Every woman dreams about the birth of her own children, not only the maternal instinct formed during childbirth leads to this, but also the desire to fulfill oneself. Children born in one fetal egg (identical twins) are extremely rare. According to scientists, the probability of having twins is about one tenth of a percent. The identical twins are outwardly practically indistinguishable. This feature is due to the fact that their formation occurs from one cell (zygote) by dividing it in the early stages of pregnancy.
Sperm, penetrating the egg, fertilize it. The interaction occurs with only one sperm, which introduces part of the male genotype into the cell of the female reproductive system.
A fertilized egg (zygote) is able at this moment to share, however, under the influence of what mechanisms and why this happens, it is not yet clear. Thus, the formation of twins from one egg occurs.
It turns out that such twins are copies of each other, not only externally, but also internally. Studies have shown that more than ninety percent of such twins are indistinguishable even from fingerprints.
The identical twins of different sexes do not exist because the genotype of both embryos is identical. The only feature of identical twins that may occasionally be present is the formation of mirror twins. In this case, one of the children is right-handed, and the other is left-handed, and the fingerprints on their hands are mirrored to each other. Often, even internal organs are located in opposite places. Often, twins even have the same type of disease, because the predispositions to pathologies in such organisms are the same. An interesting fact is that the separated (living and brought up in different families) twins not only have similar characters, but even the tastes and attitude to the objects around them are the same.
What are the features of the development of twins?
Firstly, identical twins in the womb have one common placenta, and secondly, due to the uneven circulation of blood, one of them is often underdeveloped. Sometimes there are situations when the discrepancy in the saturation (oxygenation) of the blood is so high that one of the fruits (lacking nutrition) dies. In addition, the development of Siamese twins is sometimes possible (a condition in which there was no complete separation of the fruits and they are connected with each other). In the best case, their connection may be insignificant and amenable to operational rupture, however, quite often there are severe cases when children are joined together by their heads or have one trunk. In this case, surgery is almost impossible. And successful attempts to separate such twins are single and well known.
For many women, identical twins are a desirable goal, however, their formation under the influence of any medical or non-medical effects is impossible. Separation of the egg, which ultimately leads to the formation of twins, occurs spontaneously. After a series of studies by scientists, it was found that there is a certain genetic predisposition to the possibility of twin births. So for women who have relatives with such children, the likelihood of having twins, including identical ones, is significantly higher than the average level.
Thus, identical twins, although they are desirable women, are often a real punishment. Difficulties in childbirth, the possibility of the development of Siamese twins, and even the death of one of the fetuses lead to a great risk for both children and the mother's body.