Official guidelines recommend treating postpartum moderate to severe anaemia (defined as Hb level ≤ 9.5 g/dL) with intravenous iron supplements such as iron sucrose12–14, which was found to be superior to oral iron supplements in terms of more rapid rise in serum ferritin and Hb, and improved maternal fatigue scores in the postpartum period3,13,15–17. This evidence concerns the gene GSTM1 and anemia (phenotype).