There is a special beauty in pregnancy. The promise of a new life in a woman’s body looks very life-affirming. Complex processes take place inside at all stages of the “interesting situation”. The exact day of conception can not always be established. The doctor will record in the documents the first day of the last menstruation as the beginning of pregnancy. Although in reality a new life begins about two weeks later than the time formally fixed in the papers. How does conception occur?
Preparation stage
It all starts with ovulation. Each month, several “candidates” are prepared for release in the ovary, but as a rule, only one egg is released, sometimes two. If more than one comes out and both are fertilized, then twin brothers will be born . Strictly speaking, they are not twins at all. And they will be similar as two children of the same parents.
16 children at a time?
How does the conception of true twins occur? Like any other, but for some reason, at a certain stage, several embryos with the same genetic code are formed. Theoretically, a person can have as many as 16 twins at a time, since at the stage of 16 blastomeres each cell can give rise to the whole organism. But a huge number of twin twins usually occurs due to treatment for infertility, for a person conceiving more than two children at the same time is not normal.
Exceptional Cases
By the way, contrary to popular belief, a boy and a girl cannot be true twins, because men and women have a different genetic set, and the set of twins is identical. The only exception, theoretically possible: two children are genetically boys, but in one of them the intrauterine development went wrong, and in the girl the sex that has formed does not correspond to the present. Such "girls" are barren.
Access denied
How does conception occur? After the egg is released in the fallopian tube, it can meet a waiting sperm. But usually there are millions of them. Not every one of them can fertilize a cell. Scientists have found that each egg has a specific “access code” that manifests itself in the chemical structure of the protein at the outer border. If the sperm has the “correct” code on the membrane, then fertilization can take place. After the male cell penetrates into the egg, it becomes inactive and inaccessible to other “candidates”.
Biochemistry is to blame
The female cell is so arranged that before fertilization it is not complete - the process of meiosis ends only after the start of interaction with the sperm. If the meeting with a worthy “partner” does not occur, then the egg is destroyed, the hormonal status changes - and menstruation begins. Knowing how conception occurs can explain the infertility of some couples in which the partners seem to be both healthy. In such cases, the husband and wife are incompatible at the biochemical level. If they create families with other partners, then both can safely have children.
In the process of conception, many secrets remain. We do not know all the laws of what is happening. But one thing is clear - more research is needed on the conception. Then there will be an opportunity to help couples suffering from infertility.