All trimesters of pregnancy by week, indicating the most dangerous periods. What do you need to know about the trimesters of pregnancy by week, how to behave in the first, second and third? How are pregnancy trimesters calculated?

Knowing what happens to the baby in the belly in each trimester and being aware of the characteristics of your body at a specific stage of pregnancy, future mom will be able to prevent complications during childbirth and spend all 9 months in a positive mood.

Trimesters of pregnancy (by weeks, doctors and gynecologists decided to classify the process of a woman carrying a child in the last century) is the result of a conditional division of 9 months of fetal formation in the mother’s womb into periods, each of which lasts 3 months.

During all 3 trimesters, not only physical development occurs little man, but also the constant transformation of a pregnant woman’s body. To make it easier to monitor the condition of expectant mothers, gynecologists have developed a number of standard indicators by which they assess the health of a woman and her child during a scheduled weekly examination.

The trimesters of pregnancy by week are shown in this table.

Such assessment factors include:

• fetal weight (determined by ultrasound examination);
• body weight of a pregnant woman;
• child's body length;
• the volume of the expectant mother's abdomen;
• the woman has swelling, pain of various types, insomnia, and so on;
• results of general urine and blood tests;
• visual examination of the condition of the cervix (in the absence of complaints from the expectant mother, performed by gynecologists only in the first and third trimester);
• the heart rate of a small person in the womb;
• blood pressure of a pregnant girl.

Thanks to generally accepted indicators, based on deviations from them in each trimester, doctors can timely diagnose the onset of pathology and prevent it without causing harm to the health of the mother and child. The most dangerous is the first trimester.

It is during this period that there is a high risk of sudden termination of pregnancy due to the inattention of the expectant mother to her body (pregnant women do not always find out about their situation from the first days, they continue to lead a normal lifestyle, lifting weights, not devoting the proper amount of time to sleep, neglecting the principles proper nutrition and so on).

Dividing pregnancy into trimesters, months, weeks

During these few weeks, ovulation occurs, fertilization of the egg, as well as its “implantation” into the uterine wall, followed by laying the foundation for the further construction of the human body. The first trimester lasts until 12-13 weeks.

If no termination of pregnancy occurs during this period, then, provided there are no pathologies in the woman’s health, sudden loss of the child before the expected date of birth is unlikely. From the 13th week the second trimester begins, which, by analogy with the first, has a duration of 3 months. At this time, the child is actively gaining weight and increasing in height, acquiring human species.

At the second stage of pregnancy, a woman begins to feel the first movements of her baby, and also, in some cases, after a routine ultrasound examination, she can already find out his gender (in the second trimester, the child’s reproductive system is already fully formed, which allows the ultrasound doctor to visually guess who the woman is expecting - boy or girl).

From the 28th week of pregnancy the third trimester begins.

At the final stage of bearing a child, a woman usually begins to experience discomfort associated with a sharp increase in the load on her body (the weight of the child at the period in question already exceeds 2 kg, and the volume of blood required for normal nutrition of the placenta, which nourishes the baby’s vital systems inside the womb, extremely large).

To simplify the perception of information about dividing pregnancy into periods, gynecologists recommend that expectant mothers use a generally accepted table.

Table:

Trimester	Months	weeks
1	first; second; third.	from 1 to 4; from 5 to 8; from 9 to 12-13.
2	fourth; fifth; sixth.	from 14 to 17; from 18 to 21; from 22 to 27.
3	seventh; eighth; ninth.	from 28 to 31; from 32 to 36; from 37 to 40.

Changes in the body of the expectant mother and child during each trimester

The trimesters of pregnancy (week by week the child not only increases in size and weight, but also acquires new skills necessary for subsequent life outside the mother’s womb) determine the condition of both the fetus itself and the pregnant woman.

Understanding what changes in the body are coming during the next trimester, the expectant mother will be able to mentally prepare herself for possible difficulties and make every effort to prevent discomfort.

