Author: Rositsa Tashkova, Master of Molecular Biology and Microbiology

The article is based on materials by Marie-Claude Delahaye - a professor at Pierre and Marie Curie University in Paris. Works in the field of genetics and cell biology. She is the author of numerous scientific publications and books on women, pregnancy and motherhood.

There is no other period in a woman's life that can be compared to what happens to her body and psyche during pregnancy. The life that develops in her changes her with each passing day - this is a reality from the first day of conception, but it is most noticeable in the last months of pregnancy.

In this article, we will look at what these changes are, but also what happens invisibly in the belly of the future mother. This will be a brief description of your baby's journey from one cell to it's own cradle at home.

The beginning

Fertilization is most likely to occur with sexual intercourse in the three days before ovulation - a moment that occurs at different times for each woman, and even with each individual menstrual cycle, but most often it occurs 2-3 weeks after the onset of the last menstruation.

With ejaculation, between 60 and 500 million spermatozoa are released, which fall into the cervical mucus (which in the period around ovulation has a consistency and composition that support the survival and movement of spermatozoa) and enter through the cervix in 2 to 10 minutes. Their path to the egg passes through the uterus and fallopian tubes, where the two sex cells occur.

Only about 100-200 spermatozoa manage to reach this covenant place and only 1 - to performfertilization.

The first days of a new life

With the fusion of the egg and spermatozoa, the sex and all genetic characteristics of the child are determined. The sex of the child depends on what sperm has fertilized the egg - if he wears a sex X chromosome, then we will have a baby girl if she carries a Y - a baby boy.

The first week of life of our future child passes into intensive cell division and movement from the place of fertilization - the fallopian tube, to the uterus and implantation in its mucous membrane. The latter occurs somewhere between the 7th and 10th days of fertilization.

From this part of the fetus, from which the placenta will then develop, begins secretion of the hormone gonadotropin, which supports the secretion of progesterone from the yellow body in the ovary - a condition that is necessary for the retention of pregnancy.

First trimester of pregnancy

First month

Congratulations! On the second week after fertilization and about 4 weeks after the onset of the last menstruation, you are pregnant in the first month.

Already in the first week begins the formation of embryonic appendages - these are the placenta and umbilical cord, At this time, the mother does not know if she is pregnant and has no symptoms. The pregnancy test is good to do after at least one day of delay of menstruation to give a more accurate result, and the most accurate is the blood - but let us have patience [ref. 6].

At the end of the second week (on the 21st day of fertilization), the fetus will have reached the dizzying dimensions of... 1.5 millimeters, and only the next day will already be 2 millimeters. At that time, a heart had already formed, of course very imperfect, but still beating.

It has been 4 weeks since fertilization and the baby already has even blood circulation, as well as conceptions of hands and feet. At the end of this week the head is clearly separated, but the little one also has a tail, which will then disappear. It has the shape of a 5mm comma.

When the menstruation of the pregnant woman is delayed by 2 weeks, the life developing in her already has conceptions of all systems and organs, including a smallpimple, from which his heed will develop.

The future mother begins to experience the characteristic malaise [ref. 1]:

  • Itchy and painful breasts, itchy grains that become somehow more convex, and the areolas around them become enlarged and darkened.
  • The uterus acquires the size ofa mandarin , and compressedcervical mucus forms a "stopper" that protects the uterine cavity from entering anything.
  • Nausea manifests itself with increasing frequency, especially in the morning, and appetite disappears.
  • Insomnia occurs, or a strong desire for an afternoon nap.
  • The pregnant woman feels tired and nervous.
  • Even at this early stage, frequent urge to urinateappears , which will disappear soon when the uterus begins tolift upwards, but will reappear as pregnancy progresses.
  • The game of hormones also affects the mood , but it is temporary and patience and optimism are needed. Of course, if dark thoughts persist, it can also be about postpartum depression [ref. 2], which sometimeshappens even before birth.

Second month

At the beginning of the second month the baby is 5 mm long, and at the end of it - is as many as 30 mm. This is a period of intensive development and growth. By the end of this month of pregnancy, the baby will already have most of his organs, his face will take shape, and it will now look like a man, not a tadpole.

When the developing baby is now 5 weeks old, his heart is still located outside his calf as it hasgrown.

Symptoms of pregnancy from the first month become more palpable and the culprit for this is the hormone chorionic gonadotropin (CHG) - the same one in whose presence pregnancy tests "recognize" whether the woman is pregnant [ref. 5].

Some other disorders appear ,such as constipation, increased salivation and swelling of the legs.

In the 7th week of the baby's life, it begins to move - although the mother still can not feel this - it isonly 17-22 millimeters long.

At the end of the 10th week after fertilization, the heart tones of the 3-centimeter baby can now be heard with the help of Doppler.

Third month

This is the month in which the disorders will begin to gradually subside, and the fetuswill already be called a fetus or fetus (from here and "fetal morphology", which examines the development of the organs of the fetus [ref. 7]).

At the beginning of the month, the little baby has a huge head, relative to the size of her body, but over time her growth gradually slows down and it acquires the appearance of a real man. By the end of the month its dimensions will reach 12 cm and move, but the mother will still not feel this.

In the first week of the thirdmonth , the baby is already40,000 times larger than the egg from which it originates.

In the first weeks of this month, the baby's eyelids are already covering the eyes, which will remain closed for months. The face is getting better and better. Internal organs continue to develop and move into the baby's body.

But if the expectant mother is stressed, the rising levels of adrenaline in her body pass into her baby's small organism and accelerate his heart rate. At this time of development, his normal heart rate is 110-160 beats per minute.

At the beginning of the third month, the baby's small intestine still can not fit into its tiny abdominal cavity, so they are located curled inside the umbilicalcord , where there are also the vein and artery connecting the two bodies - to the mother and the baby. Later, they normally take their place in the baby's tummy, but in rare cases thismay not happen, and then we talk about malformation. [ref. 8]

By the middle of the third month, the development of the baby's brain is extremely turbulent, the fetuses of permanent teeth are bet, and its weight is 18 grams at "height" 7.5 cm.

A week later, the baby's weight is already 28 grams and is 1