This is a terrible "prenatal development"

The First house of every man – the uterus of the mother – almost always welcoming and comfortable. However, 38 weeks (about 266 days) between conception and birth are a major threat to life, especially for the first 8 weeks than any other for the rest of their lives until the ninth decade. But despite the potential risk, most children are in this world absolutely healthy and timely manner.

Traditionally, doctors divide prenatal development into three successive stages - trimester:

• 1st lasts up to 12 weeks;
• 2nd - from 12 to 28 weeks;
• 3rd – 28 weeks until birth into the light.

Biologists and embryologists, in turn, prefer to divide fetal development for 3 different time periods: germinal, embryonic, and fetal.

We All start our journey as inanimate matter, which has the form of two merged cells contain 46 chromosomes, which, in turn, have an enormous amount of information about this new little life. Interestingly, in China a birthday is considered the day of conception and not of birth into the light. This tradition, it is worth noting, significantly affects the number of abortions.

Intra-uterine development of the child in weeks:

0-2 weeks. the First division of the fertilized egg begins after 24-36 hours after fertilization. During the first 40 hours after the first division all the cells are still the same. 3-4 days, the zygote consists of 12 to 16 cells called the morula, its size is approximately equal to the head of a pin. After 4 days, dividing cells begin to differentiate and divide into two germ layer: forms a protective outer shell around the embryo – future placenta, and the inner will form the actual embryo. Further development occurs in the fallopian tube, resulting blastocyst. Then she approaches the uterus out of its cavity and attached 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. Up to this point, the embryo begins embryonic and fetal development. About 60% of blastocysts do not attach to the uterine wall and therefore do not reach the embryonic period. Most of them have gross abnormalities in development. Thus, nature does not allow the birth of nonviable individuals.

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3-8 weeks. the period of embryonic development. At this stage, the synthesis of various chemicals which depress the immune system of the mother to prevent rejection of the tissues of the unborn child as a foreign body in the uterus. In addition, actively synthesized hormone, human chorionic gonadotropin (on the basis of which is the pregnancy diagnosed) – he suspends the menstrual cycle of a woman. Also increases the basal metabolic rate (10-25%), breathing, circulation. Starting with 3 weeks of development the baby is in a very sensitive period of growth. First trimester development – this is the period of morphogenesis, when there is a bookmark all tissues and organs. Scientists say that this period represents the most perfect and well-oiled mechanism that you can imagine! Even the design and launch of space satellites with the participation of thousands of people and electronic devices are not as complex as intrauterine human development!

At this stage there is a lot of spontaneous abortions associated with the presence of gross chromosomal defects. Also a high probability of miscarriage due to unsuitable conditions in the woman's uterus. Only 1 out of 6 embryos survive to 8 weeks. During this period the embryo is most sensitive to harmful influences from the outside, so a woman should be very cautious and avoid medications, alcohol consumption, and Smoking.

At the end of this period to affect the morphology of the child is almost impossible.

In 3 weeks the size of the embryo exceeds the initial 10 thousand times.

On the 3rd week of development formed neural tube-the prototype of the brain and spinal cord, develops the umbilical cord and the placenta.

Week 4 – laid heart. By the end of 4 weeks it starts to beat separately from the parent. Begin to form the eyes. Closed neural tube. The growth rate of the embryo is about 1 mm per day.

Week 5 – can be the hands and feet of the unborn child.

Week 6 - begin to form the sexual organs. Failures at this stage it is possible the formation of a person having characteristics of both sexes. At this period the embryo is already visible on ultrasound.

7 week, the formation of such facial defects like cleft palate. Forming the skeleton.

8 week the process of formation of major organs. Starts the rapid development of the brain.

Since 9 weeks marks the beginning of the last fetal period of development. 13 weeks starts second trimester obstetric pregnancy. At this time the child looks just like a newborn, only smaller. Although the head is still disproportionately large. The body straightens and lengthens. The expectant mother said a surge of energy. Despite the potential danger, further development, as a rule, is successful. At this stagestarts functioning brain.

At a later date is no longer happening fundamental changes: fetus grows in size, improving its bodies, by week 16, the mother is already feeling its movement, the 20th week start to grow hair.

7 month fruit can breathe, digest food, fully functioning excretory system. In the case of premature births, babies can live on their own.

It is Proved that in the last 3 months of their fetal development, babies can react to the world. He is actively moving, hiccups, crying. Developed basic senses: smell, touch, taste, sight, hearing. With 16 weeks of development the baby responds to sound (distinguish between the voices), light.

In the end to 266 the day the child finally accepts the position of head down and ready for birth.

Only 5% of cases there is spontaneous fading of the fetus in late pregnancy (after 22 weeks).

Fetal development by weeks – extremely important information for mother – understanding of the processes in your own body and the risks associated with them, for doctors – to follow the development of the fetus and to society as a whole – to understand that from the moment of conception begins the rapid and incredibly complex process of building a new life, and not primitive biomass.