Obesity reduces uterine receptivity: clinical experience from 9,587 first cycles of ovum donation with normal weight donors

Objective: To analyze the reproductive outcome of recipients of donated ova according to their body mass index (BMI). Design: Twelve-year retrospective cohort analysis. Setting: Fertility clinics. Patient(s): 9,587 first cycles of ovum donation with ova from normoweight donors. Intervention(s): Recipients divided according to their BMI to analyze IVF laboratory and outcome parameters: lean with BMI < 20 kg/m(2) (n = 1,458; 15.2%); normoweight with BMI 20-24.9 kg/m(2) (n 5,706; 59.5%), overweight with BMI 25-29.9 kg/m2 (n = 1,770; 18.5%), and obese with BMI >= 30 kg/m(2) (n 653; 6.8%). Main Outcome Measure(s): Implantation, biochemical and clinical pregnancy, miscarriage, and live-birth rates. Result(s): In vitro fertilization laboratory parameters did not differ according to BMI. However, implantation, pregnancy, clinical pregnancy, twin pregnancy, and live-birth rates were significantly reduced as BMI increased. In the lean, normoweight, overweight, and obese groups, the implantation rate was 40.4%, 39.9%, 38.5%, and 30.9%, clinical pregnancy rate was 56.9%, 55.9%, 54.3%, and 45.3%, and live-birth rate was 38.6%, 37.9%, 34.9%, and 27.7%, respectively. However, clinical miscarriage rates were similar in all the groups. Conclusion(s): Female obesity impairs the reproductive outcome of ovum donation probably as a result of reduced uterine receptivity. (Fertil Steril (R) 2013; 100: 1050-8. (C) 2013 by American Society for Reproductive Medicine.)