This is a terrible "intrauterine development"

2024 Author: Priscilla Miln | [email protected]. Last modified: 2023-12-16 00:21

The first home of every person - the mother's womb - is almost always hospitable and comfortable. However, the 38 weeks (about 266 days) between conception and birth pose a greater threat to life, especially in the first 8 weeks, than any other throughout life until the ninth decade. But despite the potential risk, most children are born into this world in perfect he alth and on time.

Traditionally, doctors divide intrauterine development into three successive stages - trimesters:

• 1st lasts up to 12 weeks;
• 2nd - from 12 to 28 weeks;
• 3rd - from 28 weeks until the baby is born.

Scientists-biologists and embryologists, in turn, prefer to divide intrauterine development into 3 unequal periods: germinal, embryonic and fetal.

We all begin our journey as inanimate matter, having the appearance of two merged cells containing 46 chromosomes, which, in turn, carryan unimaginably vast amount of information about this new emerging life. It is curious that in China it is customary to consider birthday the day of conception, and not the birth of a child. This tradition, it is worth noting, significantly affects the number of abortions.

Intrauterine development of the child by week:

0-2 weeks. The first division of a fertilized egg begins 24-36 hours after fertilization. During the first 40 hours after the first division, all cells are still the same. A 3-4-day-old zygote consists of 12-16 cells and is called a morula, its size is approximately equal to the head of a pin. After 4 days, the dividing cells begin to differentiate and divide into two germ layers: the outer one forms a protective shell around the embryo - the future placenta, and the embryo itself will form from the inner one. Further development occurs in the fallopian tube, resulting in the formation of a blastocyst. Then it approaches the uterus, enters its cavity and attaches to the wall of the uterus to the endometrium - this process is called implantation. It occurs within 10-14 days from the moment of conception. At this stage, embryonic development ends and embryonic intrauterine development begins. About 60% of blastocysts do not attach to the uterine wall and therefore do not survive into the embryonic period. Most of them have gross deviations in development. Thus, nature does not allow the birth of non-viable individuals.

3-8 weeks. The period of embryonic development begins. At this stage, the synthesisvarious chemicals that depress the mother's immunity in order to prevent the rejection of the tissues of the unborn child as a foreign body in the uterus. In addition, the hormone chorionic gonadotropin is actively synthesized (on the basis of which pregnancy is diagnosed) - it stops the woman's menstrual cycle. It also increases the intensity of metabolism (by 10-25%), respiration, blood circulation. Starting from the 3rd week of development, the unborn child is in a very sensitive period of growth. The first trimester of development is the period of morphogenesis, when all human tissues and organs are formed. Scientists say that this period is the most perfect and well-oiled mechanism imaginable! Even the construction and launch of space satellites involving thousands of people and electronic devices is not as complex a process as human development in utero!

At this stage, there are many spontaneous abortions associated with the presence of gross chromosomal defects. There is also a high chance of miscarriage due to unsuitable conditions in the woman's uterus. Only 1 in 6 embryos survive to 8 weeks. During this period, the embryo is most sensitive to harmful external influences, so a woman should be very careful and avoid taking drugs, drinking alcohol, smoking.

After this period, it is almost impossible to influence the morphology of the child.

After 3 weeks, the size of the embryo exceeds the original 10 thousand times.

At the 3rd week of development, the neural tube is formed - the prototype of the brain and spinal cord, developsumbilical cord and placenta.

4 week - the heart is laid. By the end of 4 weeks, it begins to beat separately from the mother. Eyes are starting to form. The neural tube closes. The growth rate of the embryo is about 1 mm per day.

5 week - you can already see the arms and legs of the unborn baby.

6 week - sexual organs begin to form. In case of failures at this stage, it is possible to form a person with signs of both sexes. At this time, the embryo is already visible on ultrasound.

At the 7th week, the formation of such facial defects as the cleft palate is possible. The skeleton is forming.

By the 8th week, the process of formation of the main organs is completed. Rapid brain development begins.

Starting from the 9th week, the beginning of the last fetal period of development is marked. From week 13, the obstetric second trimester of pregnancy begins. At this time, the child looks the same as a newborn, only smaller. Although the head is still disproportionately large. The body straightens and lengthens. The expectant mother notes a surge of energy. Despite the potential dangers, further development is usually successful. At this stage, the brain begins to function.

At a later date, there are no fundamental changes: the fetus increases in size, its organs improve, by the 16th week the mother already feels its movements, by the 20th week the hair begins to grow.

By the 7th month, the fetus can already breathe on its own, digest food, the excretory system is fully functioning. In case of premature birth, the child can already liveyourself.

It has been proven that in the last 3 months of its intrauterine development, a child can already respond to the world around him. He actively moves, hiccups, cries. The main sense organs are developed: smell, touch, taste, sight, hearing. From the 16th week of development, the child reacts to sound (distinguishes voices), light.

As a result, by day 266, the baby finally assumes the head-down position and is ready to be born.

Only in 5% of cases there is spontaneous fetal death in the later stages (after 22 weeks).

Intrauterine development of the fetus by weeks is extremely important information: for the mother - to understand the processes in her own body and the risks associated with them, for doctors - to monitor the development of the fetus, and for the whole society as a whole - to understand that that from the moment of conception begins a rapid and incredibly complex process of the formation of a new life, and not a primitive biomass.