for which a woman is simply at three stages of understanding and the fetus, each trimester has its own characteristics. For example, in the first trimester there is a rapid the formation and development of the organs of the child, then miscarriages most often occur. In the third trimester it is necessary to prepare for the manifestation of possible problems associated with pregnancy - hypertension, toxicosis.

There are 3 calendar months in one trimester, the first trimester is 1-13 weeks, the second trimester is 14-27 weeks, the third is 28-42 weeks .

1st trimester

2nd trimester

3rd trimester

or all three ways:

1. Add the average duration of pregnancy, which is 280 days, to the first day of the last menstruation.
2. Add 9calendar months to the first day of the last menstruation and subtract 7 days from the resulting date.
3. Subtract three months from the first day of your last period and add 7 days to the result.

Absolutely the same way they calculate the term in the antenatal clinic, the same methods are used in round paper obstetric calendars.

Other ways to determine and confirm the due date

There are no other scientific methods for determining the gestational age and due date. But there are methods using which can be confirmed or corrected. Again, almost all of them are based on the obstetric method, statistical data and data from an objective examination of the expectant mother.

The main objective sign of pregnancy is an increase in the size of the uterus, which in the first months is determined by vaginal examination, and after the third - by the height of the fundus of the uterus. By the end 1st month (28 days) the uterus corresponds to the size of a chicken egg, 2nd month (56 days) - an average fist women, then each month has its own size. There is no need to talk about the accuracy of this method.

Additional information about the due date and due date can be obtained by measuring the length of the fetus. measurements produce a tazomer in the position of a woman lying on her back. One button of the tazomer is placed on the lower pole head, the second - at the bottom of the uterus. Calculations are made using a special formula, but the result is also approximate due to different assumptions, for example, the thickness of the abdominal walls can be taken in both 3 and 5 cm.

According to the level of hCG

At the earliest stages (from the 4th to the 8th week), pregnancy is confirmed by the level of hCG. By date of conception or, if it is unknown, then the obstetric period is determined from the first day of the last menstruation, and from it the hCG rate is determined. If the pregnancy is proceeding normally, then the hormone levels will correspond, or rather be within the range of valid values. The accuracy of this method is very low, as hormone levels are indicated in a wide range and the main thing for which this method is used is to determine the normal development fetus. The hCG level may not fall within acceptable limits, but if it doubles in two days, the fetus is considered to be developing normally. As you can see, this method is not always possible to use.

Ultrasonography

Ultrasound examination can also confirm pregnancy, this method is used to detect fetal egg and registration of heartbeats. Ultrasonography is currently the only method allowing with the greatest degree of accuracy to establish the gestational age and follow the development of the fetus, starting from the very first weeks of its intrauterine development.

The date of the last menstruation is entered into the ultrasound machine and, upon further scanning, the doctor determines how embryonic development corresponds to the obstetric term. Statistical tables of sizes are set in these devices fruit for each week and day.

In early pregnancy, when embryos develop at about the same rate, it is easier to compare their sizes are with average statistical norms and it is possible to more accurately determine the age. In this case, the doctor evaluates parameters of the baby, compares with the tables, gets the gestational age and, after adding two weeks, calculates obstetric period. If a woman did not remember the start date of the last menstruation, then the only way to determine the date pregnancy.

Later, when the fetus begins to develop according to its individual genetic program laid down by the parents (large or petite build, large or small height), it becomes more difficult to accurately determine the week.

By movements

In the middle of pregnancy, usually at 20 weeks in nulliparous women and at 18 weeks in multiparous women first fetal movement. Before the advent of ultrasound, this method was used without alternative to confirm the term pregnancy, there was no other way. Now this is an auxiliary method, it cannot be considered exact, since not everyone is able to recognize the first stirring. Currently no longer used for its intended purpose.

How accurate is the calculator?

The same as the calculator, the method of calculating the gestational age is used by an obstetrician-gynecologist in the women's consultations, in a hospital for conservation, in a maternity hospital, in medical equipment - ultrasound machines and laboratory equipment. That is, the calculator is as accurate as medical equipment and an obstetrician. If the obstetrician, due to an irregular cycle, early or late ovulation can make a small error, then this will happen with the calculator, because the calculation method is used one. In most cases, this method, and therefore the calculator, is very accurate.

It is important to remember that the expected date of delivery (ED) is not an exact, but an approximate calculated date, the term itself includes the word "alleged". Only one woman out of twenty gives birth exactly on the calculated day. The rest are giving birth. one to two weeks earlier or later than expected.

