Mapping the Milk: Integrating Donor Human Milk into Infant Nutrition Systems

A human milk diet is an important part of the health and survival of all infants. A human milk diet is especially crucial for the most vulnerable preterm infants as it promotes a healthy gut and protects from Necrotizing Enterocolitis (NEC). However, many preterm infants are unable to consume their mother’s own milk due to breastfeeding challenges resulting from early delivery. Therefore, nutritional supplementation is often necessary for preterm infants and donor human milk (DHM) is highly superior to baby formula. DHM in the United States is processed at the 29 not-for-profit Human Milk Banking Association of North America (HMBANA) milk banks. Milk banks play a key role in providing optimal nutrition to vulnerable babies all over the country. Currently, there is a lack of research on the use of and access to DHM. The current thesis proposes a data repository to identify disparities in the use and access of DHM and look for correlations in the data. There are predicted links between low breastfeeding rates at 6 months and low access to DHM, high early formula use and low use of DHM, and a correlation between low access and low use. The proposed data repository would allow the landscape of milk banking to be better understood, and would create room for policy change, government funding and public health reforms that work to further integrate DHM into part of infant nutrition and care. Acknowledgments I would like to thank my first reader Dr. Elise Ferree for her thoughtful support and guidance through my thesis, as well as her willingness to listen to my silly stories about milk. Additionally, I would like to thank Dr. Lars Schmitz for reading my thesis and for all the long runs over the years in Claremont. I also thank my mentors and colleagues at Northwest Mothers Milk Bank who introduced me to the world of human milk banking and gave me a newfound passion during my gap year. Finally, I dedicate this thesis to milk donors across the country. The generosity of milk donors saves the lives of our most vulnerable populations, and I am inspired by their spirit and donations of love. Introduction History of breastfeeding in the United States The practice of infant breastfeeding in the United States has changed throughout the past century, and is influenced by economic and cultural factors. Economic factors may involve the necessity of working outside the home and cultural factors may include education surrounding breastfeeding (Eidelman et al, 2012). In the colonial era, it was common for mothers to breastfeed their babies for the first two years of life. However, the late 1800s saw a shift to primarily feeding babies with cow's milk due to a mothers' need to work outside the home (Salmon, 1994; Wolf, 2003). The shift to cow's milk and artificial food was coupled with a high infant death rate due to diarrhea in the early 1900’s (Wolf, 2003). Public health reforms in the 1910’s advocated for infant feeding with pasteurized cow’s milk. In the 1920’s physicians around the United States started to strongly promote breastfeeding’s importance as well as putting public health funding into breastfeeding education (Wolf, 2003). While physicians continued to inform people of the positive health benefits of breastfeeding for both mothers and babies, breastfeeding hit an all-time low in the 1970’s in the United States. With only 24% of infants being breastfed at all before leaving the hospital, physicians and public health experts were concerned. Breastfeeding rates seemed to rise and surge following the 1970’s (Wolf, 2003). The importance of breastfeeding and health benefits to both mother and baby are continuing to be discovered, and public health reforms work to match these discoveries. While breastfeeding rates are significantly higher today than in the 70’s, public health experts continue to campaign for breastfeeding education (Ryan, 1997). In 2017, the United States national percentage of babies that were ever breastfed (engaged in at least one breastfeeding session) was 84.1%, while the breastfeeding rate at 6 months was 58.3% (CDC, 2017). However, breastfeeding rates and feeding practices in general vary significantly across regions of the United States. This variation is likely due to economic and cultural factors. Additionally, there are a number of correlates to low breastfeeding rates including lack of breastfeeding education, low income, and employment outside of the home (Calnen, 2007; Heck et al, 2006). With about 2/3 of all new mothers returning to work in the first year after giving birth, there are many challenges to breastfeeding. The issue of a standardized maternity leave and lack of nationwide policies in place that support breastfeeding in the workplace are both factors that likely lead to the large range of breastfeeding rates across the country. Additionally, the education behind the importance of breastfeeding also varies across the country. While the importance