Effect of Early Expressed Human Milk on Insulin-Like Growth Factor 1 and Short-Term Outcomes in Preterm Infants

Preterm breast milk contains high levels of bioactive components, including insulin-like growth factor 1 (IGF-1), that are reduced by Holder pasteurization. Animal studies have shown that milk-borne IGF-1 is likely absorbed intact in a bioactive form by the intestines. The aim of this study was to assess if early non-pasteurized expressed breast milk nutrition may affect IGF-1 plasma levels in premature infants. We also investigated the possible association between early expressed milk nutrition and short-term outcomes.

Fifty-two preterm infants with gestational age < 31 weeks were divided into two groups according to expressed breast milk intake (< or ≥ 50 mL/Kg/day) until 32 weeks of postmenstrual age when blood sampling for IGF-1 analysis was performed.

In our population, early expressed breast milk does not affect IGF-1 plasma levels (p 0.48). An association was observed between early expressed milk nutrition and a lower incidence of bronchopulmonary dysplasia, sepsis, feeding intolerance, need for parenteral nutrition and length of hospitalization.

Contrary to the results in some animal studies, our results did not seem to show that early expressed breast milk can help to maintain postnatal IGF-1 near foetal levels in preterm infants. The observed protective effect of expressed breast milk on short-term outcomes can be the starting point for further study of the effects of non-pasteurized human milk in preterm infants.