Background: The goal of this study was to evaluate the dynamics of blood cell and iron status laboratory analytes in preterm and full-term infants during the first year of life.
Methods: This was a prospective study of 100 preterm and 50 full-term infants. Preterm infants received iron supplementation beginning at 3 weeks of age. Laboratory tests were serially analyzed up to 12 months of corrected age.
Results: Estimated means and the 95% reference intervals (RIs) from 20 weeks of age and onwards are presented separately for preterm and full-term infants. At the age of 20 weeks, mean hemoglobin (Hb) in preterm infants was lower than mean Hb in full-term infants, but this difference changed during follow-up. Ferritin concentrations were initially lower in preterm infants, but decreased to similar levels in both groups. Estimated mean values for transferrin receptor and reticulocyte Hb content were quite stable between the ages of 20 and 55 weeks in both groups.
Conclusions: Our study suggests that the same RIs for preterm and full-term infants can be used from the age of 20 or 30 weeks onwards, depending on the analyte. The RIs will help physicians detect iron deficiency or other problems of erythropoiesis in infants.