It is considered absolutely normal that labor can begin on any day from 38 to 42 weeks and there is no way to know for sure calculate this date. It all depends on nature, mother and child.

Weekly Pregnancy Calendar | Fetal development, trimesters

• Fetal development by week: what happens
• 1-2 weeks
• 3-4 weeks
• 5-6 weeks
• 7-8 weeks
• 9-10 weeks
• 11-12 weeks
• 13-14 weeks
• 15-16 weeks
• 17-18 weeks
• 19-20 weeks
• 21-22 weeks
• 23-24 weeks
• 25-26 weeks
• 27-28 weeks
• 29-30 weeks
• 31-32 weeks
• 33-34 weeks
• 35-36 weeks
• 37-38 weeks
• 39-40 weeks
• What problems might a future mother face
• Advice for pregnant women

Pregnancy is one of the most beautiful and exciting periods in a woman's life, when the expectant mother begins to change her usual way of life, feels responsible not only for herself, but also for her unborn baby. To bear and give birth to a healthy child, it is useful to know what happens in the body at all stages of pregnancy, how the fetus develops, what sensations and changes to expect. A weekly pregnancy calendar will help with this. This is a kind of guide for the expectant mother, who will accompany her for 40 weeks. It will contain interesting answers to questions, which will allow you to properly prepare for the upcoming birth and meeting with the baby.

Fetal development by week: what happens

A normal pregnancy lasts from 37 to 41 weeks. From the moment of conception to the birth of a child, a number of physiological changes occur in a woman's body, which can affect her well-being, appearance, and lifestyle. Many are accustomed to considering pregnancy in trimesters, but if the expectant mother wants to know everything about the development of the unborn child, here you will need a weekly pregnancy calendar.

The terms of gestation are divided into obstetric - counted from the first day of the last menstruation and embryonic - more than the true one by 2 weeks. Doctors, with the correct calculation and date of the last menstruation, can determine the expected date of birth.

Keeping and knowing the pregnancy calendar is not only useful, but also convenient. In it, the expectant mother will find answers to such questions:

• what happens in the body during each week of pregnancy;
• how the fetus develops and forms;
• when you need to undergo scheduled examinations;
• what sensations to expect, what to prepare for;
• when the belly begins to grow;
• when to wait for the first fetal movements;
• how to prepare for childbirth;
• what are the signs that you need to go to the hospital.

Information from the manual will allow you to eliminate unnecessary worries, consult a doctor if necessary, carry and give birth to a healthy baby.

Weeks 1–2

Pregnancy starts from the moment of fertilization. This is a complex process in which the fusion of the egg and sperm takes place. This leads to the formation of a zygote. If it contains two X chromosomes, it is a girl; if it contains an X chromosome and a Y chromosome, it is a boy. There is no way to influence the gender of the child. After fertilization of the egg, a multicellular embryo is formed - the blastocyst.

Throughout the first week after conception, the villi of the fallopian tube move the blastocyst to the uterus, by the second week the embryo sinks into the endometrium, attaches to the wall.

If the peristalsis of the fallopian tube is slow, inflammatory processes are present, or the woman suffers from other gynecological diseases, the embryo can attach to the fallopian tube, which will lead to an ectopic pregnancy, which cannot be saved.

Normal embryo implantation occurs within 7-8 days after conception. During this period, the hormone chorionic gonadotropin is produced, which gives the woman the first signals of a possible pregnancy. To determine its presence in the body, a test or analysis for hCG will help. In some cases, during the implantation of the egg, a woman may have small spotting, which she takes for menstruation, so if there is a suspicion of a frowning conception, it is better to buy a test.

3–4 weeks

At this stage, the woman's body begins to undergo the first changes that affect her well-being. The first signs of pregnancy appear:

• absence of menstruation;
• frequent mood swings;
• frequent urination;
• nausea, urge to vomit;
• restructuring of taste preferences;
• basal temperature above 37°C.

All these symptoms indicate the initial development of toxicosis, which appears against the background of hormonal changes in the body.

In the first trimester of pregnancy, it is important for a woman to register, undergo the necessary examinations, and follow all medical recommendations.

Changes also occur in the development of the fetus, which outwardly resembles a small shell, 4 mm in size. Starting from the 21st day, the formation of the brain and spinal cord takes place, and by the end of the first month, the umbilical cord appears, which holds the connection of the embryo with the future placenta.