Trimester	Changes in the body of a pregnant woman	Changes in the child's body
1	the appearance of signs of toxicosis, most often manifested already at 5-7 weeks of pregnancy (nausea, vomiting, changes in taste preferences; dizziness); increase in breast size; increased sensitivity of the mammary glands (in some cases, at this stage of pregnancy, pregnant women complain of pain and a feeling of fullness in the breasts); increased urge to urinate (the uterus with the “implanted” fetus puts pressure on the bladder); drowsiness; excessive fatigue; excessive emotionality caused by hormonal changes.	formation of the neural tube (the basis for the future central nervous system); the heart muscle begins to function; the beginning of the formation of the spinal column, the brain and its hemispheres, in particular; laying the foundations for the future formation of eyes, ears, limbs, organs gastrointestinal tract and thyroid gland; formation of genital organs, fingers on the upper and lower extremities; the beginning of the production of hormones by the endocrine system, as well as the formation of the rudiments of baby teeth in the gums; the baby begins to move inside the mother's womb.
2	increase in abdominal size; possible occurrence of pain in the lumbar region and thoracic spine; discomfort in hip joints; probability of development varicose veins veins (due to rapidly growing weight).	increase in height and body weight; completion of the formation of the reproductive and skeletal systems of the child’s body; active development of muscles and brain; increase in physical activity.
3	increasing the size of the uterus to its maximum size; difficulty breathing associated with increased pressure from below on organs respiratory system; sleep disorders; frequent urge to urination; excessive fatigue; the occurrence of “false contractions” (a kind of preparation of the uterus for the upcoming labor).	final formation of all vital organs and systems of the body; improving the ability to perceive information through hearing and perform breathing movements; the appearance of taste perception; active growth hair on the head; the formation of lubricant throughout the body, designed to facilitate the baby’s passage through the birth canal during birth.

Fetal development by weeks and months

Keeping track of how the fetus is developing each month or week of pregnancy helps reduce the overall anxiety of the expectant mother, as well as strengthening her parental feelings towards her child.

First trimester

Table:

A week
1 — 2	Based on the fact that the beginning of pregnancy is considered to be the first day menstrual cycle, then the first two weeks of bearing a child are conditional, since actual conception has not yet occurred.
3	Fertilization of the egg occurs, as a result of which the color of the eyes and hair of the unborn child is determined at the genetic level. The egg begins its division and moves towards the uterus.
4 (end of 1 month of pregnancy)	The fertilized cell implants in the uterus and grows to the size of a poppy seed.
5	The embryo grows up to 2-3 mm in length, while acquiring two poles, where the lower and upper limbs will subsequently begin to form. 3 functional layers are formed, which are the basis for the further formation of the vital systems of the little person’s body. The neural tube appears.
6	Formation of the upper and lower limbs child and increased embryonic growth.
7	Increasing the size of the embryo to the proportions of a black currant or raspberry. Division of the child's brain into 3 functional sections. Active formation of limbs and laying the foundations for the formation of ears and nose.
8 (end of 2 months of pregnancy)	Formation external features face, limbs and vital organs. Beginning of fetal motor activity.
9	Increasing the size of the embryo to the size of a plum tree fruit. Formation of the reproductive system of a small person.
10	Active development brain. The film membrane between the fingers of the upper and lower extremities disappears. Increasing the strength of the skeletal system.
11	Increase in fetal size and weight. The gradual acquisition by his body of a human proportional appearance.
12	The child grows to the size of a small orange. External genitalia are formed. Nail plates appear on the fingers and toes.
13 (end of 3 months of pregnancy and first trimester)	The child’s brain and visual organs are actively developing. The rudiments of baby teeth appear in the baby’s gums. Hair slowly begins to grow on the head.

Second trimester

Table:

A week	Fetal development at a specific stage of pregnancy
14	The endocrine system begins to produce hormones. The strength of the chest increases. As the upper palate completes its formation in the child’s mouth, he acquires a sucking reflex.
15	The production of specific proteins of a particular blood group begins. The emergence of skills to change facial expressions. Increases physical activity(the expectant mother most often does not yet feel the movements of the fetus).
16	Active weight gain occurs and mucous membranes are formed. If the fetus carried by a woman is a girl, then at week 16 the little person will begin to form her own eggs - the basis for the reproductive system.
17 (end of 4 months of pregnancy)	The first fat deposits appear under the baby’s skin. He is actively increasing his height and weight while continuing to practice high physical activity.
18	The emergence of the ability to perceive the world through the organs of hearing. The formation of an emotional connection between the little person and his parents begins (the child gets used to their voices, hears the mother’s heartbeat, and so on).
19	Molars begin to form under the rudiments of baby teeth. A special mucus appears on the child’s body, which promotes proper thermoregulation.
20	The final formation of the child's facial features. The emergence of taste perception.
21 (end of 5th month of pregnancy)	The skeletal system actively develops and the bone marrow begins to function.
22	Color change skin(becomes whitish). Hairs on the face (in particular, eyebrows and eyelashes) are formed.
23	The brain and central nervous system are actively developing. Completion of the formation of vital organs.
24	The formation of the organs of visual perception is completed, despite the continued absence of pigment (colorless eyes). The child begins to practice various movements, thus studying his body.
25 (end of 6 months of pregnancy and 2 trimesters)	Maturation of the gastrointestinal tract and the formation of meconium in the intestines.

