Intravenous iron therapy in pregnancy anemia: hematological response in relation to gestational age

This study was undertaken to evaluate the response to parenteral administration of iron in 62 pregnant patients with asiderotic anemia and mean initial hemoglobin (Hb) concentrations (Hb1) of 9.91+/-(SD) 1.13 g/dl. Iron (742+/-366 mg) was administered intravenously, and the response to treatment was classified according to the rise in Hb (VarHb; 0.97+/-0.77 g/dl) and evaluated after 19.5+/-14.6 (range 4-57) days. It was found that the VarHb was inversely correlated with the Hb1 value (r = -0.46; p<0.001) and only weakly correlated with the number of vials administered. In addition, two-cluster analysis of patients on the basis of VarHb and gestational age resulted in two significantly different groups (p<0.001): >28 weeks of pregnancy (n = 39, group 1: 1.27+/-0.66, range 0.1-3.3 g/dl) and < or =28 weeks of pregnancy (n = 23, group 2: 0.45+/- 0.69, range 0.4-2.3 g/dl). No difference was found between groups 1 and 2 in relation to Hb1, iron dose, and therapy duration. The number of patients with VarHb >0.8 g/dl was found to be higher in group 2 than in group 1: 31/39 versus 8/23 (p<0.001). These results indicate that the response to intravenous iron therapy in pregnancy anemia is related to Hb1 level and gestational age at the onset of treatment and probably depends on the erythropoietin response to anemia.