Pregravid body mass index, psychological factors during pregnancy and breastfeeding duration: is there a link?

Breastfeeding rates in the United States are low, and one possible reason may be the high prevalence of overweight/obesity among women of childbearing age. This analysis examined the association between pregravid body mass index and breastfeeding duration, and explored whether depressive symptoms, perceived stress and anxiety during pregnancy mediated this relationship. Participants (n = 550) in the Pregnancy, Infection and Nutrition Postpartum Study were recruited through prenatal clinics prior to 20 weeks gestation and followed to 12 months post-partum. Duration of any breastfeeding was categorized as none, less than 4 months, 4-6 months, 7-12 months and more than 12 months (referent). Exclusive breastfeeding was categorized as less than 1 month, 1 to less than 4 months and 4 months or more (referent). Being overweight/obese before pregnancy (35.7% of 550) was inversely associated with the durations of any and exclusive breastfeeding. Women who entered pregnancy overweight or obese were more likely to not initiate breastfeeding [relative risk ratio (RRR)=5.39 (95% confidence interval: 2.41, 12.04)] and to breastfeed less than 4 months [RRR=2.38 (1.33, 4.27)] compared with women of normal weight status. Among women who initiated breastfeeding, being overweight or obese vs. normal weight was related to exclusively breastfeeding less than 1 month [RRR=2.09 (1.24, 3.51)]. We did not find evidence to support mediation by depressive symptoms, perceived stress or anxiety during pregnancy. Future research needs to explore the reasons behind the association between overweight/obesity and breastfeeding duration.