Infant Feeding Practices Study II: Methods and sample characteristics

The Infant Feeding Practices Study II is a longitudinal mail survey of adult mothers from late pregnancy through their infant's first year of life. Data were collected from May 2005 through March 2007. The purposes of the study were to understand the infant feeding practices of mothers of healthy, near or full-term singleton infants and to evaluate the National Breastfeeding Awareness Campaign. This data collection consists of one prenatal questionnaire, a short telephone interview near the time of the infant's birth, and 10 questionnaires about infant feeding, health, and related issues sent approximately monthly during the infant's first year. Not all questions were asked each month. The study also includes maternal dietary assessments in late pregnancy and at about four months postpartum, and a non-pregnant comparison group. All questionnaires were developed by FDA in collaboration with CDC. The survey questions were based on the 1993/1994 Infant Feeding Practices Study, and the diet assessment questions were based on the NCI Diet History Questionnaire. New questions were evaluated by a working group of federal and academic experts and tested in cognitive interviews and three pretests. The study sample of about 4,800 pregnant women was drawn from a nationally distributed consumer opinion panel. About 2,000 women continued the study. Select sample characteristics include these: 30% primiparous, 22% high school or less education, 42% <185% poverty index, 37% WIC participant, 5% Black, 6% Hispanic, 84% married, and 12% near term birth. Public use databases will be available from CDC in the summer of 2008.