Is Sharing Breast Milk Safe?

Margie Smith has always produced much more breast milk than her children need. When her son was born three years ago, Ms. Smith — who pumps exclusively — was making more than 50 ounces of breast milk per day, “enough to feed twins at least,” she said. With her 10-month-old daughter, she is producing less, but still more than her baby can drink.

So Ms. Smith, 32, has donated breast milk she pumped for both of her babies, giving away roughly 3,500 ounces to families she has found online. “It’s been nice that I’m doing this for my children, but I’ve also been able to help other little babies,” she said. Her children each did brief stints in the neonatal intensive care unit, where they received some donor breast milk, so she feels as though she is paying it forward in a way.

“Someone was kind enough to donate so that my babies can have it, so I’ve always felt the need to give back and help another mom that’s struggling,” said Ms. Smith, who works as an X-ray technician and lives in Elgin, Ill.

As the nationwide baby formula shortage continues to wear on new parents struggling to keep their babies fed, some have turned to informal breast milk sharing — a practice that predates the current crisis by thousands of years. Human Milk for Human Babies, a Facebook-based, peer-to-peer breast milk sharing platform, says that “potential donors and recipients are joining in higher numbers than before the shortage,” and notes that there has been a particular increase in one-time donations from mothers who have never donated before.

While parents use donor milk because they believe it is good for their babies, and lactating mothers may donate out of a sense of altruism, experts say the practice can come with serious risks. The American Academy of Pediatrics and the Food and Drug Administration both discourage casual sharing, pointing to the potential for contamination, as well as the chance that parents with the best of intentions will unwittingly expose their babies to harmful medications or drugs.

What is informal breast milk sharing?

The A.A.P. recommends that babies be breastfed exclusively until they are about 6 months old, and continue breastfeeding along with complementary foods until they are at least 1 year old. But the reality is that only one-quarter of babies in the United States are exclusively breastfed by the time they’re 6 months old, and only 35 percent are still breastfed at all by the time they turn 1.

Mothers may not breastfeed or might stop earlier than recommended for a host of reasons, from physical challenges to insufficient parental leave policies. Others simply do not lactate — as in the case of foster or adoptive parents. All of which means the majority of parents in the United States rely on formula at some point when their children are young.

Read More on the Baby Formula Shortage

Understand the Shortage: With just a handful of companies making infant formula for the U.S. market, the shutdown of an Abbott Laboratories plant had an outsize effect.Missing Safeguards: The shortage has revealed regulation gaps that make it hard to monitor the deadly bacterium that led to a recall.A Desperate Search: As the United States faces a baby formula shortage, some parents are rationing supplies, or driving for hours in search of them.A Misleading Narrative: Amid the crisis, Republicans have suggested that the Biden administration is sending baby formula to immigrants at the expense of American families.An Emotional Toll: The shortage is forcing many new mothers to push themselves harder to breastfeed, with some even looking for ways to start again after having stopped.

But parents may also seek out donor breast milk, through formal or informal routes. Formal milk sharing is done through milk banks that do comprehensive donor screening, checking for everything from H.I.V. and hepatitis B status to medications. Milk banks also pasteurize all donations. All of this is overseen by the Human Milk Banking Association of North America, which sets the standards for formal donor milk sharing in the United States and Canada. But most of that milk is distributed through hospitals for preterm babies, to help lower the risk of serious health complications like necrotizing enterocolitis — a dangerous intestinal disorder.

“The milk banks in this country are very good, but milk tends to be prioritized for high-risk infants,” said Dr. Casey Rosen-Carole, a pediatrician and director of the breastfeeding and lactation medicine program at the University of Rochester Medical Center in New York.

“In the outpatient world, it’s very difficult to get donor milk and it tends to be very costly —$4 to $5 an ounce, even,” she said.

In the absence of easily accessible and affordable donor milk banks, many parents end up going the informal route and swap breast milk with people they know or with people they find on the internet.

For parents of healthy, full-term babies who want to give their child breast milk but are unable to, “there aren’t a lot of options other than casual milk sharing,” said Dr. Lisa Hammer, a board-certified pediatrician and lactation consultant with Trinity Health IHA Medical Group in Michigan.

Ms. Smith sometimes pumps up to 50 ounces of breast milk a day, far more than her children have needed. Credit…Mary Mathis for The New York Times

There aren’t good estimates of how widespread casual milk sharing is, but experts believe it is not uncommon. A 2018 online survey of 456 U.S. mothers found that 12 percent had donated milk informally, and just under 7 percent had given their babies donated milk.

What are the risks and benefits of informal milk sharing?

The health benefits of breastfeeding are well-established: Breast milk is designed to meet babies’ core nutritional needs and offers protection against infection, particularly early on. Recent research has found, for example, that mothers who have been infected with the coronavirus or who have gotten an mRNA Covid vaccine produce breast milk with SARS-CoV-2 antibodies, which are passed on to their babies.

