What symptoms are more common on each stage of pregnancy? How does the fetus develop?
It is normal for these questions to arise during pregnancy. A woman should know in advance what symptoms will appear at different stages. Pregnancy can differ from woman to woman. Even for the same mother from one pregnancy to the next.
A typical pregnancy lasts about 40 weeks from the first day of a woman's last menstrual cycle, which is about two weeks before conception.
Pregnancy is divided into three trimesters. Each of these periods lasts 12 to 13 weeks.
Stages of development of the embryo during 38 weeks
During each trimester, changes occur in the body of the pregnant woman as well as in the developing fetus, and a summary of these stages will be described below.
Concept and implantation
About two weeks after the woman has spent her period, she ovulates and her ovaries release one mature egg. An egg can be fertilized within 12-24 hours of its release as it travels up the fallopian tube towards the uterus.
If an egg meets a sperm cell that has made its way into the fallopian tube, it merges into one cell, a process known as fertilization or conception.
At fertilization, the sex of the fetus is already determined, depending on whether the egg receives the X or Y chromosome from the sperm. If the egg receives an X chromosome, the baby will be a girl; The Y chromosome means the baby will be a boy.
According to the Cleveland Clinic, it takes about three to four days for a fertilized egg (or embryo) to move to the lining of the uterus, where it attaches or implants to the wall of the uterus. After implantation of the embryo, the cells begin to grow. It eventually becomes the fetus and the placenta, which is tissue. This tissue can transport oxygen, nutrients and hormones from the mother's blood to the developing fetus throughout pregnancy.
First trimester (weeks 1-12)
A woman will have many symptoms during the first trimester as she adjusts to the hormonal changes in her pregnancy. In the first weeks, the pregnancy may not show up on the outside of her body, but inside, many changes take place.
For example, human chorionic gonadotropin (hCG) is a hormone that will be present in a woman's bloodstream from the moment of conception. HCG levels can be detected in women's urine about a week after a missed cycle. This is why a woman will have a positive result on a home pregnancy test.
Other hormonal changes can contribute to pregnancy symptoms: An increase in estrogen and hCG levels can cause nausea and vomiting, known as morning sickness, which a woman usually experiences during the early months of pregnancy. Despite its name, morning sickness can occur at any time of the day.
The woman will also feel more tired than usual. This is due to increased levels of the hormone progesterone, which increases sleepiness. She may also need to urinate more often as her uterus grows and presses on her bladder.
At the beginning of pregnancy, a woman's breasts will feel more tender and swollen, which is another side effect of increased pregnancy hormone levels. Her areola, the skin around each nipple, will darken and enlarge.
A pregnant woman's digestive system may slow down to increase the absorption of beneficial nutrients. But decreased mobility of the digestive system can also cause common complaints such as heartburn, constipation, bloating, and gas.
As more blood circulates to the woman's face, it will give her skin a more rosy color, described as the "pregnancy glow."
Besides physical changes in a woman's body, she can also experience emotional highs and lows in the early months of pregnancy and throughout. These emotions can range from decay, mood swings, and forgetfulness to fear, anxiety, and excitement.
First trimester embryo / fetal development
A developing baby is called an embryo from the moment of conception, which occurs until the eighth week of pregnancy.
During the first month of pregnancy, the heart and lungs, arms, legs, brain, spinal cord, and nerves begin to develop, according to the American College of Obstetricians and Gynecologists (ACOG).
The embryo will be the size of a pea for about a month. In the second month of pregnancy, the embryo will grow to the size of a bean. In addition, ankles, wrists, fingers and eyelids appear, bones appear, genitals and inner ear appear.
After the eighth week of pregnancy and before the baby is born, the developing baby is called a fetus.
By the end of the second month, eight to ten of the main organs of the fetus have formed. During this stage of pregnancy, it is extremely important that pregnant women do not take harmful medications such as illegal drugs. The first trimester is also the period when most miscarriages and birth defects occur.
During the third month of pregnancy, bones and muscles begin to grow, buds appear for future teeth, and fingers and toes grow. The intestines begin to form and the skin is almost translucent.
Second trimester (weeks 13-27)
By the second trimester, some of the unpleasant effects of early pregnancy may diminish or disappear as a woman's body adjusts to her changing hormone levels. Sleep may become easier and energy levels may increase.
Nausea and vomiting usually get better and go away. But other symptoms can occur as the fetus continues to grow and develop.
A more visible baby appears when the uterus grows behind a woman's pelvis, and the skin on her expanding belly may look like stretch marks.
As the fetus gets larger and the woman gains more weight, she may also experience lower back pain.
Between the 16th and 18th weeks of pregnancy, the mother may feel the first fluttering movements of the fetus. If a woman has had a baby before, she is more likely to feel the fetus kicking, wriggling, or turning even earlier because she knows what to expect.
Week 20 usually marks half of a woman's pregnancy.
Second trimester embryo / fetal development
In the second trimester, the fetus grows faster and will be 3 to 5 inches long. Between 18 and 22 weeks, an ultrasound scan can reveal the gender of the baby if parents want to know this information in advance.
By the fourth month of pregnancy, eyebrows, eyelashes, nails and neck are formed, and the skin has a wrinkled appearance. In addition, during the fourth month, the arms and legs may bend. The kidneys begin to work and can produce urine and the fetus can hear.
In the fifth month of pregnancy, the fetus is more active and the woman can feel her movements. The fetus also sleeps and wakes up in regular cycles. Fine hair (called lanugo) and a waxy coating (called vernix) cover and protect the delicate skin of the fetus.
By the sixth month of pregnancy, hair begins to grow, the eyes begin to open, and the brain develops rapidly. Although the lungs are fully formed, they are not yet functional.
Pregnancy stages over a period of nine months. Third trimester (weeks 28-40)
In the third trimester, when a woman's enlarged uterus pushes her diaphragm. The main muscle involved in breathing may become short of breath because the lungs have less room to expand. Her ankles, arms, legs, and face can swell as she retains more fluid and blood circulation slows down.
The mother will need to urinate more often because there will be more pressure on her bladder. She may also have more back pain and pain in the hips and pelvis as these joints relax in preparation for childbirth.
Dark spots may develop on her face and stretch marks may appear on her abdomen, thighs, chest, and back. She may also notice varicose veins in her legs.
During the third trimester, female breasts may experience some leakage of colostrum, a yellow fluid, as they prepare to breastfeed. The child will sink lower into the stomach.
