Those caring for the newborn have long appreciated the contribution made by breast milk to short-term and long-term health. In this issue Boyd et al¹ report their systematic search for unbiased evidence comparing outcomes of very low birthweight babies fed donor human milk or formula. The paucity of data identified from such adequately controlled studies is remarkable, given that most very low birthweight infants cared for in the neonatal units of industrialised countries will receive formula at some point during their clinical course. Boyd et al nevertheless demonstrate that formula-fed very low birthweight babies are at significantly increased risk of necrotising enterocolitis (NEC) compared with those fed exclusively on breast milk. Particularly striking is the observation that the estimates of risk and associated confidence intervals were virtually identical—about a fivefold increase—in the studies cited, which were carried out on three continents. This, coupled with the observation that other indicators of feeding intolerance also occurred more frequently in those receiving formula, suggests that the increase in risk is real and not a chance finding.

Mortality related to NEC and severity of morbidity among survivors make this important. The eleventh annual report of the British Paediatric Surveillance Unit cited an incidence of 2.1/1000 neonatal unit admissions, 65% of whom weighed under 1500 g at birth.² Overall mortality was 22% but it was significantly lower in those fed human milk compared with those fed on formula (5% v 26%, p<0.05). Late morbidity among survivors was not reported but data from the USA³ suggest it is considerable.

Despite these observations many neonatal paediatricians continue to cite concerns about the use of donor breast milk when mother’s own is not available. …