ART outcomes in lean compared to obese phenotypes of polycystic ovarian syndrome

To investigate differences in reproductive outcomes among IVF patients with lean compared to obese polycystic ovarian syndrome (PCOS) phenotypes.

A retrospective cohort study of patients with PCOS who underwent IVF in a single, academically affiliated infertility center in the USA between December 2014 and July 2020. The diagnosis of PCOS was assigned based on Rotterdam criteria. Patients were designated as lean (< 25) or overweight/obese (≥ 25) PCOS phenotype based on BMI (kg/m²) at cycle start. Baseline clinical and endocrinologic laboratory panel, cycle characteristics, and reproductive outcomes were analyzed. The cumulative live birth rate included up to 6 consecutives cycles. A Cox proportional hazards model and Kaplan-Meier curve for estimating live birth rates were used to compare the two phenotypes.

A total of 1395 patients who underwent 2348 IVF cycles were included. The mean (SD) BMI was 22.7 (2.4) in the lean and 33.8 (6.0) in the obese group (p < 0.001). A number of endocrinological parameters were similar between lean and obese phenotypes: total testosterone 30.8 ng/dl (19.5) vs 34.1 (21.9), p > 0.02 and pre-cycle hemoglobin A1C 5.33% (0.38) vs 5.51% (0.51) p > 0.001, respectively. The CLBR was higher in those with a lean PCOS phenotype: 61.7% (373/604) vs 54.0% (764/1414) respectively. Miscarriage rates were significantly higher for O-PCOS patients (19.7% (214/1084) vs 14.5% (82/563) p < 0.001) and the rate of aneuploids was similar (43.5%, 43.8%, p = 0.8). A Kaplan-Meier curve estimating the proportion of patients with a live birth was higher in the lean group (log-rank test p = 0.013). After adjusting for potential confounders, the lean phenotype was associated with an increased hazard ratio for live birth: HR = 1.38 p < 0.001.

Lean PCOS phenotype is associated with a significantly higher CLBR compared to their obese counterparts. Miscarriage rates were significantly higher among obese patients, despite comparable pre-cycle HBA1C and similar aneuploidy rates in patients who underwent PGT-A.