Altered ferrokinetics in toxemia of pregnancy: a possible indicator of decreased red cell survival.

Abstract

Serum iron concentration was increased in women with toxemia of pregnancy (mean 135 mcg/dl) compared to normotensive parturients (62 mcg/dl) and chronic hypertensive parturients (72 mcg/dl). Mean iron for eclamptics was 203 mcg/dl; for severe preeclamptics, 137 mcg/dl, independent of hepatic or renal function. Recovery to normal postpartum levels occurred in 1-3 days. Concomitant increase in serum ferritin (mean: 59 ng/ml vs. 19 ng/ml for normals) persisted longer. When hepatocellular injury occurred, mean ferritin increased to 421 ng/ml. Increased iron was independent of transferrin concentration. Serum hemoglobin was detectable in 15 of 25 toxemic patients who had elevated serum iron; only 3 of these patients had clinically significant levels. Serum haptoglobin was significantly decreased in 4 of 25 patients. Reticulocyte count averaged 2.5%, with an average hematocrit of 38%. It is hypothesized that serum iron and ferritin increase in response to catabolism of released hemoglobin. The magnitude of iron increase is greater than could be derived from intravascular hemolysis and suggests an extravascular locus.