Informal breast milk sharing

Lactation consultant Marie-Louise Steyn explores the controversy surrounding informal breast milk sharing.


Your breast milk is the perfect food for your baby. It’s tailor-made for his age and is constantly adapting to meet his changing needs. Suckling is also essential, as this action helps your baby to reach his full potential. Most moms – even moms of multiples – are capable of breastfeeding successfully.

However, in exceptional circumstances, a baby may need milk from another source. If his mom has died, is critically ill, or physically unable to produce a full supply due to breast surgery, there are several alternatives to consider. Using another mom’s breast milk is one option – as long as you make an informed decision.

Milk banks

Many studies have emphasised the health benefits and life-saving properties of breast milk. Due to this, milk banks were established worldwide. They provide extremely premature and/ or ill babies with breast milk when their own moms can’t do so.

In 2008, The Human Milk Bank Association was founded to oversee milk-banking in South Africa. Voluntary donors are visited at home, screened for possible health and lifestyle risks, informed about collecting and storing breast milk safely, and given containers. The milk banks then pasteurise and refreeze the milk. This destroys bacteria and viruses (including HIV), while preserving immunological and nutritional components.

Breast milk in the global village

The Internet has changed the face of breast milk sharing. Nowadays, mothers who ‘know’ each other virtually, can request or offer expressed breast milk via social media. Is this safe? In a nutshell: it’s complicated and there are no clear-cut answers.

Dr Jennifer Naudé, a lactation consultant in private practice, says that informal milk-sharing is certainly an option if a mom can’t fully meet her baby’s needs. The risks and benefits should be weighed up to make a truly informed decision. “Breast milk is a living fluid, packed with nutritional and immunological properties. It’s human milk that’s made for human babies, so digestion is better. In emergencies like natural disasters or premature birth, breast milk can make the difference between life and death,” she explains.

What does the WHO say?

The World Health Organisation (WHO) states that “For those few health situations where infants cannot, or should not, be breastfed, the choice of the best alternative – expressed breast milk from an infant’s own mother, breast milk from a healthy wet-nurse or a human-milk bank, or a breast-milk substitute…depends on individual circumstances”.

The risks of informal sharing

  • Breast milk may contain pathogens like HIV, Cytomegalovirus (CMV), Epstein-Barr virus, as well as the bacteria Salmonella and Group B Streptococcus.
  • Breast milk can also be contaminated when it’s not collected, stored or transported safely.
  • Medication or drugs can be excreted into the donor’s breast milk.

Assessing the risk

Donor milk shouldn’t be compared to donor blood. While a single transfusion of HIV+ blood carries an 89% risk of infection, the mother-to-child transmission rate over six months of exclusive breastfeeding is about 4%. With antiretroviral treatment, this risk drops to less than 1%.

The Centre for Disease Control and Prevention states that, “The risk of infection from a single bottle of breast milk, even if the mother is HIV+, is extremely small. For women who do not have HIV or other serious infectious diseases, there is little risk to the child who receives her breast milk.”

Dr Naudé cautions: “Choosing informally donated breast milk means accepting full responsibility. The risk of infection is slight, but if it happens, the consequences may be catastrophic.” Yet the risk can be minimised. Flash-heating breast milk kills HIV and freezing destroys CMV. Dr Ameena Goga, paediatrician, lactation consultant and medical researcher says: “I’m wary of informal breast milk sharing, as it isn’t controlled. On the other hand, artificial feeding isn’t risk-free either. If you use someone else’s milk, flash heat it. It’s quick and easy, and you need to warm the milk anyway.”

The risks of formula

  • It may contain bacteria like Enterobacter sakazakii, which causes meningitis, bacteraemia, necrotising enterocolitis, and encephalitis – particularly in premature and young babies.
  • Formula may also be prepared, handled or stored unhygienically. Even in hospitals, accidental contamination has caused disease outbreaks. Breast milk contains antibacterial properties but formula is an ideal growth medium for bacteria.
  • Formula may contain dangerously low or high levels of certain ingredients. In 2008, six Chinese babies died and an some 54 000 were hospitalised due to melamine poisoning.
  • Formula-feeding is linked to short- and long-term health risks like infections, sudden infant death syndrome (SIDS), childhood cancers, obesity and diabetes.

A quick buck?

Breast milk is ‘liquid gold’. But think twice before buying (or selling) it on the Internet. Researchers from the Nationwide Children’s Hospital found that three quarters of breast milk samples bought online contained potentially harmful bacteria due to unsafe collection, storage or shipping.


Culture influences milk sharing beliefs. In Muslim culture, cross-nursing creates a special bond between kids. They become family and can’t marry each other – despite being genetically unrelated. This is problematic if the donor mom doesn’t know where her milk’s going. When her child’s grown-up, he or she could accidentally marry a ‘milk sibling’.

The ‘yuk’ factor

In a 2012 article in the Australian Medical Journal, authors Kathleen Gribble and Bernice Hausman argue that the risks of informal milk sharing are exaggerated. In their opinion, all infant-feeding methods carry risks. Warnings against sharing breast milk stem from cultural distaste – what Rhonda Shaw calls ‘the yuk factor’ – instead of evidence-based research.

The four pillars of safe milk-sharing

The non-profit organisation Eats on Feets recommends the following safeguards:

  • Informed choice: Know your options and understand the risks and benefits.
  • Donor screening: The donor should be honest about potential risk factors like medical conditions, drug use, smoking and alcohol consumption. Ideally, she should be screened for viruses transmitted via breast milk.
  • Safe handling: The donor should keep her hands, skin and equipment clean. Proper shipping and storage methods are essential.
  • Home pasteurisation: Donated milk can be flash heated (unless the parents make an informed decision to use unpasteurised milk).


A history of wet-nursing

Women have been sharing breast milk for thousands of years. Before the mid-20th century, when sterile techniques and antibiotics were discovered, moms often died from ‘childbed fever’. Orphans rarely survived without wet-nurses. Formula only emerged as a relatively safe substitute in the 20th century. But it still contributes to child deaths – especially in resource-poor areas.

Wet-nurses were also used for social reasons among the well-to-do. Ancient Romans preferred Greek wet-nurses, hoping their children would absorb the language through their milk. In the 17th century, doctors warned that breastfeeding would ruin a woman’s figure, while sex would spoil her breast milk. Upper-class moms also used wet-nurses, as they hoped to fall pregnant again immediately. They believed that having many kids might improve their chances of raising a few to adulthood.

In Britain, wet-nursing declined after the mid-17th century. Physicians warned that wet-nurses passed diseases and ‘poor moral character’ to nurselings.

Wet-nursing and cross-nursing (where relatives fed each other’s babies) remained common in developing countries. But these practices were discouraged after it was found that HIV could be transmitted through breast milk.

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