Within the lactation field, we're required to rely on guidance from the World Health Organization as it pertains to which milks should be outlined as preferrential for families when "mothers own milk" isn't available- whether that be completely substituting it or supplementing. WHO currently outlines the order preference as
mother's own milk
donor milk from a human milk-bank
healthy wet nurse
infant formula
Though there's an established preference within health agencies and organizations regarding this sort of hierarchy of feeding, it doesn't have any relation to the accessibility of these options the or support we have to pursue them. Unfortunately for many of us, the option of formal donor milk or healthy wet nurse (milk sharing) just isn't practical or possible, especially in the volume that would entail formula is no longer necessary. Many of us rely on formula because it is the only option we have available. That's not to say that formal donor milk or milk-sharing isn't a great option for a lot of us... I just think that this component of accessibility is ignored within a lot of conversations we have about donor milk and why we use formula and it's important to preface conversations about donor milk with that acknowledgment.
Formal Donor Milk
Here in the US, it’s becoming increasingly common for parents to be offered donor milk in the hospital if supplementing is indicated.
Outside of that, donor milk is really prioritized for NICU patients. The milk banks that supply hospitals with donor milk sell to the public when there’s an excess of milk, but generally there’s a cap on quantities you can purchase and it can be pretty costly, around $3-5 per ounce. If you want to contextualize that: to supplement half of the needs for a 1 month-old (consuming 25 ounces of milk a day) it would cost at least $1,050-$1,750 a month.
Formal milk banks, under the umbrella of HMBANA here in the US, require milk donors to undergo blood testing for communicable diseases. Milk is tested for bacteria and nutrient levels, they have to adhere to specific guidelines for collection and storage; milk is then pasteurized before being made available.
Informal Donor Milk (Milk Sharing)
Whereas formal donor milk is rigorously screened and treated through testing and pasteurization, informal milk sharing is 100% based on a trust system and the responsibility to screen potential donors is entirely carried by the person receiving the donation. This fact can sometimes create discomfort for someone considering milk sharing, and no one should be pushed into the notion that they should give their baby shared milk vs formula.
If you are going to use informal donor milk, knowing how to minimize risks in milk sharing is really important. A lot of times when we think about safety with milk sharing we think of communicable diseases and conditions. The truth is that when milk is exchanged for free from trusted sources, it’s actually more common that risks involving pumping hygiene and milk storage practices are more common, which is why having transparent and vulnerable conversations is all the more crucial. I highly encourage anyone exploring milk sharing to explore the resources outlined by the organization Eats on Feets here.
Outside of the safety concerns that some have for milk sharing, some may opt for formula instead as there is still stigma attached to milk sharing within some communities, especially here in the US.
In a study in the Journal of Human Lactation, researchers set out to find maternal perceptions about donor milk and formula. Within the study they identified the following themes:
“(a) Donor milk is seen as temporary whereas formula is seen as an ongoing plan, (b) formula is viewed as familiar whereas donor milk is viewed as unfamiliar, (c) donor milk is costly and challenging logistically, and (d) donor milk is "healthier." “
Recently I asked other low suppliers about their donor milk experiences, and there were a lot of mixed reactions: immense gratefulness, joy and healing, anxiety in sustaining that stash; nervousness in the confidence of their donor. Those parents who hadn’t used donor milk or had reservations echoed some of those sentiments, some also expressing guilt or discomfort associated with using another person’s milk.
In the Research
In a Cochrane Database systematic review, researchers studying (milk bank) donor milk vs formula supplementation in preterm and low birth-weight infants found that “feeding with formula, particularly preterm formula, compared with donor breast milk, may increase rates of weight gain, linear growth, and head growth in preterm or [low birth-weight] infants in hospital. Formula feeding is associated, however, with a near‐doubling of the risk of necrotising enterocolitis” (an intestinal disease that effects 1-5% of NICU patients).
The safety of donor milk has also been studied. In a report done by the Department of Neonatology Wesley Medical Center, researchers reported the frequency of detected markers of potential harm in donors, and over a 4 year period found that 29.7% of willing donors screened resulted in milk rejection or hold. The most prevalent reason for rejection was detection of cotinine (a biomarker for exposure to tobacco smoke).
Reviewing these studies gives us great insight as to the applications of using donor milk, namely:
1. Donor milk provides bioactive ingredients not available in formula most beneficial to intestinal health, but formula is most beneficial to increase weight gain and linear growth in low-birth weight infants.
2. Donor milk has been shown to contain potentially harmful substances, therefore screening and maternal confidence in donor (if informal) is crucial.
3. Donor milk is somewhat stigmatized in long-term use, but considered a valuable option.
Donor milk, like all feeding options- has no right or wrong answer. It’s not as simple as “just give the baby some milk” and it’s a deeply personal decision for each family to make on their own. Weighing your options and understanding more about risk reduction measures can help you make a more informed choice and lead you to the practice that's right for you and your family.
Sources Quigley, M, et al. (2018). Formula versus donor breastmilk for feeding preterm or low birth weight infants. Cochrane Database Systematic Review. doi:
Kair, LR, et al. (2017). Donor Milk or Formila: A Qualitative Study of Postpartum Mothers of Healthy Newborns. Journal of Human Lactation. doi:
Meier, P, et al. (2017). Donor Human Milk Update: Evidence, Mechanisms and Priorities for Research and Practice. Journal of Pediatrics. doi:
Bloom, BT. Safety of donor milk: a brief report. Journal of Perinatology. doi:
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