Risk factors and correlates of neonatal growth velocity in extremely low gestational age newborns: the ELGAN Study

Objectives: To identify maternal and infant characteristics associated with reduced growth velocity (GV) in extremely premature newborns.

Methods: We evaluated 1,187 infants born between 23 and 27 weeks' gestation at 14 institutions between 2002 and 2004 who survived until day 28 to identify the maternal and infant characteristics associated with a GV and caloric intake in the lowest quartile.

Results: Newborns in the lowest gestational age and low birth weight categories, as well as those with intrauterine growth restriction, or high SNAP-II received relatively fewer kcal/kg/day than their peers without these risk factors, but were not at increased risk of being in the lowest GV quartile. Newborns with bacteremia, patent ductus arteriosus, retinopathy of prematurity stage 3-5, or pulmonary illness received fewer calories, as did those who received medications or blood transfusions. However, in a multivariable model adjusting for confounders, only ventilator dependence on day 7 (OR 2.2, 95% CI 1.5-3.2), early persistent pulmonary dysfunction (OR 1.8, 95% CI 1.3-2.5), and postnatal exposure to dexamethasone (OR 2.8, 95% CI 1.2-6.5) were associated with an increased risk of being in the lowest GV quartile. In this model, low caloric intake was not associated with low GV (OR 1.3, 95% CI 0.9-1.9).

Conclusion: Variables associated with severe pulmonary disease convey more information about the risk of reduced GV during the first 28 postnatal days than does low caloric intake.