Polycystic ovary syndrome (PCOS) is characterized by heterogeneous ovarian responsiveness and a heightened risk of ovarian hyperstimulation syndrome (OHSS) during gonadotropin stimulation. Strictly unstimulated in vitro maturation (IVM) avoids ovarian stimulation and may reduce treatment burden; however, long-term cumulative live birth outcomes remain insufficiently defined, especially across baseline ovarian phenotypes. This retrospective matched cohort study included women aged 20–42 years with PCOS, diagnosed by the Rotterdam criteria, treated at a university-affiliated fertility center between January 2010 and December 2022 (follow-up through December 2023). Women undergoing unstimulated IVM (n = 545) were matched 1:3 by age and BMI to women undergoing conventional in vitro fertilization (IVF) using a GnRH antagonist protocol (n = 1,635). The primary outcome was the 36-month cumulative live birth rate (CLBR) per initiated oocyte retrieval cycle. Secondary outcomes included implantation and live birth after the first transfer (fresh vs. frozen), OHSS, and obstetric/perinatal outcomes. Odds ratios (ORs) were calculated for the freeze-all subset. The 36-month CLBR per initiated retrieval cycle was significantly lower with IVM than IVF (22.20% vs. 47.95%; P < 0.001). CLBR/embryo transfer cycles was also lower with IVM (31.43% vs. 50.19%; P < 0.001). Implantation was lower in the IVM group after fresh transfer (22.94% vs. 29.45%; P = 0.005) but higher after frozen embryo transfer (43.86% vs. 32.62%; P = 0.007). Live birth after the first fresh transfer was lower with IVM (25.96% vs. 33.20%; P = 0.029), whereas after the first frozen transfer, live birth was comparable (33.33% vs. 36.61%; P = 0.486). No severe OHSS occurred in the IVM group, compared to 0.98% in IVF cycles. In women with AFC ≥ 24, live birth after the first frozen transfer was similar between groups (OR 0.99, 95% CI 0.57–1.72). Obstetric and neonatal outcomes were broadly comparable. Unstimulated IVM in PCOS women yielded a lower 36-month CLBR compared to IVF, primarily due to lower embryo yield. IVM eliminated OHSS and achieved comparable live birth rates following the FET, particularly in women with high AFC. These findings advocate for a ‘freeze-all’ IVM strategy to optimize both safety and reproductive outcomes in this high-risk population. Not applicable.
Guo et al. (Tue,) studied this question.