Reproductive and Genetic Hospital of CITIC-Xiangya, Clinical Research Center for Reproduction and Genetics in Hunan Province, Changsha City, China.
Chinese Evidence-Based Medicine Center and CREAT Group, West China Hospital, Sichuan University, Chengdu, China.
Front Endocrinol (Lausanne). 2022 Jun 30;13:920973. doi: 10.3389/fendo.2022.920973. eCollection 2022.
To date, evidence regarding the effectiveness and safety of two consecutive cycles of single embryo transfer (2SETs) compared with one cycle of double embryo transfer (DET) has been inadequate, particularly considering infertile women with different prognostic factors. This study aimed to comprehensively summarize the evidence by comparing 2SETs with DET.
PubMed, Embase, Cochrane Library databases, ClinicalTrails.gov, and the WHO International Clinical Trials Registry Platform were searched up to March 22, 2022. Peer-reviewed, English-language randomized controlled trials (RCTs) and observational studies (OS) comparing the outcomes of 2SETs with DET in infertile women with their own oocytes and embryos were included. Two authors independently conducted study selection, data extraction, and bias assessment. The Mantel-Haenszel random-effects model was used for pooling RCTs, and a Bayesian design-adjusted model was conducted to synthesize the results from both RCTs and OS.
Twelve studies were finally included. Compared with the DET, 2SETs were associated with a similar cumulative live birth rate (LBR; 48.24% vs. 48.91%; OR, 0.97; 95% credible interval (CrI), 0.89-1.13, τ 0.1796; four RCTs and six observational studies; 197,968 women) and a notable lower cumulative multiple birth rate (MBR; 0.87% vs. 17.72%; OR, 0.05; 95% CrI, 0.02-0.10, τ 0.1036; four RCTs and five observational studies; 197,804 women). Subgroup analyses revealed a significant increase in cumulative LBR (OR, 1.33; 95% CrI, 1.29-1.38, τ 0) after two consecutive cycles of single blastocyst transfer compared with one cycle of double blastocyst transfer. Moreover, a lower risk of cesarean section, antepartum hemorrhage, preterm birth, low birth weight, and neonatal intensive care unit admission but a higher gestational age at birth and birth weight were found in the 2SETs group.
Compared to the DET strategy, 2SETs result in a similar LBR while simultaneously reducing the MBR and improving maternal and neonatal adverse outcomes. The 2SETs strategy appears to be especially beneficial for women aged ≤35 years and for blastocyst transfers.
迄今为止，关于连续两个单胚胎移植周期（2SETs）与一个双胚胎移植周期（DET）相比的有效性和安全性的证据还不够充分，特别是考虑到具有不同预后因素的不孕女性。本研究旨在通过比较 2SETs 与 DET 来全面总结证据。
检索了PubMed、Embase、Cochrane 图书馆数据库、ClinicalTrails.gov 和世界卫生组织国际临床试验注册平台，截至 2022 年 3 月 22 日。纳入了比较 2SETs 与 DET 在具有自身卵子和胚胎的不孕女性中的结局的同行评审的英文随机对照试验（RCTs）和观察性研究（OS）。两位作者独立进行了研究选择、数据提取和偏倚评估。采用 Mantel-Haenszel 随机效应模型对 RCTs 进行汇总，采用贝叶斯设计调整模型对 RCTs 和 OS 的结果进行综合。
最终纳入了 12 项研究。与 DET 相比，2SETs 的累积活产率（LBR）相似（48.24%比 48.91%；OR，0.97；95%可信区间（CrI），0.89-1.13，τ 0.1796；4 项 RCTs 和 6 项观察性研究；197968 名女性），累积多胎率（MBR）显著降低（0.87%比 17.72%；OR，0.05；95%CrI，0.02-0.10，τ 0.1036；4 项 RCTs 和 5 项观察性研究；197804 名女性）。亚组分析显示，与 DET 相比，连续两个单囊胚移植周期的累积 LBR 显著增加（OR，1.33；95%CrI，1.29-1.38，τ 0）。此外，2SETs 组剖宫产、产前出血、早产、低出生体重和新生儿重症监护病房入院的风险较低，而出生时的胎龄和出生体重较高。
与 DET 策略相比，2SETs 可获得相似的 LBR，同时降低 MBR，并改善母婴不良结局。2SETs 策略似乎对年龄≤35 岁的女性和囊胚移植特别有益。