During the last weeks of pregnancy, it becomes more difficult to find a comfortable sleeping position, so women can be very tired.
As labor approaches, some women enjoy the experience of being pregnant, while others may feel like they can't wait for it to end.
Embryo / fetal development in the third trimester
By the seventh month of pregnancy, the fetus is hitting and stretching, and may even respond to light and sound and music. The eyes can open and close.
During the eighth month of pregnancy, the fetus gains weight very quickly. The bones harden, but the skull remains soft and flexible to facilitate labor. According to ACOG, different areas of the brain are forming and the fetus is capable of hiccups.
The lungs are now fully matured to prepare to function on their own. The fetus continues to gain weight rapidly.
The new definition of prolonged pregnancy is when a baby is born after 39-40 weeks.
A woman was created by nature in such a way that at least once in her life she can give the world a new person. The period of expectation and childbirth is the brightest and at the same time alarming time. But the expectant mother shouldn't worry in vain. She should know that a normal pregnancy is the key to the correct development of her child.
If a woman has a clear idea of how the baby's body is formed throughout pregnancy, then it will be quite simple for her to do everything necessary to avoid the development of pathologies.
Should a woman know how her baby is developing?
Knowing how the intrauterine development of the fetus takes place by week, the expectant mother can correctly organize her nutrition and daily routine. Also, having complete information about what changes are considered the norm, a woman will avoid a state of unreasonable anxiety.
Calculating the intrauterine development of the fetus by week, it should be noted that it lasts 40 of these calendar periods. In other words, a woman's pregnancy lasts 280 days. During this time, the child undergoes a complete process of formation and development of all organs and systems.
Doctors-gynecologists consider the intrauterine development of the fetus by weeks and by periods, of which there are two: embryonic and fetal.
The first lasts from the moment the egg is fertilized until the 8th week of pregnancy. During this period, after fertilization, an embryo is formed, which descends into the cavity and attaches to it. The fetal period lasts from the beginning of the 9th week until the moment of delivery. The embryo transforms into a fetus, develops and grows.
The division of pregnancy into trimesters is also common:
- First trimester (1 - 12 weeks).
- Second trimester (13 - 27 weeks).
- Third trimester (28-40 weeks).
Now you can consider in more detail how the intrauterine development of the fetus occurs by week.
What happens during the embryonic period?
The most important thing from this period of development is the formation of the embryo. Over time, it begins to take on the shape of a person. The embryo is formed from the moment the egg is fertilized. This usually occurs in the fallopian tube.
From the moment of fertilization of the egg, the development of the fetus begins.
By weeks of pregnancy, a morula is formed in the first seven-day period. It is a multicellular organism, the prototype of the embryo. Morula attaches to the wall of the uterus, and the umbilical cord and outer membranes of the fetus are formed from its outer cells. From the cells that are located inside it, the organs and tissues of the unborn child are formed.
What does a woman feel?
In the first week of pregnancy, a woman has a slightly increased body temperature, it is close to 37˚С. There are no hormonal changes in the body yet, but the expectant mother instinctively feels the changes taking place. From this moment on, a woman should be very careful about her diet and lifestyle, exclude bad habits and follow the doctor's recommendations.
Each expectant mother will be very interested in how the fetus develops by weeks of pregnancy. This information will help a woman prevent many dangerous conditions. The third week of pregnancy is alarming because it is during this period that there is the greatest risk of fetal rejection. The woman's immune system tries to reject the embryo. However, in response, a special protein is released that suppresses this protective reaction, and the unborn child has a great chance of survival.
What happens to the embryo in the first weeks of pregnancy?
This period is also characterized by the formation of the placenta. An unborn child at three weeks is a ball with a diameter of 0.2 mm. But during this period, the lungs and respiratory organs, the cardiovascular system, the spinal cord and the brain are actively formed, and the baby's face and gender are also laid.
The woman begins to feel mood swings, drowsiness and fatigue, early toxicosis may occur.
Further development of the fetus (this is the fourth week of pregnancy) is very intensive. The unborn child forms three germ layers:
- endoderm - the basis for the development of internal organs;
- mesoderm - what the skeleton and bones will be formed from;
- ectoderm is a material for the formation of the nervous system.
The embryo already has a pulsating tube that turns into a heart. On an ultrasound, a heartbeat is heard during this period. The respiratory organs, the brain continue to form, the face is more clearly visible. The embryo has limbs, and by the end of the week they are already bent. The embryo is located in the placenta and maintains contact with the mother through this organ.
His heart is already beating!
During this period, many women only find out about their pregnancy, especially if it is the first one. Having found out for herself this fact, the expectant mother is interested in the main question: how does the development of the fetus take place?
By weeks of pregnancy, this is the fifth calendar period. At this time, the embryo still has little resemblance to a person, but his heart is already beating, gender is clearly defined, kidneys, liver, pancreas and thyroid glands are being formed.
Already at the 8th week, the future baby acquires the outlines of a person, his height is 3-4 cm. He has already formed arms and legs, his forehead is clearly visible, the outlines of his eyes, lips and nose are outlined. Internal organs are actively formed and developed. The stomach is already capable of producing juice, the heart is formed, the intestines are growing, the trachea and bronchi have appeared. The spine, brain and limbs are actively developing.
By the end of the eighth week of pregnancy, the embryonic period of development ends, but the first trimester is still ongoing. The unborn child has already acquired a human form, the placental-uterine circulation has been formed.
Fetal period
This stage begins from the 9th week of pregnancy and lasts until the very birth. The fetal period is divided into two parts:
- early (9 - 28 weeks);
- late (29 - 40 weeks).
In the early fetal stage, fetal development continues. This is the ninth week of pregnancy. At this time, the growth of the fetus is 40-50 mm. He begins to be active: bends his arms and legs, turns his head, brings his fingers to his mouth. But mom is not yet able to feel this, the fetus is still too small.
Outwardly, the future baby looks like a man with a big head. The eyes are still closed, and the skin is transparent. The genitals begin to form, and this process will continue for the 20th week. The cerebellum and pituitary gland develop. The heart has four chambers. The tail disappears, being replaced by the tailbone.
The embryo turns into a fetus
In the tenth week of pregnancy, the embryo is already called the fetus, and weighs 5 grams. In his photographs, isolated fingers, neck, elbows, knees, eyelids and upper lip are already visible.
