As I watched a woman leave my house with a carrier bag full of my breast milk, I felt proud. Although my breastfeeding journey had not worked out as I had imagined, it comforted me to know that my breast milk would be nourishing other babies. When I gave birth to my daughter, five months previously, she did not take to breastfeeding. After losing 15% of her body weight due to severe tongue tie that prevented her from feeding directly, I picked up my breast pump and began pumping exclusively – I would feed her my milk, just not from the breast. Before long, I had filled my family’s freezer with my milk, then a whole new freezer.

I heard about milk sharing through Facebook, via the page Human Milk 4 Human Babies (HM4HB), which is an informal group for women to share milk with other mothers. One of the veteran pumpers on the group had donated her milk to between 20 and 30 babies and suggested I give it a try. I wrote on HM4HB’s page: “Baby is 20 weeks, five litres to donate, no cigarettes or alcohol,” and was inundated with messages from women willing to collect my milk.

Milk sharing has been recorded as far back as Ancient Egypt. More familiar to many people in the form of wet nursing, it was traditionally an informal practice between mothers. In the 19th century, hospitals started building directories of wet nurses whom they could contact should breastfeeding falter, such as when a mother was too ill or her milk had not come in.

The first formal milk bank opened in 1939, at Queen Charlotte’s hospital in London, as a place to collect, process and distribute donated milk to sick babies. As the birthing and feeding of infants became medicalised during the 50s, more milk banks opened within hospitals. “There used to be milk banking mechanisms in most hospitals with maternity services,” says Dr Natalie Shenker, the co-founder of Hearts Milk Bank in Hertfordshire. “That’s how sick babies were largely fed in hospitals until the 80s.”

Facebook Twitter Pinterest Natalie Shenker was inspired to start Hearts Milk Bank because ‘there was no way in the NHS to make sure that milk could be provided’. Photograph: Alicia Canter/The Guardian

However, the development of formula milk – which became widespread due to heavy marketing campaigns and cheap supply to hospitals – caused donations to dry up. When the HIV crisis hit, it almost eradicated milk banks entirely, because the infection could be carried in mothers’ milk; by the 90s, only the six milk banks with pasteurisers remained. If you were unable to breastfeed, you had little choice but to use formula.

Now, however, social media has fostered a revival of milk sharing, much of it informal, as women are able to contact each other via groups such as HM4HB. Sourcing milk from strangers is legal, but it is not ideal, as not only HIV but also bacteria and diseases can be transmitted. “We are aware that, with social media, there have been developments in [informal sharing],” says Clare Livingstone, a professional policy adviser for the Royal College of Midwives. “No one is telling women not to do it, but they need to be aware there are some risks.” A spokesperson for the Department of Health said it “does not recommend informal breast milk sharing, without the safety controls offered by the official NHS milk banks.”

There are 16 NHS milk banks in the UK, 14 in England and one each in Northern Ireland and Scotland. They are closely regulated. Donating mothers are screened for viruses, then their milk is tested, pasteurised and tested again before being distributed. Almost all the banks are funded by the NHS and contained within hospital neonatal wards. This means that NHS donor milk is extremely difficult to obtain and that funding for it is usually limited to babies who are born extremely prematurely. This is how informal groups such as HM4HB came about. Set up in 2010, the network has 130 local Facebook pages and more than 20,000 members. “Through our pages, hundreds of babies in need receive breast milk every single day,” it states on its website.

Harriet Tutton has donated milk informally through HM4HB for more than two years, since the birth of her daughter Luna. Her first recipient was an expectant mother who had previously experienced breastfeeding problems; she drove for five hours to collect the milk. “Her baby came 10 weeks early. Luckily, it was two weeks after I had given her milk. She didn’t have to supplement with formula, because she had milk ready and waiting for her baby,” Tutton says.

Facebook Twitter Pinterest Ruby Abbiss stores her excess milk in a chest freezer at home before donating it to Hearts Milk Bank. Photograph: Alicia Canter/The Guardian

Tutton, who has spoken about her experience in the media, has received mixed reactions: “The people who have heard about it before, the mums, they think it’s amazing. But then you get the odd couple of people who tell you they think you’re disgusting, you’re doing something illegal. I was called a paedophile once [in comments under an article].”

Anne (not her real name), an NHS speech and language therapist, says that some health professionals frown on donor milk. She recalls going to visit the mother of one baby and noticing on the file that the woman had been reported to social services by hospital nursing staff for sourcing milk from another woman, despite the fact that it is legal. “What I discovered was that none of the staff felt confident or skilled enough to sit the mother down to ask the right questions. When I spoke to the mother, she was just desperate to do what was best for her baby. I don’t think she was producing any milk. It was the best of intentions.”

