Single fresh blastocyst transfer or single cryopreserved-thawed blastocyst transfer: which is preferable for infertile patients in IVF/ICSI cycles? A meta-analysis

Abstract

Purposes: Nowadays, an increasing number of studies have proposed single embryo transfer (SET), especially single blastocyst transfer (SBT). To compare the clinical outcomes of single fresh blastocyst transfer (BT) and single cryopreserved-thawed BT in patients undergoing in vitro fertilization or intracytoplasmic sperm injection (IVF/ICSI) cycles.

Methods: The PubMed, Embase, and Cochrane Library databases were searched from the start dates until February 2018. The primary outcomes were clinical pregnancy rate (CPR) and embryo implantation rate (IR). The secondary outcomes were multiple pregnancy rate (MPR), live birth rate (LBR), and miscarriage rate (MR). Using the Mantel–Haenszel random effects model to analyze summary risk ratio (RR) with 95% confidence intervals (CIs). Statistical heterogeneity scores were assessed with the standard Cochrane’s Q test and I² statistic.

Results: In total, eight studies (two prospective studies, six retrospective studies) were included in our analysis. There was no statistically significant difference regarding clinical pregnancy (RR = 1.18, 95% CI = 0.91–1.55) and embryo implantation (RR = 1.04, 95% CI = 0.77–1.41). Regarding secondary outcomes, there was no significant difference regarding miscarriage (RR = 0.79, 95% CI = 0.60–1.03) and multiple pregnancy (RR = 1.23, 95% CI = 0.75–2.04). However, single fresh BT is associated with an increased live birth (RR = 1.28, 95% CI = 1.05–1.57) compared with single cryopreserved-thawed BT.

Conclusions: In summary, this meta-analysis supports the hypothesis that single cryopreserved BT might not be the best choice compared with single fresh BT in patients undergoing IVF/ICSI cycles.

摘要

目的：目前, 越来越多的研究提出单胚胎移植(SET), 尤其是单囊胚移植(SBT)。本研究旨在比较体外受精或胞浆内精子注射(IVF/ICSI)周期中患者单新鲜囊胚移植(BT)和单冻存解冻BT的临床疗效。

方法：检索PubMed、Embase和Cochrane图书馆的数据库从开始日期到2018年2月。主要结局为临床妊娠率(CPR)和胚胎着床率(IR)；次要结局是多胎妊娠率(MPR)、活产率(LBR)和流产率(MR)。利用Mantel-Haenszel随机效应模型、用95%置信区间(CIs)进行风险比(RR)评估。采用标准Cochrane s Q检验和I2统计量进行统计学异质性评分。

结果：本研究共纳入8项研究(2项前瞻性研究, 6项回顾性研究)。临床妊娠(RR 1.18, 95% CI 0.91 1.55)和胚胎植入(RR 1.04, 95% CI 0.77 1.41)差异无统计学意义。至于次要结局, 流产(RR 0.79, 95% CI 0.60 1.03)和多胎妊娠(RR 1.23, 95% CI 0.75 2.04)没有显著差异。然而, 与单冻存解冻BT相比, 单新鲜囊胚移植可增加活产率(RR 1.28, 95% CI 1.05 1.57)。

结论：综上所述, 这项荟萃分析支持了这样一个假设, 即在体外受精/ICSI周期患者中, 与单新鲜BT相比, 单冻存解冻BT可能不是最佳选择。

Keywords:

• Clinical outcome
• single
• cryopreserved
• fresh
• blastocyst transfer

Disclosure statement

This paper is our original unpublished work and it has not been submitted to any other journal for reviews. All authors have read and approved the content, and agree to submit for consideration for publication in the journal. Our research has no potential conflict of interest. There are no any ethical/legal conflicts involved in the article. The authors declare that they have no conflict of interest. This article does not contain any studies with animals performed by any of the authors. Informed consent was obtained from all individual participants included in the study.