Use of the Ganzoni formula would generally have resulted in higher dosing (eg, up to 1500 mg, given over two doses).2 We recognise this concern but emphasise that the trial was specifically designed to test a pragmatic single-dose intravenous strategy of iron replacement in a resource-constrained setting; treatment with a second dose would require spacing by 7 days, adding complexity to the implementation of a health programme and adding further costs for drugs and infusion. The results of our trial indicate that the single dose was successful in reducing the prevalence of iron deficiency at 36 weeks’ gestation from approximately 42% in the standard-of-care group to 18% in the intervention group (a prevalence ratio of 0·4).1 Whether further doses of iron to reduce the residual iron deficiency in the active group are warranted would depend on an analysis of the efficacy as well as the feasibility and cost of this approach. S-RP reports grants to his institution from the Australian National Health and Medical Research Council and the Bill & Melinda Gates Foundation, providing salary and research support.