Administration of Oxytocin Receptor Antagonist during Frozen Embryo Transfer: Potential Improvement in Live Birth Rates for Women with Recurrent Implantation Failure, Adenomyosis, and Myoma

Abstract

Background The primary objective of this investigation was to assess the potential improvement in pregnancy outcomes among infertile women undergoing in vitro fertilization (IVF) cycles, specifically during frozen embryo transfer (FET), following the administration of an oxytocin receptor antagonist. This study aimed to examine this impact across various subgroups, including individuals experiencing recurrent implantation failure (RIF), adenomyosis, and myoma. Methods This retrospective cohort study involved 431 patients who underwent their initial IVF-FET cycle at our reproductive center between January and December 2021. The study group (n = 162) received an oxytocin receptor antagonist during FET, while the control group (n = 227) underwent FET without this antagonist. A comparative analysis of baseline and cycle characteristics was conducted between the two groups, with additional subgroup analyses. Results There were no significant differences in baseline or cycle characteristics between the study and control groups. Overall, there was no significant difference in live birth rate between the two groups. However, in specific subgroups, the study group demonstrated significantly greater live birth rates than did the control group for patients with RIF (43.9% vs. 26.2%, P = 0.016), adenomyosis (37.7% vs. 22.1%, P = 0.039), or myoma (46.3% vs. 20.4%, P = 0.004). Multivariate analysis indicated a positive association between oxytocin receptor antagonist use and live birth rates in women with RIF (adjusted OR 2.17, 95% CI 1.08–4.35; P = 0.030), adenomyosis (adjusted OR 3.44, 95% CI 1.43–8.28; P = 0.006), and myoma (adjusted OR 3.11, 95% CI 1.23–7.85; P = 0.016). Conclusions While the administration of an oxytocin receptor antagonist during FET did not increase live birth rates in the overall population, it exhibited potential benefits in improving live birth rates in women with RIF, adenomyosis, or myoma.