st week

The size of the fruit is 27 cm, weight is about 360 grams. The digestive system is preparing to function outside the mother's body. The fetus sleeps up to 20 hours a day and constantly dreams.

A pregnant woman's belly becomes noticeably larger, and the load on her back and legs increases. The breasts become larger and the areolas become darker. Periodically, dizziness, shortness of breath, and a feeling of lack of air occur.

Week 22

The size of the fruit is 28 cm, weight is about 430 grams. Brain development is completed and neural connections are established. Tactile sensations develop. The child actively reacts to light and sounds, and the woman feels this.

The pain in the back, shoulders, and legs intensifies, which does not go away until the end of pregnancy. It is important to monitor blood pressure and hemoglobin levels to prevent the development of anemia.

Week 23

The size of the fruit is 29 cm, weight is about 500 grams. All systems and organs are functioning, from this moment on, in case of premature birth, the child will survive. The fetus has formed a certain mode of life. A woman can determine what time he is awake and when he is resting. Shoes become too small as the foot lengthens due to the development of flat feet.

Week 24

The size of the fruit is 30 cm, weight - up to 600 grams. The child is actively gaining weight, accumulating adipose tissue, and it becomes crowded in the uterus. Brown fat is deposited mainly on the tummy and in the area between the shoulder blades.

The tremors are felt not only by the mother, but also by the father if he puts his hand to his stomach. Digestive disorders occur due to compression of the liver and gall bladder by the uterus. During this period, the woman’s skin and hair condition improves.

Week 25

The size of the fruit is 34.5 cm, weight - 660 grams. All parts of the brain are formed, and its weight is 100 grams. The formation of the lungs has been completed. The face is formed. It is determined which hand will become the leading one - the right or left. The fetus is able to distinguish voices and sounds and respond to them. He may press his hands over his ears and push when he hears sharp sounds.

The growing belly puts pressure on the diaphragm. It is harder for a woman to breathe and shortness of breath appears. The amount of discharge (colostrum) from the nipples increases.

Week 26

The size of the fruit is 35.5 cm, weight - 760 grams. The baby's skin smooths out and changes color. The fetal adrenal glands begin to produce growth hormone. The baby periodically pushes against the mother's ribs, which causes pain. The fetus will change position if you lie on its side, stroke its belly, or talk a little. Fatigue and drowsiness increase, and some women experience fainting.

Week 27

The size of the fruit is more than 36 cm, weight reaches 900 grams. The endocrine system is actively developing. The baby is already opening his eyes. Tactile sensations increase, so the fetus feels everything around. A woman feels aching pain in her lower back and muscles. Nausea and weakness appear. The discharge from the genitals should not contain any impurities of blood or pus.

Week 28

The size of the fruit is 38-38.5 cm, weight is about 1 kg. The body prepares for oxygen exchange with the blood. The baby's chest moves rhythmically. The pupillary membrane disappears from the eyeballs, so the child reacts more acutely to light. The belly continues to grow and the pain in the back and legs increases. Nausea may occur due to compression of the digestive organs.

Week 29

The size of the fruit is 38.6 cm, weight is 1150 grams. The fetus's nostrils are freed from mucus plugs, so it smells. The child fixes his gaze on the details that interest him. The fetus accumulates white fat and its body becomes rounded. All organs and systems work as a single organism.

The volume of circulating blood increases, and the woman's pulse increases and her blood pressure decreases. The blood vessels dilate and protruding veins appear on the arms, feet and abdomen.

30th week

The size of the fruit is more than 40 cm, weight is 1.3-1.5 kg. Nerve cells function, nerve fibers are formed. The fetus consciously reacts to stimulation. The formation of the genital organs is nearing completion. The woman’s feelings are the same as in previous weeks. The stomach prevents you from performing many usual actions. Unable to lean forward.

31st week

The size of the fruit is 41 cm, weight is 1.5 kg. Pancreatic cells produce insulin. The liver performs a detoxification function, that is, it filters the blood and removes toxins. The fetal brain is 1/4 of an adult's organ. A corneal reflex appears, which involves closing the eyes when the cornea comes into contact with foreign objects.

A woman's metabolism increases, and therefore sweating increases. Feels dizzy when lying on your back.

Week 32

The size of the fruit is 43 cm, weight is 1.7-1.8 kg. At this stage, the fetus takes the optimal position for childbirth - upside down. The child's skin smoothes out and takes on a natural shade. The growth of the abdomen is accompanied by itching and the appearance of stretch marks. Insomnia is a concern; sleep becomes more restless due to the approaching birth.

Week 33

The size of the fruit is 44 cm, weight is about 2 kg. The immune system is functioning and antibodies are being produced. The body became proportional, rounded, and cheeks appeared on the face. Nails grow on the fingers. The child reacts to light and sounds, feels the mother’s emotions. Therefore, stressful situations should be avoided. A woman may experience itching in the chest and abdomen.

Week 34

The size of the fruit is 45 cm, the weight already slightly exceeds 2 kg. The thyroid gland and adrenal glands produce 10 times more hormones than in an adult. The nails have grown to the end of the nail plate. The hairs on the head have their own pigment. A woman can roughly determine the character of her unborn baby by his activity. The child should move almost every hour if he is awake.

Week 35

The size of the fruit is 46 cm, weight is 2.4 kg. Muscle and fat mass increases. The marigolds have become long, so the fruit can scratch itself. The immune system continues to improve, however, the production of antibodies is not enough to fully protect against infections.

By week 35, fatigue accumulates, especially due to constant lower back pain. The digestive organs have difficulty coping with their task due to increased pressure.

Week 36

The size of the fetus is 47 cm, weight exceeds 2.6 kg. A center has been formed in the brain that coordinates the work of the cardiovascular system, breathing and thermoregulation. Immediately after the baby is born, these systems are ready for use. The fetus continues to develop sucking reflex skills.

The woman feels increasing anxiety and panic. Therefore, nervousness and irritability increase, which prevents proper sleep.

Week 37

The size of the fruit is 48-49 cm, weight is about 2950 grams. In the brain, the control centers for breathing, cardiac activity, and movement are improved. The airways produce surfactant, which will help the baby's lungs open after birth. All muscle groups of the woman are tense. The mother's pain and tension increases towards evening.

38th week

The size of the fruit is 49-50 cm, weight is 3.1 kg. The child’s skeleton becomes stronger every day, only the cranial bones remain soft and are connected by cartilage. After birth, the bones will harden. Eye color is not fully formed due to insufficient pigment. The anxiety of the expectant mother in connection with the upcoming birth is intensifying. Panic worries both in sleep and while awake.

Week 39

The size of the fruit is 50-53 cm, weight - 3250 grams. Original feces (meconium) has formed in the intestines, which will be released after birth. The fetus moves less due to tightness in the womb. It is difficult for the mother to catch the movement.

Possible symptoms of a pregnant woman are a stiff abdomen, increased tone of the uterus, nagging pain in the lower back, and loose stool. In the near future, the mucous plug will be released. It is necessary to monitor these signs of impending labor.

40th week

The size of the fruit is more than 51 cm, weight is about 3.5 kg. The baby turns over and, as a rule, labor occurs this week. The child moves about 10 times a day. The mucus plug falls out and the amniotic fluid drains. Mild nausea and loose stools appear a day before delivery. A woman's weight is maintained or reduced. The abdomen sinks, so the urge to go to the toilet becomes more frequent and incontinence occurs.

In some cases, birth occurs later than 40 weeks. This is often due to incorrect calculation of the deadline.