P-473 The reproductive performance of euploid blastocysts declines after each consecutive embryo transfer: The pendulum is swinging back?

Abstract Study question the impact of euploid blastocysts on reproductive performance by association between number previous failed IVF cycles and live birth rate per transfer Summary answer Our findings suggest a negative transfers. implantation rates decreased following each consecutive FE-ET What is known already In assisted technologies, failure presents challenging clinical dilemma since its underlying etiology unknown. Implantation very complex process which involves variety factors related to embryo, endometrium, immune system (Fox et al. 2016). Therefore, also pathological condition that involve both embryonic defects and/or endometrial dysfunctions (Das al.2012). This situation poses therapeutic dilemma. Hence etiologies treatments remain unresolved. results in ongoing debate over whether chromosomal aneuploidy major contributor or within endometrium itself. design, size, duration observational cohort study included 387 patients undergoing embryo January 2015 until October 2022. Participants/materials, setting, methods Participants: Women with an anatomically normal uterus who underwent autologous vitrified-warmed blastocyst (Frozen Euploid Embryo Transfer: FE-ET) were study. Setting: Fertility center at university-affiliated public hospital. Intervention(s): Trophectoderm biopsy comprehensive preimplantation 24-chromosome analysis using Next Generation Sequencing (NGS). Main Outcome Measure(s): Cumulative outcomes from these analyzed. A logistic regression model was used assess differences first, second, third FE-ET. role chance The mean age patient population under investigation 33.4 ± 5.3 years. Maternal oocyte retrieval negatively associated euploidy biopsied (m-ER). m-ER did not show any (0/1-2/≥3) among different ranges maternal (≤30/31-35/36-39/≥40). first single (IR) 47%, miscarriage 17.9% (LBR) 33.9%. Miscarriage LBR sensitive cycles, showing statistically significant women no ≥3 (11.3% versus 27.8%, P = 0.04) (40.7% 26.3%, 0.05) respectively. Sustained 40.5%, 30% transfer, sustained IR transfers (P 0.03). Limitations, reasons for caution retrospective nature data should be verified multicenter approach, increase sample size. Wider implications After experiencing multiple unsuccessful transferring leads improved outcomes, but improvements eventually level off. Additional information beyond needed further enhance outcomes. Trial registration applicable