During this period, other rudiments of organs begin to form: eye sockets, arms and legs, liver, kidneys, gastrointestinal tract. The neural tube is laid - the future brain, the cardiovascular system. It is during this period that folic acid should be present in the woman's body in sufficient quantities, since its deficiency can lead to neural tube defects, intrauterine pathologies. With the choice of vitamins for pregnant women, a gynecologist who leads the expectant mother will help.

5–6 weeks

During this period, there is no doubt that pregnancy has occurred. A woman should undergo the necessary tests:

• general clinical urine and blood tests to determine the blood type and Rh factor;
• coagulogram;
• TORCH analysis - detects herpes viruses, toxoplasmosis.
• Ultrasound of the pelvic organs.

If the woman has a history of chronic diseases, the doctor may prescribe additional tests.

At 5 weeks there is a high risk of abortion, so a woman should be very careful about her health. Eliminate heavy physical labor, stress, it is forbidden to lift weights. A possible miscarriage is evidenced by symptoms such as pain in the lower abdomen and lower back, a feeling of pressure in the rectal area, and spotting vaginal discharge. Such symptoms should be a reason for immediate medical attention.

In the normal course of pregnancy, a woman is worried about toxicosis: nausea, heartburn, urge to vomit. A cervical plug is formed, which isolates the uterus from the external environment. Breasts increase in size, frequent urination worries.

The fetus increases in size. An umbilical cord appears, through which he receives all the nutrients from his mother. Visually, the embryo looks like a tadpole. By week 6, the face begins to form: eyes, nose, upper and lower limbs. The cartilaginous tissue is already formed, the skeletal system begins to develop, and the retina is formed in the eyes.

The size of the embryo is up to 20 mm. It begins to grow rapidly, vital organs and systems are formed, so it is important for a woman to take vitamins for pregnant women, to exclude factors that can harm the unborn child.

7–8 weeks

Starting from the 7th week, the formation of the placenta ends, which passes only the necessary substances for the fetus, protects it from potentially dangerous compounds that are present in the mother's blood. To provide the unborn child with nutrients, the mother's body begins to work in an enhanced mode, which puts a strain on the heart. Toxicosis worries, the expectant mother gets tired quickly, so it is recommended to rest more.

The fetus still looks like a tadpole, but it loses its “tail”, increases to 30 mm. Fingers and toes appear, and eyelids appear in front of the eyes. The heart already has 4 chambers, the genitourinary and excretory systems are being formed, the bile ducts are appearing. Large blood vessels, endocrine glands and the brain begin to develop. The embryo begins to move. By the 8th week, under the influence of the Y chromosome, the male gonads (testicles) are formed in the fetus, testosterone begins to be produced, which in the future will make it possible to determine the sex characteristics of the baby.

9-10 weeks

In a woman's body, metabolic processes work more intensively, so the symptoms of toxicosis may increase. The change in metabolism allows you to provide the baby's body with "building materials" - amino acids, energy. Of the symptoms that were not there before, there is heaviness and fatigue in the legs. It is important to adhere to proper nutrition, do not skip meals. If the body does not have enough essential minerals, this can lead to growth retardation in the fetus or the development of anemia in the expectant mother.

During this period, the embryo has already formed all the organs, some of which are already working, and the other will start working after birth. The fetus is actively growing, its weight can reach 10 g. Its brain is divided into hemispheres, the Rh factor and blood type are formed. By the 10th week of pregnancy, the formation of the oral cavity, rectum ends, the cerebellum develops.

11–12 weeks

The first trimester is over, the future mother's condition improves, toxicosis no longer worries. The fetus touches the walls of the uterus, moves in the amniotic fluid. A woman can detect skin pigmentation, but this condition will pass and not everyone appears. A slight roundness of the abdomen may appear. A woman is recommended moderate physical activity, proper and healthy nutrition.

The size of the fetus is about 6 cm. Its skin is covered with small villi, it begins to actively move its limbs, and white blood cells are formed.

The body of the expectant mother slowly adapts to new conditions, the general condition normalizes, strength and confidence appear. A second scheduled ultrasound is scheduled.

13-14 weeks

Due to the growth of the fetus, the load on the heart increases, blood flow changes. In such cases, the doctor may prescribe iron supplements. The unborn child puts pressure on the intestines, constipation may disturb, a dark stripe appears on the abdomen, the chest enlarges, and a small amount of colostrum can be observed. In the abdomen, slight flutters are sometimes felt.

At this stage it is worth thinking about special clothes for pregnant women. The fetus has completed the formation of the main organs and systems. On ultrasound, he already looks like a little man. The final stage of face formation takes place, eyebrows appear. The length of the fetus is from 7 to 10 cm.

