Transitions in breastfeeding: daily parent diaries provide evidence of behavior over time.

This study addressed a key question for assessing breastfeeding duration: at what point is an infant considered no longer exclusively breastfed or no longer breastfed at all? Mothers provided longitudinal infant feeding data via daily checklists. Transitions between exclusive to partial breastfeeding and partial to no breastfeeding were compared across 11 time periods for 10 age groups of infants. Daily transitions between exclusive and partial breastfeeding were common, especially for infants 6 months of age and younger, and transitions from partial to no breastfeeding occurred much more quickly than transitions from exclusive to partial breast-feeding. Ages at supplementation and weaning calculated in 1-day or 7-day spans correlated highly (intraclass correlation = .99). These results support the Breastfeeding Definitions and Data Collection Periods guideline recently developed by the Breastfeeding Committee for Canada and may bring the breastfeeding research and clinical communities closer to a consensus on the definition of breastfeeding over time.