The WHO/UNICEF definitions of breastfeeding will be used for the purposes of this study. It is also important to define initiation and duration of breastfeeding. For purposes of this study, breastfeeding initiation is defined as the infant’s first intake of breast milk, and includes those infants that were only breastfed once, or were only given expressed breast milk; “ever breastfed/ever given breast milk”. Breastfeeding duration is defined as the total length of time that an infant receives any breast milk at all.