Combination Feeding of Breast Milk and Formula: Evidence for Shorter Breast-Feeding Duration from the National Health and Nutrition Examination Survey

Objective To examine combination breast milk and formula-feeding (CBFF), defined as daily breast-feeding and formula-feeding begun in the first week of life and to examine associations between CBFF and overall breast-feeding duration. Study design We used the National Health and Nutrition Examination Survey, 1999-2006, to determine the prevalence of CBFF in both univariable and multivariable analyses. We examined breast-feeding duration using Kaplan-Meier and Cox proportional hazards analyses. Results Among 6788 children ages 0-71 months, 8% were CBFF and 55% were exclusively breast-fed during the first week of life. Factors independently associated with CBFF were Hispanic ethnicity (adjusted OR, 3.81) and black race (adjusted OR, 2.59). CBFF was associated with decreased overall breast-feeding duration in the full cohort (P < .001) but not in the Hispanic or black subgroups. CBFF and formula-feeding, when compared with 4 months of exclusive breast-feeding, were associated with an increased risk for overweight/obesity between ages 2 and 6 years. Conclusions In a nationally representative sample, CBFF is associated with shorter overall breast-feeding duration in white but not Hispanic or black mother-baby dyads. A significant number of US infants, though breast-fed, do not receive the health benefits of exclusive breast-feeding. (J Pediatr 2011; 159: 186-91).