Purchasing breast milk online isn't a safe practice, according to new research expected to be published in the journal Pediatrics.

After analyzing 100 samples of Internet-purchased breast milk, researchers found that three out of every four posed potential dangers to a newborn, according to USA Today.

Unsafe samples contained "either high levels of bacterial growth overall or contained disease-causing bacteria, including fecal contamination," according to USA Today. Contaminations most likely arose from unsanitary collection techniques, containers, and shipping. Nineteen percent of sellers didn't even attempt to keep the milk chilled during transport.

"This study confirms what people have suspected in terms of online milk purchases," said Anne Eglash, a co-founder of the Academy of Breastfeeding Medicine. "You don't know what you're getting, you don't know the quality, how honest people are about how old the milk is, and so many other issues. It's important to realize that this may not be the safest way to get breast milk when you don't have enough."

Bacteria in breast milk is normal and in fact necessary to a child's health, according to Keim. The risky samples either had high levels or contained bacteria most associated with sickness in infants.

Parents purchase breast milk online or through other sources when they can't produce enough themselves, USA Today reported. Besides its profitability, research is lacking when it comes to the online breast milk trade. No current data tracks the frequency of such interactions.

According to USA Today, women would be safer using "milk banks", which follow strict guidelines imposed by the Human Milk Banking Association of North America. Even unpasteurized samples of milk from the 12 banks under the Association's watch were deemed safer than online samples.

Milk banks, in addition to careful sharing between two known parties, are better alternatives.

"I don't think the message should be that women should never share milk, but that this behavior of buying it on the Web from someone you don't know should not happen," Eglash said.