Association of maternal and environmental factors with infant feeding behaviors in a birth cohort study

Background: Breastfeeding is well known to be beneficial to both infant and maternal health. Complementary feeding can also have direct or later consequences on infant health. WHO recommends that infants be exclusively breastfed for the first six months post-partum. However, adherence to this guideline in the U.S. is low. It is critical to understand determinants of breastfeeding duration and timing of complementary food introduction. ❧ Methods: This is a secondary analysis using data collected from the Maternal and Child Health Study. Forty-three mother-infant pairs followed through 9-months post-partum were assessed for this analysis. Maternal and infant characteristics (e.g. maternal age, maternal educational level, pre-pregnancy BMI, birth weight, baby’s gender as well as maternal smoking status) were obtained from baseline questionnaire and electronic medical records. Infant feeding practices were collected through the 9-month follow-up telephone interview. The relationships of potential predictors with breastfeeding duration and introducing time of formula milk as well as complementary foods were analyzed using Cox proportional hazards model while dichotomous outcomes such as early introduction of baby cereal were studied using an exact logistic model. ❧ Results: Babies with at least one reported occurrence of diarrhea during the 9 months (HR=2.6, 95% CL: 0.9, 7.2, p=0.06), mothers’ exposure to secondhand smoking (HR=3.0, 95% CL: 1.1, 8.6, p=0.04) and mothers who drank caffeinated beverages during pregnancy (HR=2.4, 95% CL: 0.7, 8.2, p=0.18) were more likely to stop any breastfeeding in our analysis. As for the start of formula milk, baby boys (HR=0.5, 95% CL: 0.2, 1.2, p=0.14) and babies with history of vomiting (HR=0.4, 95% CL: 0.2, 1.2, p=0.12) were less likely to start having formula milk early while higher pre-pregnancy BMI seemed to be positively associated with early introduction of formula milk (p=0.23). Babies’ history of diarrhea (p=0.29), pre-pregnancy BMI (p=0.56) and mothers’ exposure to secondhand smoking (p=0.08) were positively related to early introduction of baby cereal.