Iron nutritional status in preterm infants fed formulas fortified with iron

AIMS To prospectively evaluate the iron nutritional status of preterm infants fed either a term (0.5 mg/dl iron) or preterm (0.9 mg/dl) formulas fortified with iron after hospital discharge. METHODS Healthy low birthweight preterm infants were randomly assigned into three groups at the time of hospital discharge. Group A were fed an iron fortified preterm formula (0.9 mg/dl iron) until 6 months corrected age; group B, a fortified term formula (0.5 mg/l iron) until 6 months corrected age group C, the preterm formula between hospital discharge and term, then the term formula until 6 months corrected age. RESULTS Seventy eight infants were followed up to 6 months corrected age. Iron intake from formula differed significantly between the groups (A, 1.17 mg/kg/day (SD 0.32) > C, 0.86 mg/kg/day (SD 0.40) = B, 0.81 mg/kg/day (SD 0.23); p < 0.0001). Haemoglobin concentrations were similar to those of iron sufficient preterm infants of the same postnatal age, and term infants of the same postmenstrual age (after 3 months of age). There were no significant differences in haemoglobin concentration (p = 0.391), plasma ferritin (A vs B, p = 0.322), or in the incidence of iron deficiency (A vsB, p = 0.534). CONCLUSIONS Iron fortified formulas containing between 0.5 and 0.9 mg/dl iron seem to meet the iron nutritional needs of preterm infants after hospital discharge.