Breast-fed Newborns: How Much Weight Loss Is Normal?

Diedtra Henderson  Mescape Pediatrics December 01, 2014

Exclusively breast-fed newborns typically lost as much as 10% or more of their birth weight before beginning to gain again in the first days after birth, according to a recent study. By 48 hours, almost 5% of babies born vaginally and 10% of those born by cesarean delivery lost at least 10% of their birth weight. By 72 hours, 25% of cesarean delivered infants lost at least 10% of their birth weight. These metrics may help identify babies with steeper weight loss trajectories that could increase morbidity risk.

Valerie J. Flaherman, MD, MPH, from the Department of Pediatrics and the Department of Epidemiology and Biostatistics, School of Medicine, University of California, San Francisco, and colleagues report the findings of their study in an article published online December 1 in Pediatrics.

According to the authors, 60% of newborns in the United States are breast-fed exclusively in the first 2 days after birth, in keeping with recommendations from a number of expert organizations, including the American Academy of Pediatrics. Most of those infants lose weight daily, but a small number of infants suffer complications from excessive weight loss, including hyperbilirubinemia and dehydration.

"These results provide the first graphical depiction of hourly weight loss for exclusively breastfed newborns from a large, diverse population," Dr Flaherman and coauthors write. "Because weight changes steadily throughout the birth hospitalization and is measured at varied intervals from the hour of birth, these new nomograms should substantially aid medical management by allowing clinicians and lactation support providers to categorize newborn weight loss and calibrate decision-making to reflect hour of age."

The authors note that hour-by-hour bilirubin levels, tracked to guard against jaundice, have been incorporated into practice guidelines. To provide a similar type of nomogram for neonate weight loss in exclusively breast-fed newborns, Dr Flaherman and coauthors studied data from 108,907 newborns born at 36 weeks' gestation at Northern California Kaiser Permanente hospitals from January 1, 2009, through December 31, 2013.