Purpose

To evaluate whether adjusting timing of modified natural cycle frozen embryo transfer (mNC-FET) 1 day earlier in the setting of a spontaneous LH surge has an impact on pregnancy outcomes.

Methods

This retrospective cohort study evaluated all mNC-FET with euploid blastocysts from May 1, 2016 to March 30, 2019, at a single academic institution. Standard protocol for mNC-FET included ultrasound monitoring and hCG trigger when the dominant follicle and endometrial lining were appropriately developed. Patients had serum LH, estradiol, and progesterone checked on day of trigger. If LH was ≥ 20 mIU/mL, trigger was given that day and FET was performed 6 days after surge (LH/HCG+6), with the intent of transferring 5 days after ovulation. If LH was < 20 mIU/mL, FET was performed 7 days after trigger (hCG+7). Primary outcomes included clinical pregnancy and live birth rates. To account for correlation between cycles, a generalized estimating equation (GEE) method for multivariable logistic regression was used.

Results

Four hundred fifty-three mNC-FET cycles met inclusion criteria, of which 205 were in the LH/HCG+6 group and 248 were in the HCG+7 group. The overall clinical pregnancy rate was 64% and clinical miscarriage rate was 4.8%, with similar rates between the two groups. The overall live birth rate was 60.9% (61.0% in LH/HCG+6 group and 60.9% in HCG+7 group). After implementing GEE, the odds of CP (aOR 0.97, 95% CI [0.65–1.45], p = 0.88) and LB (aOR 0.98, 95% CI [0.67–1.45], p = 0.93) were similar in both groups.

Conclusions

In our study cohort, mNC-FET based on LH/HCG+6 versus HCG+7 had similar pregnancy outcomes.

中文翻译：

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基于自发性促黄体激素激增的时机改良自然周期冷冻胚胎移植的影响

目的

评估在自发性 LH 激增的情况下提前 1 天调整改良自然周期冷冻胚胎移植 (mNC-FET) 的时间是否会影响妊娠结局。

方法

这项回顾性队列研究评估了 2016 年 5 月 1 日至 2019 年 3 月 30 日在一个学术机构中所有具有整倍体囊胚的 mNC-FET。mNC-FET 的标准协议包括超声监测和 hCG 触发，当优势卵泡和子宫内膜内层发育适当时。患者在触发当天检查了血清 LH、雌二醇和孕酮。如果 LH ≥ 20 mIU/mL，当天触发并在激增后 6 天进行 FET (LH/HCG+6)，目的是在排卵后 5 天转移。如果 LH < 20 mIU/mL，则在触发后 7 天进行 FET (hCG+7)。主要结局包括临床妊娠和活产率。为了说明周期之间的相关性，使用了多变量逻辑回归的广义估计方程 (GEE) 方法。

结果

453 个 mNC-FET 循环符合纳入标准，其中 LH/HCG+6 组 205 个，HCG+7 组 248 个。总体临床妊娠率为64%，临床流产率为4.8%，两组的发生率相似。总活产率为 60.9%（LH/HCG+6 组为 61.0%，HCG+7 组为 60.9%）。实施 GEE 后，CP（aOR 0.97，95% CI [0.65-1.45]，p  = 0.88）和 LB（aOR 0.98，95% CI [0.67-1.45]，p  = 0.93）的几率在两组中相似。

结论

在我们的研究队列中，基于 LH/HCG+6 与 HCG+7 的 mNC-FET 具有相似的妊娠结局。