Third trimester

Table:

A week	Fetal development at a specific stage of pregnancy
26	The child develops his own daily routine, which does not depend on the time of wakefulness and rest of the expectant mother. The respiratory organs are actively forming, preparing to function outside the womb.
27	The child learns to open and close his eyes in response to bright light. The baby calms down and falls asleep when gently rocked (the pregnant woman may be in public transport, walk or do household chores). The amount of hormones produced increases.
28	Increase in height and weight.
29 (end of 7 months of pregnancy)	Active brain development. During sleep, a child begins to dream, he develops emotions - he learns to be scared and enjoy.
30	The child begins to actively convey to the mother his attitude towards external circumstances. For example, he may start kicking if a woman is near the source of noise.
31	The child increases in all parameters, while at the same time reducing his motor activity.
32	The fetus is positioned as it will lie in the mother's belly until birth, which determines the type of labor that will occur (natural birth or Caesarean section).
33 (end of 8 months of pregnancy)	The child begins to adapt to his mother’s daily routine, repeating periods of activity and rest after her.
34	Completion of the formation of the respiratory organs.
35	Significant increase in the child's weight. The lubricant on the body acquires a thicker consistency, which will help the little person pass through the birth canal less painfully.
36	The final stage of formation of the nervous and immune systems. Subcutaneous fat accumulates.
37	Completion of the formation of all systems and organs of the child’s body.
38 – 40 (end of 9 months of pregnancy)	With cephalic presentation, the baby's head drops into the pregnant woman's pelvis, which is a sign of the body's readiness for the upcoming birth.

A woman’s feelings as the fetus develops

The trimesters of pregnancy according to the weeks of child development determine not only the physical, but also the emotional state of the expectant mother. In the first trimester, a pregnant woman is overcome by manifestations of toxicosis (nausea, vomiting, dizziness). Most women lose a lot of weight in the first months and do not yet feel an emotional attachment to their child.

Due to hormonal changes in the body, they often cry, laugh for no reason, become more irritable and require increased attention.

As the fetus develops, by the second trimester, toxicosis ends, and the stomach becomes rounded and increases in size, which allows the woman to begin to enjoy her position. The psychological background is leveled out and an emotional connection with the little person in the stomach is born (usually it is especially intensified after the first mother feels the kicks of her baby).

In the third trimester, despite the re-emerging physical discomfort (swelling, insomnia, frequent urge to urinate), the expectant mother is stable in her emotions, looking forward to meeting the baby and enjoying her pregnancy. At this stage, girls usually attend a 3D ultrasound in order to take a photo of the child as a memory of the period it was in the womb.

Possible deviations

Pregnancy lays the foundation for the future health of the little person. Knowing what abnormalities can be identified in a specific week of fetal life, the expectant mother will be able to prevent their occurrence by adjusting her lifestyle at each trimester.

Most often doctors diagnose during pregnancy:

• Down syndrome(chromosomal mutation leading to dementia and serious developmental delay in the child);
• Patau syndrome(a genetic mutation, the owners of which rarely live longer than a year. It provokes deafness, mental retardation and a number of other serious pathologies);
• heart disease(some of them are subject to surgical correction, others allow a person to live, forgetting about their existence);
• pathologies of the development of limbs or vital organs(they are not congenital and arise at the stage of laying the foundations of the body systems during pregnancy).

First trimester

If the expectant mother leads an incorrect lifestyle, the foundation for the subsequent development of diseases is laid in the first trimester.

They are:

Second trimester

The second trimester is dangerous for a little person in terms of development:

• pathologies of the brain and organs of vision (with a deficiency of lutein entering the mother’s body);
• disturbances in blood circulation (in the absence of routine-containing foods or synthetic vitamins in the mother’s diet);
• dysfunction of the mucous membranes (to prevent this, the pregnant woman should take vitamin complexes with a high content of vitamins A);
• infertility (if the fetus carried by a woman is a girl);
• pathologies bone marrow and the skeletal system of the body as a whole.

Third trimester

During the third trimester, an incorrect lifestyle or insufficient vitamin enrichment of a pregnant woman’s diet can lead to the development of certain pathologies in the child’s body.

