Research question

Day of cryopreservation, inner cell mass (ICM) grade, trophectoderm grade and blastocyst expansion grade have been associated with differences in live birth rate in frozen embryo transfer (FET) cycles. This study sought to examine the likelihood of live birth and whether the morphological grade of the blastocyst is more or equally useful in FET cycles among preimplantation genetic testing for aneuploidies (PGT-A) tested and untested blastocysts.

Design

This was a retrospective cohort study of 6271 vitrified-warmed, autologous, single-embryo transfer cycles among patients undergoing IVF from July 2013 to December 2017 at a single, university-affiliated infertility practice. The primary outcome was live birth, calculated by generalized estimating equations.

Results

Among PGT-A tested embryos, inferior ICM grade was associated with a lower chance of live birth (ICM grade B versus A: adjusted risk ratio [aRR] 0.91, 95% confidence interval [CI] 0.84–0.99). Among untested blastocysts there was a lower live birth rate in blastocysts cryopreserved on day 6 versus day 5 (aRR 0.87, 95% CI 0.78–0.96), and those with inferior pre-vitrification trophectoderm grade (trophectoderm grade B versus A: aRR 0.86, 95% CI 0.79–0.94). Blastocysts with a higher pre-vitrification expansion grade (pre-vitrification expansion grade 5 versus 4: aRR 1.1, 95% CI 1.01–1.2) were associated, but ICM grade was not associated (ICM grade B versus A: aRR 0.93, 95% CI 0.86–1.02), with chance of live birth.

Conclusions

Among PGT-A untested blastocysts, assessing embryo quality by day of cryopreservation, trophectoderm grade and expansion grade may help to identify embryos with the highest likelihood of live birth. Identifying euploid embryos by PGT-A appears to homogenize the cohort, making blastocyst morphological grade and day of cryopreservation less important.

中文翻译：

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过去的爆炸：形态学在 PGT-A 测试和未经测试的冷冻胚胎移植中有用吗？

研究问题

冷冻保存天数、内细胞团 (ICM) 等级、滋养外胚层等级和囊胚扩张等级与冷冻胚胎移植 (FET) 周期中活产率的差异有关。本研究旨在检查活产的可能性，以及胚泡的形态学等级是否在 FET 周期中对非整倍体 (PGT-A) 测试和未测试的胚泡进行植入前基因检测中更有用或同样有用。

设计

这是一项回顾性队列研究，对 2013 年 7 月至 2017 年 12 月在一个大学附属不孕症诊所接受试管婴儿的患者进行了 6271 个玻璃化加热、自体、单胚胎移植周期。主要结果是活产，通过广义估计方程计算。

结果

在 PGT-A 测试的胚胎中，较差的 ICM 等级与较低的活产机会相关（ICM B 级与 A 级：调整后的风险比 [aRR] 0.91，95% 置信区间 [CI] 0.84-0.99）。在未检测的囊胚中，第 6 天冷冻保存的囊胚活产率低于第 5 天（aRR 0.87，95% CI 0.78–0.96），以及玻璃化前滋养外胚层等级较差（滋养外胚层 B 级 vs A：aRR 0.86， 95% 置信区间 0.79–0.94）。具有较高玻璃化前扩张等级（玻璃化前扩张等级 5 与 4：aRR 1.1，95% CI 1.01–1.2）的囊胚相关，但 ICM 等级不相关（ICM 等级 B 与 A：aRR 0.93，95% CI 0.86–1.02)，有活产机会。

结论

在 PGT-A 未经测试的囊胚中，按冷冻保存天数、滋养外胚层等级和扩张等级评估胚胎质量可能有助于识别活产可能性最高的胚胎。通过 PGT-A 识别整倍体胚胎似乎可以使队列均质化，从而使囊胚形态等级和冷冻保存日期变得不那么重要。