Single and double embryo transfer provide similar live birth rates in frozen cycles

Abstract

Research question: Do live birth rates (LBRs) differ in frozen cycles of women who received single versus double embryo transfer?

Design: Retrospective cohort study including women who underwent their first frozen embryo transfer (FET) in a tertiary referral University Hospital between 2009–2014.

Results: 3601 patients were included in the analysis with 1936 (53.8%) having a single embryo transfer (SET) and 1665 (46.2%) having a double embryo transfer (DET). Overall, 657/3601 (18.24%) had a live birth. LBR were similar between SET and DET either for cleavage [100/757 (13.1%) versus 153/1032 (14.8%), p = .33] or blastocyst stage FET [256/1179 (21.7%) versus 148/633 (23.4%), p = .4). Ongoing pregnancy rates were comparable between DET and SET [316/1665 (18.9%) versus 359/1936 (18.5%)]. Multiple delivery rates were significantly higher in women with DET compared to SET [53/316 (16.7%) versus 7/359 (1.9%), p < .001]. Multivariate logistic regression analysis allowing adjustment for relevant confounders showed that the number of embryos transferred in the frozen cycle was not related to LBR.

Conclusions: This is the largest study providing evidence that both SET and DET may result in similar LBR, albeit multiple pregnancy rates are significantly lower in case of SET. Therefore, SET should be the main strategy in women undergoing FET.

摘要

研究问题：冷冻周期中接受单胚胎和双胚胎移植的妇女的活产率（LBRs）有差异吗?

设计：回顾性队列研究包括2009年至2014年在三级转诊大学医院进行首次冷冻胚胎移植（FET）的妇女。

结果：3601例患者纳入分析, 其中1936例（53.8%）进行单胚胎移植（SET）, 1665例（46.2%）进行双胚胎移植（DET）。总的来说, 657/3601（18.24%）是活产。SET和DET的LBR在卵裂期[100/757（13.1%）和153/1032（14.8%）, p= .33]或囊胚期FET[156 /1179（21.7%）和148/633（23.4%）, p= .4]方面相似。持续妊娠率在DET和SET之间具有可比性[316/1665（18.9%）与359/1936（18.5%）]。DET组的多胎妊娠率明显高于SET组（53/316（16.7%）和7/359（1.9%）, p＜.001）。调整相关混杂因素的多变量logistic回归分析显示, 冷冻周期中移植的胚胎数量与LBR无关。

结论：这是迄今为止规模最大的一项研究, 证明SET和DET都可能导致相似的LBR, 尽管SET的多胎妊娠率明显较低。因此, SET应该是接受FET的妇女的主要策略。

The Chinese abstracts are translated by Prof. Dr. Xiangyan Ruan and her team: Beijing Obstetrics and Gynecology Hospital, Capital Medical University, Beijing 100026, China.

Keywords:

• Single embryo transfer
• double embryo transfer
• multiple pregnancy rates
• live birth rates

Acknowledgments

This work was presented as an oral poster discussion in Barcelona at the European Society Human Reproductive Endocrinology (ESHRE) 2019.

Disclosure statement

No research was performed at IVI-RMA and this study was not funded by any source.