Abstract

Objective: To determine the effects of maternal diabetes on fetal iron status using serum transferrin receptors (STfR) and their ratio to ferritin (TfR-F index) in cord blood.

Methods:Iron, ferritin, erythropoietin, STfR and haemoglobin (Hb) concentration were measured and TfR-F index calculated in 97 maternal/cord blood pairs. Forty- nine women had type 1 diabetes (diagnosed before pregnancy) and these were compared with forty-eight non- diabetic controls. The women with type 1 diabetes were recruited consecutively from attendance at the joint antenatal endocrine clinic while the control group of women was recruited from consecutive attendance at the remaining antenatal clinics.

Results: The infants of the diabetic women had significantly lower levels of ferritin (47 v 169 µg/l; p<0.01) and higher STfR (17.4 v 12.9 mg/l; p<0.01) and TfR-F index (10.4 v 5.8; p<0.01) than controls. They were also significantly more acidotic at birth (7.25 v 7.30; p<0.01), were born at an earlier gestation (36.7 v 39.7 wks; p<0.01) and had higher z scores for weight (0.53 v 0.02; p = 0.016).

Conclusions: Maternal diabetes causes increased depletion of fetal iron stores and is associated with higher fetal iron demands as indicated by higher STfR level and TfR-F index in cord blood. Key Words: ferritin, STfR, TfR-F index.