Objective

To investigate the relationship between the embryo frozen time and live birth rate (LBR) in women having a freeze-all cycle.

Design

Retrospective cohort study.

Setting

Academic hospital.

Patient(s)

Women who underwent their first vitrified-warmed cycles from January 2013 to December 2019.

Intervention(s)

Embryo storage time.

Main Outcome Measure(s)

The primary outcome was the LBR.

Result(s)

A total of 14,928 women were eligible for the analysis. Women with the frozen time of transferred embryos for 2–5 months were associated with a higher LBR compared with other groups. The results were confirmed by an inverted U curve in the restricted cubic splines before as well as after adjustment for covariables, which suggested that an embryo storage time of 3–4 months was associated with the highest LBR. Subgroup analyses demonstrated that the inverted U curve relationship between embryo storage time and LBR was only observed in women with the high response. Sensitivity analyses in women with at least one good-quality embryo for transfer, in women aged <36 years at embryo transfer, or in women with double cleavage embryo transfer showed that the association remained valid. The association was weakened in women with single blastocyst transfer probably because of the small sample size in these women.

Conclusion(s)

An inverted U-shaped relationship was found between embryo storage time and treatment success in women with high ovarian response in freeze-all embryo transfer cycles. Prolonged storage time of >6 months was associated with reduced pregnancy rates.

中文翻译：

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接受全冷冻胚胎移植的女性胚胎储存时间与治疗成功率之间的关联

客观的

调查冷冻全周期女性的胚胎冷冻时间与活产率 (LBR) 之间的关系。

设计

回顾性队列研究。

环境

学术医院。

病人）

从 2013 年 1 月到 2019 年 12 月经历了第一次玻璃化加热周期的女性。

干预措施

胚胎储存时间。

主要观察指标）

主要结果是 LBR。

结果）

共有 14,928 名女性符合分析条件。与其他组相比，移植胚胎冷冻时间为 2-5 个月的女性与更高的 LBR 相关。结果通过协变量调整前后受限三次样条中的倒 U 曲线得到证实，这表明 3-4 个月的胚胎储存时间与最高 LBR 相关。亚组分析表明，胚胎储存时间与 LBR 之间的倒 U 型曲线关系仅在具有高反应的女性中观察到。对至少有一个用于移植的优质胚胎的女性、胚胎移植时年龄 <36 岁的女性或进行双卵裂胚胎移植的女性进行的敏感性分析表明，这种关联仍然有效。

结论

在冷冻全胚胎移植周期中，在卵巢反应高的女性中，胚胎储存时间与治疗成功率之间存在倒 U 形关系。超过 6 个月的延长储存时间与降低的妊娠率相关。