For example:

• gastrointestinal diseases;
• pathologies of the respiratory system (for example, insufficient amount of surfactant - a substance that prevents the lungs from sticking together);
• disorders of the circulatory system;
• diseases of the central nervous system.

Despite the almost complete formation of the child’s body and its partial readiness to function outside the mother’s womb, a pregnant woman during the third trimester should still be extremely attentive to her health.

Premature birth on recent months Pregnancy of a small child is rarely fatal, but can predispose the child to serious diseases in the future (for example, lung pathologies or heart disease).

Features of the lifestyle of the expectant mother in each trimester

The trimesters of pregnancy determine the lifestyle of the expectant mother week by week. Despite the presence of peculiarities in the formation of a child’s body at each stage of intrauterine life, gynecologists recommend that pregnant women, in order to avoid the development of pathologies in the fetus, adhere to standard recommendations throughout the entire period of bearing a child.

They are:

The trimesters of pregnancy determine the condition of not only the little person in the mother’s womb, but also the condition of the pregnant woman herself.

By carefully studying the changes in her body during each week of pregnancy, the expectant mother will be able to think in advance about options for alleviating possible physical and moral discomfort in a way that is safe for herself and her baby.

Article format: Lozinsky Oleg

Video about the features of the trimesters of pregnancy

In this article:

From the moment of conception to birth, 9 months will pass. For convenience, they were divided into 3 periods of 3 months - trimesters. Ideally, if the mother manages to carry the baby for the entire term, up to 39-41 weeks. If labor starts earlier, be sure to call an ambulance. Today, even very premature babies can be saved and released in a hospital setting. This improves the life chances of every child.

Throughout pregnancy, a woman must lead a healthy lifestyle, follow nutritional conditions and not drink alcohol or drugs. Otherwise, the child may have developmental pathologies. The first trimester is considered the most important. During this period there is rapid growth the fetus, its organs and tissues are formed. He is still very small - only 10 centimeters. At the end of the second trimester, the baby begins to hear sounds - it’s time to talk to him, read to him. The mother's voice calms the baby, even if he is in her tummy.

9 months of pregnancy - three trimesters

Pregnancy lasts 9 months, or 3 trimesters. During this time, simply incredible changes occur in the baby: from a tiny cell to a fully formed child weighing 3500-4000 g. An average of 240 days pass from conception to birth, and every day there is a threat that the mother’s body will begin to reject the fetus. But also every day is
constant development of the baby in the mother's belly.

Today, not 40 weeks may pass before the baby is born, but only 28: even at such a short period, doctors have learned to save babies. Of course, he will be born very premature, but alive and ready to fight for his life. Doctors give the mother a list of recommendations, following which she can avoid premature birth.. Even if today we know how to save and care for such babies, this does not mean that all premature births end successfully. It is better to follow all the rules of pregnancy and carry your baby to term.

First trimester

The first trimester of pregnancy is the most important. Embryonic development begins the moment two cells fuse. They immediately begin to divide, and the embryo quickly increases in size. Just a few days from conception, this is already a large accumulation of cells, which is constantly increasing. Often for the first 1-2 months a woman does not even know that she is pregnant. If the cycle was irregular, then a slight lag does not bother her. And this is the most dangerous thing for the fetus.

A week after conception, it moves towards the uterus and attaches to its wall. Now the fetus is nourished through the mother’s blood, receiving all the nutrients and vitamins from her. But he can also get the real one through blood.

If a woman drinks alcohol, smokes, takes drugs or simply drinks strong drugs, this often has a detrimental effect on the embryo.

To prevent this from happening, you need to monitor your cycle and plan your pregnancy.

What's happening to the baby

In the first trimester, the most important thing is that all organs, bones and tissues are being formed. The baby already has a beating heart at 5 weeks. You will be able to hear it on an ultrasound. As well as the stomach, intestines, nervous system, blood, liver and kidneys. All organs are tiny, just like him.

Now at your It’s not the calmest time for a child: the mother’s toxicosis can negatively affect him. Sometimes, due to severe toxicosis, fetal development progresses the wrong way. To prevent this from happening, visit a doctor and watch your diet. For proper development, the baby needs vitamins, calcium, and folic acid.

By the end of the first trimester, the baby's height reaches 10 centimeters. Mom's belly is already clearly visible, she feels pregnant. There are still 5-6 months left before birth. The baby already has all the most important things, and now the daily development of the body and organs will continue until the end of pregnancy.

