Multiple pregnancy

Multiple pregnancy is one in which more than one fetus develops. This occurs as a result of the fertilization of two or more eggs, or when one egg divides, giving rise in this case to genetically identical twins. Twins can be monozygotic, in which case they are identical, or dizygotic. Monozygotes come from a single egg that has divided into two parts that have continued to develop separately until forming two genetically identical babies, of the same sex and physically very similar. Dizygotic twins, on the other hand, are the result of multiple fertilization. That is, the mother had more than one egg, and these eggs were fertilized by different sperm. So even if they were conceived at the same time, they are totally different babies. They could be of the same sex, or not, and whose physical resemblance is similar to that of siblings born on different dates. Although it is rare, and dangerous for both the mother and the babies, it can also happen that there are three, four, five embryos, or even more (this is especially rare). In this case, babies can also be genetically identical, different, or a combination of both types. Causes In the last two decades there has been a spectacular increase in multiple pregnancies as a result, above all, of the extensive use of fertility techniques. There are various factors that influence the occurrence of a pregnancy of this type: Genetics: a family history of multiple pregnancy increases the chances of its recurrence. Late pregnancy: the older the woman is, the more likely she is to have double ovulation. Especially between 30 and 35 years old. Previous pregnancies: if woman has had several pregnancies, the possibility of having twins increases. Fertility treatments: medications administered to improve fertility considerably increase the incidence of multiple pregnancies. Some are those that stimulate the ovaries to produce multiple eggs, and assisted reproduction techniques, in which several embryos are transferred to the uterus (such as in vitro fertilization). Dangers Multiple pregnancies are considered high risk, both for the mother and the fetuses. When there are more than two embryos, especially from four, parents are sometimes advised to undergo embryo reduction. This consists of injecting a substance into one or more embryos to eliminate them and thus facilitate the viability of the rest. The best thing, however, is to avoid a large number of embryos to avoid having to resort to this measure; For example, do not implant more than two fertilized eggs in the uterus when using the in-vitro method.