This terrible "intrauterine development"

The first house of each person - mother's womb - is almost always hospitable and comfortable. Nevertheless, 38 weeks (about 266 days) between conceiving and giving birth represent a great threat to life, especially for the first 8 weeks, than any others throughout the subsequent life until the ninth decade. But, despite the potential risk, most children are in this world completely healthy and on time.

Traditionally, doctors divide intrauterine development into three consecutive stages - the trimester:

• The first lasts up to 12 weeks;
• The second - from 12 to 28 weeks;
• 3rd - from 28 weeks until the child's birth.

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

We all begin our journey as an inanimate matter that looks like two merged cells containing 46 chromosomes, which in turn carry an unbelievable amount of information about this new born life. It is curious that in China, it is considered the day of birth to be the day of conception, and not the appearance of a child. This tradition, it is worth noting, significantly affects the number of abortions.

Intrauterine child development by week :

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

3-8 weeks. The period of embryonic development begins. At this stage, a synthesis of various chemicals that depress the immune system of the mother, 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 the pregnancy is diagnosed) - it stops the woman's menstrual cycle. Also, the intensity of metabolism (by 10-25%), breathing, blood circulation increases. Beginning from the 3rd week of development the future child is in a very sensitive period of growth. The first trimester of development is the period of morphogenesis, when all tissues and organs of man are laid. Scientists say that this period is the most perfect and well-established mechanism that can only be imagined! Even the design and launch of space satellites involving thousands of people and electronic devices are not as difficult as the intrauterine development of a person!

At this stage, many spontaneous abortions occur, due to the presence of gross chromosomal defects. Also, the probability of miscarriage due to improper conditions in the woman's womb is high. Only 1 in 6 embryos survive to 8 weeks. During this period, the embryo is most sensitive to harmful influences from outside, so a woman should be very careful and avoid taking medication, drinking alcohol, smoking.

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

At 3 weeks, the size of the embryo exceeds the original one by 10,000 times.

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

4 week - the heart is pawned. By the end of 4 weeks it starts to beat separately from the mother. The eyes start to form. The neural tube closes. The growth rate of the embryo is about 1 mm per day.

5 week - you can already consider the arms and legs of a future child.

6 week - the sexual organs begin to form. With 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 week 7, it is possible to form such facial defects as the wolf mouth. A skeleton is formed.

By the 8th week the process of forming the main organs is coming to an end. Rapid development of the brain begins.

Beginning with the 9th week , the beginning of the last fetal development period begins. From the 13th week, the obstetric second trimester of pregnancy begins. At this time the child looks just like a newborn, only a smaller size. Although the head is still disproportionately large. The body straightens and lengthens. The future mother marks a surge of energy. Despite the potential dangers, further development, as a rule, is successful. At this stage, the brain begins to function.

In later terms, there are no fundamental changes: the fetus increases in size, its organs are improved, by 16 weeks the mother already senses its movements, by the 20th week, hair begins to grow.

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

It is proved that in the last 3 months of its intrauterine development the child can already react to the surrounding world. 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 266 the child finally takes a position head down and is ready to be born.

In only 5% of cases, spontaneous fetal fading is observed in late terms (after 22 weeks).

Fetal development of the fetus for weeks is extremely important information: for the mother - for understanding the processes in one's own organism and the risks associated with them, for doctors - to monitor the development of the fetus, and for the whole society - to understand that from the moment Conception begins a rapid and incredibly complex process of forming a new life, rather than a primitive biomass.