Efficacy of atosiban for repeated implantation failure in frozen embryo transfer cycles.

Atosiban was commonly added to improve pregnancy outcomes of patients with repeated embryo implantation failure (RIF). In this study, we aimed to investigate the effect of atosiban before transferring the frozen-thawed embryo to RIF patients. This retrospective study was conducted in the Hospital for Reproductive Medicine affiliated to Shandong University from August 2017 to June 2021. A total of 1774 women with a history of RIF undergoing frozen embryo transfer (FET) were included in this study. All the participants were classified into atosiban or control group: Group A included 677 patients who were administered atosiban intravenously 30 min prior to FET with a dose of 37.5 mg; Group B included 1097 patients who received no atosiban before the transfer. There were no significant differences observed in the live birth rate (LBR) (39.73% vs. 39.02%, P = 0.928) between the two groups. Other secondary outcomes including biochemical pregnancy rate, clinical pregnancy rate, implantation rate, clinical miscarriage rate and preterm birth rate were similar between the two groups (all P > 0.05). However, subgroup analysis demonstrated significantly higher preterm birth rates in the control group compared with the atosiban group (0 versus 3.0%, P = 0.024) in the natural FET cycles. Atosiban may not improve pregnancy outcomes of RIF patients in FET cycles. However, the effects of Atosiban on pregnancy outcomes should be assessed in clinical trials with larger sample sizes.