Some mothers with healthy babies seek out donated breast milk when their supply runs dry. Some experts say there are safety risks to using someone else’s milk.

Josephine Scoville and Courtney Donaldson had only met in person a few times before Donaldson offered Scoville a gift: 30 ounces of breast milk.

The two women were blogging friends who had come to know each other while both were writing about infertility struggles.

As the years passed and they each became mothers, they stayed in touch and met up at blogging conferences and when they were traveling through each other’s towns.

That was the case in September 2014, when Donaldson was traveling through Telluride, Colorado, with her husband. They met up with Scoville and her husband while in town.

When Donaldson mentioned feeling guilty about pumping and dumping milk while away from her baby, Scoville joked that she’d happily take that milk off her hands.

A few days later, Donaldson dropped off the milky donation before heading home.

Scoville had used donated breast milk before and had even previously donated herself. But when she lamented on Facebook about her diminishing supply after that Colorado meeting, Donaldson decided to extend an even greater gift.

She overnighted Scoville nearly 200 ounces of frozen breast milk she didn’t think her son (who was a few months older) would ever finish.

“I was so grateful I cried,” Scoville told Healthline. “Using donated breast milk had never been on my radar before having children of my own, but when push came to shove, I so appreciated the help from my breastfeeding village.”

In 2013, NPR reported that the demand for donated breast milk was “booming.” Today, that demand can be seen on both buy and sell websites, Facebook groups dedicated to connecting donors and recipients, and pleas by desperate mothers across social media platforms.

But is that desperation called for?

The benefits of donor milk for premature infants have been well documented, with the World Health Organization (WHO) recognizing the reduced risk of necrotizing enterocolitis as the greatest advantage.

But that risk is already low for healthy, full-term babies. And in most other areas comparing formula to donor milk, the WHO report finds either no significant difference, or a difference in favor of formula. For example, infants fed formula have greater short-term increases in weight and head circumference than those on donor milk.

While donor milk can literally save lives in neonatal ICUs, the question of whether it’s especially beneficial to healthy, full-term babies has never been answered or studied.

In fact, when Healthline reached out to La Leche League (an international nonprofit breastfeeding advocacy group) for comment on this story, they never responded. One active member, who requested to remain anonymous, did tell Healthline the organization has no position on donor milk for healthy infants.

So, Healthline contacted Pauline Sakamoto, executive director of the Mothers’ Milk Bank, to ask the question, Should mothers of healthy, full-term infants be seeking out donor breast milk for their own babies if they have trouble with supply?

Her answer was passionate but complicated.

Sakamoto and her organization work primarily to provide needed breast milk to families with children in the NICU, where that breast milk can truly mean the difference between life and death.

“We services all infants,” she told Healthline. “Premies. Babies who are on the higher end of the pre-term spectrum and not doing well with formula. Children who are home after surgery for necrotizing enterocolitis. As long as there is a prescription that there is a medical necessity, we serve it.”

Sakamoto would love to see donor breast milk available to all families who want it.

But she worries about the lack of regulation of online breast milk trading. And she wishes more women would consider donating to nonprofits first, so that those most in need could have their supply met.

“If you look at the sharing sites,” she told Healthline, “they think they are doing a great favor because they are serving without asking people to pay them. But they are basically just a blackboard where they match people who have milk and those who want milk. They aren’t determining which infants need it most. They are serving families with babies whose average age is 4 to 6 months. And they aren’t able to guarantee the milk is safe.”

“We ask questions,” she went on. “We talk to doctors. We blood test donors. We heat-treat the milk. We test the milk for bacteria levels. We really work to make sure the milk we provide is safe. And it’s hard. The thing that really worries me is when there’s not enough milk for pre-term infants because all the other milk is being syphoned out to the public through these sharing sites. There is a grave equity issue.”

That equity issue comes even more into play when money is on the table. Healthline posted an article in late December about the growing controversy over whether donors should be compensated for their milk — a practice that nonprofit milk banks don’t participate in but some for-profit banks do.

Sakamoto did acknowledge she understands why some mothers might hesitate to donate through a non-profit milk bank. The process is certainly more involved than simply going online and shipping your milk to the nearest buyer.

“What would we say to women who donate elsewhere?” she asked. “Good job. You’re a success, congratulations that you have extra milk. And I get that it’s a wonderful feeling to know that you are sending your milk to a baby whose progress you can often see and hear about. But on the flip side, we have premature infants who are very much in need. And the reason our process is so multi-faceted, with all the screening, is because our population of babies is not the same that you are driving your milk to. I want the sharing groups to understand that I need help sometimes. That I’m running low and may not have the prescribed supply for a child who is truly in need.”

She reiterated that nonprofit milk banks are not making money. They aren’t collecting as much milk as possible to be profitable and sell it. They are genuinely just trying to save the lives of babies.

So to her, the stakes are higher. And in her perfect world, all the mothers on sharing sites would be donating to nonprofit banks instead — where those banks could then screen and distribute the milk based on need.

Jody Segrave-Daly of The Fed Is Best Foundation has other concerns about donated breast milk for healthy, full-term infants.

