Reproductive Medicine Center, The First Affiliated Hospital, Sun Yat-Sun University, ZhongshanEr Road No. 1, Yuexiu District, Guangzhou, 510080, Guangdong, China.
The First Affiliated Hospital of Guangzhou University of Chinese Medicine, Guangzhou, China.
Arch Gynecol Obstet. 2022 Dec;306(6):1901-1911. doi: 10.1007/s00404-022-06511-6. Epub 2022 Mar 20.
Chromosomal mosaicism becomes a common phenomenon in Preimplantaion genetic testing (PGT). This meta-analysis was conducted to study which feature of chromosomal mosaicism was compatible for embryo transfer.
After searching the database PubMed, Embase, CCTR and related reviews up until May 2021. Two reviewers extracted relevant information and assessed study quality by the Newcastle-Ottawa scale independently. Summary Odd Radios (OR) were calculated using fixed- or random-effects models for clinical outcomes. A network meta-analysis compared the clinical outcomes of different chromosomes.
A total of six studies with 1,106 cycles of single mosaic embryo transferred were included. Significant results of implantation rate (IR), miscarriage rate (MR), and ongoing pregnancy/live birth rate (OP/LBR) were observed when comparing embryos with mosaicism level < 50% and ≥ 50% [OR 1.42, 95% CI (1.06, 1.89); OR 0.45, 95% CI (0.27, 0.75); OR 1.74, 95% CI (1.28, 2.37)], and embryos with mosaicism with only affecting segmental chromosome(s) and only involving whole chromosome(s) [OR 1.31, 95% CI (1.01, 1.71); OR 0.57, 95% CI (0.36, 0.93); OR 1.51, 95% CI (1.15, 2.00)]. Embryos with only mosaic gains or losses had significant higher IR and OP/LBR than complex mosaicism [Gains vs complex: OR 1.75, 95% CI (1.20, 2.54); OR 1.73, 95% CI (1.16, 2.58). Losses vs complex: OR 1.90, 95% CI (1.34, 2.71); OR 2.10, 95% CI (1.44, 3.07)]. Mosaic embryos with only one chromosome involved had significant favorable outcomes of IR and OP/LBR than with three or more chromosomes involved [OR 1.76, 95% CI (1.23, 2.52); OR 1.86, 95% CI (1.25,2.78)]. Chr. 7, Chr. 2, Chr. 1, Chr. 18, Chr. 11, Chr. X, Chr. 13, Chr. 14, Chr. 12, and Chr. 9 were considered as prioritized chromosomes of mosaic embryos for transfer.
This analysis support the embryos with mosaicism level ≥ 50%, whole chromosome(s) involved, multiple mosaic abnormalities were associated with worse pregnancy outcomes. Mosaicism level of 50% could be used as a threshold to assess the mosaic embryos.
染色体嵌合在胚胎植入前遗传学检测（PGT）中成为一种常见现象。本荟萃分析旨在研究染色体嵌合体的哪些特征适合胚胎移植。
检索数据库 PubMed、Embase、CCTR 和相关综述，截至 2021 年 5 月。两名评审员独立提取相关信息，并使用纽卡斯尔-渥太华量表评估研究质量。使用固定或随机效应模型计算临床结局的汇总比值比（OR）。网络荟萃分析比较了不同染色体的临床结局。
纳入了 6 项共 1106 个单镶嵌胚胎移植周期的研究。当比较嵌合率 <50%和≥50%的胚胎时，着床率（IR）、流产率（MR）和持续妊娠/活产率（OP/LBR）有显著结果[OR 1.42，95%CI（1.06，1.89）；OR 0.45，95%CI（0.27，0.75）；OR 1.74，95%CI（1.28，2.37）]，以及仅影响节段染色体的嵌合体和仅涉及整条染色体的嵌合体[OR 1.31，95%CI（1.01，1.71）；OR 0.57，95%CI（0.36，0.93）；OR 1.51，95%CI（1.15，2.00）]。仅存在镶嵌增益或丢失的胚胎的 IR 和 OP/LBR 显著高于复杂镶嵌[增益与复杂：OR 1.75，95%CI（1.20，2.54）；OR 1.73，95%CI（1.16，2.58）。丢失与复杂：OR 1.90，95%CI（1.34，2.71）；OR 2.10，95%CI（1.44，3.07）]。仅涉及一条染色体的镶嵌胚胎的 IR 和 OP/LBR 显著优于涉及三条或更多染色体的镶嵌胚胎[OR 1.76，95%CI（1.23，2.52）；OR 1.86，95%CI（1.25，2.78）]。Chr.7、Chr.2、Chr.1、Chr.18、Chr.11、Chr.X、Chr.13、Chr.14、Chr.12 和 Chr.9 被认为是可移植的镶嵌胚胎优先染色体。
本分析支持嵌合率≥50%、整条染色体受累、多个镶嵌异常与妊娠结局较差相关。50%的嵌合率可作为评估镶嵌胚胎的阈值。
