#48 : Blastocyst Versus Day-3 Embryo Transfers After In Vitro Maturation with Pre-Maturation Step (CAPA-IVM) in PCOS Patients

Abstract

Background and Aims: IVM combined with a pre-maturation step known as capacitation IVM (CAPA-IVM) improves the competence of in-vitro matured oocytes. According to our previous study, the current clinical practice of transferring day-3 embryos resulted in a live birth rate of 35.2% after the first frozen embryo transfer (FET) following CAPA-IVM. Advances in embryo culture systems have allowed us to extend the duration of embryo culture to blastocyst. There is a lack of data on blastocyst transfer following CAPA-IVM. The aim of this study is to compare the effectiveness of blastocyst versus day-3 embryo transfer after CAPA-IVM in PCOS patients. Methods: A retrospective cohort study was conducted at two infertility centers in Vietnam from 1 January 2018 to 28 February 2022. The study compared two groups of PCOSwomen who had frozen embryo transferred (FET) with CAPA-IVM. Group 1 had blastocyst transfer and Group 2 had day-3 embryo transfer. The couples made the final decision on the stage of embryos transferred. The inclusion criteria were women aged between 18-40 years and had freeze-all their embryos. The primary outcome was the live birth rate after the first FET. Results: Out of 275 eligible women for the study, 87 of themhad blastocyst transfer, and 188 had day-3 embryo transfer. The mean number of embryos transferred for blastocyst transfer and day-3 embryo transfer were 1.27 and 1.93, p < 0.001, respectively. Live birth rate after the first transfer was comparable between blastocyst and day-3 embryo transfers (34.5% vs. 37.8%, p=0.696, respectively). The blastocyst transfer group had a significantly lower multiple pregnancy rate as compared to day-3 embryo transfer group (4.6% vs. 18.0%; p=0.005, respectively). Conclusions: Blastocyst transfer had comparable live birth rate but lower multiple pregnancy rate to day-3 embryo transfer after the first FET following CAPA-IVM in PCOS women.