There’s an assumption that bottle-feeding breast milk to a child is equivalent to breastfeeding, but that may not be the case.

Breastfeeding is about more than the milk. Babies don’t just breastfeed for nutrition; they nurse for comfort, closeness, soothing, and security.

Exclusive pumping—feeding your baby only breast milk, only from a bottle—is traditionally the territory of mothers whose babies are in the neonatal intensive care unit or otherwise medically unable to suckle directly at the breast. With the widespread availability of portable, personal electric breast pumps that can empty both breasts at the same time, hands-free, in a matter of minutes, more moms have begun to jump on the “EPing” bandwagon. These moms, like Boss, were unable to establish a successful breastfeeding relationship despite their best efforts, but they still wanted to feed their babies breast milk.

“UNBEKNOWNST TO MOST HEALTH professionals, a revolution is taking place in the way U.S. infants are fed human milk. The possible benefits or harms resulting from exclusive pumping merit careful study,” a recent commentary in the American Journal of Public Health noted. The authors wrote that this “quiet revolution in milk expression” (when milk is removed from the breasts sans baby, either manually or with a pump) could be good for babies if they receive more human milk and for a longer period; where it may be problematic is if babies are fed too much, given milk that is an inappropriate composition, or, worse, contaminated.

More specifically, “While expressed breast milk is recognized as far superior to infant formula, the lactation community has begun to question whether [it] confers similar protection to that derived by directly breastfeeding,” according to Donna Chapman, writing in the Journal of Human Lactation. Such protections include reducing the incidence of gastrointestinal illnesses, upper respiratory infections, asthma, obesity, both types of diabetes, and certain childhood cancers.