“The biggest benefit that really we can’t replicate with formula has been some of the immunity and antibodies that can be obtained through breast milk,” Dr. Hammer said. “A lot of parents, especially now in the middle of a pandemic, have been much more aware of those immune benefits and are really seeking that out through breast milk.”

It is logical that otherwise healthy, full-term babies fed with donor breast milk would get those same benefits, but experts cannot say that with certainty — nor can they offer parents a data-driven risk-benefit analysis — because the whole practice of milk swapping is deeply underresearched.

“We don’t know anything about infant outcomes,” said Dr. Sheela Geraghty, a board-certified pediatrician and lactation consultant and a co-director of the Center for Breastfeeding Medicine at Cincinnati Children’s.

Navigating the Baby Formula Shortage in the U.S.

Card 1 of 6

A growing problem. A nationwide shortage of baby formula — triggered in part by supply-chain issues and worsened by a recall by the baby food manufacturer Abbott Nutrition — has left parents confused and concerned. Here are some ways to manage this uncertainty:

Checking your supplies. Abbott Nutrition has recalled several lots of its Similac, Alimentum and EleCare formulas after at least four babies became sick with bacterial infections. To find out whether a formula in your home may be affected by the recall, check the lot number on the Abbott website. If you learn that you fed your child a recalled product, contact your pediatrician.

Finding formula. If your baby’s formula was not affected by the recall, but is still not available, you can try calling local stores to ask when they expect to get it back in stock. You may also be able to buy it online. If your baby is on special formula, reach out to your doctor’s office: They might have samples in stock.

Picking a new formula. If you typically use a name-brand formula, look for its generic version. Alternatively, seek a new formula that matches the ingredients listed in your usual one. If your baby is on a special formula for health reasons, check with your pediatrician before switching.

Transitioning to a new product. Ideally, you will want to switch your child gradually. Start by mixing three quarters of your usual formula with one quarter of the new one and gradually phase out the old product. If you can’t transition gradually because you’ve run out of your usual formula, that’s OK, although you might notice more gassiness or fussiness during the transition.

What not to do. If you can’t find your baby’s usual formula, don’t make your own — homemade formulas are often nutritionally inadequate and at risk of contamination. Don’t try to “stretch” your formula by adding extra water, and don’t buy it from unvetted online marketplaces like Craigslist. For a baby less than 1 year old, don’t use toddler formula.

Dr. Geraghty worked on a widely cited 2013 study that found that breast milk purchased online was frequently contaminated with high levels of bacteria, including salmonella. Some of it was diluted with cow’s milk; other times, the milk arrived warm or leaking. She said the study made her and her co-authors “pariahs” among some breastfeeding experts who believed the study exaggerated the possible risks, because the researchers purchased milk that was sold for profit, and did not screen the sellers. And because the milk was shipped, it increased the risk of bacterial growth.

But since then, there have not been any studies that have directly looked at how casual milk sharing can affect the health of otherwise healthy babies.

And for that reason, Dr. Geraghty said she simply does not see it as a safe alternative for parents who are in need — even though “we want it to be safe” and “we know mothers are doing it.” She said it is never her intention to make parents feel guilty about how they are feeding their babies, but she believes it is important that mothers and fathers know about the risks.

How can parents reduce the risks?

In recent guidance from the A.A.P. about navigating the formula crisis, the group said parents simply cannot know for sure whether breast milk they get from a friend or an online group is safe, and instead urged them to connect with an accredited milk bank. But again, getting breast milk that way is not easy.

And for many parents, the advice to avoid informal milk sharing “falls on deaf ears,” said Aunchalee Palmquist, a medical anthropologist and board-certified lactation consultant with the UNC Gillings School of Global Public Health. They’ve been told again and again that breast milk is good for babies. So the idea that there are no benefits to using donor breast milk over infant formula “doesn’t exactly make sense to them,” she added.

A 2017 position statement from the Academy of Breastfeeding Medicine offers a set of best practices around informal breast milk sharing for healthy, full-term babies — guidance it aimed at doctors who may be counseling parents through these decisions.

The guidelines say it is critical for parents to have an open screening process with anyone they are considering getting breast milk from. They should discuss whether the donor is taking any medications or herbs; whether they have been screened for conditions like H.I.V. and hepatitis B (which can be transmitted via breast milk); and whether they engage in activities like drinking alcohol or using marijuana. Open conversations are important, because individuals are not set up to do the kind of in-depth testing a milk bank can.

“We don’t have good research on this, but the risk is probably progressively increased the further you move away from people you know,” Dr. Rosen-Carole said.

The Academy of Breastfeeding Medicine also notes that home pasteurization of human breast milk may help remove harmful viruses and bacteria, and its guidance includes directions for using a flash heating method.

Any parent contemplating an informal milk swap — during the current formula shortage, or at another point in time — should talk to their child’s pediatrician first. There may not be hard data doctors can provide on the effect that informal milk sharing will have on a baby’s health, but a conversation can offer parents guidance on how to minimize the risks should they choose to move forward.