Preimplantation development of human embryos with numerical chromosome abnormalities in vitro

The study was focused on morphokynetic characteristics of in vitro cultured human embryos that were considered to be aneuploid or euploid according to the preimplantation genetic screening results. Among all the embryos examined, only 34.2% were chromosomally balanced. Although morphological features of cleaving pathologic and euploid embryos did not differ significantly, on the fifth day of culture, a chromosomally balanced specimen formed an “expanded” blastocyst twice more frequently than abnormal ones. Moreover, development of 38.4% of aneuploid embryos was compromised before the initiation of cavitation. Thus, prolonged embryo culture advances selection of samples with the highest implantation potential for the transfer on the basis of the morphokynetic characteristics and helps to avoid additional genetic testing.