ROLE OF ATOSIBAN IN REPEATED IMPLANTATION FAILURE IN FROZEN EMBRYO TRANSFER AND FRESH EMBRYO TRANSFER CYCLES

Background and Objectives: Repeated implantation failure (RIF) poses a signicant challenge in assisted reproductive technology (ART), affecting approximately 15% of patients undergoing in vitro fertilization (IVF). Excessive uterine contractions have been implicated in failed embryo implantation. To evaluate the role of atosiban in improving implantation rates and clinical pregnancy rates in patients with RIF undergoing frozen embryo transfer (FET) and fresh embryo transfer cycles. Methods: A prospective study was conducted at the DELHI-IVF center, New Delhi, in January 2025. Twenty patients with RIF were enrolled and divided into two groups: the atosiban group (n=10) and the control group (n=10). Atosiban (6.75 mg IV bolus) was administered 30 minutes before embryo transfer in the atosiban group, while the control group received no intervention. Endometrial preparation and luteal support were standardized for all participants. Results: Implantation rate was signicantly higher in the atosiban group (58%) compared to the control group (42%) (p=0.035). Clinical pregnancy rate was also higher in the atosiban group (70%) versus control (50%) (p=0.048). Ongoing pregnancy rate showed an increasing trend in the atosiban group (60%) compared to control (45%), though not statistically signicant. Miscarriage rate was lower in the atosiban group (10%) versus control (20%). Endometrial receptivity parameters improved with atosiban, showing signicantly lower resistance index (RI: 0.52 vs. 0.61, p=0.031) and pulsatility index (PI: 1.10 vs. 1.25, p=0.045). Uterine contractions per minute were signicantly reduced in the atosiban group (1.8 vs. 2.5, p=0.028). Conclusion: The administration of atosiban before embryo transfer signicantly improved implantation and clinical pregnancy rates in patients with RIF. These ndings suggest that atosiban may enhance endometrial receptivity and reduce uterine contractions, providing a benecial adjunct in ART cycles.