STUDY QUESTION Compared to the ‘single biopsy + single vitrification’ approach, do ‘double biopsy + double vitrification’ or ‘single biopsy + double vitrification’ arrangements compromise subsequent clinical outcomes following euploidy blastocyst transfer? SUMMARY ANSWER Both ‘double biopsy + double vitrification’ and ‘single biopsy + double vitrification’ led to reduced live birth/ongoing pregnancy rates and clinical pregnancy rates. WHAT IS KNOWN ALREADY? It is not uncommon to receive inconclusive results following blastocyst biopsy and preimplantation genetic testing for aneuploidy (PGT-A). Often these blastocysts are warmed for re-test after a second biopsy, experiencing ‘double biopsy + double vitrification’. Furthermore, to achieve better workflow, IVF laboratories may choose to routinely vitrify all blastocysts and schedule biopsy at a preferred timing, involving ‘single biopsy + double vitrification’. However, in the current literature, there is a lack of systematic evaluation of both arrangements regarding their potential clinical risks in reference to the most common ‘single biopsy + single vitrification’ approach. STUDY DESIGN, SIZE, DURATION A systematic review and meta-analysis were performed, with the protocol registered in PROSPERO (CRD42023469143). A search in PUBMED, EMBASE, and the Cochrane Library for relevant studies was carried out on 30 August 2023, using the keywords ‘biopsy’ and ‘vitrification’ and associated variations respectively. Only studies involving frozen transfers of PGT-A tested euploid blastocysts were included, with those involving PGT-M or PGT-SR excluded. PARTICIPANTS/MATERIALS, SETTING, METHODS Study groups included blastocysts having undergone ‘double biopsy + double vitrification’ or ‘single biopsy + double vitrification’, with a ‘single biopsy + single vitrification’ group used as control. The primary outcome was clinical pregnancy, while secondary outcomes included live birth/ongoing pregnancy, miscarriage, and post-warming survival rates. Random effects meta-analysis was performed with risk ratios (RR) and 95% CIs were used to present outcome comparisons. MAIN RESULTS AND THE ROLE OF CHANCE A total of 607 records were identified through the initial search and nine studies (six full articles and three abstracts) were eventually included. Compared to ‘single biopsy + single vitrification’, ‘double biopsy + double vitrification’ was associated with reduced clinical pregnancy rates (six studies, n = 18 754; RR = 0.80, 95% CI = 0.71–0.89; I2 = 0%) and live birth/ongoing pregnancy rates (seven studies, n = 20 964; RR = 0.72, 95% CI = 0.63–0.82; I2 = 0%). However, no significant changes were seen in miscarriage rates (seven studies, n = 22 332; RR = 1.40, 95% CI = 0.92–2.11; I2 = 53%) and post-warming survival rates (three studies, n = 13 562; RR = 1.00, 95% CI = 0.99–1.01; I2 = 0%) following ‘double biopsy + double vitrification’. Furthermore, ‘single biopsy + double vitrification’ was also linked with decreased clinical pregnancy rates (six studies, n = 13 284; RR = 0.84, 95% CI = 0.76–0.92; I2 = 39%) and live birth/ongoing pregnancy rates (seven studies, n = 16 800; RR = 0.79, 95% CI = 0.69–0.91; I2 = 70%), and increased miscarriage rates (five studies, n = 15 781; RR = 1.48, 95% CI = 1.31–1.67; I2 = 0%), but post-warming survival rates were not affected (three studies, n = 12 452; RR = 0.99, 95% CI = 0.97–1.01; I2 = 71%) by ‘single biopsy + double vitrification’. LIMITATIONS, REASONS FOR CAUTION All studies included in this meta-analysis were retrospective with varying levels of heterogeneity for different outcomes. Not all studies had accounted for potential confounding factors. Only one study reported neonatal outcomes. WIDER IMPLICATIONS OF THE FINDINGS Our data indicated adverse impacts of ‘double biopsy + double vitrification’ and ‘single biopsy + double vitrification’ on clinical outcomes following euploid blastocyst transfers. Patients should be carefully consulted about the risks when offered such approaches. The biopsy process should be carried out as carefully and competently as possible to minimize an inconclusive diagnosis. STUDY FUNDING/COMPETING INTEREST(S) R.W. is supported by a National Health and Medical Research Council Emerging Leadership Investigator Grant (2009767). There is no other external funding to report. All authors report no conflict of interest. REGISTRATION NUMBER CRD42023469143.