Second trimester

In the second trimester, the mother feels much better, because the toxicosis has almost passed. Your eating habits return to normal. And for the first time you will feel how your baby pushes in your stomach. At first these are light touches, small pushes. The more
the size of the child, the stronger they are felt. Towards the end of this trimester, it may even interfere with your sleep.

Now is the time for nervous system and brain development. Nerve fibers grow from the brain to all organs. A period begins when the baby not only feels, but already sees and hears. At the end of 4 months you can start talking to him - he remembers his mother’s voice, hears the beat of her heart. Now the skin is forming and subcutaneous fat is gaining. In addition, you will now know the gender of the baby. He may not show himself to you right away, but by the end of the second trimester you will already know for sure whether you are having a boy or a girl.

Now you need
calcium, and dairy products are a good source. Choose the ones you like: cottage cheese, milk, fermented baked milk, kefir, yogurt. Your baby's bones grow, harden and take a lot of calcium from the mother's body - something women often suffer from due to tooth decay. Therefore, it is very important to provide yourself with calcium so that you both have enough.

In addition, the expectant mother needs to be prepared for sudden “training” contractions of the uterus. These are not contractions or childbirth – your uterus is just trying its hand, learning to work. They can last only 10 seconds, start suddenly and end without any consequences. This is a common occurrence, so don't be alarmed. Contractions should be painless and without bleeding. If you are in pain, call an ambulance immediately.

Third trimester

The third trimester begins, and this is global preparation for childbirth. The baby is fully formed: he already has arms and legs with fingers, all organs and tissues. The task of the next 3 months is the gradual development, “ripening” of organs. But
the most important thing is that at the beginning of the third trimester the baby is already viable if born prematurely. Mom should be very careful, not to carry heavy things, not to be nervous. Now her tummy is already impressive in size.

The child is active in the evening and may kick a lot. Every day he swallows amniotic fluid and then pees. This is how the bladder is “trained”. The gastrointestinal tract also begins to work even before the baby is born.

How does mom feel?

When 1-1.5 months remain before birth, pregnancy ceases to be comfortable. With a big belly, you won’t find a particularly comfortable position. My back hurts, my legs swell. It is important to remember that you often go to the toilet, sweat, which means a lot of fluid is lost. Therefore, you need to drink at least 1 liter of water per day.

How does a baby prepare for childbirth?

When there are only 1-2 weeks left before birth, the baby descends closer to the exit of the uterus. His head begins to press on the neck. Here the mother can feel some relief in her situation. The child’s development does not stop even now: the lungs and brain are still forming. Already at 40 weeks you can give birth - the baby is completely ready.

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In the images you can see an approximate illustration of the baby's development inside the womb for each week. To the left of the images is short description fetal growth for a given week. You can find more complete and detailed information by clicking on the “More details” link, which is located under each description.

The pregnancy calendar by week is very convenient.

Knowing how pregnancy progresses week by week is not only interesting, but also very useful! The pregnancy calendar will help you with this. It is designed to keep mom informed of all events intrauterine development, help adjust nutrition and lifestyle during different periods of pregnancy. In addition, the pregnancy calendar allows you to calculate the expected date of birth.

Pregnancy calendar by week

It will facilitate medical supervision of the expectant mother and her baby, and will also give answers to the most important questions that will certainly arise in front of you: when the belly begins to grow, why does one feel sick during pregnancy, how to recognize the first movement of the fetus.

Thanks to this calendar, you will not forget that the time has come to undergo screening, take tests, or go for a routine ultrasound. And as the due date approaches, such a weekly calendar will help you best prepare for the long-awaited event.

This pregnancy calculator will allow you to calculate how far along you are now, the date of your future birth, the date of conception, and even the zodiac sign of the future baby and its zodiac animal. eastern calendar. You will also be able to determine the age of the fetus, its weight and height, and how much time is left before birth. To do this, you need to enter the date of the first day of your last menstrual period and the length of your menstrual cycle. In addition, our calculator generates a very convenient and practical pregnancy table by week. Using it, you can figure out what week of pregnancy you are currently in, as well as track the height and weight of your unborn child.

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Pregnancy calendar by month.

By month

The monthly pregnancy calendar will become your guide to all 40 weeks of pregnancy. Every expectant mother will be able to leave her reviews, observations, share experiences and useful information. Together we will watch how quickly our babies grow and develop! And give advice on the right lifestyle, diet and safe treatment of all sorts of ailments.

Each month of pregnancy is characterized by serious changes in the development of the child: he achieves greater success in physical and mental development, the baby’s brain grows rapidly, becomes stronger muscle mass, vital organs and systems and even the first natural skills are formed! The pregnancy calendar by month will familiarize you in detail with these events at each stage.

