The process of woman's fertilization leads to the onset of pregnancy - this, perhaps, everyone knows today. At first you, perhaps, parents tried to explain this, of course, resorting to all sorts of allegories and metaphors. Then they told you about this teacher, already using medical terms. In both cases, the story, as a rule, was either too veiled or overwhelmed with incomprehensible words and phrases.
The process of fertilization
After the termination of the sexual certificate or act in an organism of the woman there are on the average from 100 up to 300 million spermatozoons. The most active and viable of them already after a couple of minutes get to the uterus, where in 2-3 hours in the end sections of the fallopian tubes merge with the ready for fertilization egg.
Fertilization of an egg is possible, as a rule, in a certain period of a month - the time when ovulation occurs. At this point, the egg leaves the ovary and prepares to meet with the sperm. The process of woman's fertilization is the fusion of one sperm with one egg, as a result of which an embryo is formed. Of course, at the initial stage the embryo is a single-celled creature - a zygote, which for a long time to grow and develop.
Unusual fertilization
If there are several active spermatozoa, then a multiple pregnancy occurs. Perhaps the fertilization of two spermatozoa of one egg, then the light appears odnoyaytsovye twins, which are similar to each other as two drops of water. Such children still have everything in common in the mother's womb: circulation, shell, placenta and even genetics. It is worth noting that the twins in the development process are related to each other, so the death of one often leads to the death of the second.
If two spermatozoa fertilize different eggs, then children are obtained only by neighbors. Such babies can be of different sexes and completely different from each other, since they still have different placenta, blood circulation, membrane and genes during development. If during pregnancy one fetus perishes, to the second it only facilitates the existence.
Multiple pregnancy can often be the result of artificial insemination of a woman. For example, during infertility treatment, ovarian hyperstimulation is carried out, which leads to the maturation of two or three eggs. ECO also means placing several embryos in the uterus, because the chance that the child will take root is quite small. But there are cases when not only one embryo is viable - so there are twins and triplets.
Recently, cases of cross-fertilization in women, which until recently seemed to be a kind of fairy tale, also increased. In order for fertilization to take place and pregnancy become natural in a natural way, a woman needs a functioning ovary and a fallopian tube. But often it happens that, due to an operation or a transferred illness, only one ovary works, and a passable fallopian tube is on the other side. But as practice shows, a woman's fertilization can occur even in this case.
Ovum after fertilization
How much you would not try to see signs of fertilization - the process takes place only a few hours after the end of the sexual intercourse. And the pregnancy itself comes in 6-7 days, when a fertilized egg gets to the uterus. Therefore, the symptoms of pregnancy you will notice not earlier than a week.
Practitioners of contraception to couples based on the period of ovulation should be aware that fertilization can occur and much later. The ovum after ovulation retains its viability for another 24 hours, and spermatozoa can be active for several days.