冻融胚胎卵裂球完整性及继续发育与临床结局的相关性

Correlation of blastomere integrity and continued development with pregnancy outcome of freeze-thawed embryo

目的探讨玻璃化冷冻胚胎解冻后胚胎卵裂球完整性及胚胎是否继续发育与临床结局的相关性。方法回顾性分析420例冻融胚胎移植周期,按照移植胚胎的完整性分为两组:完整组(解冻后移植胚胎的卵裂球均完整,n=312),损伤组(解冻后移植胚胎至少有一个卵裂球损伤但损伤比例≤50%,n=108)。根据解冻后体外培养18-24 h内胚胎恢复有丝分裂的情况将完整组和损伤组分为完整组A1、损伤组B1,所有胚胎均恢复有丝分裂的FET周期组;完整组A2和损伤组B2,部分胚胎恢复有丝分裂的FET周期组;完整组A3和损伤组B3,无胚胎恢复有丝分裂的FET周期组。比较各组的临床妊娠率和胚胎种植率。结果完整组中,患者年龄、内膜厚度、移植胚胎数等因素差异无统计学意义,完整组A1临床妊娠率和胚胎种植率高于完整组A3(P<0.05);完整组A2与完整组A1、完整组A3相比在临床妊娠率和胚胎种植率方面差异均无统计学意义。损伤组中,患者年龄、内膜厚度、移植胚胎数等因素差异无统计学意义,损伤组B1胚胎种植率高于损伤组B3(P<0.05),而这两组之间的临床妊娠率差异并无统计学意义;同样的,损伤组B2与损伤组B1、损伤组B3比较,临床妊娠率和胚胎种植率差异均无统计学意义。在有同样继续发育情况的前提下,移植卵裂球损伤胚胎损伤组B比移植完整存活胚胎完整组A的胚胎种植率明显降低(P<0.05)。结论冻融胚胎解冻后可通过过夜培养,甄选有发育潜能的胚胎进行移植,以改善妊娠结局。而无论胚胎本身是否发生损伤,过夜培养后全部未恢复有丝分裂的胚胎,应慎重考虑该周期是否进行移植。

Objective To investigate the integrity of blastomeres from vitrified embryos after thawing,and explore the correlation of the continuous development of embryos with clinical outcomes.Methods The transfer cycle of 420 frozen-thawed embryos was retrospectively analyzed.Based on the integrity of transplanted embryos,the embryos were divided into integrity group（group A;blastomeres of transplanted embryos were all integrate after thawing;n = 312） and injury group（group B;at least 1 blastomere of transplanted embryos was damaged after thawing with injury ratio≤50%;n = 108）.According to the restoration of mitosis in the embryos cultured in vitro within 18-24 h after thawing,integrity group and injury group were divided into integrity group A1 and injury group B1（FET cycle of mitosis was restored in all embryos）,integrity group A2 and injury group B2（FET cycle of mitosis was restored in partial embryos）,integrity group A3 and injury group B3（no FET cycle of mitosis was restored in the embryos）.Clinical pregnancy rate and embryo implantation rate were compared.Results In group A,patients＇ age,endometrial thickness and the number of transplanted embryos showed no statistically significant differences among three subgroups.Clinical pregnancy rate and embryo implantation rate in integrity group A1 were higher than those in integrity group A3（P 〈0.05）.No statistically significant differences were found in clinical pregnancy rate or embryo implantation rate between integrity group A2 and integrity group A1,integrity group A3.In injury group B,patients＇ age,endometrial thickness and the number of transplanted embryos also presented no statistically significant differences among three subgroups.Embryo implantation rate in injury group B1 was higher than that in injury group B3（P 〈0.05）,while clinical pregnancy rate showed no statistically significant difference between the two groups.Similarly,clinical pregnancy rate and embryo implantation rate demonstrated no statistically significant differences between injury group B2 and injury group B1,injury group B3.Under the same continuous development,embryo implantation rate in injury group B decreased significantly compared with integrity group A（P〈 0.05）.Conclusion Embryos with developmental potential can be screened out from frozen-thawed embryos after thawing by overnight culture for transplantation to improve pregnancy outcome.For damaged and non-damaged embryos without restoration of mitosis after overnight culture,transplantation should be carefully considered in this cycle.