Human milk feedings and infection among very low birth weight infants

Background. Preterm infants are immunologically immature at birth. Previous studies have demonstrated that human milk protects against infection in full-term infants, but there are few studies of its effect for preterm infants. Objective. To examine the effect of human milk feedings on infection incidence among very low birth weight (VLBW) infants during their initial hospitalization. Study Design. The sample consisted of 212 consecutive VLBW infants admitted to the Georgetown University Medical Center neonatal intensive care unit (NICU) during 1992-1993 and surviving to receive enteral feeding. Type of feeding (human milk vs formula), presence of infection and sepsis/meningitis (clinical signs and positive cultures for pathogenic organisms), and potential confounding variables were abstracted from medical records. Multiple logistic regression was used to control for confounders. Results. The incidence of infection (human milk [29.3%] vs formula [47.2%]) and sepsis/meningitis (human milk [19.5%] vs formula [32.6%]) differed significantly by type of feeding. Major risk factors for infection were similar in both groups. Human milk feeding was independently correlated with a reduced odds of infection (odds ratio [OR] = 0.43; 95% confidence interval [CI]: 0.23-0.81), controlling for gestational age, 5-minute Apgar score, mechanical ventilation days, and days without enteral feedings; and was independently correlated with a reduced odds of sepsis/meningitis (OR = 0.47, 95% CI:0.23-0.95), controlling for gestational age, mechanical ventilation days, and days without enteral feedings. Conclusions. The incidence of any infection and sepsis/meningitis are significantly reduced in human milk-fed VLBW infants compared with exclusively formula-fed VLBW infants.