Third pregnancy is a multiple pregnancy with three fetuses in the womb. Around 10-20 are born in Finland every year.
Pregnancy can start spontaneously without any hormone or fertility treatment, but there is a greater risk of pregnancy. Finland has, for example, for this reason, in fertilization treatments, it is usually transferred to single embryo transfers. Third risk of pregnancy increases the genetic heritage, especially the mother’s side of the family.
You can also shed three eggs at a time. Each of these ova can be fertilized by a different sperm, whereby all three children are non-identical. Most commonly, however, a third pregnancy occurs when two concurrent erythrocytes are fertilized by different spermatozoa. One of these fertilized eggs divides into two, giving rise to an identical twin pair and the third remaining unidentified. Identical twin pairs are of the same genus and thus of the same sex. The third may be of the same or different sex. The rarest mechanism for the birth of a third pregnancy is that a woman breaks down one egg, which, after fertilization, is split in half, and then split in half by another half. Then all three children are identical with each other. Early pregnancy ultrasound screening aims to determine chronostasis, the number of fetal membranes from which identity can be determined.