REDUCTION OF OBSTETRIC AND PERINATAL RISKS IN IVF: THE STRATEGY OF SINGLE BLASTOCYST-STAGE EMBRYO TRANSFER
Annotatsiya
Background. Determining the optimal day for embryo transfer in in vitro fertilization (IVF) is a key factor influencing reproductive outcomes. Transferring a single embryo at the blastocyst stage (day 5) provides better synchronization with the endometrial receptivity window and allows for selection of embryos with higher developmental potential. This strategy is associated with improved implantation rates and a reduced risk of multiple gestations. The aim of this study was to compare clinical outcomes of embryo transfers performed on day 3 (cleavage stage) versus day 5 (blastocyst stage) in IVF cycles, focusing on implantation efficiency and pregnancy outcomes. Methods. A retrospective cohort study was conducted involving 576 women who underwent IVF treatment between 2022 and 2024 at a major reproductive center in Uzbekistan. Patients were grouped based on the timing of embryo transfer: Group 1: cleavage-stage embryo transfers (day 3) (n = 200); Group2: blastocyst-stage embryo transfers (day 5) (n = 376). Trends in transfer practices, number of embryos transferred, implantation rates, and pregnancy outcomes were analyzed. Results. Between 2022 and 2024, the proportion of blastocyst-stage transfers increased significantly from 65 % to 96 %, while cleavage-stage transfers declined to 4 %. The average implantation rate for day 5 transfers (64.2 %) was significantly higher than for day 3 transfers (51.2 %). Simultaneously, the proportion of elective single embryo transfers (eSET) rose from 30 % to 62 %, contributing to a reduction in multiple pregnancy rates. This information is based on retrospective analysis of clinical records from our IVF center. Сonclusions.The shift toward blastocyst-stage embryo transfer and eSET in Uzbekistan reflects a broader alignment with international IVF standards. These changes are associated with improved implantation outcomes and reduced perinatal risks, supporting a more personalized and evidence-based approach to reproductive care.