Breast milk and neonatal necrotising enterocolitis.

In a prospective multicentre study on 926 preterm infants formally assigned to their early diet, necrotising enterocolitis developed in 51 (5.5%). Mortality was 26% in stringently confirmed cases. In exclusively formula-fed babies confirmed disease was 6-10 times more common than in those fed breast milk alone and 3 times more common than in those who received formula plus breast milk. Pasteurised donor milk seemed to be as protective as raw maternal milk. Among babies born at more than 30 weeks' gestation confirmed necrotising enterocolitis was rare in those whose diet included breast milk; it was 20 times more common in those fed formula only. Other risk factors included very low gestational age, respiratory disease, umbilical artery catheterisation, and polycythaemia. In formula-fed but not breast-milk-fed infants, delayed enteral feeding was associated with a lower frequency of necrotising enterocolitis. With the fall in the use of breast milk in British neonatal units, exclusive formula feeding could account for an estimated 500 extra cases of necrotising enterocolitis each year. About 100 of these infants would die.