早期卵裂与常规体外受精胚胎质量的相关性研究

A retrospective study on evaluating the association of early cleavage and embryo quality in human IVF

目的探讨早期卵裂(EC)与常规体外受精(IVF)胚胎质量的关系,评估EC能否作为胚胎体外发育潜能的一个预测指标。方法对619个IVF周期共3 646枚正常受精胚胎进行早期卵裂观察和第3天(D3)卵裂期胚胎质量评估;对其中682枚D3优质胚胎和2 180枚D3非优质胚胎进行囊胚培养,于第5天(D5)和第6天(D6)进行囊胚期胚胎质量评估。根据EC观察结果,将胚胎分成三组:EC组、原核消失(PNBD)组和原核还在(NPNBD)组。结果 D3胚胎平均卵裂球数EC组胚胎显著多于PNBD组和NPNBD组(P <0. 05),NPNBD组最低; D3优质胚胎率EC组与PNBD组差异无统计学意义(P> 0. 05),但是两组均显著高于NPNBD组; EC组D3可冻胚胎率和D3可用胚胎率均显著高于PNBD组和NPNBD组(P <0. 05),NPNBD组最低。D3优胚行囊胚培养,D5囊胚形成率和D5优质囊胚率三组之间差异无统计学意义(P> 0. 05),D5可冻囊胚率PNBD组显著高于NPNBD组(P <0. 05);总囊胚形成率、总优质囊胚率和总可冻囊胚率在三组之间差异无统计学意义(P> 0. 05)。D3非优胚行囊胚培养,EC组D5囊胚形成率、D5优质囊胚率、D5可冻囊胚率、总囊胚形成率、总优质囊胚率和总可冻囊胚率均显著高于PNBD组和NPNBD组(P <0. 05)。结论发生EC的胚胎发育速度较快,更容易发育成高质量的D3卵裂期胚胎,EC可以作为D3胚胎质量的一个预测指标。早期卵裂D3优质卵裂胚胎体外囊胚发育结局与非早期卵裂D3优质胚胎相比没有明显差异,EC可能不足以作为D3优质卵裂胚胎囊胚体外发育潜能的额外预测指标。

Objective To evaluate the association of early cleavage（EC） with in vitro fertilization（IVF） embryo quality and to investigate the predictive value of EC as an indicator of subsequent embryonic development potential in vitro. Methods A total of 3 646 individually cultured 2PN embryos from 619 IVF treatment cycles were included, and the early cleavage status and day 3 embryo scoring were assessed. The blastocyst culture of day 3 optimal embryos（ n =682） and the non-optimal embryos（ n =2 180） were carried out and the embryo quality evaluations were performed on day 5 and day 6 respectively. According to the results of EC observations, the embryos were divided into three groups： EC group, pronuclear breakdown（PNBD） group and non-pronuclear breakdown（NPNBD） group. Results The mean number of blastomeres per embryo on day 3 of the EC group was significantly larger than that of PNBD group or NPNBD group（ P 〈0.05）, and the least number was in the NPNBD group. There was no significant difference in the high-quality embryonic rate on day 3 between the EC group and the PNBD group（ P 〉0.05）, but the high-quality embryonic rates of both groups were significantly higher than the high-quality embryonic rates of the NPNBD group（ P 〈0.05）. The rates of frozen embryo and available embryo on day 3 in the EC group were significantly higher than those in the PNBD group and the NPNBD group（ P 〈0.05）, and the lowest rates were in the NPNBD group. For the optimal embryonic blastocyst culture on day 3 or on day 5, the frozen blastocyst ratio of the PNBD group was significantly higher than that of the NPNBD group（ P 〈0.05）, but on day 5, the differences in the blastocyst formation rate and the high quality blastocyst rate were not significant among the three groups（ P 〉0.05）.The differences in total blastocyst formation rate, the total quality blastocyst rate and the total frozen blastocyst rate were not statistically significant among the three groups（ P 〉0.05）. For the non-optimal embryonic blastocyst culture on day 3, the blastocyst formation rate, the high quality blastocyst rate, the frozen blastocyst rate, the total blastocyst formation rate, the total high quality blastocyst rate and the total frozen blastocyst rate on day 5 of the EC group were significantly higher than those of the PNBD group and the NPNBD group. Conclusion EC embryos have a relatively fast embryonic development, and they are more likely to develop into a high-quality cleavage embryo on day 3. EC can be used as a predictor of embryo quality on day 3. For in vitro blastocyst development, there is no significant difference between the good-quality EC embryos and the non-EC embryos on day 3. For high quality cleavage embryos, EC may not be sufficient to be an additional predictor of the development potential of blastocyst in vitro.