Outcomes after first IVF/ICSI attempts (fresh and frozen) differ between overweight and obese patients

Background: Women with high body mass index (BMI) may have reduced natural fecundity and compromised In vitro fertilization outcomes. However, data are discordant.. Our objective was to evaluate the relationship between BMI and outcomes of IVF and/or ICSI, for the first fresh embryo transfers, and for complete (fresh and frozen) cycles. Methods We included 1912 consecutive cycles; 1286 (67.3%) first fresh embryo transfers and 626 (32.7%) frozen embryo transfers, all performed between 01/01/2013 and 12/31/2018 in the Department of Reproductive Medicine and Biology - Cryobiology of the University Hospital of Besançon (France). The study population comprised infertile women undergoing IVF/ICSI treatment divided into 3 groups :obese, overweight and normal BMI. Results The cumulative live birth rate (after fresh and frozen cycles) was lower in overweight women compared to those with normal BMI (respectively 110/421 (26.1%) vs 406/1273 (31.9%), p = 0.025), while there was no significant difference between obese (58/214 (27.1%)) and normal BMI women. The cumulative clinical pregnancy rate was lower for overweight women compared to normal BMI (respectively 128/421 (30.4%) and 467/1277 (36.6%), p = 0.021), but did not differ between obese (66/214 (30.8%)) and normal BMI women. Conclusion Our results raise questions about the optimal management of women undergoing IVF/ICSI. They highlight complexity of management for women with high BMI. Further research is warranted to clarify the exact contribution of overweight and obesity to outcomes. Pending further research, we might consider overweight to be as impairing as obesity in this setting.