Personal pregnancy calendar

Every woman can keep a personal pregnancy calendar. Moreover, it is welcomed and recommended. After all, now you are in a very special state. Many sensations are new to you, and can even cause worries and fears - the body of a pregnant woman undergoes enormous changes, both in the physiological sense and in the psychological sense.

The pregnancy calendar by week and month is compiled with an attempt and purpose to explain each of them.

You can keep a personal pregnancy calendar in a separate notebook, which you decorate in accordance with your mood, tastes, experiences, as well as whether you are expecting a boy or a girl. Such an album will be an excellent start to a family chronicle or a chronicle of the life of your heir.

Interactive pregnancy calendar

But in addition, modern expectant mothers resort to the Internet and choose an interactive pregnancy calendar for observations. It is convenient, easy to use, accurate, practical, informative and completely free!

You can resort to its help when you need to quickly determine the date of birth or accurately determine the current stage of pregnancy (using a special calculator for this), divide your pregnancy into trimesters, months or weeks.

Online pregnancy calendar is becoming increasingly popular. Women want to know more about this special period: what are the first signs of pregnancy, how to avoid miscarriage, what to do with increased uterine tone, how to recognize the first warning signs of labor, how to determine the sex of the child. The calendar will contain articles, tips, explanations, as well as a calculator for determining the duration of pregnancy and the expected date of birth.

You can conduct personal monitoring of your own pregnancy, your condition and that of your child, and carry out calculations that interest you.

Online pregnancy calendar - at your service! Keep your finger on the pulse of the most important events in your life!

Duration of pregnancy, according to obstetric period, i.e. the one used by doctors is 280 days. The countdown comes from last day last menstruation. The entire pregnancy, for greater convenience and monitoring the development of the fetus, is usually divided into trimesters. The duration of one such time period is 3 months. Let's take a closer look at how pregnancy is divided into trimesters by week and give brief description each of them.

When does the 1st trimester begin and how long does it last?

The first trimester in obstetrics is usually called the early fetal trimester. It lasts directly from the moment of conception until the 13th week of pregnancy.

If we consider the 1st trimester of pregnancy by week, then Special attention must be applied at 2-3 and 8-12 weeks.

So, at the beginning of the 1st trimester (approximately 2-3 weeks) of pregnancy, such an important phenomenon occurs as implantation of the fertilized egg into the uterine endometrium. Future pregnancy will directly depend on the results of this process. If for some reason this process does not occur, or occurs but with disturbances, the pregnancy is terminated, which the woman learns by bloody discharge, which is accompanied by pain in the lower abdomen, nausea, vomiting, dizziness, etc.

The second critical period in the 1st trimester is 8-12 weeks. It is during this time period that there is a high probability. The reason for this, as a rule, is a change in the hormonal background of the body.

How long is the 2nd trimester of pregnancy?

2nd trimester - mid-fetal, begins at 14 weeks and lasts directly until 27 inclusive.
Considering the 2nd trimester of pregnancy week by week, doctors pay special attention to the formation and growth of the main organs. Everything is normal by 16 weeks internal organs and the baby's place (placenta) are fully formed.

The critical period of this time period is 18-22 weeks. It is this that is associated with the active increase in the size of the uterus. The danger for the fetus is posed by incorrect placement of the placenta (incomplete and complete presentation, low presentation).

If still on early It was found that the placenta is not positioned correctly, then at this time there is a high probability of its partial detachment, which can lead to bleeding and miscarriage.

What dangers await the fetus in the 3rd trimester of pregnancy?

The 3rd trimester of pregnancy lasts by week from 28 to 40 weeks, at which, normally, childbirth should occur. However, in reality, the birth process can begin either earlier or later than indicated above, due to various reasons.

Directly from 28 to 32 weeks, intensive growth of the fetus continues, and at the same time the size of the uterus increases. Termination of pregnancy at this stage is very rare. Most often it is caused by:

• severe form of toxicosis;
• isthmic-cervical insufficiency;
• sudden change in hormonal levels;
• placental abruption.

In such cases, they talk about premature birth, because the baby is already viable by this time. Children born at this time are practically no different from those born at term, with the exception of slightly lower weight and body size.

Thus, each trimester of pregnancy, which is determined by week, as can be seen from the corresponding table, has its own characteristics and critical periods. Doctors pay special attention to the latter, because It is at this time that there is a high probability of developing a disorder or even terminating the pregnancy.

