One of the first warnings new mothers hear is that offering babies formula soon after birth can lead to problems with breast-feeding. Sating infants' hunger with formula can prevent them from nursing vigorously, interfering with milk production; letting them use a bottle and nipple can interfere with their ability to latch properly at the breast. Some research has shown that mothers who offer formula in the hospital stop breast-feeding sooner than mothers who don't.
But a new study, published online Monday by the journal Pediatrics, suggests that there are situations in which limited formula use might actually help some mothers breast-feed their children for a longer period of time, perhaps by smoothing their path through the difficult period immediately following birth. In the couple of days it takes for milk production to ramp up, some babies lose weight or seem hungry and unhappy -- and mothers can get discouraged.
UC San Francisco pediatrician and researcher Dr. Valerie Flaherman and colleagues conducted their small randomized trial with 40 infants, all of whom had lost at least 5% of their birth weight within their first 36 hours of life. The babies were randomized into two groups. Half were given 10 milliliters of formula, administered with a syringe, after each breast-feeding session with their mothers. Formula feeding ended once the mothers' milk came in.
The other half of the babies continued breast-feeding exclusively. When the researchers noted feeding progress at a one-week assessment, only two of the 20 babies who had received the syringe feedings had received formula in the previous 24 hours; among 19 control babies, nine had. Three months after birth, 79% of the babies who had the early formula feedings were breast-feeding exclusively, while 42% of the control babies were.
The keys to this success, the team suggested, may have been the strict limitations placed on the formula feeding: The infants were not given enough to satisfy their appetite for breast milk, using a syringe made sure they didn't learn to prefer bottles to the breast, and having a clear time to end formula use (i.e., when milk came in) made sure mothers didn't slide into offering formula on an ongoing basis.
"By partially ameliorating weight loss and signs of fussiness and hunger, early limited feeding may provide mothers with a strategy to allay their milk supply concern and continue with their desire to breast-feed for a longer duration," the team wrote.
At least one physician has already expressed skepticism about the approach: In a commentary also published Monday in Pediatrics, Case Western Reserve pediatrician Dr. Lydia Furman questioned the team's methods -- and implied unintended bias, noting that one coauthor has "financial ties to the formula industry."
"There are critical limitations to study design that bring their conclusion into question and restrict the generalizability of their results," she wrote.
The team acknowledged limitations in the work, noting the small study size and relative homogeneity of the study participants. Still, they wrote, if future studies confirm the practice's merit, offering small amounts of formula might keep more babies breast-feeding longer -- with significant health benefit. Today, according to background information provided in the study, groups such as the World Health Organization, the Centers for Disease Control and Prevention and the American Academy of Pediatrics recommend breast-feeding for at least a year and exclusive breast-feeding for at least six months -- but only 30% of babies in the U.S. get breast milk through their first three months, and only 21% are still breast-feeding by the time they reach their first birthday.