The Incidence Of Monozygotic Twining After Assisted Reproductive Technology:A Meta-Analysis

Objective:To study the incidence of monozygotic twining(MZT)after assisted reproductive technology(ART).Methods:The PubMed、Embase、Cochrane Library、CNKI、WanFang database、CQVIP and CBM databases were searched before February 2019.We selected studies which were about the incidence of monozygotic twinning in ART,the factors which included fresh versus frozen-thawed embryos,cleavage-stage embryos versus blastocyst,IVF versus ICSI.The fixed effects model and random effects model were used to evaluate the summary odds ratios with 95%confidence intervals.Results:Fifteen retrospective studies were included in our meta-analysis.Eight studies were included for the rate of MZT between fresh and frozen-thawed embryos transfer.Contrasted to fresh embryos,frozen-thawed embryos transfer can increase the risk of MZT(OR=0.80,95%CI=0.68-0.94,P=0.006,fixed effects model,I~2=34%).The blastocyst transfer can increase the risk of MZT in contrast to cleavage-stage embryos transfer with including the ten studies(OR=0.51,95%CI=0.38-0.69,P<0.0001,random effects model,I~2=61%).And there was no significantly difference between IVF and ICSI after analyzed eight studies(RR=0.92,95%CI=0.71-1.21,P=0.56,fixed effects model,I~2=28%).Conclusion:Contrasted to fresh embryos,frozen-thawed transfer can increase the risk of MZT in ART.Also blastocyst transfer can increase the risk of MZT in contrast to cleavage-stage embryos.Thus,the rates of MZT were no significantly difference between IVF and ICSI.