囊胚移植对增加单卵双胎风险的研究

目的 比较囊胚期胚胎移植和卵裂期胚胎移植单卵双胎的发生率. 方法 回顾性分析2009年1月—2011年12月在本院生殖中心行体外受精-胚胎移植/卵胞浆内单精子显微注射患者的资料,根据移植胚胎的发育阶段,分为卵裂胚移植组和囊胚移植组.比较两组单卵双胎的发生率及其临床结局. 结果 卵裂期胚胎移植组移植胚胎的数目多[（2.0±0.3）个],多胎率高（32.1％）,与囊胚移植组比较,差异有统计学意义;卵裂期胚胎移植组和囊胚移植组的单卵双胎率（2.6％和3.6％）、流产率（33.3％和29.4％）、活胎分娩率（66.7％和70.6％）、早产率（75.0％和66.7％）及低体重儿出生率（50.0％和78.3％）差异均无统计学意义. 结论 囊胚移植不增加单卵双胎发生率的风险.

The risk of monozygotic twinning not increased after blastocyst transfer

Objective To compare monozygotic twinning rate of blastocyst transfer with cleavage embryo transfer.Methods All patients received in vitro fertilization embryo transfer or intracytoplasmic sperm injection during January 2009 to December 2011 were enrolled in this study.According the development stage of transfer embryos,patients were divided into two groups,the blastocyst transfer group and the cleavage embryo transfer group.The monozygotic twinning rate of the two groups were compared.Results Significant differences in twinning rate and multiple pregnancy rate between the blastocyst transfer group and the cleavage embryo transfer group were observed,but no difference was observed in monozygotic twinning rate between the two groups.Rates of miscarriage,live birth,premature birth,and low birth weight were not different between the two groups.Conclusion The risk of monozygotic twinning was not increased after blastocyst transfer.