Ovulation induction versus artificial cycles in polycystic ovary syndrome: higher live birth rate but elevated...

Polycystic ovary syndrome (PCOS) is a common endocrine disorder associated with infertility, and frozen-thawed embryo transfer (FET) has become a mainstream assisted reproductive technology for PCOS patients. Two primary endometrial preparation protocols are widely used for FET: ovulation induction cycles and artificial cycles (AC). However, the comparative clinical efficacy, maternal outcomes, and perinatal outcomes of these two protocols in PCOS women remain inconsistent in existing literature, highlighting the need for large-scale cohort studies to provide evidence-based guidance. This study aimed to investigate whether clinical, maternal, and perinatal outcomes following FET differ between ovulation induction cycles and artificial cycles in women with PCOS.

This was a retrospective cohort study conducted at a public fertility center in China. A total of 3,255 PCOS women who underwent FET between January 2018 and December 2023 were included. After propensity score matching (1:1), 530 patients in the ovulation induction group were compared with 530 patients in the artificial cycle group. The primary outcome was live birth rate. Secondary outcomes included clinical pregnancy, miscarriage, maternal outcomes, and perinatal outcomes.

After PSM, the ovulation induction group exhibited a significantly higher live birth rate than the artificial cycle group (57.5% vs. 51.3%; odds ratio [OR] 1.3, 95% confidence interval [CI] 1.0-1.7). The ovulation induction group also had a lower miscarriage rate (11.1% vs. 15.8%; OR 0.7, 95% CI 0.4-0.9). Regarding maternal outcomes, the ovulation induction group was associated with a significantly elevated risk of gestational diabetes mellitus (GDM) (17.6% vs. 9.0%; OR 2.2, 95% CI 1.4-3.4; P < 0.01). In singleton pregnancies, the ovulation induction group showed a reduced risk of large for gestational age (LGA) infants compared to the artificial cycle group (22.7% vs. 36.9%; OR 0.5, 95% CI 0.3-0.7; P < 0.01).

Within the limitations of a retrospective design and single-center setting, this study shows that in PCOS women undergoing FET, ovulation induction cycles were associated with higher live birth rates and lower risks of miscarriage and LGA infants in singleton pregnancies. However, this protocol is associated with an increased risk of GDM. These findings provide valuable evidence for individualizing endometrial preparation protocols in PCOS patients undergoing FET, balancing efficacy and maternal safety.