The infant formula shortage has led some parents to consider informal milk sharing — looking for breast milk donations for their babies from neighbors or online, like in Facebook groups.

But there are potential risks, and the U.S. Food and Drug Administration advises against the practice.

To learn more, Side Effects Public Media’s Darian Benson spoke with Dr. Lisa Hammer, a pediatrician and lactation consultant at Trinity Health IHA Medical Group in Michigan.

What’s the difference between getting milk from a milk bank and informal milk sharing?

Milk banks provide donated breast milk to babies in the neonatal intensive care unit and babies with medical needs who benefit from human milk, like very premature infants. The milk from screened donors is pasteurized to ensure that it is safe for sick babies.

Depending on supply, milk can be purchased from milk banks for full-term, healthy babies, but it can cost more than $4 an ounce. And milk banks prioritize sick babies in the NICU.

“The Milk Bank does not have an unlimited supply of milk and we have a really small donor population as well,” said Jenna Streit, advancement director at The Milk Bank in Indianapolis. Streit said The Milk Bank is currently trying to increase their donor pool to meet the demand of milk requests.

In the meantime, parents with healthier babies are left without a lot of options when it comes to donor milk.

“The problem with [pasteurization] is that it is expensive, and that makes it cost-prohibitive for most healthy-term babies,” Hammer said. “So parents who are seeking breast milk for healthy infants usually turn to casual milk sharing, if they aren’t able to provide enough themselves.”

Informal or casual milk sharing is the practice of receiving donated breast milk from a source other than a milk bank.

“Usually that’s a family connecting with another family who has extra milk,” Hammer said. “Either someone that they know, a family member or a coworker, someone in their community, or possibly someone that they match up with, through various internet connections.”

Facebook groups like Human Milk for Human Babies serve as a platform for informal milk sharing where donors and recipients can connect. Amid the infant formula shortage, some of these groups are seeing an increase in parents looking to donate or receive breast milk.

What are the risks of informal milk sharing?

Both the U.S. Food and Drug Administration and the American Academy of Pediatrics discourage informal milk sharing due to potential risks when using donor milk that has not been adequately screened and properly stored. The FDA recommends parents consult a health care provider before feeding a baby human milk from a source other than the baby’s mother.

Hammer said possible transmission of various viruses is a primary concern.

“Also, medications can pass through breast milk,” she said. “And then there’s the additional risk of substances such as alcohol, marijuana – which could pose some risk through breast milk.”

How should parents weigh the risks?

Hammer said because most medical associations can’t endorse informal milk sharing, it is up to parents to weigh the risks on their own.

“I work with some families who just really aren’t comfortable assuming that risk on their own and would definitely make the choice to choose formula over donor milk due to those risks,” Hammer said. “On the other hand, I have other families I work with who understand the risk and understand that I, as a medical professional, am not in a position to screen that donor for them, but that is something that they’re willing to take on, on their own, and assume the risk.”

Parents should have conversations about the donor’s medical history and how they store milk before accepting donations.

This story comes from Side Effects Public Media — a public health news initiative based at WFYI. Follow Darian on Twitter: @HelloImDarian