Ovulation induction versus artificial cycles in women with polycystic ovary syndrome: a retrospective cohort study

We aim to clarify the comparative clinical efficacy of ovulation induction and artificial cycle (AC) protocols for frozen-thawed embryo transfer (FET) in reproductive-aged women with polycystic ovary syndrome (PCOS), given the conflicting findings and ongoing controversy surrounding this issue in existing studies.

This was a retrospective cohort study conducted at a public fertility center in China, which included a total of 1331 women with PCOS who underwent FET between January 2021 and December 2024; the study compared the efficacy of two endometrial preparation interventions during FET, ovulation induction cycles (n = 543) and AC (n = 788). The primary outcome measure was live birth rate, while the secondary outcome measures were categorized into three types: clinical outcomes, maternal outcomes and perinatal outcomes.

Endometrial thickness on the day of progesterone administration was significantly greater in the ovulation induction group (10.3 (9.0-12.2) vs. 9.2 (8.0-10.8), p < 0.001) than in the AC group. Following adjustment for potential confounding factors, the ovulation induction cycle group exhibited a significantly higher clinical pregnancy rate (59.5% vs. 51.5%, aOR = 1.3, 95%CI: 1.1-1.7) and live birth rate (48.8% vs. 39.7%, aOR = 1.4, 95%CI: 1.1-1.7) relative to the artificial cycle group. Perinatal outcomes were comparable between AC and ovulation induction.

In conclusion, ovulation induction significantly improves live birth rates over artificial cycles in PCOS women undergoing FET, with comparable perinatal safety. Despite the limitations of retrospective, single-center data, this study provides real-world evidence to guide endometrial preparation. Prospective randomized trials are warranted to confirm these findings.