Effect of weight loss before in vitro fertilization in women with obesity or overweight and infertility: a systematic review and meta-analysis

The effect of weight loss before in vitro fertilization (IVF) procedures on pregnancy outcomes in women with overweight or obesity and infertility remains controversial. In this systematic review and meta-analysis, we investigated whether weight loss before IVF in these women affected the IVF results and reproductive outcomes. PubMed, Embase, and the Cochrane Library databases were searched from the inception dates until December 2022, using combinations of relevant keywords. Only six randomized controlled trials, including 1627 women with obesity or overweight, were analyzed. The weight change in the intensive care group, compared to the control group who underwent IVF without weight loss was - 4.62 kg (mean difference; 95% confidence interval [CI] - 8.10, - 1.14). Weight loss before IVF did not significantly increase the live birth rate in women with obesity or overweight and infertility (odds ratio, 1.38; 95% CI 0.88, 2.10). The clinical pregnancy, miscarriage, ongoing pregnancy, and ectopic pregnancy rates did not differ between the weight loss and control groups before IVF. This meta-analysis demonstrated that even significant weight loss before IVF in women with obesity or overweight and infertility did not improve the live birth, clinical pregnancy, ongoing pregnancy, or ectopic pregnancy rates. PROSPERO Registration Number: CRD42023455800.