Effect of weight loss on In Vitro fertilization treatment outcome

Background: To assess the effect of weight loss in overweight and/or obese women on the in vitro fertilization (IVF) treatment outcome before IVF cycles by a systematic review and meta-analysis of clinical trials. Methods: Systematic review and meta-analysis of randomized controlled trials (RCTs) and cohort studies were conducted. Systematic literature searches were conducted, and all randomized trials that evaluated the impact of weight loss in IVF treatment cycles were included in the study. Study selection, quality estimation, and data extractions were performed independently and in duplicate. Results: A total of 924 patients were enrolled in seven studies; the effects of weight loss on the IVF treatment outcome before the IVF treatment cycle were assessed. The clinical pregnancy rate (risk ratio [RR]: 1.61, 95% confidence interval [CI]: 1.15–2.27), miscarriage rate (RR: 0.56, 95% CI: 0.34–0.93), and live birth rate (RR: 1.86, 95% CI: 1.41–2.45) had a statistically significant difference between the intervention and control group. No significant differences were observed in the number of oocytes retrieved (weighted mean difference [WMD]: 0.84, 95% CI: −0.12–1.79), gonadotropin consumption (WMD: 2.59, 95% CI: −6.61–1.42), or the duration of stimulation (WMD: −0.46, 95% CI: −1.64–0.71). Conclusions: Before IVF treatment, obese and overweight women should lose weight by physical activity and/or dietary management because weight loss can improve pregnancy rate, reduce miscarriage rate, and meliorate live birth rate. At the same time, further prospective RCTs are required to establish which methods of weight loss are most suited to this purpose, as well as determining whether cut points for body mass index need to be recommended before accessing IVF.