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/m(2) (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.