预防卵巢过度刺激综合征取消新鲜移植后首次冻融胚胎移植时间与妊娠结局关系OA

Objectives:To determine the optimal timing for the first frozen embryo transfer(FET)following cancellation of fresh transfer to prevent ovarian hyperstimulation syndrome(OHSS). Methods:A retrospective analysis of clinical data(4 326 cycles)of patients who underwent assisted reproductive technology and had their fresh transfer cancelled for OHSS prevention and subsequently underwent their first FET in our hospital between January 2015 and December 2024 was conducted.Based on the interval between oocyte retrieval and FET,patients were categorized into four groups:Group A(≤32.6 days,n=1 090),Group B(＞32.6-62.6 days,n=1 076),Group C(＞62.6-92.6 days,n=1 079),and Group D(＞92.6 days,n=1 081).The live birth rate,human chorionic gonadotropin(HCG)positivity rate,clinical pregnancy rate,and miscarriage rate among different groups were compared.A multiple factor logistic regression model was used to analyze variables that affected pregnancy outcomes.The restricted cubic spline(RCS)modeling was conducted,generating spline function terms,further analyzing the correlation between transplant interval days and live birth rate,and verifying the robustness of the conclusions. Results:Significant differences were observed across the four groups in the HCG positivity rate,clinical pregnancy rate,live birth rate,miscarriage rate,and multiple-birth rate(P＜0.05).Group B exhibited the highest rates of HCG positivity,clinical pregnancy and live birth(P＜0.05),whereas Group D showed the lowest rates of HCG positivity,clinical pregnancy and live birth(P＜0.05).Multivariable logistic regression analysis demonstrated that the number of high-quality embryos transferred[aOR=2.64,95％CI(2.23,3.12)]and the number of blastocysts transferred[aOR=1.78,95％CI(1.56,2.03)]were significant protective factors for increased live birth rate(P＜0.001),while advanced maternal age[aOR=0.94,95％CI(0.92,0.96)]was an independent risk factor for live birth rate(P＜0.001).The non parametric locally weighted regression model shows a significant non-linear"inverted U-shaped"relationship between the number of days between transplantation and live birth rate(P＜0.05),with the optimal time window for FET is 55-85 days post-oocyte retrieval.And consistent trends across different ovulation stimulation protocols had no significant interaction effect(interaction P＞0.05).All robustness analyses confirmed the reliability of the primary findings. Conclusions:After the cancellation of fresh cycle transplantation to prevent OHSS,the live birth rate can be maintained at a high level when there is a 55-85 days interval between the first FET and oocyte retrieval day.