Determined zygosity for multifetal pregnancy. Literature date and own cases of spontaneously conceived triplet pregnancies
The literature date about determined zygosity for multifetal pregnancy were offered. The own results of study of the chorionicity and zygosity cross-distribution in spontaneously triplet pregnancies (n=10) were presented. Chorionicity was determined by placental analysis and 20 % of the triplets were monochorionic, 20 % were trichorionic, 60 % were dichorionic. Molecular-genetic analysis zygosity by short tandem repeats DNA (STR markers) was made for 7 cases. We detected 42.9 % monozygotic, 28.6 % dizygotic, 28.6 % trizygotic triplet pregnancy. It was demonstrated, that zygote can divide one or more times, and multiple pregnancy with different placentation can arise. Most of the triplet pregnancy conceived without IVF or induction ovulation was monozygotic.