FEEDING IRON-FORTIFIED PREMATURE FORMULA DURING INITIAL HOSPITALIZATION TO INFANTS LESS-THAN 1800 GRAMS BIRTH-WEIGHT

Objective. A randomized, double-blind study was conducted comparing hi gh-iron content (15 mg/L) with low-iron content (3 mg/L) premature for mula given during initial hospitalization to infants with birth weight s less than 1800 g to determine the influence of these differing intak es on the iron nutritional status during the first 4 months of life. A third group of similar infants received human milk mixed with an equa l volume of liquid fortifier resulting in an iron content of approxima tely 1.7 mg/L. Patients and methods. Mean birth weight, gestational ag e, age at study entry, volume of blood removed for studies, and volume of red cells transfused were not different among the three groups. Af ter hospitalization both formula-fed groups were given a cow milk form ula with an iron content of 12 mg/L, and breast-fed infants were given an iron-containing multivitamin with a resulting iron intake of 10 mg /d. Infants were observed to 8 weeks after discharge. Results. There w ere no differences in serum iron, ferritin, transferrin, transferrin s aturation, hemoglobin, hematocrit, or reticulocyte count among the thr ee groups at study entry, although mean corpuscular hemoglobin and mea n corpuscular volume were lower in infants in the low-iron formula gro up. Mean plasma ferritin was significantly lower in infants receiving low-iron content premature formula at the time of hospital discharge c ompared with the other two groups. The incidence of anemia (hemoglobin < 9.0 g/dL) and low transferrin saturation (<24%) was also greater in the low-iron content formula group. Eight weeks after discharge, the incidence of low plasma ferritin (<19 ng/mL) remained greater in infan ts receiving low-iron content formula than in the other two groups. No adverse effects of iron intake were observed. Growth was not differen t among the three groups. Conclusions. These data indicate that preter m infants with <1800 g birth weight receiving premature infant formula benefit from formula given during initial hospitalization containing 15 mg/L iron compared with that containing 3 mg/L.