Because of the huge amount of sperm rushing to the egg, fertilizing is only one. The rest helped him to penetrate the core of the egg and strengthen it. So pregnancy occurs. This occurs in about 99 out of 100 cases, and is a singleton pregnancy. When a woman's body matures just two eggs are fertilized by sperm at the same time or in the egg formed just two embryonic germ, which are then fertilized, - 9 months born twins .
Unless identical twins (monozygotic) they are exactly the same, always the same sex and similar as two drops of water, after all, the egg and sperm, "took part" in their birth are the same for both. In addition to the physical similarity they are also extremely similar psychic properties. In such "mirror" twins completely identical genes. Although the twins, whatever they may be, are always different fingerprints.
Fraternal (dizygotic) twins born as a result of fertilization of two mature eggs during ovulation different sperm. External similarity between them is not greater than that of siblings born at different times.
In exceptional cases, it happens that in one month, in one or in two ovaries mature egg, not two, and more. All of them can also be fertilized and as a result a woman can give birth to just three or four kids. Thus each human embryo will develop quite independently, in a separate ovum and a separate children's place.
Pregnancy with twins
Since the internal contents of the uterus is larger than normal, the abdomen of a pregnant woman can be very large. One fourth of all pregnancies end with a double before the expected date of birth. Usually the doctor finds pregnant with twins already under examination in consultation, but it is possible only in the last months of pregnancy. However, it happens that the children are in the womb each other - one child in front and the other behind. In this case, to detect twins during pregnancy is virtually impossible.
Schedule the birth of twins You can artificially. The probability of multiple pregnancy, for example, increased during stimulation of ovulation when the woman designate special drugs that stimulate egg growth, rupture of the follicle and so on. D. This often happens in the treatment of infertility in women.
In this situation, the female body is activated, and it can mature multiple eggs in one month. However, it should be borne in mind that such stimulation should be performed only by very experienced professional who chooses the woman drugs prescribed dose and controls the whole process of treatment. If a woman decides to take these drugs on their own, it risks exceeding the dosage, which can lead to ovarian cysts, bleeding.
When artificial insemination the probability of conception and birth of twins is even higher than when using stimulant medications. The fact that artificial insemination introduced into the woman's uterus several fertilized eggs (it increases its chance of becoming pregnant). And in the case of pregnancy she optional leave one embryo or all.
What you need to know about twins
Twins and prematurity. The probability of premature birth to the twins is high. But experienced obstetricians say fine if the twins are hatching a little less - not 40 weeks, as is the case at the birth of one child, and 37 weeks.
Twins and extrasensory abilities. There is a very widespread opinion that the twins feel each other at a distance. But in fact, clear scientific evidence on this point. The twins spend a lot of time with each other. This, according to many scientists, and it is determined by their particular susceptibility.
Twins and school. Numerous studies have shown that no permanent form of placing students in the school is not suitable for the Twins. They must sit together and at the same time apart. To do this, they need to be swapped his desk each year.
Pregnancy and Gynecology
Go back to the main page
Немає коментарів:
Дописати коментар