Can the elimination of lactose from formula improve feeding tolerance in premature infants?

OBJECTIVE: To determine whether a low-lactose formula (LLF, <5% lactose) would ameliorate feeding intolerance in premature infants.

STUDY DESIGN: Prospective, randomized, controlled trial involving 306 infants <36 weeks' gestation and weighing <1800 g who received either lactose-containing formula (LCF) 24 kcal/oz or a specially prepared LLF, which was comparable to the LCF except for the functional replacement of lactose with maltose. We examined outcome variables of feeding intolerance and cases of necrotizing enterocolitis (NEC) and suspected NEC.

RESULTS: One hundred forty-nine infants were assigned to receive LCF, of which 99 infants received LCF only. One hundred fifty infants were assigned to receive LLF, of which 102 infants received LLF only. The remaining infants received LCF or LLF plus some quantity of human milk or human milk alone. Infants receiving LLF had improved enteral caloric intake and weight gain, reached full feeds faster, had less gastric residual, spent less time without oral intake, and had fewer feedings stopped than the LCF group. The number of cases of NEC and suspected NEC was similar in both groups.

CONCLUSION: Low-lactose premature infant formula improved feeding tolerance. There was no evidence that LLF altered the incidence of NEC, but the incidence of NEC in this study was too low to draw conclusions.