The tongue has taste buds, the thickness of the umbilical cord increases.
The eleventh week of pregnancy is characterized by the further development of the fetus. He already has eyelashes and milk teeth. The rectum is formed. The spinal cord is already producing red blood cells. The intestines are ready to go.
Many mothers during this period are sent by a gynecologist for a planned ultrasound scan. Undergoing this procedure, women are interested in the main question: is the development of the fetus normal?
In the weeks of pregnancy, the twelfth period begins. During this period, the child has formed phalanges of the fingers and earlobes, he opens and closes his eyes. The intestines are already contracting, and the liver is able to secrete bile. The baby's circulatory system is functioning, leukocytes appear.
At the twelfth week, the first trimester of pregnancy ends and the second begins.
The kid is actively growing
During this period, all systems of the fetus are formed, they are developing and growing. At the thirteenth week, which marks the beginning of the second trimester, the baby reaches 80 mm in length and weighs about 20 g. At this time, the skeleton is intensively forming in the fetus, the pancreas begins to produce insulin.
The gynecologist will send the expectant mother to the first genetic study. After examining the results of the ultrasound, the doctor will be able to tell you how the intrauterine development of the fetus occurs by weeks of pregnancy, whether the indicators are normal.
At the 14th week, the child's face continues to form, facial expressions, eyebrows and hair on the head appear. On the body of the fetus, fluff and cheese-like grease are formed. The thyroid gland begins to work, its own hormonal background develops.
The excretory system is functioning, the child makes breathing movements.
In the antenatal clinic, you probably saw a stand showing the intrauterine development of the fetus by week.
A table with this kind of information will be useful to every woman.
At the fifteenth week of pregnancy, the child develops hearing, the intestines form the original feces, and the placenta thickens. The fruit weighs about 50 g and is 60 mm tall.
The expectant mother feels the first movements of the baby
The sixteenth week of pregnancy is marked by an increase in the volume of amniotic fluid. The child is actively moving, and the mother begins to feel it. The muscles on the face are developed and the child is characterized by facial expressions at this time. Bones and nails are almost completely formed, the skin is very thin and blood vessels are clearly visible through it.
During this period, the gynecologist directs the woman for a second genetic screening. For this, the expectant mother will have to undergo a second ultrasound scan. It clearly shows the intrauterine development of the fetus by week. Photos that can be taken at this stage are presented below.
We consider fetal movements
From the 28th week of pregnancy, the third trimester begins, and from the 29th - the late fetal period. At this time, the child is cramped in the womb, and his movements are not so active. Nevertheless, a woman should clearly track the tremors, their number should be at least 10 per hour. The brain is actively developing, and grooves appear on it. The teeth are covered with enamel, the eyes are capable of focusing. The baby's weight is about 1250 g, and his height is 37 cm.
At the 30 - 31st week of pregnancy, the baby already takes the final position in the uterus. The fetus is actively gaining weight by increasing muscle mass and subcutaneous fat. If a child is born during this period, he has every chance of survival.
Further intrauterine development of the child (this is the 32nd calendar period by weeks) is characterized by the improvement of the immune and nervous systems. The child has its own routine of waking and sleeping, it has its own temperament. The baby weighs 1800 g, and his height is 42 cm.
At the 33rd - 34th week of pregnancy, the baby actively trains the lungs, perceives the entire environment to the fullest. The skin of the fetus becomes smooth, the bones of the skull harden.
The baby is preparing for birth
At 36 - 37 weeks of gestation, the fetus is preparing for birth. His mother’s stomach is already cramped for him and it’s more and more difficult for him to move.
His body has enough fat reserves for thermoregulation after birth, the lungs are ready to breathe. The fluff on the body is already absent, but the hair on the head and nails grow back.
At 38 - 40 weeks, all mothers are expecting childbirth. This can happen at any time. The baby sinks and it becomes easier for mom to breathe. The woman carefully monitors the discharge of the mucous plug and the appearance of contractions.
And finally, it happened! Mom and baby are now together. The crumb is still very small, but full of strength for the knowledge of the new world. Now his status is newborn.
Table of intrauterine development of the fetus by weeks of pregnancy
This article provides a full description of how the intrauterine development of the child takes place by week. The table below will serve as a kind of conclusion to all of the above and will serve as a reminder for the expectant mother.
| Pregnancy period in weeks | Fruit length, cm | Fruit weight, g | Development of organs and systems |
| 4 | 0,1 | Fertilization of the egg, its implantation, embryo and organ rudiments. | |
| 5 | 0,15 - 0,2 | Bookmark of the liver, pancreas, upper respiratory organs, heart. | |
| 6 | 0,4 - 0,6 | The appearance of the rudiments of the limbs, listening to the heartbeat, the neural tube closes, parts of the larynx and middle ear are formed. | |
| 7 | 0,7 - 0,9 | The trachea, esophagus, small intestine, adrenal glands and sternum develop. The brain is actively forming. | |
| 8 | 0,9 - 1,2 | The embryo has a clearly distinguished body and head, equal in size. The rudiments of the nose, eyes, mouth and organs of the reproductive system are formed. | |
| 9 | 1,3 - 1,5 | 1 | The cerebellum develops, the fingers are formed on the limbs. |
| 10 - 11 | 2,7 - 3,5 | 4 | The joints, upper lip, auricles, external genital organs, rudiments of milk teeth develop. |
| 12 | 9 | 20 - 25 | The face is formed, the intestines contract, the liver produces bile, the child moves. |
| 13 | 10 | 28 | The limbs are fully formed. The pancreas produces insulin. |
| 14 - 15 | 12,5 | 50 - 90 | The excretory system is active, the child produces urine. |
| 16 | 16 | 120 | We distinguish the sex of the fetus. The skin is very thin, muscles are formed. The child does not move so chaotically, the mother feels the first tremors. |
| 20 | 25 | 280 - 300 | There is fluff on the baby's skin and a cheese-like lubricant. The intestines form the original feces. The child is able to hear. |
| 24 | 30 | 600 - 800 | The work of the kidneys is activated, the fetus is dynamically gaining weight. |
| 28 | 35 | 1200 | The muscles and reproductive system of the child are being formed. |
| 32 | 40 | 1500 - 1600 | There is an active development of the senses and the nervous system: the baby is able to see the light and feel the taste. |
| 36 | 45 | 2400 - 2500 | The child quickly gains weight, his activity decreases. |
| 40 | 50-52 | 3200 - 3500 | The baby is ready for birth. |
Of course, it is best to study this information when a pregnancy is just being planned. Then the woman has more chances to properly organize nutrition, regimen, intake of necessary vitamins and minerals. However, information about the intrauterine development of the baby will always be timely and interesting for the expectant mother, regardless of the length of her pregnancy.
