Background: Psychosocial factors influence breastfeeding outcomes, but little is known about these characteristics and how they influence breastfeeding behavior of obese women, who are a group that experiences poor breastfeeding outcomes.
Objectives: Our objectives were to determine whether 1) maternal prepregnancy body mass index (BMI) is associated with social knowledge of, social influence toward, maternal confidence in, and behavioral beliefs about breastfeeding; 2) BMI and these psychosocial factors predict outcomes of intention to breastfeed, ever breastfed, and the duration of breastfeeding; and 3) BMI and psychosocial factors are associated with these breastfeeding outcomes independent of each other.
Design: Participants (n = 2824) in the Infant Feeding Practices Study II provided data on psychosocial characteristics and breastfeeding outcomes. In this prospective cohort study, data were analyzed by using logistic and proportional hazards regression models.
Results: Prepregnancy BMI was associated with confidence in (P < 0.0001), social influence toward (P = 0.02), and social knowledge of (P < 0.0001) breastfeeding but not with behavioral beliefs about breastfeeding (P = 0.45). Obese women did not differ from under- and normal-weight women in the intention to breastfeed (P = 0.07) but had lower odds of ever breastfeeding (P = 0.04) and were at greater risk of an earlier cessation of exclusive (P = 0.0009) and any (P = 0.03) breastfeeding. Only the association with exclusive breastfeeding remained significant after controlling for psychosocial factors (P = 0.01). All psychosocial factors were positively associated with each breastfeeding outcome.
Conclusions: Despite their intentions to breastfeed, women with high prepregnancy BMI had psychosocial characteristics associated with poor breastfeeding outcomes. However, these characteristics did not fully explain the association between maternal obesity and breastfeeding outcomes.