Breast milk sharing between moms, a practice not without risk

Elise Armoiry My Baby Moon
Feb 3
3 min read

Breast milk sharing outside of official channels, often called informal milk donation, is experiencing significant growth via social media. This is especially true with health alerts related to infant formula contamination that I discuss here.

While the intention is for mothers to help each other, health authorities and 2025 scientific publications warn of significant safety issues. Here is what you need to know before considering this practice.

1. Breast milk donation between moms or Milk Bank: What is the difference?

Unlike donation via a milk bank (formal circuit), informal donation does not benefit from any standardized control protocol.

In a milk bank: Donors undergo rigorous serological tests (HIV, Hepatitis B and C, HTLV), and the milk is pasteurized to eliminate bacteria and viruses while preserving its essential nutritional properties.
Informally: The milk is "raw," it has been stored in the fridge or frozen. The hygiene conditions observed during collection (cleanliness of pumping equipment, hand hygiene) and storage (compliance with storage procedures) are unknown. Even if the donor appears healthy, certain viruses or bacteria can be present without apparent symptoms.

2. Identified risks in cases of informal breast milk sharing

Recent studies highlight three major types of risks associated with uncontrolled donation:

Infectious risks: Viruses such as Cytomegalovirus (CMV), HIV, or hepatitis can be transmitted through breast milk. Additionally, improper handling during pumping or transport can promote the proliferation of staphylococci or streptococci.
Chemical and medicinal risks: Milk may contain traces of medications (even over-the-counter), psychoactive substances (nicotine, alcohol, cannabis), or lipophilic environmental pollutants.
Storage and hygiene: Without a certified cold chain, the milk may undergo invisible thaw/refreeze cycles, altering its bacteriological safety.

3. Recommendations from health organizations

In 2025, the World Health Organization (WHO) maintains a cautious position:

Priority to breast milk: The mother’s own milk remains the absolute gold standard.
Milk bank milk: This is the only recommended alternative, particularly for premature or fragile babies, as it guarantees optimal safety.
Transparency with caregivers: If you are considering using informal donor milk, it is imperative to speak with your pediatrician or midwife to assess the risks and, if possible, request recent tests from the donor.

4. Limiting the risk

There are cases where the donor is known, as well as her medical status and lifestyle (I have had cases of donations between friends or sisters), in which case the risk is limited compared to a donation from a stranger. The act of "flash-pasteurizing" the donor's milk to limit bacterial risk is mentioned in an LLL article on this topic. (But there will be no impact on the risk related to medications, pollutants, and others).

5. How to act if you do not have enough milk?

If you wish to increase your milk production, your IBCLC lactation consultant can help you analyze the causes of a drop in lactation and optimize your lactation.

Book with Elise

How to act if you have too much milk?

Instead of going through social media groups, turn to the Association of Milk Banks of France (ADLF). Official milk donation saves lives every day in neonatology. A simple questionnaire and a blood test are enough to become a donor and ensure that your milk will be used in a safe and ethical manner.