We invite you not only to learn interesting facts, but also yourself, week after week, to observe how the baby is developing. Birth of life and pregnancy week by week with unique photographs taken by Swedish photographer Lennart Nilsson back in 1965. The photographer himself was born in 1922 and became the first who, with the help of special equipment and cameras, was able to penetrate into the female body and capture the entire process of the birth of a new life.
The first photographs of the embryo appeared in print in 1953, and this event inspired the photographer to create new works.
In order to show human development from the very beginning, he placed a micro-camera and a micro-light on the end of the cystoscope tube, which is used to examine the bladder, and took his unique photographs right from where people take their first step into the world. We will tell you about the most important moments of pregnancy, the formation of a new life.
"IMPORTANT" * The development of pregnancy in this article is by week of development of the embryo. Those. if you want obstetric week, add 2 weeks to the fetal period
Here is the sperm moving towards the egg.
The sperm in the folds of the mucous membrane of the fallopian tubes moves towards the egg.
Egg..
Will the meeting take place?
Fallopian tube walls.
Two sperm are in contact with the egg membrane. The enzymes contained in the sperm head dissolve the egg membrane, but only the genetic material of one sperm is involved in fertilization.
One of the 200 million father's sperm, breaking through the membrane of the egg, literally pours into it ...
Longitudinal section of a sperm cell. The genetic material is contained in the sperm head
Pregnancy by week - 1 week
The beginning of a new life begins with a change in the female body, ovulation occurs. It is this moment that is favorable for conception. After all, a woman can get pregnant only 3-4 days a month. Some women experience ovulation, some do not. Signs of ovulation can be an increase in vaginal mucus, an increase in basal temperature, as well as minor pain in the ovarian area. Also during ovulation, under the influence of hormones, a woman, as a rule, feels a desire for intimacy.
After a week, the embryo, sliding down the fallopian tube, moves into the uterus ...
Embryo attached to the lining of the uterus
Pregnancy by week - 2 weeks
The fertilized egg starts dividing. Of the 46 parental chromosomes, the child inherits 23, 2 of them -X and Y affect the sex of the unborn child. Whether you will be born a girl or a boy depends on the sperm that fertilized the egg.
During this week, the embryo travels through the fallopian tube and ends up in the uterine cavity. Towards the end of the week, it attaches to the wall of the uterus, growing into its mucous membrane. Sometimes the implantation can cause a little bleeding.
Embryo development. Gray color - future brain
Pregnancy by week - 3 weeks
24 days. A month-old embryo does not have a skeleton yet - there is only a heart, it begins to pulsate on the 18th day
Pregnancy by week - 4 weeks
4 weeks after fertilization
Pregnancy by week - 4 and a half weeks
Around this time, and most likely even later, a woman learns about her pregnancy, provided that her cycle is about 28 days. There is no menstruation. Possible signs of pregnancy appear, such as fatigue, drowsiness, nausea in the morning and in transport, increased salivation.
Pregnancy by week - 5 weeks
A five week old embryo, 9 mm long, already a face with openings for the mouth, nostrils and eyes. The central nervous system begins to develop, the spinal cord and brain are formed. These processes directly depend on the availability of the necessary substances in the mother's body. First of all, we are talking about folic acid - the most important element for the first trimester of pregnancy. Doctors advise taking 400 mcg of folic acid daily to prevent neural tube defects. By the way, by the end of the fifth week, the baby's heart will begin to beat. Only now, most likely, a young mother will begin to think about the possibility of pregnancy and take a test or see a doctor.
Pregnancy by week - 6 weeks
40 days. The outer cells of the embryo have grown together with the loose surface of the uterus and form the placenta, or baby's place. This spongy piece of flesh serves a person in the first nine months of his life and lungs, and stomach, and liver, and kidney ...
Pregnancy by week - 7 weeks
Unlike the second trimester, when your waist expands rapidly, in the first trimester, your breasts are mainly enlarged. This happens regardless of toxicosis. Blouses and sweaters become tight, the bra is difficult to fasten.
The fruit continues to grow and develop. The brain and limbs are being formed. The mass of the tiny body is already a whole gram, and the size is about the size of a small grape. The kid begins to master the habitat and move, but you still do not feel it.
Pregnancy by week - 8 weeks
The fast-growing embryo is well protected in the womb. With the help of an electron microscope, Nilsson was able to magnify the image hundreds of thousands of times.
Pregnancy by week - 9 weeks
From this week on, the baby is proudly awarded the title "fetus". The most common problem "the threat of early termination of pregnancy" has long been over. Everything is fine with your baby, the pregnancy is developing as it should, so the uterus does not try to get rid of the pregnancy.
On the ultrasound, of course, they will not tell you who you are waiting for, a boy or a girl. External sexual characteristics are just beginning to form.
Pregnancy by week - 10 weeks
The eyelids are already half open. They will be fully formed within a few days. The kid is becoming more and more like a little man. Now there is one of the most important periods in the development of the baby, the development of the nervous system and almost all organs is underway. The placenta does not yet fully protect the baby from adverse factors, therefore, during these weeks of pregnancy, alcohol intake or another damaging factor can cause significant harm both during pregnancy and on the development of the embryo as a whole.
Pregnancy by week - 11 weeks
Many pregnant women at this time note that their palms and feet have ceased to freeze. This is explained very simply: the amount of blood increases and its circulation improves, and hormones produced during pregnancy also affect the thermoregulation of the body. That is why from that moment on, the pregnant woman increasingly begins to feel stuffiness, weakness, frequent dizziness and changes in blood pressure.
Pregnancy by week - 12 weeks
This week marks the end of the first trimester. A lot of fun is happening with your little one this week. Erythrocytes are already present in his blood and white blood cells, leukocytes, which are responsible in the future for the protection of the body, begin to be produced. While they cannot protect the baby from infection. The guarantee of its safety during intrauterine life and the first months after birth is passive immunity - antibodies coming from the mother through the blood, and subsequently, through breast milk.
