Objectives: Our goal was to determine why women stop breastfeeding at various times during their infant's first year.

Methods: We analyzed self-reported data from 1323 mothers who participated in the Infant Feeding Practice Study II. Mail questionnaires were sent to mothers approximately 2, 3, 4, 5, 6, 7, 9, 10 1/2, and 12 months after their child's birth, in which they were asked to rate the importance of 32 reasons for their decision to stop breastfeeding. We applied exploratory factorial analysis to extract meaningful constructs of mothers' responses to the 32 reasons. We then compared the percentages of mothers who indicated that each reason was important in their decision to stop breastfeeding among various weaning ages and used multiple logistic regression models to examine sociodemographic differences in the most frequently cited reasons for stopping breastfeeding.

Results: The perception that their infant was not satisfied by breast milk alone was cited consistently as 1 of the top 3 reasons in the mothers' decision to stop breastfeeding regardless of weaning age (43.5%-55.6%) and was even more frequent among Hispanic mothers and mothers with annual household incomes of <350% of the federal poverty level. Mothers' concerns about lactation and nutrition issues were the most frequently cited reasons for stopping breastfeeding during the first 2 months. Starting from the third month, self-weaning reasons were increasingly cited as important, with the statements "My baby began to bite" (31.7%), "My baby lost interest in nursing or began to wean himself or herself" (47.3%), and "Breast milk alone did not satisfy my baby" (43.5%) cited as the top 3 reasons at > or = 9 months of age.

Conclusions: Our findings about the major reasons why mothers stop breastfeeding at various times during their child's first year should be useful to health professionals when attempting to help mothers overcome breastfeeding barriers and to health officials attempting to devise targeted breastfeeding interventions on those issues prominent for each infant age.