Reproductive Outcomes Of Single Embryo Transfer In Women With Previous Cesarean Scar

The state of high cesarean section rate and the releasing of two-child policy in China,has led to more women with a history of cesarean section seeking assisted reproductive technology(ART)for second child.The ideal goal of ART is to obtain a full-term,healthy baby,in vitro fertilization-embryo transfer(IVF-ET)significantly increased the incidence of iatrogenic multiple pregnancies(IMPs)while helping infertile couples.Multiple pregnancies increase the incidence of maternal and child complications,the burden of family and society,especially for women with a uterine scar.To ensure safety,the Reproductive Medicine Branch of the Chinese Medical Association recommends that women with a uterine scar undergo selective single embryo transfer(eSET)without affecting on the reproductive outcomes,and that the effective eSET strategy should include the fresh cycle and all subsequent freeze-thawed embryos.At present,there are few studies on the effect of single embryo transfer in women with cesarean section,it is necessary to consider whether cesarean section affects pregnancy outcomes,and single embryo can achieve a good pregnancy outcomes in the implementation of single embryo transfer strategy.objectiveWe aim to provide clinical guidance for safe and successful reproductive assistance by investigating whether cesarean section affects clinical outcomes of the embryo transfer cycle,evaluating the reproductive outcomes of single embryo transfer during embryo transfer cycle and complete cycle in patients with a history of cesarean section,and stratifying the age.Materials and methodsA retrospective study of 5479 IVF/ICSI/Thaw-ET cycles in the Reproductive Medicine Center of the First Affiliated Hospital of Zhengzhou University from January1,2014 to June30,2017.IVF/ICSI-ET cycle: cesarean section group(n=1191)and vaginal history group(n=1802),Thaw-ET: cesarean section group(n=1251)and vaginal history group(n=1235).The cesarean section group can be divided single embryo transfer(single cleavage stage embryo transfer,SCT;single blastocyst stage embryo transfer,SBT)and double embryo transfer(double cleavage stage embryo transfer,DCT;double blastocyst stage embryo transfer,DBT;)according to the number of transfer embryos,each group according to age,treatment plan 1:2 propensity score matching(PSM),IVF/ICSI-ET cycle: SCT(n=79)/DCT(n=158),SBT(n=121)/DCT(n=242),first IVF/ICSI-ET cycle SBT(n=100)/DCT(n=200);Thaw-ET: SCT(n=102)/DCT(n=204),SBT(n=162)/DCT(n=324),DBT(n=150),further stratified evaluation according to age <35 /≥35-year-old.The main outcome measures include clinical pregnancy rate,multiple pregnancy rate,live birth rate,and cumulative live birth rate.Secondary outcome measures include biochemical pregnancy rate,ectopic pregnancy rate,abortion rate,multiple pregnancy reduction rate,preterm birth rate,and neonatal low body weight rate.Clinical baseline data were collected according to inclusion and exclusion criteria.The follow-up date was until December 31,2018.Results1.There was no significant difference in the implantation rate,clinical pregnancy rate and live birth rate between the cesarean section and the vaginal history groups(P>0.05).The multiple pregnancy reduction rate of cesarean section history group,and preterm birth rate of multiple births were significantly higher than those of the vaginal delivery group(P<0.05).2.The preterm birth rate and low birth weight rate of multiple birth were significantly higher than single birth in cesarean section and vaginal delivery groups(P<0.05).3.The clinical pregnancy rate,multiple pregnancy rate and live birth rate of SCT group were significantly lower than those in the DCT group of IVF/ICSI-ET cycle in women with cesarean section(P<0.05).4.There was no significant difference in the clinical pregnancy rate and live birth rate between the SBT group and the DCT group of the IVF/ICSI-ET cycle in women with cesarean section(P>0.05),and the multiple pregnancy rate of SBT group was significantly lower than DCT group(P<0.05).There was no significant difference in clinical pregnancy rate and live birth rate between two groups(P>0.05),the multiple pregnancy rate in SBT group was significantly lower than that in DCT group for patients aged <35 years old(P<0.05);The clinical pregnancy rate and live birth rate were higher of the SBT group than those in the DCT group(P<0.05),and the multiple pregnancy rate was lower than the DCT group for patients aged≥35 years old(P<0.05).5.The clinical pregnancy rate,multiple pregnancy rate and live birth rate of the Thaw-ET cycle of the SCT group were significantly lower than those of the DCT and the SBT groups in women with cesarean section(P<0.05).There was no significant difference in clinical pregnancy rate and live birth rate between SCT group and other two groups(P>0.05),the multiple pregnancy rate of the SCT group was significantly lower than that in the DCT group(P<0.05)for patients aged <35 years old.The clinical pregnancy rate and live birth rate were significantly lower in the SCT group compared with the DCT and SBT groups for patients aged≥35 years old(P<0.05),the multiple pregnancy rate did not reach statistically significant difference(P>0.05).6.The clinical pregnancy rate and live birth rate of Thaw-ET cycle had no significant difference between the SBT and the DCT groups in patients with cesarean section(P>0.05),and the multiple pregnancy rate of the SBT group was significantly lower than DCT group regardless of age(P< 0.05).Compared with the DBT group,the clinical pregnancy rate,multiple pregnancy rate,and live birth rate of the SBT group were significantly lower than DBT group(P<0.05).There was no significant difference in the clinical pregnancy rate and live birth rate between the SBT group and the DBT group(P>0.05),the multiple pregnancy rate of SBT group was significantly lower than that of DBT group(P<0.05)for patients aged <35 years old.The clinical pregnancy rate,multiple pregnancy rate and live birth rate of SBT group were significantly lower than DBT group for patients aged≥35 years old(P<0.05).7.In the first IVF cycle,there was no significant difference in clinical pregnancy rate,live birth rate,and cumulative live birth rate between the SBT and the DCT groups(P>0.05),and the multiple pregnancy rate was significantly lower regardless of age(P<0.05).Conclusion1.The history of cesarean section does not affect the implantation rate,clinical pregnancy rate and live birth rate of the embryo transfer cycle,but increase the multiple pregnancy reduction rate and the preterm birth rate of multiple births should reduce the number of transferred embryos.2.SCT of IVF / ICSI-ET cycle are mostly non-selective single embryo transfer in patients with cesarean section,the most critical of these patients is to choose the appropriate treatment to increase the number of available embryos,the effect of single cleavage stage embryo transfer needs further study;SBT can reduce the rate of multiple pregnancy without reducing the clinical pregnancy rate and live birth rate.3.Regardless of embryo stage,single embryo transfer is feasible of thaw-ET cycle for patients aged <35 years old with cesarean section;SBT is an ideal solution to reduce the rate of multiple pregnancy or patients aged ≥35 years old with cesarean section.4.SBT of the first IVF / ICSI-ET cycle maintains cumulative live birth rate while reducing the rate of multiple pregnancy.