of breastfeeding should be emphasized for all babies, the practice is especially important for preterm infants that are born at or before 37 weeks gestation (Eidelman et al, 2012). Despite the great value of breastfeeding for preterm infants, the rates are lower for this population than for full term babies (Nyqvist, 2008). It is predicted that lower incidence of breastfeeding in preterm infants is due to feeding challenges related to establishing and maintaining a milk supply, and the transition from tube feeding in the hospital to breastfeeding (Callen & Pinelli, 2005). Given the difficulties in feeding for preterm infants, it is often necessary to supplement the diets of these infants while in the hospital. Common methods of nutritional supplementation are baby formula and donor human milk (DHM). DHM is pasteurized breast milk that is processed outside of the hospital, and highly regarded as the superior nutrition supplementation strategy when compared with infant formula (Abrams et al, 2017; Eidelman et al, 2012). While DHM is the best option for a nutritional supplement, there is a lack of research on the use and access of DHM (Updegrove, 2013). The current proposed study hopes to survey DHM use and access in a way that indicates disparities, and promotes policy and public health reforms that integrate DHM into newborn nutrition and care. Importance of a human milk diet A human milk diet is important for the health and survival of all babies, especially for vulnerable and preterm infants. The American Academy of Pediatrics recommends that all preterm infants receive human milk over formula supplementation. Premature infants make up the largest and most vital group of donor milk recipients, because their own mother’s milk is often not available in sufficient quantities (Abrams et al, 2017; Haiden & Ziegler, 2016). It has been shown that receiving human milk for vulnerable infants is incredibly important for preventing Necrotizing Enterocolitis (NEC) (Richard, 2017). NEC is a disease of an infant’s intestinal tissue which can lead to bloodstream infections. NEC can make the infant unable to properly feed and move food through the digestive tract (NIH, 2022). Premature infants are especially at risk for NEC because of the immaturity of their immune and digestive systems. Human milk can be helpful to a preterm infant by enhancing intestinal motility, lowering gastric acidity and epithelial permeability and changing the composition of bacterial flora. Additionally, human milk provides bacteria that prevents pathogen adhesion and allows for gut colonization of beneficial microbes (Lyons et al, 2020). Human milk can be considered as having its own microbiome, which makes important probiotics for infant development (Lyons et al, 2020). Nutritional supplementation through formula does not provide the same benefits and protection against NEC. Infants who are fed over 50% of their own mother’s milk in the first 2 weeks after birth are significantly less likely to suffer from NEC (Richard, 2017). When a mother’s own milk is not available, DHM can be used as an alternative over formula. Declining rates of NEC can be linked to increasing use of DHM (Kantorowska et al, 2016). Due to the huge benefits of supplementing with DHM, the use and access of DHM should be studied to promote the health of the most vulnerable infants. Human milk banking and HMBANA Donor human milk use is increasing in the United States with the growth of the Human Milk Banking Association of North America (HMBANA). Milk banks are the largest and safest providers of human donor milk (Haiden & Ziegler, 2016; Abrams et al, 2017; HMBANA, 2022). There are 29 not-for-profit HMBANA milk banks in the United States and two in Canada. The United States milk banks are shown on a map in figure 1. Figure 1. A map of the 29 not-for-profit HMBANA milk banks. The fully established milk banks are shown in red while the developing milk banks are shown in blue. This map does not show any milk banks that may be in the planning phase. Source: caltopo, HMBANA All HMBANA milk banks are modeled after receiving milk from mothers who have an oversupply of milk for no payment or compensation other than the knowledge their donation is going to help babies in need. Donors are recruited through a variety of channels depending on the milk bank (HMBANA, 2022). Some milk banks provide written information to be left in general practitioners offices, hospitals to be shown to mothers during perinatal periods, volunteer and other organizations working in public health, and stores for new mothers and babies. Donors can also be found through direct referrals from other donors, staff in NICUs, pediatricians, childbirth educators, organizers or attendees of pre and/ or postnatal classes, breastfeeding mothers’ groups, and organizations including La Leche League or the National Childbirth Trust. Some milk banks also recruit donors through marketing strategies such as placing advertisements in newspapers, newsletters, ma