Abstract
BACKGROUND: Infertility is an inability to achieve pregnancy after 12 or more months of unprotected sexual intercourse, with recurrent implantation failure being a major challenge in assisted reproductive techniques (ARTs). Endometrial receptivity analysis (ERA) identifies the optimal implantation window, while variable embryo transfer (VET) optimizes embryo transfer by considering both endometrial readiness and embryo development stages. However, limited studies have directly compared the effectiveness of VET and ERA in improving pregnancy outcomes in RIF patients. OBJECTIVES: This study aims to compare the effectiveness of VET and ERA in improving implantation and clinical pregnancy rates in patients with RIF. It seeks to determine whether individualized embryo transfer timing based on VET yields better outcomes compared to ERA-guided embryo transfer. METHODOLOGY: A prospective study will be conducted at Wardha Test Tube Baby Centre, AVBRH, involving 94 women aged 18-40 years with RIF undergoing IVF/ICSI. Participants will undergo ovarian stimulation, embryo culture, and assessment of the Window of Implantation through either ERA or VET. In the ERA group, embryo transfer will be scheduled based on biopsy results, whereas in the VET group, embryo transfer timing will be adjusted based on both endometrial receptivity and embryo development stage (day 3, 5, or 6). Clinical outcomes, including implantation rates, pregnancy success, and live birth rates, will be analyzed. EXPECTED RESULTS: It is anticipated that VET will provide superior implantation and clinical pregnancy rates compared to ERA alone by aligning embryo development with endometrial receptivity more precisely. This study aims to establish a more effective embryo transfer strategy to improve ART success rates. STUDY IMPLICATIONS: The findings will contribute to advancing personalized embryo transfer strategies and refining ART protocols. This research could support the integration of VET as a more effective alternative or complementary approach to ERA in infertility treatment.