15–16 weeks

In the body of the future mother, the volume of blood increases, the need for iron increases. There may be increased weakness, dizziness. For many, due to sprains, discomfort appears in the abdomen, the nipples darken, there is a pronounced line on the abdomen. After childbirth, these symptoms will disappear.

The fetus continues to grow actively, its proportions become harmonious. The intestines produce the first portions of stool, but it does not consist of digested food, but of amniotic fluid. The rudiments of nails appear on the fingers. The formation of the placenta ends, which makes it and the fetus one. According to the composition of the amniotic fluid, the doctor can determine the condition of the child.

17–18 weeks

The weight of the expectant mother increases, her legs often swell, spider veins appear. The doctor recommends resting more, walking less, wearing compression stockings or stockings. It is important to avoid high heels. Due to increased load and weight gain, shortness of breath, increased sweating may occur. The abdomen acquires roundness, becomes noticeable.

The development of adipose tissue occurs in the fetus, the first rudiments of teeth appear - milk and molars. The skin is covered with a special lubricant that protects the baby from contact with the amniotic fluid. The child is actively growing and developing, begins to recognize sounds.

19-20 weeks

A growing fetus often causes digestive problems due to pressure on the diaphragm, heartburn, nausea, and constipation in a woman. The doctor often advises using a special support pillow during rest and after meals.

At this stage, there is a risk of developing preeclampsia, which is dangerous for both the fetus and the expectant mother. Its symptoms include increased blood pressure, swelling throughout the body, severe nausea, and protein is found in the urine. Treatment is carried out in a hospital under medical supervision.

The endocrine glands are actively working in the fetus, the formation of blood cells ends, but the nervous system continues to develop. The baby reaches a weight of 300 g, knows how to sleep and stay awake. The expectant mother clearly feels his movements, which are sometimes so strong that they cause discomfort. The belly is quite prominent.

Screening ultrasound is recommended at this stage of pregnancy.

21–22 weeks

A pregnant woman gets tired quickly, often complains of pain in her legs and back. These symptoms appear due to the active growth of the fetus.

The fetus continues to grow, its weight reaches 450 g, its height is about 20 cm. Its lungs and respiratory system are actively developing, but they will work only after birth. There is a rapid heartbeat that can be easily heard through a stethoscope. Joints and bones develop, therefore, to strengthen them, the doctor may advise the expectant mother to take calcium supplements.

23-24 weeks

Increased stress on the pelvic muscles, which can cause frequent urination, up to urinary incontinence. The first stretch marks may appear on the skin, so the doctor will advise you to use a special cream. Occasionally, primary non-birth contractions are disturbing, which should not cause alarm and are the norm.

The fetus develops and intensifies swallowing and grasping reflexes, he can squeeze and unclench his hands, imitate sucking movements. There is an increase in muscle and subcutaneous tissue. All internal organs and systems are almost completely formed. Only the lungs are immature, but by the beginning of the 24th week, the lung cells begin to produce a surfactant that lubricates the alveoli and prevents them from sticking together during inhalation and exhalation. But it is too small, so a child born during this period cannot breathe on its own. With deep prematurity, the baby will need breathing equipment, incubators, and artificial surfactant. Such children are nursed in perinatal centers. Their weight is 600–800 g, their height is about 25–30 cm.

25–26 weeks

A pregnant woman often complains of swelling of her legs, so she is advised to reduce the load, avoid wearing tight clothing, reduce fluid intake. The fruit puts pressure on the intestines, so you should eat small portions, but often, avoid foods that irritate the mucous membrane or increase gas formation. At week 25, a scheduled visit to the doctor, a blood test is recommended.

The child quickly gains weight, subcutaneous tissue gives the skin elasticity, it is not translucent. Body weight is about 0.8–1 kg. The sense organs are sharpened, the production of surfactant is enhanced. The brain is improved, which communicates with the adrenal cortex and stimulates the production of corticoids. The pituitary gland, which begins to produce hormones, also acquires maturity.

27–28 weeks

The baby is noticeably enlarged, which makes it difficult to live a normal life, disturbs sleep. Doctors recommend maintaining physical activity, attending water aerobics and yoga groups.

The child's brain continues to develop actively, the first convolutions appear. On ultrasound, you can see that he reacts to sounds and noise. The expectant mother is recommended to include foods high in iodine, polyunsaturated fatty acids (PUFAs) in the diet. The child is active, often pushes. The hair on his skin is gone.

