NEW YORK (Reuters Health) - Enriched milk formula is no better than standard formula for feeding preterm infants after hospital discharge, according to a report in the American Journal of Clinical Nutrition.

"Our study challenges the current dogma on the use of special milk formulation for feeding the premature infants after hospital discharge," Dr. Winston W. K. Koo from Wayne State University and Hutzel Hospital, Detroit, told Reuters Health.

Koo and co-investigator Elaine M. Hockman compared the growth, bone mass, and body composition in 89 preterm infants who were randomly assigned to receive a nutrient-enriched formula or a standard formula for one year after discharge.

The infants fed the standard formula had significantly higher scores for all growth variables than did infants fed the enriched formula, the researchers report. The rates of weight gain and length increase were also significantly higher in the infants fed standard formula.

The results of X-ray imaging studies also indicated that the standard formula group had significantly higher bone mineral content, fat mass and lean mass than did the enriched formula group.

"The earlier clinical trials were inconclusive despite the theoretical benefits of enriched formulation and our study could not demonstrate any benefits from its use either in body weight, length, or different components of tissue growth, namely, the amount of bone, fat and lean tissue," Koo commented.

"Our study is, therefore, akin to finding that a drug may not work quite as well as intended when one takes a closer look."

The findings raise "multiple important issues" that require further study, he said. "Hopefully, our continuing studies of nutrition support in premature infants will provide scientifically sound recommendations in the not too distant future."

Meanwhile, he concludes: "Careful follow-up of the infant, critical review of scientific studies, and being skeptical of advertisements would go a long way in providing good patient care."