55 Milk Expression Habits in Maternal Milk Donors: Should We Favor Hindmilk Banking for Extremely Preterm Infants?

Abstract

Abstract Background A maternal milk bank was established in 2014 in Québec. The caloric contents of pooled milk lots ranges from 58-73 calories/100 ml, whereas most babies need ≥82 calories/100 ml. Hindmilk is 2-3 times fatter than foremilk, contains more protein and would be ideal for the most fragile extremely preterm infants. This would avoid adding cow-milk protein fortifier in the first weeks of life. Hindmilk is only released 2-3 minutes post-letdown, so that the milk expression habits of donating mothers may influence caloric content. These habits are ill-documented, and precise recommendations on milk expression habits are needed. Objectives The objective of this study was to examine the feasibility of hindmilk expression by breastmilk donors so as to provide it for the most fragile preterm infants. Design/Methods In 2021, an electronic questionnaire was emailed to all active milk donors in Québec to collect data on their milk expression habits and their willingness to change them. The questionnaire contained both closed and open-ended questions. Response were analyzed using mixed methods. Results In total, 126 out of 181 donors (70%) completed the questionnaire. Most participants (78%) had a university degree, and 65.0% had >1 pregnancy. Overall, 98% were comfortable or very comfortable with current recommendations on milk expression, and 91% were aware or well aware of the benefits of maternal milk for preterm babies. Concerning breastfeeding habits, 68% reported expressing milk for banking between breastfeedings; 18% reported expressing milk for banking from one breast while keeping the milk from their other breast for their baby; and 14% reported breastfeeding their baby on each breast and keeping hindmilk for banking. Overall, 66% of participants said they would be willing to change their habits most or all the time to provide hindmilk for the most fragile babies. The main theme invoked in open-ended answers was altruism, and gratitude for being able to help others. On the other hand, few participants commented on the complexity of milk expression or reported that additional restrictions might discourage them from donating. Conclusion Most participating mothers were already giving foremilk and hindmilk. A significant proportion of respondents said they would agree to change their expression habits in favour of giving hindmilk to be used for only the most fragile infants. More information is needed on how changing recommendations for milk expression might impact the supply and caloric content of mothers’ milk.