RÉSUMÉ
Objective To observe the effect of spontaneous blastocyst collapse on pregnancy and neonatal outcomes in fro-zen-thawed transfer cycle.Methods The clinical data of 10120 single blastocyst frozen-thawed transfer cycles from January 2018 to December 2020 was retrospectively analyzed,of which 133 cycles were spontaneous collapsed blastocysts(collapse group),133 cycles of transplanted embryos were obtained as non-collapse blastocysts(non-collapse group)after balancing the co-variates between groups by 1∶1 propensity score matching(PSM),pregnancy and neonatal outcomes were compared between the two groups.Results The live birth rate in collapse group was significantly lower than that in non-collapse group(30.08％vs.45.86％,P＜0.01).The implantation rate and clinical pregnancy rate in collapse group were decreased,and the early abor-tion rate was increased,but the differences were not statistically significant(all P＞0.05).Logistic regression analysis showed that women's age,infertility type and spontaneous blastocyst collapse had significant effects on live birth(all P＜0.05).The odds ratio of live birth between collapse group and non-collapse group was 0.54(95％CI:0.32～0.91).There was no statistical-ly significant difference in the gestation days at birth,birth weight and the proportion of male newborns between the two groups(all P＞0.05).There were 2 premature births in live birth of each group,and 1 birth defect in singleton pregnancy in collapse group,which was the enlargement of infant adrenal gland.There was no birth defect in singleton pregnancy newborns in non-collapse group.Conclusion In frozen-thawed transfer cycle,the transplantation of spontaneous collapsed blastocysts can reduce the maternal live birth rate,spontaneous collapsed blastocysts for implantation may not increase incidence rates of poor perinatal outcomes and neonatal defects.Spontaneous collapsed blastocysts can be used as a means to improve embryo selection,so as to improve the live birth rate and improve the pregnancy outcome of assisted reproductive technology.