(CNN) -- Donated breast milk is "liquid gold at our house," says Stacy Richards, 37.
The liquid gold is for Simeon, Richards' adopted 11-month-old son. He was born with Down syndrome and suffers from chronic lung disease. Richards believes "breast is best" but couldn't breastfeed, so she turned to the next best thing.
Initially, she sought milk on community milk sharing sites, like "Eats on Feets," and "Human Milk 4 Human Babies," but didn't feel comfortable getting milk from strangers. "We didn't know who those women were. They didn't have a safety net," said Richards. Instead, she relied on trusted friends.
Richards had every right to worry, according to a new study published Monday in the journal Pediatrics. The study found milk bought off of the Internet through social media sites was more than twice as likely to be contaminated with infection-causing bacteria and three times more likely to contain salmonella than milk from the Human Milk Banking Association of North America (HMBNA). While only 5% of the HMBNA milk tested positive for herpes viruses, 21% of milk from the Internet contained bacteria and viruses.
HMBNA consists of 16 self-regulated, nonprofit milk banks across North America and has pre-screened donors. The milk banks further pasteurize the milk to ensure its safety.
But HMBNA milk isn't always available to everyone. Babies that are the neediest, like preemies and those born with special conditions, receive priority, say Kim Updegrove, HMBNA president, "In 2012, our milk banks dispensed 2.5 million ounces of human milk. Three-quarters went to hospitals in every state in the country; the remaining quarter went to outpatients, largely babies from the NICU that were unable to tolerate formula."
Authors of the study also found that 74% of the milk purchased from the Internet failed to meet HMBNA criteria before pasteurization.
This is of particular concern for pre-term babies, said Dr. Lisa Thebner, a pediatrician in New York City. "They are more vulnerable, their immune systems are more immature, and they can't fight off infection like full-term babies," said Thebner, who was not associated with the study.
Sarah Kein, lead author of the study, was surprised by the differences between the 101 samples bought over the Internet and the 20 samples from the HMBNA banks. Shipping, or "the number of days it took to get there," was a significant factor, she said.
In fact, the study found that each additional shipping day resulted in increased bacteria counts. About half of the samples arrived in two days, and 19% of the shipped milk didn't have any sort of ice pack or cooling agent.
Emma Kwasnica, founder of Human Milk 4 Human Babies, said the study in itself was problematic, because most milk is donated without profit, at a local community level, and rarely is transported for several days to get to a recipient.
Kwasnica did agree that the study showed how "milk is expressed, stored, and transported is important."
The American Academy of Pediatrics and the FDA both recommend against using breast milk directly from a donor or the Internet, because of the safety risks.
"The bottom line is, if you are going to get milk from an unknown source, you open that baggie of milk and you have to decide ... given the consequences are pretty serious, I just don't think it's worth the risk," said Keim. Instead, she recommended using milk from a bank, or donating to a bank, knowing that it undergoes additional safety measures.
"We recognize there's a risk, but we felt the risk outweighed the benefits," Richards said.
If you do consider milk sharing, the FDA says to make sure to:
-- consult your pediatrician
-- consider the risks
-- do not use milk directly sourced from individuals or the Internet
-- If you decide to milk share, only use a source that has been screened and take whatever precautions to ensure its safety.
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