Exclusive Breastfeeding Rates at 6 Weeks Postpartum as a Function of Preconception Body Mass Index Are Not Impacted by Postpartum Obstetrical Practices or Routines

Objective: Women with overweight/obesity have significantly lower rates of exclusive breastfeeding (EBF) at 6 weeks postpartum compared with women of normal weight. We sought to determine whether differences in Baby-Friendly Hospital Initiative (BFHI) adherence, obstetric practices, or social support explain these weight-related EBF disparities. Methods: One hundred forty-two healthy women who intended EBF (61 normal weight, 50 overweight, and 31 obese by preconception body mass index [BMI]) were enrolled in a cross-sectional study. Obstetric data were collected and participants completed modified Infant Feeding Practices Study II surveys at 6 weeks postpartum. Results: Women with obesity were significantly less likely to undergo spontaneous labor and more likely to receive synthetic oxytocin and epidural anesthesia compared with women with overweight or normal weight. Women who were overweight were less likely to report extended family support for breastfeeding compared with women with obesity or normal weight; however, BFHI components and composite BFHI score did not differ by maternal BMI. Furthermore, regardless of BMI, women with greater adherence to BFHI practices were more likely to be EBF at 6 weeks postpartum (p-value <0.001). Nonetheless, at 6 weeks postpartum, women with obesity were expressing milk more frequently and less likely to have met their own breastfeeding goals compared with women with overweight and normal weight. Conclusions: Differences in EBF rates by BMI were not explained by BFHI adherence or obstetric practices. These data suggest physiological differences, rather than intrapartum practices and support services, may explain differences in EBF rates by maternal overweight/obesity.