Body mass index is not associated with donor oocyte recipient success: an ideal study using a paired analysis of sibling-oocytes

OBJECTIVE: To determine whether a higher body mass index (BMI) adversely affects endometrial receptivity. DESIGN: Retrospective cohort study. SETTING: Academic medical center. PATIENT(S): All donor egg recipients (DERs) who received fresh sibling-oocytes (oocytes from a donor that were retrieved from a single controlled ovarian hyperstimulation [COH] cycle and split between two recipients) at our center over a 7-year period were included. INTERVENTION(S): COH of a donor with fresh embryo transfer to recipients of differing BMI. The two recipients of the sibling-oocytes were paired and categorized based on BMI: group A (normal weight, BMI 18.5−24.9 kg/m(2)) and group B (overweight/obese, BMI >25.0 kg/m(2)). MAIN OUTCOME MEASURE(S): The primary outcome was implantation rate. Secondary outcomes were positive pregnancy rate and live birth rate. RESULT(S): A total of 408 patients had received oocytes from a split donor oocyte cycle. There were 71 pairs of patients (142 recipients) that had discrepant BMI categories and were analyzed. Implantation rates were similar for the two groups (54.5%±5.3% vs. 56.3%±4.8% for group A and B, respectively, P=0.72). The positive pregnancy rate (77.5% vs. 80.3%, P=0.28) and live birth rate (54.9% vs. 60.6%, P=0.33) for groups A and B were also found to be similar. CONCLUSION(S): In this idealized model that controls to the greatest degree possible for factors that would impact implantation, we found that a higher BMI did not reduce implantation, positive pregnancy, or delivery rates. These findings suggest that a higher BMI does not adversely affect uterine receptivity.