Articles on the topic

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To understand and correctly monitor changes in the body, a woman needs a pregnancy calendar. In such a calendar, each week is scheduled, what changes occur in the body and you can track your weight gain, the weight of the baby and see ultrasound readings.

Carrying a child under your heart is an important event in the life of any girl. Pregnancy is always a mysterious and at the same time frightening event with the unknown, and it is also a period of waiting for a miracle. From this article you will learn what a trimester is and the features of each of them.

Terms by week

On average, pregnancy lasts about 38-40 weeks and there are two designations for gestation periods: obstetric and embryonic. The first definition is used most often and is exactly 40 weeks, since tracking the date of conception is sometimes very difficult.
To understand and correctly monitor changes in the body, a woman needs a pregnancy calendar. In such a calendar, each week is scheduled, what changes occur in the body and you can track your weight gain, the weight of the baby and see ultrasound readings. It is very good that in our modern world, there are a great variety of electronic pregnancy calendars and you can choose the most comfortable calendar for yourself.

How are the trimesters of pregnancy divided by week?

The entire gestation period is divided into three trimesters. A trimester is three months. In weeks 38 to 42, that's 9 months. The first trimester ends at 12 weeks, the second at 24 weeks, and the third lasts until the approximate date of birth. When determining the period, gynecologists are guided by the obstetric period, that is, the countdown begins from the last menstruation.

Features of each period

• The first trimester is very important, since at this time the body begins to rebuild itself to bear the baby. At this time, toxicosis often appears, it is possible hormonal disbalance, mood swings and increased fatigue. During the first trimester, the fetus develops its nervous system.

• The second trimester is special in that at this time the signs of toxicosis disappear, and the stomach takes shape and begins to round. This trimester is considered the calmest.

• The third trimester is the hardest of all. The baby already sees, hears, waves his arms and legs with redoubled force, as if showing that he is tired of being locked up. The baby has already become very heavy and it is difficult for his mother to carry him - his back and legs begin to hurt, and the fatigue sets in many times more. The mood is often decadent and mommy prefers to stay at home or sleep than go out in public - and this is normal.

Child development by trimester of pregnancy

After the female egg has merged with the male one, a clot of cells is created in one membrane; within a week this clot must reach the uterus and take hold there. This entire process occurs during the first month of pregnancy. When ovum attaches to the wall of the uterus and the embryo begins to develop at an accelerated pace. At week 7, he already outwardly resembles the outline of a man, although he is still very tiny. Until the end of the first trimester, that is, up to 12 weeks, all organs and systems are formed. On days 21-22, when the embryo is approximately 3 weeks old, its heart begins to beat. It does not yet look the same as in adults, but it already performs its function. By the end of the second trimester, the baby receives the status of a fetus and is already completely human-like, all its organs and systems are formed, they gradually begin to work. During the third trimester, unborn child It’s just growing, gaining weight and “ripening.” Nervous system, digestive system and brain continue to improve after birth.

Changes in the female body by trimester

Immediately after conception, female body begins to change in such a way that the baby survives and can be born. For this, a hormonal boom occurs, the level of progesterone in the blood rises, which throughout pregnancy “adjusts” the female body to the presence of the fetus and suppresses immune system so that she doesn't get rid of the child.
The most striking reaction to hormonal changes is nausea and vomiting. Toxicosis usually begins at the end of the first trimester. Each woman experiences toxicosis individually, but for most it stops by the second trimester. By the end of the 2nd trimester, the belly already becomes noticeable, the breasts increase several times.
The third trimester - it is already difficult for a woman to move around much, it is difficult to get enough sleep, she wants to be relieved of the burden as quickly as possible. Throughout pregnancy, the body prepares for labor. In the last trimester, training contractions occur, which resemble real ones, but are not as painful and do not last long, only from time to time. The uterus has increased in size by more than 500 times compared to the first weeks of pregnancy. Appear dark spots, areolas darken, skin dries and itches, hair, nails and teeth deteriorate. This is because the baby needs a lot of nutrients and takes them from the mother’s body. Therefore, during pregnancy you need to eat well, and most importantly, eat right. If the deficiency of certain vitamins and microelements is too noticeable, then you need to add vitamin complexes, which are prescribed by your doctor.

Prohibitions in each trimester of pregnancy

Why is the 1st trimester dangerous?

