Abstract：
OBJECTIVE: 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?
METHODS: 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.
RESULTS: 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.
CONCLUSIONS: 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.
METHODS: 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.
RESULTS: 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.
CONCLUSIONS: 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.
摘要：
目的：在人类原核期胚胎中，原核轴与第一卵裂平面形成之间存在关系吗？
方法：对移植的胚胎进行随访直至其预后。在延时培养箱中正常受精后，总共有762个胚胎形成了两个细胞，并达到了胚泡期。胚胎分为三组：A组：第一个分裂平面平行于原核轴形成的胚胎；B组：观察到斜向形成的胚胎；C组：观察到垂直形成的胚胎。
结果:A、B组的整倍体率明显高于C组(P<0.01),而C组的非整倍体率显着高于A组和B组（P<0.01）。基于HCG的妊娠试验阳性频率三组之间没有差异，临床妊娠的频率，流产率或分娩率。
结论：相对于原核轴的第一分裂平面的形成模式是胚胎倍性的预测指标，当第一个分裂平面垂直于原核轴时，观察到的整倍体率降低，非整倍体的可能性很高。
方法：对移植的胚胎进行随访直至其预后。在延时培养箱中正常受精后，总共有762个胚胎形成了两个细胞，并达到了胚泡期。胚胎分为三组：A组：第一个分裂平面平行于原核轴形成的胚胎；B组：观察到斜向形成的胚胎；C组：观察到垂直形成的胚胎。
结果:A、B组的整倍体率明显高于C组(P<0.01),而C组的非整倍体率显着高于A组和B组（P<0.01）。基于HCG的妊娠试验阳性频率三组之间没有差异，临床妊娠的频率，流产率或分娩率。
结论：相对于原核轴的第一分裂平面的形成模式是胚胎倍性的预测指标，当第一个分裂平面垂直于原核轴时，观察到的整倍体率降低，非整倍体的可能性很高。
