Sharing breast milk may sound kooky or unsavory to some, but it's a growing practice that can carry benefits or risks for a baby, depending on who's doing it -- and how. While casual arrangements like Stiebel's experience are a relatively new trend, milk banking -- donating screened expressed milk for at-risk babies, for whom breast milk's immunity-boosting components can be lifesaving -- has been around for more than 100 years and is on the rise. Banking gets a thumbs-up from experts because donating moms adhere to strict lifestyle guidelines (no smoking or drinking). The women also go through a screening process to ensure that no diseases, such as HIV or hepatitis, are passed to the infant.

Beyond the Bank
In addition to exchanging expressed breast milk, some moms skip the bottle and cross-nurse, splitting breastfeeding duties with another woman and her baby. Cross-nursers say they enjoy the flexibility as well as the four-way bonding that occurs between the moms and their children. And some moms go as far as hiring a wet nurse -- a woman paid to breastfeed another child -- when they can't perform the task themselves. Informal sharing is naturally more controversial, but a significant number of moms are open to the idea. According to a nationally representative Babytalk survey on momconnection.com, 40 percent had either a positive response ("beautiful!") or a neutral reaction ("each to her own") when asked how they felt about milk sharing.

Yet the majority of the medical community warns against it. "We support breastfeeding, but if you can't nurse, we recommend breast milk from a milk bank, or that you use formula," says Ari Brown, M.D., a spokesperson for the American Academy of Pediatrics and author of Baby 411. "Even if you have a good friend who wants to donate milk, you can't guarantee that it's free of infections, like HIV. Breast milk is a bodily fluid, just like blood. Would you be willing to give your baby a blood transfusion without first having it tested?"