Intravenous infusions of ferumoxytol compared to oral ferrous sulfate for the treatment of anemia in pregnancy: a randomized controlled trial

Abstract

Iron-deficiency anemia in pregnancy is highly prevalent and presents significant risk to patients. Initial treatment is often with oral medication. We hypothesized that intravenous ferumoxytol would result in superior treatment of anemia as compared to oral ferrous sulfate. This study aimed to investigate whether 2 infusions of intravenous ferumoxytol are superior to the use of twice-daily oral ferrous sulfate for the treatment of iron-deficiency anemia in pregnancy. A randomized controlled trial was performed in which participants with anemic (hemoglobin <11 g/dL and hematocrit <33%) were allocated to receive either 2 infusions of 510 mg of intravenous ferumoxytol approximately 7 days apart, or 325 mg oral ferrous sulfate twice daily from enrollment to the end of their pregnancy. Participants were randomized in a 1:1 ratio to each treatment. Our primary outcome was the change in maternal hemoglobin. Secondary outcomes included maternal iron indices, maternal safety, and maternal tolerability. There were 124 participants (N=62 per group). In the intravenous iron group, the mean change in hemoglobin was 1.86 g/dL (95% confidence interval, 1.57 g/dL-2.14 g/dL) and in the oral group was 0.79 g/dL (95% confidence interval, 0.42 g/dL-1.17 g/dL) (P<.0001). The median change in ferritin between groups was 64.5 (range, 31-364) vs 8 (range, -436 to +167) (P=.0001). The median change in iron between groups was also statistically significant with 47.5 ug/dL (range, -133 ug/dL to +664 ug/dL) in the intravenous group vs 8.5 ug/dL (range, -313 ug/dL to +437 ug/dL) in the oral iron group (P=.001). Intravenous ferumoxytol was well tolerated, and it was associated with statistically significant increases in maternal hemoglobin, hematocrit, iron, and ferritin compared to oral ferrous sulfate.