If milk sharing were better funded, women would not have to take the risks associated with informal sharing. It was after I had donated to four women who contacted me on Facebook that I heard about Shenker’s Hearts Milk Bank, which is aiming to transform the way milk is collected. Set up in 2016, it is the only formal milk bank in the UK not run by the NHS. It accepts donor milk from women across the country, rather than regionally, as with local hospital milk banks.

The drawback is that Hearts Milk Bank can distribute only to women who have been given funding for donor milk on the NHS, so in August it helped set up a charity called the Human Milk Foundation, which provides grants for parents to access donor milk when they have been turned down. According to Shenker, “there was no way in the NHS to make sure that milk could be provided, beyond the most extremely premature babies”. And while the Chester based Northwest Human Milk Bank is not limited to premature babies, milk provision is in response to clinical requests from an appropriate medical professional. “That’s really the issue that we are trying to tackle.” Shenker wants the milk banking system in the UK to be as efficient as the blood service. “The blood transfusion service has two centres where they can process blood, but you can give blood and receive blood anywhere in the country. There is no reason why that can’t exist for milk banking,” Shenker says. Northwest Human Milk Bank is already employing this system, managing four depots around the country where mothers can donate milk.

Sourcing milk from strangers is legal, but it is not ideal – HIV, bacteria and diseases can be transmitted

“The idea is not to expand the banks, but to expand the knowledge about donation so that it becomes the norm,” says Tanya Cassidy, a researcher at the University of Central Lancashire who has co-written a book on the subject, Banking on Milk. The way to alleviate the risks of informal sharing, Cassidy says, is for informal sharing sites such as HM4HB to work alongside NHS milk banks. Shenker agrees that the plan should be to make the existing milk banks more efficient, rather than to open more of them.

However, the Department of Health has no plans to change the way milk banks are funded, which Shenker believes is a false economy. She points to a World Health Organization study from 2014 that compared the effects of formula milk versus donor breast milk on babies with a low birth weight. While the formula-fed babies gained weight quicker than those on breast milk, their risk of necrotising enterocolitis – a serious inflammation of the intestine – almost tripled. Shenker says it would cost the NHS roughly £250,000 to treat one baby with necrotising enterocolitis until the age of five. In contrast, she believes she would need £1m to get a national milk service, with four banks across the country, off the ground. “Four necrotising enterocolitis cases saved by the babies being fed with an exclusively human milk diet could potentially pay for a national milk banking service,” Shenker says.

Facebook Twitter Pinterest There are 16 NHS-approved milk banks in the UK; Hearts Milk Bank is the only one not run by the health service directly. Photograph: Alicia Canter/The Guardian

Changing the perspective on milk sharing, and helping to raise funds to make it safer and more efficient, can only be beneficial to the overall health of the UK. “We’re not talking about a small impact,” says Shenker.

Shenker says mothers are far more likely to go on to breastfeed when they receive donor milk, rather than formula, when trying to iron out breastfeeding problems. These can include delayed lactation, issues with building supply, waiting for tongue-tie surgery or dealing with allergies. My sister Scarlett needed extra milk while she focused on increasing her supply. Advised by her midwives to pump after every feed, she was either feeding her daughter directly or attached to her pump. The weight gain was slow. “There was a lot of pressure on me; I absolutely dreaded every weigh-in,” she says.

The midwives suggested formula supplementation. Luckily, my niece is five months younger than my daughter, so I donated some of my extra milk. Scarlett is now six months into breastfeeding exclusively and has no plans to stop in the near future. “There wasn’t that intense pressure on me any more; it gave me the space to step back and concentrate on getting to know my baby, myself, my body and what was happening with my milk supply.” Now that her supply is fully established, Scarlett is building her own freezer stash and hopes to donate milk in the future. “It’s such a selfless act and, for the mum who is receiving it, they are going through such a difficult time – having any sort of support and help is vital.”

For me, donating is not selfless. Empowering another mother’s feeding journey, or supplementing their child with some breast milk, was what healed my grief around my breastfeeding experience. Whenever I dread pumping, I remember that my milk has helped so many women and their babies. If this were the norm, if mothers were supported to donate and receive donor milk, if milk banks received better funding, imagine the health benefits this country would reap.

• This article was amended on 18 October 2018. An earlier version referred to “Chester milk bank” having around 15 depots around the country. This has been corrected to Northwest Human Milk Bank, which is based in Chester, having four depots. In addition, the article has been clarified to say that before the Human Milk Foundation, milk was provided beyond extremely premature babies by the Northwest Human Milk Bank, which has supplied donor milk to term babies for many years in response to clinical requests.

