{Reference Type}: Journal Article
{Title}: Formation of the first plane of division relative to the pronuclear axis predicts embryonic ploidy.
{Author}: Mizobe Y;Kuwatsuru Y;Kuroki Y;Fukumoto Y;Tokudome M;Moewaki H;Orita Y;Iwakawa T;Takeuchi K;
{Journal}: Reprod Biomed Online
{Volume}: 49
{Issue}: 3
{Year}: 2024 Sep 13
{Factor}: 4.567
{DOI}: 10.1016/j.rbmo.2024.104110
{Abstract}: <B>OBJECTIVE: </B>Is there a relationship between the pronuclear axis and the first cleavage plane formation in human pronuclear-stage embryos, and what are the effects on ploidy and clinical pregnancy rates?<BR><B>METHODS: </B>Transferred embryos were followed up until their prognoses. A total of 762 embryos formed two cells and reached the blastocyst stage after normal fertilization in a time-lapse incubator. Embryos were classified into three groups: group A: embryos in which the first plane of division was formed parallel to the axis of the pronucleus; group B: embryos in which cases of oblique formation were observed; and group C: embryos in which cases of perpendicular formation were observed.<BR><B>RESULTS: </B>The euploidy rate was significantly higher in groups A and B than those in group C (P < 0.01), whereas the aneuploidy rate was significantly higher in group C (P < 0.01) than in groups A and B. No differences were found between the three groups in frequency of positive HCG-based pregnancy tests, frequency of clinical pregnancies, miscarriage rates or delivery rates.<BR><B>CONCLUSIONS: </B>The formation pattern of the first plane of division relative to the pronuclear axis was a predictor of embryonic ploidy, with a reduced rate of euploidy and a high probability of aneuploidy observed when the first plane of division was perpendicular to the pronuclear axis.