Erythropoietic activity and soluble transferrin receptor level in neonatesand maternal blood

Serum transferrin receptor (sTfR) concentration reflects functional iron st atus and erythropoietic activity. The aims of this study were to examine ge nder differences of erythropoiesis in newborns and to evaluate the influenc es of maternal anaemia or iron deficiency on foetal cord blood parameters f or iron status and sTfR. In total, 527 newborns and their mothers were exam ined. Reticulocytes were analysed by flow cytometry and sTfR was measured b y an immunoenzymometric method. There were no sex differences in haematolog ical or iron parameters. However, the reticulocyte maturity index (RMI) of male neonates was 37.45%, significantly higher than the 26.81% in female ne onates (p < 0.01). The high fluorescence reticulocytes (HFR) and middle flu orescence reticulocytes (MFR) of male neonates were 4.91% and 22.36%, respe ctively, while those of female neonates were 3.31% and 17.83%, respectively (p < 0.01 for each gender). The sTfR concentrations of male and female neo nates were 6.27 mg/l and 5.09 mg/l, respectively (p < 0.01). Values for ser um iron, ferritin and reticulocyte subpopulations were significantly lower in the newborns of anaemic mothers. However, newborns of iron-deficient mot hers showed no differences in iron parameters from those of non-iron-defici ent mothers. Conclusions: The higher values of RMI and sTfR observed in male neonates in dicate that erythropoietic activity is higher in this group. Iron transport to the foetus appears to be independent of matenal iron deficiency. Howeve r iron transport and erythropoises in newborns seems to decline from the ti me that the mothers aquire frank iron deficiency anaenia.