Objectives: Although much has been published about breastfeeding rates, little is known about how breastfeeding is practiced in the United States. We describe the distributions and characteristics of practices related to common advice about breastfeeding during the infant's first year of life.
Participants and methods: Participants in the 2005-2007 Infant Feeding Practices Study II received monthly questionnaires during their infants' first year of life. Among breastfeeding respondents, we investigated patterns and trends in types of breastfeeding (supplementing with formula or not, and at the breast or not) and maternal report of infant feeding behaviors corresponding to common breastfeeding advice on frequency, duration, and intervals of feedings.
Results: More than half of the breastfeeding mothers fed their infants nothing other than breast milk until 4 months of age. Formula supplementation declined from 42% at 1 month to 15% at 1 year; adding other foods/liquids increasingly surpassed supplementing with formula beginning at 5 months of age. Six percent of the mothers reported that the only breast milk the infant was fed was expressed, rather than at the breast. Frequency of breast milk feedings per day declined from 8 at 1 month to 3.5 at 1 year. Reported feeding durations of <20 minutes increased from 46% at 1 month to 88% at 1 year. Feeding from both breasts per feeding decreased 15% over the infant's first year (from 69% to 59%). Longest interfeeding intervals more than doubled over the year.
Conclusions: Exclusive breastfeeding was common up to 4 but not to 6 months of age. Breastfeeding with only expressed milk was rare. Considerable variation existed in maternal report of practices that correspond to common breastfeeding advice. More research is needed to better understand how these variations relate to breastfeeding outcomes and the role of common breastfeeding advice in infant feeding decisions.