Prospective randomized trial of early versus late enteral iron supplementation in infants with a birth weight of less than 1301 grams

Objectives. To examine whether early enteral iron supplementation (EI) woul d improve serum ferritin as a measure of nutritional iron status at 2 month s of age and would prevent definite iron deficiency (ID) in infants with a birth weight of <1301 g. Methods. Infants were randomly assigned to receive enteral iron supplementa tion of 2 to 6 mg/kg/day as soon as enteral feedings of >100 mL/kg/day were tolerated (EI) or at 61 days of life (late enteral iron supplementation [L I]). Nutritional iron status was assessed: 1) at birth, 2) at 61 days of li fe, 3) when the infants reached a weight of 1.6 times birth weight, and 4) before blood was transfused at a hematocrit of <.25. ID was defined by any one of the following criteria: ferritin, <12 mu g/L; transferrin saturation , <17%; or increase of absolute reticulocyte counts by >50% one week after the onset of enteral iron supplementation. Restrictive red cell transfusion guidelines were followed and all transfusions were documented. Erythropoie tin was not administered. The primary outcome variables were: 1) ferritin a t 61 days and 2) the number of infants with ID. Results. Ferritin at 61 days was not different between the groups. Infants in the LI group were more often iron-deficient (26/65 vs 10/68) and receive d more blood transfusions after day 14 of life. No adverse effects of EI we re noted. Conclusions. EI is feasible and probably safe in infants with birth weight <1301 g. EI may reduce the incidence of ID and the number of late blood tra nsfusions. ID may occur in very low birth weight infants despite early supp lementation with iron and should be considered in the case of progressive a nemia.