She told Healthline, “Breast milk does have very desirable benefits, but they are grossly exaggerated in the breastfeeding community. It’s unfortunate because breast milk is depicted as ‘magical,’ which makes moms seek out untested donor breast milk and feed it to their baby, putting them at risk for various things. The American Academy of Pediatrics does not support mothers using untested donor milk — because safely prepared formula has fewer risks for a full-term baby.”

The cleanliness and safety of milk collection was a concern Donaldson echoed.

“Peer-to-peer donating is great if you know and trust the person … but I have close friends I wouldn’t take milk from,” she said.

Joan Meek, an American Academy of Pediatrics pediatrician, took some time to speak to Healthline about this topic.

“There’s definitely some risk to the peer-to-peer sharing sites,” she told Healthline. “If it’s someone you know really well, it’s probably safe to use their milk. The problem is you don’t always know all the health history for a particular individual. And there’s also the issue of storage for the milk. Is the donor maintaining her pump? Cleaning the parts appropriately? Is she putting them in containers that have been cleaned appropriately? Is she storing the milk correctly?”

“Buying from a stranger and buying online does have higher risks. There has been evidence that some of the milk donated online hasn’t been stored right,” she added. “And when they are testing that milk, they are finding that some of it has proteins that are not from human milk — cow’s milk may have been added. That’s really risky and I would encourage families not to purchase milk through unknown sources and definitely not through the internet.”

There’s also the question of how much benefit is lost during the donation process. Every source Healthline spoke to agreed that a mother’s own milk should always be the No. 1 choice. Donor milk is secondary to that because of what it can’t provide.

“In a donor situation at a milk bank, all of the milk is pooled together, which gives the baby additional passive antibodies because of multiple donors,” Segrave-Daly told Healthline. “However, frozen breast milk is flash pasteurized to make it safe for babies and there is some breakdown of micro-nutrients, fats, lactoferrin, and immune properties.”

Sakamoto backed this statement up. “You do lose about 20 percent of the immune properties in processing.”

While that may sound like a benefit for peer-to-peer donations over milk bank donations, immune properties may be lost there as well — especially if the donor and recipient are not from the same area.

“The new research about biogenetics and epigenetics is fascinating,” Sakamoto told Healthline. “Some of the bio geneticists are saying it really doesn’t matter what the composition of the milk is, it really matters where the mother is living. That’s what has the greatest impact on how her milk is produced and what benefits it may have for her child. So if you’re in Sacramento and have a friend in New York you know and trust who is willing to donate, some of the bio geneticists are saying it would actually be better to seek out someone in your neighborhood, even if you don’t know them as well, because that person is going to have built up the immunity to the same flu going around your neighborhood that your baby may be exposed to — and that immunity is in their breast milk, but not your friend’s breast milk from New York.”

Obtaining a safe supply of donor milk for a healthy, full-term infant is complicated. And for some, it can be an arduous task. Yet many people undergo it despite a lack of research backing up the benefits of donor milk versus formula for those infants.

So why are so many mothers putting themselves through that process?

“I believe the reasons why informal milk sharing has become very popular is for reasons most of us don’t think about,” Segrave-Daly said. “A parent who uses formula to feed their baby is subjected to massive judgment and shame because formula is being depicted as ‘poison’ in breastfeeding classes, in WIC offices, and in many mommy online groups, just to start. In addition, the benefits of breast milk that are taught are very overstated for full-term, healthy babies. So mothers will do anything, including using unscreened/untested donor milk, to avoid using formula as a result of this misguided belief. And many mothers have told me they use unscreened/untested donor milk because it’s free. Formula is expensive and their babies need to be fed, so they accept the risk of using donor milk.”

“Mothers contact me from their hospital rooms when their babies are crying out for milk and they are being denied supplementation for help,” she continued. “Mothers contact me when they get home from the hospital for guidance on how to safely supplement their starving babies because their milk is delayed coming in. My primary objective is to educate parents on how to prevent unintended infant starvation from lack of colostrum intake or transfer, before the onset of full milk supply.”

Segrave-Daly advises mothers of the risk of giving their baby untested donor milk.

“I have seen babies who got sick from using contaminated and untested breast milk in the NICU. One was from a used breast pump contamination, and the baby barely survived,” she said.

So when she hears from mothers who have excess milk and want to donate, “I encourage and also assist them to donate to a milk bank instead of offering it informally. I explain that milk donation will save the lives of premature infants who don’t have access to human milk.”

For those mothers with healthy, full-term infants, though, the demand is still there. And Meek believes it’s worth it for those mothers to find sources of donor milk they feel comfortable with.

“I really do believe that the science suggests there is enough benefit to seek it out. In an ideal world, we would have enough milk donated to meet those needs,” she said.

Donaldson and Scoville would agree.

“Though I had never intended to use donated breast milk,” Scoville said, “I firmly believe it was one of those crucial parenting decisions that I will never regret.”

Women wanting to donate breast milk to non-profit milk banks can get more information on the website of the Human Milk Banking Association of North America (HMBANA).