by Jean M. Drulis, B.A., Director and Co-founder, Mother’s Milk Bank of Iowa
Thank you to Mother’s Milk Bank of Iowa for their contribution to our blog by sharing this article. Donor human milk (DHM) is available from non-profit milk banks, for-profit companies and peer-to-peer milk sharing. The focus here is on non-profit milk banking in North America where the operational milk banks follow essential safety standards established by the Human Milk Banking Association of North America (HMBANA).
Milk banking, in some form, has existed for all time. The Babylonian Code of Hammurabi circa 1800 BC makes reference to wet nursing which is the predecessor of milk banking. Dr. Theodor Escherich (1857-1911) studied the gut microbes of breastfed infants and found they differed significantly from non-breastfed infants.1 Ultimately, the common colon bacillus he discovered was named after him, Escherichia coli (E. coli). He highlighted the value of breast-feeding and developed the volumetric system of infant feeding that involved the weighing of infants before and after nursing.2 His research formed the establishment of the 1st human milk bank, in Vienna, Austria, in 1909.1 In 1910, the 2nd human milk bank, in Boston, was founded and more were established throughout the world in the next decades. In 1943, the American Academy of Pediatrics Committee on Maternal Milk published milk bank standards.3 Human milk was not pasteurized. In the 1980’s, almost all of the North American milk banks closed because of safety concerns regarding the transmission of viruses, especially HIV, which can be transmitted through human milk. HMBANA was founded in 1985 and guidelines were developed for screening milk donors and for pasteurizing human milk.3 Four milk banks that didn’t close in the mid-1980s and are still in operation today are located in San Jose, CA (established 1974), Vancouver, BC (1974), Raleigh/Cary, NC (mid-70s) and Denver/Arvada, CO (1984). They became the cornerstone of HMBANA. The revival of milk banking in North America happened as research in human milk and its benefits mounted and the safety of pasteurized donor human milk was demonstrated. Slowly new milk banks emerged, in Austin, TX (1999) and Iowa City, IA (2002). The Mother’s Milk Bank of Iowa (MMBI) was founded to improve the health of infants across the United States (US) by providing pasteurized donor human milk to hospitals (mainly neonatal intensive care units) and infants at home. MMBI was the 5th milk bank in the US and the 1st in the Midwest from this resurgence in milk banking. At present, there are 29 HMBANA-member milk banks, 3 in Canada and 26 in the US.4
The Mother’s Milk Bank of Iowa and the other 28 member milk banks adhere to HMBANA’s mandatory standards, “Guidelines for the Establishment and Operation of a Donor Human Milk Bank.”3 It contains evidence-based instructions for screening milk donors and serologic testing, pasteurizing donor milk using the Holder method and microbial testing thereafter, appropriate handling, freezing, defrosting, pooling, labeling and dispensing milk by prescription or hospital order and shipping it. Banks are required to have a manual that contains the operational standards of procedures. The standards include facility structure, operation, maintenance and equipment. The Guidelines do not include nutritional analysis of DHM as a requirement but if a bank does analyze it, they are responsible for the accuracy of the results and should ensure they follow Good Laboratory Practices regarding regular calibration and record keeping.3 In a 2019 International Childbirth Education Association website blog post on analyzing mother’s milk, Walls raised concern about analyzing a small sample of human milk to determine whether its protein, fat and carbohydrate content was suitable.6 It may not demonstrate accurately the milk an infant would receive over the course of that day. Jo et al.7 analyzed 75 DHM samples from 5 milk banks that had labeled their DHM as 24 kcal/oz. The results revealed that the calorie content differed considerably from what it was labeled. The Mother’s Milk Bank of Iowa does not nutritionally analyze the DHM it dispenses. In a pilot study, the MMBI did analyze DHM after it opened (in 2002) and did so for approximately 2 years. The results showed that pooling of DHM from multiple donors led to relatively constant protein and fat content.8 Variation was less than what had been reported for maternal expressed milk. DHM dispensed from MMBI routinely has 3-5 donors in each batch to more evenly distribute the components and their variability. Protein was higher in the pools that contained variable proportions of DHM from mothers of premature infants (“premature milk”). When MMBI receives donated premature milk, it is portioned into as many pools as possible.
Operational milk banks have an annual assessment for HMBANA accreditation. An assessor from HMBANA’s Accreditation Committee visits each bank and reviews it for compliance to the standards. A detailed report of findings is submitted by the assessor to the Committee with a recommendation for accreditation or remediation. A self-assessment is done the following year by the milk bank management.
Safety of Donor Milk
The majority of the DHM dispensed by HMBANA-member milk banks is to premature infants. In 2019, the Mother’s Milk Bank of Iowa dispensed 89% of its DHM to hospitals with the remaining 11% going to infants at home. Human milk has strong trophic effects on the infant gut which allows full enteral feedings to be achieved sooner for the premature infant.5 And it protects these fragile and vulnerable infants from necrotizing enterocolitis and sepsis.5 Donor milk has at least 4 layers of recipient protection from disease transmission:
- Donor screening for medical and lifestyle risk factors
- Serum screening
- Post-pasteurization microbial testing
In the 35 years of HMBANA Guidelines, there is not a single documented case of disease transmission through feeding banked donor milk.5
1 Moro, G.: History of milk banking: From origin to present time. Breastfeed. Med. 13:S-16, 2018. 2 Shulman, S.T. et al.: Theodor Escherich: The first pediatric infectious diseases physician? Clin. Infect. Dis. 45:1025, 2007. 3 Human Milk Banking Association of North America. Guidelines for the establishment and operation of a donor human milk bank. 2018. 4 https://www.hmbana.org/find-a-milk-bank, 2020. 5 Haiden, N. and Ziegler, E.E.: Human Milk Banking. Ann. Nutr. Metab.69(suppl. 2):8, 2016. 6 Walls, D.: Analyzing mother’s milk. Online Blog (https://icea.org/analyzing-mother-milk), International Childbirth Education Association, 9/16/2019. 7 Jo, D.B. et al.: Macronutrient analysis of donor human milk labelled as 24 kcal/oz. J. Perinatol. 40:666, 2020. 8 Drulis, J.M. et al.: Fat and protein content of pooled donor human milk is relatively constant. Mother’s Milk Bank of Iowa. Poster. International Society for Research in Human Milk and Lactation (ISRHL) Conference. Perth, Australia, February, 2008.