Which is the ideal target for preterm growth?

Abstract

In the last two decades the improved survival of very low birth weight (VLBW) and extremely low birth weight (ELBW) infants has underscored the problem of postnatal growth failure of these subjects. Notwithstanding the evident improvements in the general management of these infants during the hospital stay, most of them acquire a significant extrauterine growth restriction (EUGR). Frequent illnesses, medical and surgical therapies, feeding intolerance and, most of all, inadequacy of nutrient deliveries are responsible for the great part of this growth failure. However other factors, such as genetics, prenatal environment, hormones and metabolic pathways may contribute to growth impairment, that my persist until adulthood. Most of VLBW infants exhibit some catch-up growth, especially in late childhood and adolescence, but they generally remain smaller than their term peers. However, the most worrying aspect is related to the detrimental effect of growth impairment, especially if involving head circumference, on neurodevelopment outcomes of these infants. The endocrine, metabolic and cardiovascular long term consequences of under- and/or hypernutrition of VLBW infants are still to be elucidated. In the meantime, the efforts of the neonatotolgists should be focused on improving, how much as possible, the early nutrient management of these infants, allowing them to reach an adequate growth rate (at least 18-20 g/kg/d), then avoiding the need of a late unphysiological catch-up growth.