Concentrations of Epidermal Growth Factor and Transforming Growth Factor-Alpha in Preterm Milk

Abstract

Human milk is the major source of nutrients and growth promoting substances in the first weeks of life for the majority of neonates (Goldman 2000). As neonatal care has improved, survival of extremely prematurely born neonates has increased significantly. Yet these infants have the highest incidence of morbid events, such as necrotizing enterocolitis (NEC) (Lucas & Cole 1990). Questions have arisen about the most suitable and relevant nutritional support for these immature infants. Epidermal growth factor (EGF) and transforming growth factor-alpha (TGF-α) are trophic peptides present in human milk with significant healing effects on injured gastrointestinal tract mucosa. Human milk EGF levels are highest in the first days after parturition and then gradually decrease during the first two weeks of lactation (Read et al. 1984). Another structural homologue of EGF, TGF-α also is present in human colostrum and milk (Okada et al. 1991; Wagner et al. 1995), but at much lower concentrations than is EGF. However, neither peptide is found in commercial infant formulas. Decreasing gestational age of neonates is associated with higher risk to develop gastrointestinal tract disorders, and human milk provides better protection against these diseases compared with formula. The aim of this study was to determine whether the concentration of growth factors in human milk varies with gestation time. Concentrations of EGF and TGF-α in human milk collected during the first month of lactation from mothers with 1) extremely preterm born (EPT), 2) preterm born (PT), and 3) full-term born (FT) infants were measured.