Effects of storage time on clinical pregnancy and neonatal outcomes of the first frozen embryo transfer
Objective:To explore the effects of embryo storage time after vitrification on clinical pregnancy and neonatal outcomes for the first frozen embryo transfer cycle.Methods:A retrospective cohort study was conducted on 4 075 women who underwent the first frozen embryo transfer after fresh embryo transfer in Assisted Reproductive Center of Jiangxi Maternal and Child Health Hospital from January 2014 to June 2022.According to the storage time,the patients were divided into four groups:group A(≤3 months,n=993),group B(4 to 6 months,n=1 757),group C(7 to 12 months,n=880),and group D(13 to 24 months,n=445).Baseline characteristics,the embryo transfer,clinical pregnancy and neonatal outcomes among four groups were compared,and multiple logistic regression model was used to analyze the impact of embryo storage time on pregnancy and neonatal outcomes.Results:There were significant differences in embryo cryopreservation time,age at the time of egg retrieval,body mass index(BMI),and the proportion of primary infertility among the four groups(P＜0.05).There were significant differences in the number of retrieved eggs,available embryos,the year of embryo freezing,endometrial preparation scheme,and single embryo transfer rate among the four groups(P＜0.01),while there was no significant difference in the blastocyst transfer rate among the four groups(P＞0.05).There were no significant differences in clinical pregnancy rate,multiple pregnancy rate,and the miscarriage rate among the four groups after FET(P＞0.05).The live birth rates of group A,B,C and D after first frozen embryo transfer were 50.86％,53.27％,49.55％ and 51.01％,respectively,showing no significant differences among the four groups(P＞0.05).As for all singletons born after frozen embryo transfer,no significant differences in preterm birth,very preterm birth,low birth weight,very low birth weight,fetal macrosomia,sex ratio and birth defects were observed among the four groups(P＞0.05).The results of multiple logistic regression showed that embryo storage time had no significant effects on live birth rate,β-HCG positive rate,clinical pregnancy rate,the implantation rate and the miscarriage rate.Conclusions:The storage time within 2 years does not affect the live birth rate after the first frozen embryo transfer,nor does it increase the risk of preterm birth,low birth weight and birth defects.
Storage timePregnancy outcomeOffspringFrozen embryo transfer
国家科技期刊平台
NSTL
万方数据
维普
