The influence of female and male body mass index on live births after assisted reproductive technology treatment: a nationwide register-based cohort study

ObjectiveTo investigate the independent and combined associations between female and male body mass index (BMI) on the probability of achieving a live birth after treatments with in vitro fertilization (IVF) or intracytoplasmic sperm injection (ICSI) under adjustment for relevant covariates.DesignPopulation-based cohort study.SettingDanish national registers.Patient(s)Patients with permanent residence in Denmark receiving IVF or ICSI treatment with use of autologous oocytes from January 1, 2006, to September 30, 2010.Intervention(s)None.Main Outcome Measure(s)Live birth. Analyses were adjusted for age and smoking at treatment initiation and results stratified by BMI groups and presented by IVF/ICSI treatment.Result(s)In total, 12,566 women and their partners went through 25,191 IVF/ICSI cycles with 23.7% ending in a live birth. Overweight and obese women with regular ovulation had reduced odds of live birth (adjusted OR 0.88, 95% CI 0.79-0.99 and adjusted OR 0.75, 95% CI 0.63-0.90, respectively) compared with normal-weight women. IVF-treated couples with both partners having BMI ≥25 kg/m2 had the lowest odds of live birth (adjusted OR 0.73, 95% CI 0.48-1.11) compared with couples with BMI <25 kg/m2. BMI showed no significant effect on chance of live birth after ICSI.Conclusion(s)Increased female and male BMI, both independently and combined, negatively influenced live birth after IVF treatments. With ICSI, the association with BMI was less clear.