IVM - Fresh ET (THE SAIGON PROTOCOL) Versus IVF - FET in PCOS Women

Assisted Reproductive Technologies (ART) aim to increase success rates while minimizing patient risks. For women with high AFC or PCOS, conventional IVF carries a high risk of OHSS (Ho et al., 2019). A modern IVF strategy to prevent this uses a GnRH agonist trigger, requiring a "freeze-all" and subsequent FET (Wong et al., 2017). This reduces OHSS risk but can increase time to pregnancy (Vuong et al., 2021) and treatment burden. IVM is a patient-friendly alternative that eliminates OHSS risk by avoiding high-dose gonadotropins. A 2020 trial by Vuong et al. compared CAPA-IVM-FET to conventional IVF-FET in women with high AFC. IVM yielded a comparable live birth rate (35.2%) versus IVF (43.2%), with a 0% OHSS rate in IVM compared to 0.7% in IVF (Vuong et al., 2020). The optimal transfer method (fresh or frozen) in IVM cycles is debated. A 2021 pilot RCT by Vuong et al. found a freeze-only strategy after CAPA-IVM led to a significantly higher live birth rate (60%) than a fresh transfer (20%) (Vuong et al., 2021), but increased time to pregnancy (194 vs. 150 days) (Vuong et al., 2021). A refined CAPA-IVM protocol, which uses no gonadotropins, allowed for fresh embryo transfer in the same cycle, resulting in a numerically higher ongoing pregnancy rate (43.3% vs. 33.3%) than FET (Vuong et al., 2025). This raises an important question: how does a simplified IVM strategy with fresh transfer compare to the established "safety-net" IVF strategy with FET? These two approaches represent opposing clinical philosophies. No large-scale study has yet compared them in women with PCOS. Therefore, this study is designed to compare the SAIGON protocol (gonadotropin-free CAPA-IVM with fresh ET) against a standard GnRH-antagonist IVF protocol with agonist trigger and subsequent FET.