Intravenous iron isomaltoside versus oral iron supplementation in women with postpartum anaemia: a retrospective study

Abstract

Objectives: To compare oral and intravenous (IV) iron therapies in terms of haemoglobin (Hb) level, ferritin level, and fatigue at 2 and 6 weeks in women with severe postpartum anaemia.
Methods: Medical records of patients with severe postpartum anaemia (Hb ≤8 g/dL), irrespective of mode of delivery, between January 2023 and December 2024 at Kwong Wah Hospital were retrospectively reviewed. Patients either
received a single 500 mg dose of IV Monofer or oral iron supplementation, and then both were prescribed oral iron supplements for 12 weeks if the Hb level was ≤8.0 g/dL at discharge. Primary outcome measures included changes in Hb and ferritin levels, as well as Multidimensional Fatigue Inventory (MFI) scores, from baseline to weeks 2 and 6. Secondary outcome measures included adverse reaction rates and changes in blood transfusion rates after implementation of the new IV Monofer protocol for severe postpartum anaemia.
Results: In total, 177 patients who chose either IV Monofer (n=141) or oral iron supplementation (n=36) were included in the analysis. Compared with the oral iron group, the IV Monofer group showed greater increases in mean Hb levels at week 2 (3.11 vs 2.37 g/dL, p<0.001) and week 6 (4.89 vs 3.55 g/dL, p<0.001), as well as higher mean ferritin levels at week 2 (599.5 vs 109 pmol/L, p<0.001) and week 6 (189 vs 100 pmol/L, p<0.001). No patients experienced serious adverse reactions or anaphylaxis following IV Monofer administration. Only two (1.1%) patients reported mild adverse reactions, which resolved spontaneously.
Conclusion: A single fixed dose of IV iron isomaltoside (Monofer) resulted in more rapid improvements in Hb levels and iron stores in women with severe postpartum anaemia, compared with oral iron. IV iron is an effective alternative to blood transfusion for the management of severe postpartum anaemia.