Study of maternal influences on fetal iron status at term using cord blood transferrin receptors

Aims-To determine effects of maternal iron depletion and smoking on iron status of term babies using serum transferrin receptors (STfR) and their ratio to ferritin (TfR-F index) in cord blood. Methods-Iron, ferritin, STfR, and haemoglobin (Hb) concentration were measured and TfR-F index calculated in 67 cord /maternal blood pairs. Twenty six mothers were iron depleted (ferritin <10 g/l) and 28 were smokers. Results-Maternal iron depletion was associated with decreased cord ferritin (113 v 171 mug/l) and Hb (156 v 168 g/l) but no change in STfR or TfR-F index. Smoking was associated with increased cord Hb (168 v 157 g/l) and TfR-F index (4.1 v 3.4), and decreased ferritin (123 v 190 mug/l). Cord TfR-F index and Hb were positively correlated (r = 0.48). Conclusions-Maternal iron depletion is associated with reduced fetal iron stores but no change in free iron availability. Smoking is associated with increased fetal iron requirements for erythropoiesis.