Effect of different levels of weight loss on clinical outcomes in obese women with polycystic ovary syndrome underwent assisted reproduction

Background PCOS patient with a body mass index (BMI) > 30 kg / m2 have been withhold fertility treatment in the absence of weight loss by the National Health Service,there is a lack of appropriately powered studies to explore the relationships between weight loss level and the clinical improvement in obese PCOS women undergoing ART. Objective To evaluate the effect of weight loss levels on clinical outcomes in obese women with polycystic ovary syndrome (PCOS) scheduled for assisted reproduction. Methods We conducted a non-randomized controlled clinical trial on 471 patients to compare the live birth rate and clinical pregnancy rate of the two groups. 395 patients received weight loss interventions before assisted reproduction (intervention group), 76 patients underwent assisted reproduction directly (nonintervention group). Results Compared to nonintervention group, the body mass index (BMI) was significantly lower (27.30 ± 2.63 vs. 30.13 ± 2.45, p= 0.013) before embryo transfer, the rate of clinical pregnancy and live birth were significantly higher (46.6% vs. 34.2%, p=0.047; 43.4% vs. 27.6%, p=0.017) in intervention group; Compared to patients with weight loss ≥ 15%, live birth rate (OR=1.312, 95% CI: 0.699, 2.461, p = 0.398) and clinical pregnancy rate (OR= 1.77, 95% CI: 0.622, 2.229, p = 0.617) were not significantly increased in women with weight loss in the range of(≥10%, < 15%); but were significantly lower in patients with weight loss < 10%. Miscarriage rates were not significantly different among patients with every weight loss level. Conclusion Preconception weight loss could benefit the clinical outcomes, a target goal of ≥ 10% weight loss may recommend for obese women with PCOS before assisted reproduction.