Pregnancy by week - 13 weeks
Well, that's all, the first trimester with all the problems, toxicosis is left behind. Ahead of you awaits a real golden time in which you can enjoy your pregnancy. The tummy is already taking on some shape, your pride for it is growing, but at the same time it is not hard to wear it, so you can run around a whole children's store with great enthusiasm and a huge amount of strength.
The baby's task in the second trimester is skeletal development and growth. To do this, he needs a large amount of calcium, so do not forget about taking special complexes for pregnant women. According to research, at this stage of pregnancy, the baby begins to feel sounds using special vibration receptors located on the skin. This means that now he hears and, most likely, distinguishes between the sound of your voice and the voice of the future dad. His own vocal cords are still forming.
At the thirteenth week, the baby's liver begins to produce bile, and the pancreas - insulin, villi form in the intestines, which play an important role in the digestion of food.
Pregnancy by week - 14 weeks
The baby has new needs .. He "learns" breathing movements - sighs and exhalations, preparing for life outside the uterus. These training movements are very important for the development of lung tissue - for that very long-awaited first cry that he will make as soon as he is born. The urethra and bladder are formed, the kidneys begin to work, excreting urine. It mixes with the amniotic fluid and is excreted through the placenta.
The whole body of the baby gradually begins to cover with fluff, the so-called lanugo, which performs a protective function and helps to regulate the temperature of the baby's body. The pattern on the fingertips - the prints - already have a unique pattern that will last for a lifetime.
M and F are more and more different from each other. In guys, the prostate gland is formed, in girls, the ovaries move to the pelvic region.
Pregnancy by week - 15 weeks
Neonatologists say that at about this time the fetus begins to realize what is happening around - it feels, hears and understands in its own way what is happening. He can express emotions through facial expressions and gestures. He feels the mood of his mother, their sleep and wakefulness are synchronized.
The circulatory system is being improved. The first foci of hematopoiesis arise in the walls of the yolk bladder. At 2-3 months of intrauterine development, the main organ of hematopoiesis is the liver, from the end of the 3rd - the bone marrow. From the 4th month, the spleen begins to take part in hematopoiesis.
Arteries and veins provide nutrition and supply to all organs and systems: brain, heart, lungs, stomach and intestines. At the fifteenth week of pregnancy, the baby's heart beats twice as fast as the mother's. It passes through itself up to 23 liters of blood per day. If necessary, you can determine his blood group and Rh factor. This may be important when the mother has Rh- and the father has Rh +.
Pregnancy by week 16 weeks
The child learns to coordinate his actions. He actively moves - rolls, somersaults and kicks. Until all these movements are felt, the amniotic fluid softens even the most active movements of the baby.
His face is already well formed. At the sixteenth week of pregnancy, the baby's eyes open for the first time.
The skin of the fetus is very thin, translucent. In the photographs taken with the help of ultrasound, it can be seen that the subcutaneous fat layer is still completely absent - the blood vessels are visible through the skin.
Legs get tired more and more. Due to an increase in body weight and a shift in the center of gravity, the load on them increases. A duck gait, characteristic of pregnant women, appears. We have to give up high heels and shoes with slippery soles.
The curious toddler is already using his hands to explore the surroundings.
The skeleton mainly consists of a flexible shaft and a network of blood vessels visible through thin skin.
Pregnancy by week 17 weeks
During pregnancy, you discover a lot of new things, not only in reality, but also in your sleep. Many expectant mothers have crazy, vivid dreams. According to experts, this is due to the overstrain that your brain is experiencing. In addition, you get up more often at night and, thanks to this, remember more dreams than you usually do. At the seventeenth week of pregnancy, dreams are often associated with an upcoming birth or baby and can seem so real that they are constantly spinning in your head. Often, mothers complain of nightmares - in such dreams, a reflection of anxiety, which they suppress while awake.
Research shows that babies also experience rapid eye movement during prenatal life - in adults, such movements are indicative of dreams. In this regard, some scientists argue that babies can dream related to their activity and during the day. Perhaps the child is dreaming of how he stretches his legs, hears your voice, or plays with the umbilical cord.
Pregnancy by week - 18 weeks
About 14 cm. The embryo can now perceive sounds from the outside world.
Pregnancy by week - 19 weeks
Stirring. A magical sensation. At the eighteenth week of pregnancy, you constantly receive confirmation that someone is inside.
The baby becomes large and strong enough so that his movements are noticeable to the expectant mother. At first there is a vibration, then it seems that butterflies are flying in the stomach, and then it becomes distinctly clear that the child is making itself felt. Within half an hour, a 5 month old fetus can make from 20 to 60 pushes. Their strength varies depending on the time of day, on the mood and activity of the mother herself. Emotional outbursts, stuffy rooms, overexcitement, chocolates and sweets - all this makes the baby move more actively.
If you don't feel any movement yet, that's okay. Keep listening to yourself and soon you will experience the joy of the "first stir."
Pregnancy by week 20 weeks
Mid pregnancy. Equator.
You have already adapted to the many delights of an interesting position and are increasingly thinking about future childbirth. Haven't chosen a parenting course yet? It's time to think about it. Attending classes and trainings in such schools is a good prevention of complications in childbirth and psychological problems after them. You will receive information about the physiology of pregnancy and childbirth, about the features of caring for newborns. You can discuss with specialists and other pregnant women issues that concern you in connection with bearing a child, relationships with relatives or raising a future heir or heiress.
Are you interested in percussion and intrauterine developmental psychology this week? At the school you will find like-minded people and specialists who are ready to advise you on these issues.
If possible, try to attend classes with your dad-to-be.
The length of your baby is already about 20 cm. Hair is already beginning to appear on the head.
Pregnancy by week - 24 weeks
If at this time you put your ear to your stomach, you can hear the baby's heartbeat. His rhythm is much more frequent than that of an adult - 120 - 160 beats per minute. After birth, his blood will circulate in a large and small circle. In the meantime, at this time, placental circulation is of decisive importance.
Blood enriched in the placenta with oxygen and nutrients enters the body through the umbilical cord vein. The umbilical vein comes to the liver through the umbilical ring, then to the inferior vena cava. In it, arterial blood is mixed with venous blood, which comes from the lower body and viscera of the fetus. Almost all of this blood flows through the foramen ovale (the flow of blood from the right atrium to the left one stops immediately after birth) in the wall of the right atrium into the left atrium. From the left ventricle, blood is released into the systemic circulation. The upper body of the fetus is supplied with arterial blood better than the lower half of the body. This explains the relatively small size of the pelvis and lower limbs of the newborn. A very small part of the blood flows to the lungs.