At this stage, the second trimester of pregnancy ends. The fetus weighs up to 1000 g, its height is about 35 cm. It cannot live on its own due to the immaturity of the lungs, so it still needs time. The movements of the baby are more active, and periods of wakefulness alternate with sleep. On ultrasound, you can clearly see the sex of the child, his movements and even a smile.

29–30 weeks

Beginning of the third trimester of pregnancy. The abdomen is large enough, the height of the uterus is 29–30 cm. Women often complain of shortness of breath. During this period, it is important to undergo an ultrasound scan, which will help assess the condition of the fetus, measure blood flow, and examine the maturity of the placenta. At 29-30 weeks, some women may develop preeclampsia, in which there is protein in the urine, severe edema throughout the body, and increased blood pressure.

If no abnormalities are found, the doctor may advise the expectant mother to do breathing exercises to help manage shortness of breath.

Due to the large size of the fetus, its movements become less active. He already opens his eyes during wakefulness and closes during sleep. The iris is well formed, but the final eye color will be known after birth.

31-32 weeks

At this stage of pregnancy, the baby gains 300-400 g per week. From this point on, the risk of preterm birth increases. There is increased blood flow, which increases the load on the mother's heart. The doctor may recommend not to go far from home, to eat easily digestible food.

The child is fully formed, the skin turns pink, the amount of subcutaneous fat increases. Often he takes a position upside down. During this period, it is important to determine the presentation of the fetus: longitudinal, transverse, oblique. The best option would be the longitudinal position of the fetus. A woman is advised to wear a prenatal bandage that can support the anterior wall of the abdomen. Before delivery, the position of the fetus may change, so do not worry if it is in a different position.

33–34 weeks

The load on the heart increases, which can cause swelling of not only the extremities, but also the face in a pregnant woman. There is an increased risk of developing hemorrhoids, so it is important to avoid foods that can cause constipation. During this period, you can prepare for a trip to the hospital, collect the necessary things and in no case go far from home.

All tissues of the child continue to form, approaching normal values. The baby already looks like after birth. It begins to move into the small pelvis, this can reduce the load on the mother's respiratory centers. His digestive system is formed, he is ready for birth and independent intake of breast milk. All reflexes are well developed. The weight of the baby is about 1800-2100 g, height - 40 cm.

35–36 weeks

Women should prepare for childbirth. Thick discharge from the vagina indicates the discharge of the cervical plug. In such cases, it is necessary to visit a doctor, as this is a sign of an approaching birth. Often worried about prenatal contractions.

The fetus weighs about 2100-2700 g, height - 44-45 cm. At this stage, it is recommended to visit a doctor at least once every 7-10 days. The child in utero begins to lose lubrication, the placenta ages.

37-38 weeks

At this stage, the pregnancy is considered full-term, childbirth can occur at any time. The fetus is fully formed, slightly gaining weight and height. Considering that the baby is approaching the birth canal, a woman may be disturbed by minor pains in the lower abdomen, prenatal contractions.

39-40 weeks

Time to give birth. You can find out the approximate day of birth by the date of the last menstruation. The child is completely ready for birth, has all the signs of maturity. After birth, the detachment of the umbilical cord deprives him of nutrition and oxygen, but given that the baby is fully formed, he is able to scream, breathe and suck on his mother's breast.

What problems might a future mother face

During pregnancy, every woman faces certain difficulties, unpleasant symptoms that cause anxiety and make her feel worse. In the early stages of pregnancy, these may be:

• toxicosis;
• frequent urination;
• chest pain;
• increased drowsiness, fatigue;
• vaginal discharge;
• edema.

Late:

• difficult to walk due to weight gain;
• swelling of the legs;
• discomfort in the lumbar region;
• high blood pressure;
• urge to urinate frequently;
• hemorrhoids;
• stool problems.

All of these symptoms are normal for every woman and will pass fairly quickly. A little discomfort for 9 months cannot be compared with the fact that a long-awaited baby will be born, which will allow you to feel the joy of motherhood.

Advice for pregnant women

Pregnancy is not a disease, so do not restrict yourself from your usual, but healthy lifestyle. To endure and give birth to a healthy baby, some advice will help:

• in the first trimester, register with the antenatal clinic;
• strictly follow all medical recommendations;
• undergo routine examinations;
• avoid smoking and alcohol;
• eat healthy and proper food;
• take frequent walks in the fresh air;
• avoid large crowds;
• attend swimming pool, yoga and other activities for pregnant women;
• to go on maternity leave on time;
• exclude physical labor in the 1st and 3rd trimesters;
• do not hesitate to visit a doctor if something is bothering you;
• before giving birth to refuse long trips.

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