Jia Miaomiao, Shi Juanzi, Shi Wenhao, Xue Xia
The ART Center, Northwest Women's and Children's Hospital, Hou Zai Men Road 73, Xi'an, China.
J Assist Reprod Genet. 2025 Sep 14. doi: 10.1007/s10815-025-03642-y.
To evaluate the impact of multiple vitrification-warming on clinical outcomes of embryos that have undergone preimplantation genetic testing (PGT).
This retrospective, single-center study involved 512 single frozen euploid blastocyst transfer cycles conducted between January 2018 and January 2024. Using propensity score matching, 105 patients who underwent double vitrification-warming with single biopsy (DVSB) were matched in a 1:4 ratio with 407 patients in the control group, who underwent single biopsy with single vitrification-warming (SVSB). Post-warming suitability for biopsy and clinical outcomes of subsequent frozen-thawed embryo transfer (FET) cycles were evaluated. Obstetrical and neonatal outcomes were also assessed.
A total of 453 blastocysts were warmed, of which 417 (92.1%) exhibited sufficient quality to undergo trophectoderm biopsy. In FET cycles, a significant reduction in the live birth rate was observed with the additional vitrification-warming step (DVSB: 49.5% vs. SVSB: 61.2%). The pregnancy loss rate in the DVSB group was significantly higher compared to the SVSB group (20.6% vs. 12.2%). Neonatal outcomes, including sex ratio, preterm birth rate, and low birth weight rate, did not differ significantly between the two groups.
This study suggests that the inclusion of an additional vitrification-warming step in PGT may adversely affect pregnancy outcomes. Furthermore, only a portion of thawed embryos are able to re-expand and progress to the biopsy stage. PGT patients should be informed that undergoing a second vitrification-warming cycle may reduce the likelihood of a successful pregnancy.
评估多次玻璃化冷冻-复温对接受植入前基因检测（PGT）的胚胎临床结局的影响。
这项回顾性单中心研究纳入了2018年1月至2024年1月期间进行的512个单冻整倍体囊胚移植周期。采用倾向评分匹配法，将105例行单次活检的双重玻璃化冷冻-复温（DVSB）患者与407例对照组患者按1:4的比例进行匹配，对照组患者接受单次活检的单次玻璃化冷冻-复温（SVSB）。评估复温后活检的适宜性以及后续冻融胚胎移植（FET）周期的临床结局。还评估了产科和新生儿结局。
共复温453个囊胚，其中417个（92.1%）质量足以进行滋养外胚层活检。在FET周期中，额外的玻璃化冷冻-复温步骤导致活产率显著降低（DVSB：49.5% 对 SVSB：61.2%）。DVSB组的妊娠丢失率显著高于SVSB组（20.6% 对 12.2%）。两组的新生儿结局，包括性别比、早产率和低出生体重率，差异均无统计学意义。
本研究表明，PGT中增加额外的玻璃化冷冻-复温步骤可能会对妊娠结局产生不利影响。此外，只有一部分解冻胚胎能够重新扩张并进入活检阶段。应告知PGT患者，进行第二次玻璃化冷冻-复温周期可能会降低成功妊娠的可能性。
