Improved menstrual function in obese women with polycystic ovary syndrome after behavioural modification intervention—A randomized controlled trial

Summary Objective Lifestyle intervention is the recommended first‐line treatment for overweight women with polycystic ovary syndrome (PCOS). However, the efficacy of lifestyle change in improving reproductive function is still unclear. Design A randomized controlled trial (RCT) with allocation to a behavioural modification programme (intervention) or minimal intervention (control) for 4 months with a follow‐up at 12 months. Patients Sixty‐eight women, aged 18‐40 years, body mass index (BMI) ≥ 27 kg/m2, fulfilling all Rotterdam PCOS criteria were randomized to treatment. Measurements The primary outcome was improved menstrual regularity. Secondary outcomes were ovulation and pregnancy rates. Results At 4 months, the weight loss was significant in the intervention group (−2.1%, P = 0.002) and nonsignificant in the control group (−1.0%). A higher proportion of patients in the intervention group improved menstrual regularity compared to the control group, mean difference 35% (95% CI: 16‐60), P = 0.003. There was no difference in ovulation rate between groups. Logistic regression analysis showed that intervention was the only predictor of improved menstrual function, OR 3.9 (95% CI: 1.3‐11.9). At 12 months, a total of 54% of the women improved menstrual regularity compared to baseline (P = 0.000) and 43% (P = 0.000) had confirmed ovulation. 38% of the women wishing to become pregnant succeeded within 1 year of study completion. Conclusions This is the first RCT in overweight women with PCOS showing efficacy in improving reproductive function following behavioural modification intervention in comparison with minimal intervention. Although extensive weight loss is difficult to achieve in these women, behavioural modification intervention can help improve reproductive function.