Milk sharing

Is milk sharing safe?

Women have a long history of sharing breast milk, but the practice does have risks. Informal sharing has more risks than using pasteurized donor human milk from a milk bank. Doctors recommend careful screening of mothers who share milk. They should be in good health and, if using medications, the drugs must be compatible with breastfeeding. The use of illegal drugs, cannabis, tobacco, or alcohol can make a woman an unsuitable donor. Potentially dangerous microbes can be removed from breast milk by flash heating. Buying breast milk online is never advisable. It may be delivered in poor condition, contaminated with bacteria, viruses, or medication, and may be diluted with cow’s milk, water, or other products that could endanger a baby.

A) Describing milk sharing

Wet nurses (a woman who breastfeeds another’s child) have been described throughout recent human history (Baumgartel 2016; Stevens 2009). Today, wet nurses can prevent the use of infant formula in climate and geopolitical emergencies.

Milk sharing is the use of another’s expressed breast milk. The internet has made sharing easier (Perrin 2014). There are more risks in the informal sharing of breast milk than in using pasteurized donor human milk from a milk bank. The degree of risk depends on the health of the donor. Human milk can also be contaminated by unclean collection techniques or when milk is not stored properly.

Using milk bought over the internet is never advisable. 

B) Screening donors

The Academy of Breastfeeding Medicine, an international organization of doctors and researchers, has published guidelines to minimize the risk of milk sharing (Sriraman 2018). It recommends:

1) Interviewing of the donor

A mother-to-mother screening process using face-to-face or online interviews.

Donor mothers should collect and store milk safely (Eglash 2017).

2) Testing of the donor

The donor mother should test negative for:

3) Donors who are not suitable

A woman is not a suitable breast milk donor if she:

C) Cautions about milk sharing

Different organizations have a range of opinions about the risks, benefits, and costs of milk sharing (Palmquist 2019). Some examples include:

  • Eats of Feets (Lutrell)
  • Human Milk 4 Human Babies (Human Milk 4 Human Babies)
  • Perinatal Services BC. Informal milk sharing: the use of unpasteurized donor human milk (Perinatal Services BC 2016)
  • The Academy of Breastfeeding Medicine (Sriraman 2018)

The American Academy of Pediatrics states (AAP 2017):

“ … informal direct milk sharing without pasteurization exposes infants to a range of possible risks, including bacterial contamination and viral transmission…

“Because direct milk sharing is often arranged by using milk from a single donor mother, other contaminants, such as medications or drugs, may be a higher risk than with pooled milk products. It is unknown what effects paying women for milk may have on these risks.”

One U.S. study (Perrin 2018) of 30 samples of milk expressed for peer-to-peer sharing did not find a difference in nutrients or bacterial count from milk expressed for a milk bank or from that expressed for the mother’s own baby.

D) Pasteurizing shared milk

Flash heating can remove potentially harmful bacteria and viruses from milk (Besser 2013; Israel-Ballard 2005).

 To flash-heat breast milk (Sriraman 2018):

  1. Put 50 to 150 ml of the milk you want to sterilize in a heat-resistant glass (not plastic) jar.
    1. If you have more milk, divide it into two jars.
  2. Place the jar of milk in a small pan of water.
    1. Make sure the water is about two fingers above the level of milk so that all the milk will be heated well.
  3. Heat the water on a very hot fire or on the highest level of your stove until it reaches a rolling boil (when the water has large bubbles).
    1. Stay close, because this should only take a few minutes.
    2. Letting the water boil too long will damage nutrients in the milk.
  4. Immediately after the water comes to a boil, remove the jar of milk from the boiling water.
  5. Place the jar in a container of cool water, or let it stand alone to cool until it reaches room temperature.
  6. Protect the milk as it cools and during storage by placing a clean lid or small plate on it.
  7. You can safely feed your baby this milk at room temperature within six hours, refrigerate it, or freeze it as per the usual storage guidelines for breast milk.

E) Buying milk online

Internet-based sharing of breast milk, particularly the buying and selling of milk, should be strongly discouraged, say the following organizations (Sriraman 2018):

  • American Academy of Pediatrics (AAP 2017)
  • United States Food and Drug Administration (US FDA 2018)
  • The European Milk Bank Association and the Human Milk Banking Association of North America (EMBA and HMBANA 2015)
  • Academy of Breastfeeding Medicine (Sriraman 2018)
  • Canadian Pediatric Society (Pound 2020)

Breast milk bought online may:

  • Be expensive.
  • Be delivered in poor condition (Geraghty 2013).
  • Be contaminated with bacteria and viruses.
  • Contain medication that the donor is taking.
  • Be diluted with cow’s milk, water, or other products that would pose a major risk to a baby (Keim 2015; Onge 2015).

Researchers found that of 102 samples of breast milk bought online, 11 consisted of at least 10% cow’s milk. They also found high levels of dangerous bacteria thought to be due to poor collection, storage, or shipping practices (Keim 2013).


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Besser M, Jackson DJ, Besser MJ, et al. How long does flash-heated breast milk remain safe for a baby to drink at room temperature? J Trop Pediatr. 2013 Feb;59(1):73-5
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Perrin MT, Goodell LS, Allen JC, et al. A mixed-methods observational study of human milk sharing communities on Facebook. Breastfeed Med. 2014 Apr;9(3):12

Pound C, Unger S, Blair B; Canadian Paediatric Society, Nutrition and Gastroenterology Committee. Pasteurized and unpasteurized donor human milk. Paediatr Child Health 2020: 25(8);549

Sriraman NK, Evans AE, Lawrence R, et al.; The Academy of Breastfeeding Medicine’s Board of Directors. Academy of Breastfeeding Medicine’s 2017 Position Statement on Informal Breast Milk Sharing for the Term Healthy Infant. Breastfeed Med. 2018 Jan/Feb;13(1):2-4

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