Pregnancy by week - 26 weeks
At the twenty-sixth week, the baby diligently explores the space around him. He still has a place for active movements. He pushes, feels the umbilical cord and the walls of the uterus surrounding it. According to the Pearson test, which is recommended to be carried out from 28 weeks, a child normally makes about 10 pushes per hour.
One of his favorite activities during this stage of pregnancy is thumb sucking. It strengthens the muscles of the cheeks and jaws and soothes it. The sucking reflex is one of the first unconditioned reflexes, the so-called oral segmental automatisms. It forms from the first trimester of pregnancy and lasts during the first years of life. The preference for the thumb of the right hand, or, conversely, the left one, may be a sign of the dominance of one or another hemisphere of the brain. It is already possible to guess who the baby will be - right-handed or left-handed.
Over the past month, the uterus has increased in size by 4 times. Now she rests on the hypochondrium, expanding the lower ribs. 
Pregnancy by week - 28 weeks
Lanugo (thin hair that covers the entire surface of the body, with the exception of lips, palms and soles) gradually disappears, but several "islands" may remain after childbirth - on the back, on the shoulders and even on the forehead. They will disappear in the very first weeks of extrauterine life.
The hair on the head becomes thicker. Some children already at birth can boast of thick long curls, while others have a head almost bald. Both are variants of the norm. The visible lack of hair does not mean that there is none at all.
This week the eyelids open and close. Eyelashes appeared. Toenails grow. During this period of pregnancy, the mass of the brain is constantly growing, the number and depth of convolutions increases. However, the functions of the cerebral cortex develop after birth. In the prenatal period, the most important functions of the fetus are regulated by the spinal cord and other parts of the central nervous system.
There are still eight to ten carefree weeks ahead, but the little man is already cramped in the womb, and he is preparing to leave it. Turns upside down - it's easier to get out this way.
Pregnancy by week - 36 weeks
This week, the body of the expectant mother can begin active preparations for the birth of a baby. Harbingers appear - changes in the body that occur shortly before the birth itself.
- The nesting instinct is an internal need to prepare space for the imminent appearance of a child;
- Decrease in the height of the fundus of the uterus - or "ptosis" of the abdomen;
- Discharge of the mucous plug - discharge of colorless or pinkish mucus from the cervix;
- Increased urination and bowel movements. The sagging uterus puts more pressure on the bladder and intestines. Prostaglandins released during early contractions can periodically signal a bowel movement;
- Reducing the number of perturbations. The child seems to calm down and gain strength before the upcoming birth;
- The Braxton Higgs Swatches. Irregular training contractions;
- Slight decrease in body weight;
- Softening and shortening of the cervix. The opening of the external pharynx is possible by 1-2 cm;
Your baby is approximately 47 cm long this week and weighs approximately 2600 grams.
After 4 weeks, the child will see a white light. At this time, the fetus is almost full-term.
Future mothers are sensitive to the development of the baby, who is worn under the heart and want to learn as much as possible about the processes taking place with them. during pregnancy , study with interest the stages of intrauterine growth of the fetus, carefully examine the pictures that show in detail fetal development by week.
Gynecologists start counting the pregnancy from the first day of the last menstrual period. Basic unit of time for pregnancy- a week.
The first weeks for the unborn child - very important, at this moment the health of the body and its vitality are formed.
It's good if pregnancy will be planned , then the woman will begin to lead a correct lifestyle, will save the baby from many health problems. Below you will find detailed information on the formation embryo in the womb, you will be able to consider the development of the fetus by week - Pictures with all stages of intrauterine growth and development, as well as a description of the processes taking place at one stage or another of pregnancy.
Before referring to the photo with the stages of fetal development by week, we will briefly familiarize ourselves with the main periods of the formation of the organs of a little man during pregnancy. At 5-6 weeks, an embryo 6 millimeters in size (like a pear seed) lives in a bubble with a liquid. The nervous system is formed, the spine and the brain appear. Two pairs of dimples for the eyes and ears are visible on the head. Digestive tract arises already at this stage of fetal development.
It takes only 2 weeks and the main internal organs of the fetus are already formed. At the eighth week of fetal development, the face takes on the necessary shapes, nostrils, the tip of a small nose, mouth, tongue are visible. Begins to function inner ear ... The fingers of the developing baby are also looming.
12 weeks intrauterine fetal development- the age of a ten-centimeter embryo, in which the outlines of the human body are visible. Various systems and organs in the twelfth week of fetal development have already formed, and are developing safely. Upgraded ultrasound equipment allows you to find out the gender of the baby and see the features of the face at this stage of pregnancy.
The beginning of the second trimester of pregnancy is the period of fetal development, when all the baby's milk teeth are formed. The gastrointestinal tract also develops at 13 weeks, villi appear in the intestines that in the future they will accelerate the process of digestion of products.
Up to 21 weeks of fetal development, the size of the baby allows him to move in the womb in any direction. Fruit length - 26 centimeters, weight - 0.4 kilograms.
A small body is able to control its temperature from 29 weeks , the period of preparation for the birth of a baby and independent life begins.
At 31 weeks of development, the body is fully formed, it remains only to gain weight. The child is already able to feel, his condition can change depending on the mood of the mother. Hearing is developed enough to recognize voices. Sight and smell also function.
The baby is ready for birth at 37 weeks. Now childbirth cannot be called premature. Of course, ideally you need to wait a bit. But the child can already assimilate and digest mom's milk , an epithelium with villi appears on the mucous membrane of the stomach and intestines, through which nutrients enter the bloodstream from food ... Peristalsis is working, the first feces are formed - meconium.
Now let's take a closer look at fetal development by weeks of pregnancy, and also refer to the photo of the formation of the embryo in the womb with brief explanations. As you can see, already in the first weeks after conception, very important processes of formation of the structure of the fetus take place and the expectant mother needs to seriously change her lifestyle from the first days and adjust the diet. ... Visit your gynecologist regularly and go through all the necessary medical examinations.
Even pictures with the stages of intrauterine development of the fetus by week clearly demonstrate the importance of the ongoing processes of formation of the baby's internal organs. We hope that the information we have posted will help you better understand the processes, occurring in your body during pregnancy and we want to wish you that the baby was born healthy and beautiful !
