Abstract 184
Background/Aim: Low intracellular iron increases transferrin receptor (STfR) and decreases ferritin (F) production. Serum STfR to log F ratio (TfR-F index) reflects tissue iron requirement. We determined effects of maternal iron status and smoking on these indices in cord (CB) and maternal blood (MB). Methods: Iron, total iron binding capacity, F, STfR, haemoglobin (Hb) and mean cell volume (MCV) were measured and TfR-F index calculated in 67 CB-MB pairs (gest. 39± 1.3 wk; bwt. 3337±516g). Correlation coefficients (R) were calculated for MB TfR-F index vs. all CB indices. Effects of maternal iron status (26 depleted; F< 10mg/L), iron therapy (n=41) and smoking (n=28) were assessed using unpaired t-tests. Results: MB-TfR-F index correlated only with CB-F (R = -0.24; p<0.05) and TfR-F index (R=0.24; <0.05). Iron depletion was associated with decreased CB-F (133 vs. 187 mg/L; p<0.05) and Hb (15.6 vs. 16.5 g/dL; p<0.05). Maternal iron therapy improved MB iron status (TfR-F index 3.3 vs. 5.4;p<0.01) but not CB iron status. Smoking increased CB-Hb (16.7 vs. 15.5 g/dL; p<0.05) and TfR-F index (4.8 vs. 3.7; p<0.05) and decreased F (135 vs. 189 mg/L; p=0.02) without affecting maternal iron status. CB-TfR-F index correlated positively with CB-Hb (R = 0.469;p<0.001) and MCV (R = 0.305;p<0.05). Conclusions: Maternal iron deficiency reduces fetal iron stores without affecting tissue iron concentration. CB STfR-F index may measure fetal iron requirements for erythropoeisis. In this study, oral iron therapy benefited only the mother.
