Purpose: To investigate the effects of sildenafil citrate (SC) on live birth rates (LBR) during women undergoing their first frozen embryo transfers (FET) with hormone replacement therapy (HRT).
Patients and Methods: This retrospective cohort study included a total of 10,069 infertile women with adequate endometrial thickness (≥ 7 mm when progesterone was initiated) in their first FET cycle with hormone replacement therapy. Women received either vaginal SC or no adjuvant during their first transfer cycle depending on patient or physician preference. In the sildenafil group, 1098 women underwent HRT FET with adjuvant vaginal use of SC, and 8971 women were included as controls. The primary outcome measure was LBR, defined as the likelihood of live birth per transfer cycle. Endometrial thickness (EMT), implantation, chemical pregnancy, clinical pregnancy, miscarriage, ongoing pregnancy, birth weight and preterm delivery (PTB) were also recorded.
Results: Baseline characteristics were comparable between the two groups. In the crude analysis, the unadjusted LBR was significantly higher in the vaginal SC group (scHRT-FET) than in the control group (HRT-FET) (40.3% vs 36.1%). After adjustment for 12 pregnancy-related confounding factors, logistic regression analysis showed that LBR remained significantly higher in the scHRT-FET group than in the HRT-FET group (adjusted odds ratio [aOR] 1.31, 95% confidence interval [CI] 1.14– 1.49). Furthermore, after adjustment, the ongoing pregnancy rate was significantly higher (aOR 1.29, 95% CI 1.13– 1.47), and the miscarriage rate was significantly lower (aOR 0.58, 95% CI 0.43– 0.77), in the scHRT-FET group compared to the HRT-FET group. Adjuvant vaginal use of SC did not increase the endometrial thickness and had no significant effect on birth weight or PTB.
Conclusion: Adjuvant vaginal use of SC in HRT FET was associated with higher LBR and improved pregnancy outcomes in an infertile population with adequate endometrial thickness. The beneficial effect of SC may be due not to an increase in EMT but instead to improve endometrial blood flow and receptivity, which might merit clinicians’ attention for improving general IVF practices.

Keywords: sildenafil citrate, frozen embryo transfer, endometrial preparation, hormone replacement therapy, live birth rates, pregnancy outcomes


中文翻译：

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在激素替代周期中辅助阴道使用枸橼酸西地那非提高了首次冷冻胚胎移植期间 10,069 名妇女的活产率

目的：研究在接受激素替代疗法 (HRT) 的首次冷冻胚胎移植 (FET) 期间，枸橼酸西地那非 (SC) 对活产率 (LBR) 的影响。
患者和方法：这项回顾性队列研究共纳入了 10,069 名在激素替代治疗的第一个 FET 周期中具有足够子宫内膜厚度（开始使用黄体酮时≥7 mm）的不孕女性。根据患者或医生的偏好，女性在第一次转移周期中接受阴道 SC 或不接受辅助治疗。在西地那非组中，1098 名女性接受了 HRT FET 并辅助阴道使用 SC，8971 名女性作为对照。主要结果测量是 LBR，定义为每个转移周期活产的可能性。还记录了子宫内膜厚度（EMT）、植入、化学妊娠、临床妊娠、流产、持续妊娠、出生体重和早产（PTB）。
结果：两组的基线特征具有可比性。在粗略分析中，阴道 SC 组 (scHRT-FET) 的未调整 LBR 显着高于对照组 (HRT-FET) (40.3% vs 36.1%)。在调整 12 个妊娠相关混杂因素后，逻辑回归分析显示，scHRT-FET 组的 LBR 仍然显着高于 HRT-FET 组（调整优势比 [aOR] 1.31，95% 置信区间 [CI] 1.14– 1.49）。此外，调整后，与 scHRT-FET 组相比，持续妊娠率显着更高（aOR 1.29，95% CI 1.13–1.47），流产率显着降低（aOR 0.58，95% CI 0.43–0.77）到 HRT-FET 组。辅助阴道使用 SC 不会增加子宫内膜厚度，并且对出生体重或 PTB 没有显着影响。
结论：在具有足够子宫内膜厚度的不孕人群中，在 HRT FET 中辅助阴道使用 SC 与更高的 LBR 和改善妊娠结局相关。SC 的有益作用可能不是由于 EMT 的增加，而是改善了子宫内膜的血流和容受性，这可能值得临床医生注意改善一般 IVF 实践。

关键词：枸橼酸西地那非，冷冻胚胎移植，子宫内膜准备，激素替代疗法，活产率，妊娠结局