Mother’s milk may not be best for preterm babies

Contrary to results suggested by earlier studies, mother’s breast milk may not provide significant help to the brain development of very low birth weight preterm babies, according to new research in the Journal of Developmental and Behavioral Pediatrics.

The study by Lydia Furman, M.D., of Rainbow Babies and Children’s Hospital in Cleveland and colleagues found that other influences, such as health problems at birth and social factors like the mother’s race, marriage and education were more important in predicting any mental and motor development problems among the infants.

Among the babies studied, “the effects of social and neonatal risk outweighed any potential benefits of maternal milk,” Furman says.

They say their study’s conclusions may differ from others because the babies involved were smaller than in earlier studies. They also note that the gap in quality between breast milk and formula may have narrowed since the earlier studies were done.

“Methods of neonatal nutrition have changed markedly since the 1980s, and many of the infants were fed diets now known to be nutritionally inadequate,” Furman says.

The study included 98 babies younger than 33 weeks old who weighed between 1.4 and 3.3 pounds at birth. Furman and colleagues measured the amount of breast milk the children were fed for four weeks after birth. About 70 percent of the children were fed breast milk from their mothers fortified with formula and 30 percent received formula only

When the babies would have been 20 months old based on a normal-length pregnancy, the researchers tested them for signs of mental and motor development, deafness and cerebral palsy.

The overall rate of neurodevelopmental problems among the infants was 32 percent. But the researchers found no signs that the amount of mother’s milk the babies received made any difference in their likelihood of developing a problem.

The study was supported by the St. Luke’s of Cleveland Foundation, the National Institutes of Health, Rainbow Babies and Children’s Hospital Faculty Fund and the Rainbow Babies and Children’s Hospital Board of Trustees.