Milk, Growth and Microbiota: An RCT of Donor Milk vs. Formula to Supplement Breastfeeding Late Preterm Newborns

Summary: 
This small study provides estimates of weight gain for late preterm newborns requiring supplementation. These estimates may inform the design of a future, larger study to determine whether donor breast milk is better than formula for late preterm newborns.

Black mother feeding her infant with a bottle

Principal Investigators:
Valerie Flaherman, MD, MPH| Department of Pediatrics | UCSF Benioff Children’s Hospital

Background

Late preterm infants, who are born at 34, 35 or 36 weeks gestation, often have difficulty feeding, establishing growth, and fighting off infection. Breastfeeding provides improved nutrition to help fight infection, in part because breast milk encourages the growth of healthy bacteria (microbiota) in the infant’s intestine. However, when mothers give birth preterm, their breasts are usually not quite ready to make milk; it can take several days to have enough breast milk to match a baby’s nutritional needs. If there is not yet enough breast milk, formula is often used. However, formula can interfere with the growth of healthy intestinal bacteria. An alternate nutritional option is donor milk from a certified milk bank. 

Objective

This small study provides estimates of weight gain for late preterm newborns requiring supplementation. These estimates may inform the design of a future, larger study to determine whether donor breast milk is better than formula for late preterm newborns.

Method

We randomly assigned 20 late preterm, breastfeeding newborns to either donor milk or formula and collected subsequent weights as well as bowel movements for analysis of microbiota.

Results

Infants lost weight for the first 2 days after enrollment and were gaining weight by the end of the first week. There were no differences in the rate of weight gain between newborns who received formula and those who received donor milk. Analysis of microbiota is not yet complete.