NEXT ARTICLE:
Pregnancy is a unique physiological process that allows parental cells to connect and form a new organism. The development of the fetus by weeks of pregnancy is an interesting event that many mothers love to remember. Every day, weeks of pregnancy entail tremendous changes in the fetus and an unforgettable experience for the mother. From this article, expectant mothers will learn a lot of useful and interesting information: when the baby begins to lead an active lifestyle, hear her voice. It is no less interesting to know about changes in fetal weight when the long-awaited ultrasound scan will take place in order to recognize the gender of the baby.
Intrauterine development of the fetus is divided into two stages:
- the embryonic period lasts eight weeks after the fertilization of the egg. At this time, the embryo resides inside the woman;
- the fetal period is counted from the ninth week until the moment of delivery. At this stage of development, a woman already bears a fetus under her heart.
There is a real due date, which is counted from the moment of fertilization, and obstetric, which takes into account the first day of the last menstruation. Their difference is 14 days.
An exciting journey through the weeks of pregnancy
The first 
An important event took place - fertilization. The zygote begins to form. Every day and even hour, the number of embryonic cells increases by cleavage and on the third day it consists of 8 cells, and on the fourth day of 20. They form a small lump that moves to the uterus to begin full development and growth.
The second
The fertilized egg is attached to the wall of the uterus. This process is called implantation, it is a critical moment for the development of the embryo. The mother's body is rebuilding, producing hormones to protect the embryo. There may be a pink or brown discharge.
In the same week, the ovum cells are grouped:
- the inner layer is responsible for the formation of the lungs, liver, digestive organs;
- the middle layer forms the bone and circulatory system;
- the outer layer develops the nervous system, skin and hair, etc.
The third 
This week precedes the development of the spinal cord and brain, the spine is formed.
On days 20-21, it is safe to say that the conception was successful. The embryo consists of many cells, and the tiny heart begins to beat - the fetus is ready for intrauterine changes. Dark discharge that appears indicates a threat of miscarriage.
Fourth 
The embryo reaches the size of a poppy seed - 1.5 mm. During this period, the laying of the foundations for the internal organs begins, the heartbeat increases, the neural tube enters a new phase for the development of the brain, limbs are born. Extraembryonic organs are formed: the yolk sac, which provides nutrition to the embryo, the chorion is the future placenta.
The fifth 
At this stage, the embryo is no larger than a sesame seed. The placenta is responsible for its nutrition, which connects to it through the umbilical cord.
- An ultrasound specialist can already determine how many children a woman will have.
- The heart begins to divide into two chambers, changes in the reproductive system and the brain appear.
- On ultrasound, you can see inaccurate facial features, there are slits for the mouth, recesses for the eyes and nose.
Sixth 
The heart, lungs and bronchial tree are improved. The facial features continue to appear, the phalanges of the fingers appear. The uterus enlarges and reaches the size of a plum.
Seventh 
This is the time when future parents begin to replenish the family album with the first photograph of the intrauterine development of the child. The heart is already four-chambered and there are 100-190 beats per minute - this is normal. The tail at the base of the spine disappears, the placenta fully supports nutrition and intrauterine processes. There is a rapid development of the brain, the middle layer of the adrenal glands, and lymph nodes.
Eighth 
The laying of vital organs and tissues is nearing completion. The size of the embryo is only 4 mm, and it already looks like a well-formed organism with protruding fingers, joints, auricles, slits for the eyes and mouth. The nervous system is developed, the rudiments of the first teeth are formed.
The embryo begins to move, but for the expectant mother it is imperceptible.
Ninth 
The embryo enters the fetal stage. He gained weight up to 2 grams and has a size of 22-30 mm. The cerebellum, the middle layer of the adrenal glands, lymph nodes, mammary glands, and genitals continue to develop for weeks.
There are tremendous changes: the tiny creature moves its head, swims in the womb, reacts to the movements of the mother and hears sounds, grabs the umbilical cord, shoves a finger in its mouth. The urinary system begins to work, the sense of smell develops, which will help the newborn to find the breast.
Tenth 
Weight - 5 g, size 30-40 mm. These days are full of events. The diaphragm is fully formed, the brain is actively developing, ossification of the skull, skeleton occurs, the membranes between the fingers disappear. The liver begins to secrete bile, the intestines contract.
Eleventh 
The baby's weight is 8 grams, body length is 5 cm. The formation of blood vessels is coming to an end, the heart is working correctly, the placenta becomes denser and creates excellent protection for the nascent organism. The head is still large, but every day it transforms, the liver occupies 10% of the entire body.
Twelfth 
The first trimester is at the final stage. The tiny creature has grown significantly and weighs about 9 cm. The rudiments of milk teeth are formed. The digestive system, bones and muscles continue to transform. The little man is able to smile, sleeps little and has his own taste preferences. The immune system is getting stronger. The tummy of the expectant mother is rounded.
Thirteenth 
The baby's weight reaches 15-25 grams, height is 10 cm, there are 150 heart beats per minute, 30 liters of blood are pumped. The cerebral cortex becomes more complex, sweat glands are suitable for work. The fruit swallows nutrients, spits out liquid, exercising the lungs. The mouth gap is periodically opened.
Bone tissue hardens, the skin becomes multi-layered, but it is still transparent, the eyelids are covered. The placenta independently supplies oxygen, removes waste.
Fourteenth 
The intrauterine baby is becoming more and more active. Her weight is 35-45 g, height 11 cm. The skeleton is being formed, the diaphragm is preparing for the first cry, the child has a Rh factor and a blood type. The thyroid gland develops, the body prepares for the digestion of proteins and the beginning of fatty deposits. In the intestines, the first feces are produced, consisting of bile.
The eyes have taken their place, the facial features take the correct shape. The uterus becomes heavier, its weight is 250 grams.
Fifteenth 
The size of the fruit resembles an orange, it weighs 70 g, and is 13 cm tall. Most of the body is covered with hair, which retains heat. When the child has accumulated a sufficient amount of adipose tissue, heat exchange will turn on in the process, then the extra hairs will disappear.
The nails are already formed and lines are emerging at the fingertips. The child grimaces, the sucking reflex is well developed. The genitals continue to form.
