Iron Status of the Preterm Infant during the First Year of Life

Abstract

The iron status of 49 preterm infants (mean gestational age 33,1 weeks) was assessed serially during the 1st year of life. Haemoglobin concentration, serum ferritin, serum transferrin, serum iron, and transferrin saturation were measured on nine occasions in each infant. In 16 infants of gestational age 28-32 weeks the haemoglobin concentration was significantly lower at 3, 6, and 9 weeks when compared to 33 infants of gestational age 33-36 weeks. For all other measures of iron status there were no significant differences between these gestational age groups. For the entire group of 49 infants the mean haemoglobin concentration reached a nadir of 11.2 g/dl at 9 weeks. Mean serum iron and transferrin saturation reached peaks of 24 μmol/l and 65%, respectively, at 3 weeks. The mean serum ferritin remained over 100 μg/l until after 18 weeks. 13 infants (26%) had iron deficiency defined as either serum ferritin < 10 μg/l (n = 10) or transferrin saturation < 10% (n = 5) or both (n = 3).

Cord blood transferrin receptors to assess fetal iron status

“…Cord blood ferritin levels in this study are roughly one third of those we have reported previously for preterm babies during the first three days of life 16. Iron levels are about twice as high in cord blood as in samples taken during the first three days of life, and this may be explained by the fact that iron is being transferred to the fetus from the mother through the umbilical vein 16…”

Iron Therapy for Preterm Infants

“…Between 25% and 85% of preterm infants develop evidence of iron deficiency during infancy [3–8]. Unlike full term infants, in whom the condition typically occurs during the second half of infancy, preterm infants are at risk for developing iron deficiency during their first 6 postnatal months [5–9].…”

“…The Hgb nadir is lower and occurs earlier in more premature (gestational age 28–32 wk) infants when compared with those born at a gestational age of 33–36 wk [3]. However, beginning at 9 weeks and continuing until 12 months of age, Hgb concentrations are comparable in the two gestational age groups [3], implying the need for a more robust erythropoiesis and therefore, greater iron requirement in the more prematurely born infants.…”

Postnatal Changes in Plasma Ceruloplasmin and Transferrin Antioxidant Activities in Preterm Babies

“…Postnatally, copper deficiency [9] or excess iron (released from fetal erythrocytes or derived from nutritional sources) [10,11] may further impair ceruloplasmin's ferroxidase and transferrin's ferric ion binding antioxidant activity and predispose the newborn baby to oxidative Lindeman/Lentjes/van Zoeren-Grobben/ Berger damage. Yet, these possible changes in antioxidant activity have received little attention.…”