Human milk expression as a sole or ancillary strategy for infant feeding: a qualitative study

In the United States, a significant proportion of human milk (HM) is now fed to infants from bottles. This mode of infant feeding is rarely measured or described in research studies or monitored by national surveillance systems. Consequently, little is known about expressed-HM feeding as an infant feeding strategy. Our objective was to understand how mothers use HM expression and expressed-HM feeding as a sole strategy or in combination with at-the-breast feeding to feed HM to their infants. We conducted semi-structured interviews with 41 mothers with experience of HM expression and infants under three years of age. Data were analysed using a grounded theory approach for sub-themes related to the pre-selected major themes of maternal HM production and infant HM consumption. Within the major theme of maternal HM production, sub-themes related to maternal over-production of HM. Many mothers produced more HM than their infant was consuming and stored it in the freezer. This enabled some infants to consume HM weeks or months after it was expressed. Within the major theme of infant HM consumption, the most salient sub-theme related to HM-feeding strategies. Four basic HM-feeding strategies emerged, ranging from predominant at-the-breast feeding to exclusive expressed-HM feeding. The HM-feeding strategies and trajectories highlighted by this study are complex, and most mothers fed HM both at-the-breast and from a bottle-information that is not collected by the current national breastfeeding survey questions. To understand health outcomes associated with expressed-HM feeding, new terminology may be needed.