This is where geanuer explains how a twin birth is and how for example, identical twins and fraternal twins in their development differ. In this day and age, multiple births are no longer a rarity, especially the birth of twins is much higher than in the past due to the medical facilities. Hormone treatments and so-called artificial inseminations resulted that the rate of multiple births has increased. The most common multiple births is the special case of twin pregnancy, which overall can occur with a probability of 1 / 250 and thus quite often occurs as you generally like to think. Actually, the medicine namely formulated the concept of twins is very accurate, as two children, a mother and a father, which were conceived on the same day and within of the same birth process see the light of day usually on the same day, so. Here the difference in addition to the uberschwangerung, where two children experience the birth at the same time, due to its procreation but not be described as twins. During pregnancy there are four clearly distinct forms of the twin birth, the twins, Dizygotic twins, Polkorperchenzwillinge and twins two vigorous eggs, with the two latter options are extremely rare and are explained in the following unspecified twin forms of education. The fertilized egg divides identical twins where in the course of their development in two embryonic plants same genetic material with the same genes (mono-zygotisch).

This Division of the fertilized egg is also called Zwillingsschlupf. The further development of the cells provides different specializations of this in the first few days after fertilization. Depending on the vergehendem period, there are differences in the expression of placental and embryonic part, while the formation of inner and outer Eihaut plays an important role, because they can be separated anymore after emergence. The Division takes place in the first three days after fertilisation, nest contact both germ cell parts for itself in the uterus, resulting in two fruit bubbles and two Plazentas are created.