Sixteenth 
The baby's height is 14 cm. All the constituent components appeared in the blood. The neck is flattened, the liver takes over the digestive function. There is a laying of permanent teeth, which are replaced by milk teeth. The skin is still transparent and the blood vessels are visible. The baby moves all parts of the body, which has a positive effect on brain development.
Seventeenth 
Here the growth of the little man is already more than 15 cm, his weight exceeds the mass of the placenta. The neck has become stronger, now the head turns 180 degrees. There is an active accumulation of fat on the body, the bronchi are almost fully developed. The child begins to move with his eyes. He is already able to protect himself from infections that may come from his mother.
Emotional and mental development is underway, therefore, it is strictly forbidden for a pregnant woman to experience stress, worry, and be nervous.
Eighteenth 
The child's inner ear forms, the retina of the eye gains sensitivity, the blinking reflex appears, but the eyelids are still lowered, the rudiments of molars are being laid. The baby reacts better to voices, so there is no need to be ashamed of talking to the tummy.
Nineteenth 
The fruit can be compared to a small squash. The length reaches 16-17 cm, and the weight is 300 g. The skin is protected from amniotic fluid by the original lubricant. There is a leap in development, the movements become clear and correct. The head rotates and holds its position for a long time. The kid responds perfectly to the factors of the outside world, and responds to them with strong blows.
Twentieth 
A tiny creature already reaches 20 cm. It begins to show its discontent with incorrect postures of the mother or loud sounds, can distinguish the time of day.
Intervertebral discs appear, a layer of the epidermis is formed, movements become more complicated, and mom feels them perfectly.
Twenty first 
The child gains weight up to 360 grams, reaching a length of 26.5 cm. The digestive system is active, the fetus swallows amniotic fluid, and the spleen begins to function. Bones and muscles are strengthened. Taste receptors are fully formed on the tongue. Boys develop testicles and girls develop a vagina.
Twenty second 
The crumb is gaining more and more weight. Now her weight is 500 grams, and her height is 28 cm. The lungs are fully developed, the brain reaches a weight of 100 grams.
Premature birth at 22 weeks can be successful because modern equipment is available for nursing such babies.
Twenty third 
The weight of the child increases, and the uterus grows, which creates discomfort for the mother. There is a wrinkled appearance of the skin, adipose tissue grows. The arms and legs lengthen, nails and hair grow back.
The boys' genitals are lowered to the right place. Believe it or not, such a small creature is capable of dreaming. The number of perturbations reaches 10 times a day.
Twenty fourth 
The growth of a small person is 30 cm, he can already hiccup due to improper swallowing of amniotic fluid or hypoxia, you need to notify the gynecologist about this.
The child often changes position. He already has little space in the placenta and he begins to push and push more persistently.
Twenty-fifth 
The future family member has a body length of 33 cm and weighs 700 grams. The skin acquires density and color. The lungs train, prepare for the first breath, the brain begins to work with the adrenal glands. Muscles appear.
Weakness, dizziness in mom means signs of anemia, you need to see a doctor.
Twenty sixth 
Weight reaches 750 grams, height 35-36 cm. The small creature takes on individual features. Jerks become painful for the mother, and loved ones can track the baby's movements.
The brain produces the necessary hormones, hearing becomes thinner. The lungs are filled with a special substance that will help them not to stick together at the moment of the first breath and cry.
Twenty seventh 
The mass of the crumbs increases to one kilogram. The endocrine system begins to produce new functions, the amount of subcutaneous fat returns to normal. The substance that promotes the full opening of the lungs is fully developed.
Twenty-eighth 
The baby already weighs more than one kilogram and is 38 cm tall. His skin becomes smooth because adipose tissue increases.
The pupillary membrane disappears, allowing the eyes to open. The baby becomes cramped, but this does not affect ontogenesis.
Twenty ninth 
The creature inside the mother weighs 1,300 kg and is 40 cm tall. It is already preparing for birth. The nasal passages are cleared of mucus, the amount of vernix and the cannon on the body is reduced. The child receives a sufficient amount of antibodies from the parent's blood.
Thirtieth 
This is the period when the future family member is growing rapidly, thermoregulation is developed, the liver accumulates iron, the eyes open completely. The child assumes a position for an auspicious birth.
Thirty-first 
Each week is distinguished by an increase in fetal weight by 300-400 grams. At the 31st week of pregnancy, the baby's weight is 1.5 kg, the length is 41 cm.The pancreas reproduces the production of insulin, the liver is taken to cleanse the blood of toxins, the brain is 1/4 of an adult's organ.
In boys, the testicles "get" to the scrotum, in girls, a clitoris appears.
Thirty second 
The baby is growing, but his skull is still soft, the internal organs are fully functioning. The body produces immunoglobulins that replicate the infant's defense against bacteria and germs in the first year of life.
Thirty third 
The baby lies in the embryo position, because the space in the womb becomes less and less. He takes a lot of calcium and iron from the mother's body.
Thirty fourth 
The kid is preparing to meet his parents. Its weight exceeds 2 kg, its height is 47 cm. Active training of the gastrointestinal tract takes place. The woman begins to feel false signs of labor pains.
Thirty-fifth 
The fruit weighs about 3 kg, the body length reaches 48 cm. The shoulders are rounded, fat appears. The child is at the birth canal and takes the appropriate position.
Thirty sixth 
The head center coordinates the work of thermoregulation, cardiovascular and respiratory systems. After the birth of the child, they will immediately begin their work. The pregnant woman is worried about shortness of breath.
Thirty seventh 
The baby's weight is 2 950 kg, length is 48-49 cm. Breathing, movements, heart activity are improved.
Thirty-eighth
The new person has not yet been born, but weighs more than 3 kg, and his height is already 50 cm. All organs are fully developed and function well.
Thirty ninth 
Weight - 3.5 kg, height - 51 cm. The stomach is filled with enzymes that will help the child process food. A small person perfectly feels sounds and light, the sucking reflex is developed.
Fortieth
The family is waiting for replenishment, and it will happen soon. The weight of "little happiness" is 3, 5 - 4 kg, height - 51-54 cm.
The abdomen sinks significantly. The mucous plug, amniotic fluid recede, and contractions begin. After a certain time, the long-awaited baby will be born. His condition is assessed by specialists and monitors his health for several days.
So the long expedition on the weekly development of the fetus has come to an end. In order for the pregnancy to be easy and successful, you need to listen to the doctor's recommendations and monitor your health. There is only joy and happiness ahead.
Film about the development of the fetus in the womb