Research question

Is live birth of patients with excessive slow (no blastocyst on day 5) and fast mitotic rate (full blastocyst development on day 4) comparable to a matched control standard (blastocyst formation on day 5)?

Design

In this retrospective matched (age and anti-Müllerian hormone [AMH]) case-control study rates of fertilization, blastulation, implantation, clinical pregnancy and live birth were compared in couples with male factor indication, prolonged embryo culture and fresh single morula and blastocyst transfer.

Results

The rates of implantation, clinical pregnancy and live birth in the slow-developing group were significantly (P < 0.001) lower (17.6%, 13.7%, and 11.8%, respectively) compared with the fast (58.5%, 52.5%, 47.5%) and normal growing counterparts (51.5%, 42.6%, 39.6%). No differences in neonatal outcome could be observed between the three groups. Sex ratio in the fast-growing group was not different from the other cohorts.

Conclusions

Extremely slow development, as assessed by the absence of blastulation on day 5, is a negative predictor of pregnancy and live birth. In contrast, the fear that extremely fast-growing embryos may represent an aneuploid cohort of embryos is unsubstantiated. Day-4 full blastocysts can preferentially be considered for transfer.

中文翻译：

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兔子和乌龟：极端的有丝分裂率以及它们如何影响活产

研究问题

过慢（第 5 天没有胚泡）和过快的有丝分裂率（第 4 天胚泡发育完全）患者的活产是否与匹配的对照标准（第 5 天胚泡形成）相当？

设计

在这项回顾性匹配（年龄和抗苗勒管激素 [AMH]）病例对照研究中，比较了具有男性因素适应症、延长胚胎培养时间和新鲜单桑椹和囊胚的夫妇的受精率、成胚率、着床率、临床妊娠率和活产率转移。

结果

注入，临床妊娠和活产慢显影组中的比例分别为显著（P与快速（58.5％，52.5％，47.5％相比<0.001）降低（17.6％，13.7％，和11.8％，） ) 和正常生长的对应物 (51.5%、42.6%、39.6%)。三组之间未观察到新生儿结局的差异。快速增长组的性别比与其他队列没有区别。

结论

根据第 5 天没有胚泡评估，发育极其缓慢是怀孕和活产的负面预测因素。相比之下，对生长极快的胚胎可能代表一组非整倍体胚胎的担忧是没有根据的。可以优先考虑移植第 4 天的完整囊胚。