At this stage, the most dangerous things are miscarriage and infectious diseases. At the beginning of pregnancy, it is important to give up bad habits. Switch to a balanced diet. During toxicosis, drink more fluids, consume high-quality foods, eat in small portions, but more often than 3 times a day, do not overeat at night, and it is generally not advisable to overeat. Monitor your well-being and immediately respond to heavy bleeding and severe pain. Try to spend less time in crowded places and use all precautions during epidemics of colds.

Why is the 2nd trimester dangerous?

In the second trimester, you need to pay special attention to:

• Discharge, if its character changes, pain appears when urinating, itching, swelling of the genitals. The color turns green, brown or yellow. Curdled discharge is also a deviation from the norm and requires intervention. Help is needed urgently if blood appears, even in small quantities.
• Severe pain. In the head, stomach, legs, pelvis.
• Visual impairment.
• Swelling. Your legs or face began to swell greatly.
• Excessive weight gain.
• Frequent nausea or vomiting.
• Fever, chills, significantly increased body temperature.

You should also consult a doctor if you cough up blood and it becomes more difficult to breathe.

Why is the 3rd trimester dangerous?

In the last trimester, premature birth can be dangerous, especially in the first half of the trimester before 36 weeks. Early labor is indicated by a short cervix, leakage amniotic fluid, increased uterine tone, labor pains, heavy bleeding. You should also monitor the baby’s activity; if he is overly active or vice versa, you need to undergo an examination.

Nutrition during pregnancy by trimester

• 1st trimester - When a woman finds out that there is a “belly” inside, she needs to immediately reconsider her diet and habits. Quit smoking and alcohol, not to mention other psychotropic substances. If the expectant mother is taking serious medications, then she needs to determine the risks and what is best to avoid - medications or pregnancy. In case of toxicosis, food should be light and well digestible, containing all the necessary vitamins and microelements. Eat meat and fish correctly, especially low-fat varieties. Chicken eggs, various cereals, vegetable salads, seasoned vegetable oils, dairy products, fruits and berries. Drink water, compotes, fruit drinks, natural juices.
• 2nd trimester - Maintain the same diet. You can add more nuts, seeds, bran. Prepare various dishes from cottage cheese, add grated hard cheese to soups. All dishes should be consumed boiled or steamed. Avoid fast food, smoked meats, pickled foods, sweet soda, fatty sweets, and fresh baked goods. Drink enough fluids.
• 3rd trimester - Continue to eat properly, do not increase portions. If you are worried about toxicosis again, then switch to lighter meals. If you feel normal, cook food in the oven, steam, or boil. Eat some vegetables, fruits, herbs, and berries raw. Porridge is a must to minimize the risk of constipation. Drink enough fluids to avoid causing swelling, but at the same time maintain a drinking regime.

Each trimester has its own characteristics. The baby develops gradually. The mother’s task is not to harm the fetus while it is maturing inside, to think not only about herself, but also to take into account the needs of the unborn child.

Tests and procedures by trimester

You need to register with the women's office in the first trimester, preferably before 10 weeks of pregnancy. From the moment of registration until childbirth, a woman visits a gynecologist at least 2 times a month, if there are no problems with pregnancy. Over the entire period, the following studies are carried out by trimester:

• In the first trimester, a blood test is taken for sexually transmitted diseases, including AIDS/HIV, general analysis blood, urine. A vaginal swab is also taken for tank tests. Blood for biochemistry and hormones, clotting tests. Double test for hCG and PAPP-A. Tests for antibodies to rubella and toxoplasmosis. An ultrasound examination shows where the fertilized egg has attached, whether the embryo is developing correctly, whether its development meets established standards and whether there are any deviations.
• In the second trimester, an ultrasound is performed - it will show how the baby is developing, and biochemical screening to identify diseases of the baby, if any. Are his organs forming correctly, the general condition of the placenta and uterus. Urine and blood are given - general analysis. Blood for biochemistry, sexually transmitted diseases, hepatitis. Smear for infection. Triple test - hCG, AFP and the hormone estriol.
• In the third trimester, a repeat blood and urine test is taken at each doctor’s appointment, ultrasound and CTG are performed. Before 36 weeks, a smear test for sexually transmitted infections. Blood for HIV, hepatitis and syphilis. Biochemistry up to 30 weeks. Coagulogram and blood test for antibodies to toxoplasmosis and rubella as recommended by a doctor. With the help of ultrasound, you can see the gender of the unborn child. How does he feel, is there any entanglement in the umbilical cord?

With the help of ultrasound, young parents can see the child in motion, examine every detail of him and, subsequently, save these frames for a long memory. And the doctor will make sure that the fetus is developing correctly.