IMPORTANCE During FET cycles in IVF/ICSI patients (including PGT patients), transfer of embryos that have been thawed may be abandoned for medical or personal reasons, resulting in the need to refreeze embryos. Typically, embryos from patients undergoing preimplantation genetic testing (PGT) are cryopreserved after biopsy, pending test results. However, in the absence of a clear result, another biopsy is required and the embryo is frozen again to await the results for future use. OBJECTIVE To explore whether refreezing and re-biopsy affect reproductive outcomes DATA SOURCES: Computer search was conducted in PubMed, EMBASE, Cochrane Library, Web of Science, CBM, CNKI, WanFang Data, and VIP databases and searched until May, 2023. STUDY SELECTION AND SYNTHESIS STATA/MP software was utilized for conducting data analysis. Dichotomous outcome data were pooled to calculate odds ratios (ORs) and their corresponding 95% confidence intervals (CIs). Continuous outcome data were combined using an inverse variance model to determine the mean difference (MD) between the two groups. Random-effects and fixed-effects meta-analysis models were employed to assess heterogeneity. Subgroup analysis was conducted based on different freezing methods and various embryo types. MAIN OUTCOMES The primary outcome measure was the live birthrate, with secondary indicators including clinical pregnancy rate, implantation rate, miscarriage rate, ectopic pregnancy, preterm delivery, average birth weight of neonates, and neonatal malformation. RESULTS This study included 19 retrospective studies with a total of 11,024 FET cycles. Across the FET cycles, re-cryopreservation, compared to once-cryopreservation demonstrated reduced live birthrates (OR=0.79; 95% CI: 0.60 to 0.92; I2=21.7%, P=0.000), reduced clinical pregnancy rates (OR=0.74; 95% CI: 0.60 to 0.92, I2=56.9%, P=0.006), and increased miscarriage rates (OR=1.27; 95% CI: 1.03 to 1.55, I2=37.1%, P=0.024). Pregnancy outcomes following re-biopsies, revealing significantly lower live birth rates after re-biopsies compared with single biopsy (OR = 0.65; 95%CI: 0.45 to 0.94, I2=43.5%; P=0.024). Similarly, re-biopsies were associated with reduced clinical pregnancy rates (OR = 0.75; 95%CI: 0.54 to 1.03, I2=29.6%) and increased miscarriage rates (OR= 1.54; 95%CI: 0.89 to 2.66, I2=13.0%) compared to single-biopsy. CONCLUSION AND RELEVANCE Re-frozen embryos compared to once-frozen embryos suggests a decrease in live birth rates and clinical pregnancy rates, coupled with an increase in miscarriage rates, with negligible influence on neonatal outcomes. Similarly, re-biopsy yields comparable results, leading to a reduction in live birth rates.

中文翻译：

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重新冷冻和重新活检胚胎对接受冻融胚胎移植患者生殖结局影响的系统评价和荟萃分析。


重要性 在 IVF/ICSI 患者（包括 PGT 患者）的 FET 周期期间，由于医疗或个人原因，可能会放弃已解冻胚胎的移植，从而导致需要重新冷冻胚胎。通常，接受植入前基因检测 （PGT） 的患者的胚胎在活检后冷冻保存，等待检测结果。然而，在没有明确结果的情况下，需要再次进行活检，并再次冷冻胚胎以等待结果以备将来使用。目的 探讨再冷冻和再活检是否影响生殖结局 数据来源： 在 PubMed、EMBASE、Cochrane Library、Web of Science、CBM、CNKI、万方数据和 VIP 数据库中进行计算机检索，检索截止到 2023 年 5 月。研究选择和综合 STATA/MP 软件用于进行数据分析。合并二分类结局数据以计算比值比 （ORs） 及其相应的 95% 置信区间 （CIs）。使用逆方差模型合并连续结局数据以确定两组之间的平均差 （MD）。采用随机效应和固定效应荟萃分析模型来评估异质性。根据不同的冷冻方法和不同的胚胎类型进行亚组分析。主要结局 主要结局指标是活产率，次要指标包括临床妊娠率、着床率、流产率、异位妊娠、早产、新生儿平均出生体重和新生儿畸形。结果 本研究包括 19 项回顾性研究，共 11,024 个 FET 周期。在整个 FET 周期中，与一次低温保存相比，再低温保存显示活产率降低 （OR=0.79;95% CI： 0.60 至 0.92;I2=21.7%，P=0。000），临床妊娠率降低（OR=0.74;95% CI：0.60 至 0.92，I2=56.9%，P=0.006）和流产率增加（OR=1.27;95% CI：1.03 至 1.55，I2=37.1%，P=0.024）。再活检后的妊娠结局，显示与单次活检相比，再活检后的活产率显著降低（OR = 0.65;95% CI：0.45 至 0.94，I2=43.5%;P=0.024）。同样，与单次活检相比，再活检与临床妊娠率降低 （OR = 0.75;95% CI： 0.54 至 1.03，I2 = 29.6%） 和流产率增加 （OR= 1.54;95% CI： 0.89 至 2.66，I2 = 13.0%） 相关。结论和相关性 与一次冷冻胚胎相比，再冷冻胚胎表明活产率和临床妊娠率下降，加上流产率增加，对新生儿结局的影响可以忽略不计。同样，重新活检产生可比的结果，导致活产率降低。