Comparison of the ongoing pregnancy rate with Progesterone Vaginal Gel 180 mg/d vs. Progesterone Vaginal Gel 90 mg/d combined with oral dydrogesterone for luteal phase support in frozen-thawed embryo transfer cycles in Chinese women: A pilot randomized study

Abstract

Abstract Background The preferred modality of progesterone for luteal phase support in Western countries and China is different. This study investigated two different programs of Progesterone Vaginal Gel for frozen-thawed embryo transfer (FET) in terms of pregnancy outcomes. Methods This single-center, randomized pilot trial (ChiCTR2000034113) enrolled women 20–40 years old with endometrial thickness > 8mm, and at least two good-quality blastocysts. All participants received a gonadotropin-releasing hormone agonist for their first frozen-thawed single blastocyst transfer and hormonal replacement therapy (HRT) for endometrial preparation. The participants were 1:1 randomized to Progesterone Vaginal Gel 90mg bid vs. Progesterone Vaginal Gel 90mg qd combine oral Dydrogesterone10mg bid after blastocyst transfer. The primary outcome was the ongoing pregnancy rate at 12 weeks of gestation. Safety was evaluated using patient-reported outcomes. Results Ninety-seven and ninety-nine participants completed the study in the Progesterone Vaginal Gel 180mg/d and 90mg/d groups, respectively. There were no statistically significant differences between the two groups regarding the ongoing pregnancy rate at 12 weeks of gestation (57.73% vs. 65.66%, OR 1.40, 95% [CI] 0.79–2.50, P = 0.2544). The positivity, clinical pregnancy, early abortion, late abortion and ectopic pregnancy were comparable between the two groups (all P > 0.05), as well as the live birth and premature birth rate. There were no statistically significant differences in the patient-reported safety outcomes between the two groups (all P > 0.05), and no severe adverse events or adverse events leading to study termination occurred. Conclusion This study preliminarily showed comparable ongoing pregnancy rates and similar safety profile with Progesterone Vaginal Gel 180mg/d compared to Progesterone Vaginal Gel 90mg/d plus oral dydrogesterone tablets for luteal phase support in FET, which need to be further verified due to the limitation of the pilot design.