Research question

Which of the two mainstream endometrial preparation regimens, assisted natural cycle (NC) or hormone replacement treatment cycle (HRT), help frozen–thawed embryo transfer (FET) cycles after preimplantation genetic testing (PGT) achieve better clinical outcomes?

Design

This retrospective analysis included 3400 vitrified–warmed single blastocyst transfer cycles after PGT from January 2011 to November 2020, and involved 2332 patients with regular menstrual cycles. The decision to proceed with an assisted NC (n = 827) or HRT (n = 2573) before FET was reached based on a combination of patient preference and physician guidance. Clinical pregnancy rate, live birth rate, early miscarriage rate and obstetric outcomes were compared.

Results

No significant difference was observed between the assisted NC and HRT groups in terms of clinical pregnancy rate (51.6% versus 50.7%, P = 0.634), live birth rate (44.0% versus 43.4%, P = 0.746) or early miscarriage rate (12.6% versus 12.0%, P = 0.707). Multivariate analysis indicated that the endometrial preparation protocol was not an independent factor for a clinical pregnancy or live birth. In the HRT group, the Caesarean section rate (64.7% versus 51.9%, P < 0.001) and pregnancy complication rate (20.2% versus 13.8%, P = 0.003) were significantly higher. The two groups were not statistically different with respect to gestational age, early preterm birth rate, fetal weight or fetal birth defect rate.

Conclusions

For patients undergoing a PGT–FET cycle involving a single blastocyst transfer, using assisted NC and HRT for the endometrial preparation could lead to comparable rates of clinical pregnancy and live birth. Additionally, NC is safer than HRT in terms of avoiding pregnancy complications and adverse obstetric outcomes.

中文翻译：

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PGT后玻璃化加热胚胎移植中两种主流子宫内膜制备方案的比较

研究问题

辅助自然周期 (NC) 或激素替代治疗周期 (HRT) 两种主流子宫内膜准备方案中的哪一种有助于植入前基因检测 (PGT) 后的冻融胚胎移植 (FET) 周期获得更好的临床结果？

设计

这项回顾性分析包括 2011 年 1 月至 2020 年 11 月 PGT 后的 3400 个玻璃化加热单囊胚移植周期，涉及 2332 名月经周期正常的患者。 根据患者偏好和医生指导，在达成 FET 之前进行辅助 NC ( n  = 827) 或 HRT ( n = 2573) 的决定。比较临床妊娠率、活产率、早期流产率和产科结局。

结果

在临床妊娠率（51.6% 对 50.7%，P  = 0.634）、活产率（44.0% 对 43.4%，P  = 0.746）或早期流产率（12.6 % 与 12.0%，P  = 0.707）。多变量分析表明，子宫内膜准备方案不是临床妊娠或活产的独立因素。HRT组剖宫产率（64.7%对51.9%，P  <0.001）和妊娠并发症发生率（20.2%对13.8%，P  =0.003）明显更高。两组在胎龄、早期早产率、胎儿体重或胎儿出生缺陷率方面无统计学差异。

结论

对于接受单囊胚移植的 PGT-FET 周期的患者，使用辅助 NC 和 HRT 进行子宫内膜准备可能会导致临床妊娠率和活产率相当。此外，在避免妊娠并发症和不良产科结果方面，NC 比 HRT 更安全。