Objective: To identify the factors facilitating or preventing breastfeeding during the first year of life.

Research Design: Longitudinal study of a cross-section of U.S. births between February 1993 and July 1993.

Setting: Community residing mother-infant pairs, covering total U.S.

Subjects: About 1800 healthy mothers of healthy infants completed 12 instruments.

Selection Procedure: A Consumer Mail Panel, operated by Market Facts as a quota-sample of 500,000 U.S. households, is surveyed annually with demographic questionnaires and postcards regarding focal events like births/pregnancies. This panel reported 3,155 pregnancies during the 6 month recruitment period, of which 2,615 were eligible and 2,358 completed a detailed Prenatal Questionnaire about 2-3 months before delivery. All were followed-up by telephone (birth screener) to select only healthy moms and infants, leading to a final sample of 1803. Due to the demands imposed on respondents, middle-class white moms are over-represented. 22% received WIC.

Intervention: None.

Measurement/Results: Moms received 9 follow-up questionnaires, first at 1 month intervals (1 through 7 months past birth), then at 9 month and 12 month intervals. The American Academy of Pediatrics convened a workshop of experts that developed a questionnaire. Feeding practices in the previous 7 days were obtained at each time in detail. Whenever breastfeeding (BF) was stopped or formula was introduced, a set of about 25 reasons for doing so was provided. Factor analysis identified 7 sets of factors, ranging from“child outgrew BF,” to maternal health, child's growth and logistics of feeding to simple “didn't like it anymore.”

Conclusion: Although motivation to BF is high and professional and lay supports are widely available, difficulties increase from month to month, especially in low income situations, that reduce BF from 64.5% at nursery discharge to 45.4% in Month 2, 33.5% in Month 6 and 15.6% in Month 12.