中文翻译：

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双活检和双玻璃化冷冻对整倍体囊胚移植术后临床结局的影响：系统评价和荟萃分析


研究问题 与“单次活检 + 单次玻璃化冷冻”方法相比，“双活检 + 双玻璃化”或“单次活检 + 双玻璃化”安排是否会影响整倍体囊胚移植术后的后续临床结果？总结答案 “双活检 + 双玻璃化冷冻”和“单活检 + 双玻璃化冷冻”均导致活产率/持续妊娠率和临床妊娠率降低。哪些是已知的？在囊胚活检和植入前非整倍体基因检测 （PGT-A） 后收到不确定的结果并不少见。通常，这些囊胚在第二次活检后被加热以重新测试，经历“双重活检 + 双重玻璃化”。此外，为了实现更好的工作流程，IVF 实验室可以选择常规对所有囊胚进行玻璃化手术，并将活检安排在首选时间，包括“单次活检 + 双重玻璃化冷冻”。然而，在目前的文献中，参考最常见的“单次活检 + 单次玻璃化冷冻”方法，缺乏对这两种安排的潜在临床风险的系统评估。研究设计、规模、持续时间 进行了系统评价和荟萃分析，方案在 PROSPERO （CRD42023469143） 中注册。2023 年 8 月 30 日，在 PUBMED、EMBASE 和 Cochrane 图书馆中分别使用关键词 “biopsy” 和 “vitrification” 及相关变体进行了相关研究的检索。仅纳入涉及 PGT-A 检测的整倍体囊胚冷冻转移的研究，不包括涉及 PGT-M 或 PGT-SR 的研究。 参与者/材料、地点、方法 研究组包括接受“双活检 + 双玻璃化”或“单活检 + 双玻璃化”的囊胚，其中“单活检 + 单玻璃化”组作为对照。主要结局是临床妊娠，而次要结局包括活产/持续妊娠、流产和变暖后生存率。使用风险比 （RR） 进行随机效应 meta 分析，并使用 95% CI 进行结局比较。主要结果和机会的作用 通过初步检索共确定了 607 条记录，最终纳入了 9 项研究 （6 篇完整文章和 3 篇摘要）。与“单次活检 + 单次玻璃化冷冻”相比，“双重活检 + 双重玻璃化冷冻”与临床妊娠率降低相关（6 项研究，n = 18 754;RR = 0.80,95% CI = 0.71–0.89;I2 = 0%）和活产率/持续妊娠率（7 项研究，n = 20 964;RR = 0.72,95% CI = 0.63–0.82;I2 = 0%）。然而，流产率没有显著变化（7项研究，n=22332;RR = 1.40,95% CI = 0.92–2.11;I2 = 53%）和变暖后存活率（三项研究，n = 13 562;RR = 1.00,95% CI = 0.99–1.01;I2 = 0%）在“双重活检 + 双重玻璃化冷冻”后。此外，“单次活检 + 双重玻璃化冷冻”也与临床妊娠率降低有关（6 项研究，n = 13 284;RR = 0.84,95% CI = 0.76–0.92;I2 = 39%）和活产率/持续妊娠率（7 项研究，n = 16 800;RR = 0.79,95% CI = 0.69–0.91;I2 = 70%）和流产率增加（5 项研究，n = 15 781;RR = 1.48,95% CI = 1.31–1.67;I2 = 0%），但变暖后存活率不受影响（三项研究，n = 12 452;RR = 0.99,95% CI = 0.97-1。01;I2 = 71%）通过“单次活检 + 双重玻璃化冷冻”。局限性，谨慎的原因 本荟萃分析中纳入的所有研究都是回顾性的，不同结局的异质性程度不同。并非所有研究都考虑了潜在的混杂因素。只有一项研究报告了新生儿结局。研究结果的更广泛意义 我们的数据表明，“双活检 + 双玻璃化冷冻”和“单活检 + 双玻璃化冷冻”对整倍体囊胚移植术后临床结局有不利影响。当提供此类方法时，应仔细咨询患者的风险。活检过程应尽可能仔细和称职地进行，以尽量减少不确定的诊断。研究经费/利益争夺 RW 由国家健康与医学研究委员会新兴领导力研究者补助金 （2009767） 支持。没有其他外部资金需要报告。所有作者均报告没有利益冲突。注册号 CRD42023469143。