Serum ferritin as an early determinant of decreased iron stores in pregnant women.

Serum ferritin has been shown to be an excellent determinant of iron stores. In a consecutive group of women registering at the regular prenatal clinic, we measured serum ferritin, iron, iron-binding capacity, and hemoglobin to determine their hematologic status as to anemia. It was found that serum ferritin is the most sensitive determinant of depleted iron stores, with serum iron being next in sensitivity. This assay is a rapid, economic, sensitive measure of iron stores, and results are not altered significantly by other types of anemia or oral iron therapy.