Iron Supplementation During Pregnancy and Non-Transferrin-Bound Iron (NTBI)

Although the essential role of iron during pregnancy is well established, concerns have been raised that current iron supplements given routinely during pregnancy may also have harmful consequences, such as increased oxidative stress and enhanced risks of infection, pre-eclampsia and impaired glucose regulation. A potential mechanism for the production of adverse effects is the appearance of non-transferrin-bound iron after oral administration of iron supplements. Non-transferrin-bound iron is more readily available to pathogens and could promote injurious free radical reactions that might add to the oxidative stress of pregnancy.

The present study will determine if oral administration of 60 mg of iron as ferrous sulfate during the second trimester of pregnancy is followed by the appearance of non-transferrin-bound iron two hours later. The investigators will examine the influence of a variety of factors, including iron status and previous use of iron supplements. Detection of non-transferrin-bound iron after administration of an iron supplement to pregnant women would be an important new observation that could lead to re-evaluation of current methods of iron supplementation.