Human milk for preterm infants: why, what, when and how?

A mother's expressed breast milk (MEBM) is overall the best feed for her preterm baby during the neonatal period, and is associated with improved short-term and long-term outcomes. Neonatal services should commit the resources needed to optimise its use. The place of banked donor expressed breast milk (DEBM) is less clear, but it probably has a role in reducing the risk of necrotising enterocolitis and sepsis in preterm infants at particularly high risk. There is considerable variation in the composition of human milk and nutrient fortification is often needed to achieve intrauterine growth rates. Human milk can transmit potentially harmful micro-organisms, and pasteurisation, which denatures some of the bioactive factors, is the only known way of preventing this. This is carried out for DEBM but not MEBM in the UK. Future research on human milk should focus on (a) critical exposure periods, (b) understanding better its bioactive properties, (c) the role of DEBM and (d) nutritional quality assurance.