Department of Physiology, Medical School, National and Kapodistrian University of Athens, 75, Mikras Asias, 11527, Athens, Greece.
Assisted Conception Unit, 2nd Department of Obstetrics and Gynecology, Aretaieion Hospital, Medical School, National and Kapodistrian University of Athens, 76, Vasilisis Sofias Avenue, 11528, Athens, Greece.
J Assist Reprod Genet. 2019 Jun;36(6):1049-1061. doi: 10.1007/s10815-019-01475-0. Epub 2019 May 20.
The present systematic review and network meta-analysis aims to uniquely bring to literature data supporting the true place of the alternative practice of day-4 embryo transfer (D4 ET) in an IVF laboratory, beyond the one-dimensional option of facilitating a highly demanding program.
A systematic search was conducted in the databases of PubMed/Medline, Embase, and Cochrane Central Library, resulting to six prospective along with nine retrospective cohort studies meeting eligibility criteria for inclusion. A comparison of D4 ET with day-2 (D2), day-3 (D3), and day-5 (D5) ET, respectively, was performed employing R statistics.
The sourced results indicate no statistically significant difference regarding clinical pregnancy rates, and ongoing pregnancy/live birth rates stemming from the comparison of D4 with D2, D4 with D3, and D4 with D5 ET, respectively. Additionally, no statistically significant difference could be established in respect to cancelation, and miscarriage rates, following the comparison of D4 with D3 and D4 with D5 ET. Interestingly, we report statistically significant lower preterm birth rates associated with D4 ET, in contrast with D5 ET (RR, 0.19; 95% CI, 0.05-0.67; p value = 0.01).
The aforementioned results may serve as advocates buttressing the option of D4 ET as a valid candidate in the ET decision-making process. Possible limitations of the current study are the publication bias stemming from the retrospective nature of certain included studies, along with various deviations among studies' design, referring to number and quality of transferred embryos, or different culture conditions referring to studies of previous decades.
本系统评价和网络荟萃分析旨在独特地将支持替代实践——第 4 天胚胎移植（D4 ET）在体外受精实验室中真实地位的数据纳入文献，超越促进高要求方案的一维选择。
在 PubMed/Medline、Embase 和 Cochrane 中央图书馆数据库中进行系统搜索，结果纳入了符合纳入标准的 6 项前瞻性研究和 9 项回顾性队列研究。使用 R 统计数据分别对 D4 ET 与第 2 天（D2）、第 3 天（D3）和第 5 天（D5）ET 进行比较。
来源结果表明，D4 与 D2、D4 与 D3 和 D4 与 D5 ET 比较的临床妊娠率和持续妊娠/活产率无统计学差异。此外，D4 与 D3 和 D4 与 D5 ET 比较的取消率和流产率也无统计学差异。有趣的是，我们报告了与 D4 ET 相关的统计学上显著较低的早产率，与 D5 ET 相比（RR，0.19；95%CI，0.05-0.67；p 值=0.01）。
上述结果可以作为支持 D4 ET 作为胚胎移植决策过程中有效候选者的依据。本研究的可能局限性是某些纳入研究的回顾性性质导致的发表偏倚，以及研究设计、转移胚胎数量和质量或涉及前几十年研究的不同培养条件的各种偏差。
