Intravenous ferric carboxymaltose versus oral ferrous sulphate for the treatment of moderate-to-severe postpartum anaemia in Nigerian women (IVON-PP): an open-label, randomised controlled trial

BACKGROUND: Intravenous iron could be better tolerated and adhered to than oral iron. We compared the effectiveness and safety of a single dose of intravenous ferric carboxymaltose versus oral ferrous sulphate for treating moderate-to-severe anaemia in postpartum women in Nigeria. METHODS: We conducted a multicentre, parallel, open-label, randomised controlled trial among postpartum women aged 15-49 years with moderate-to-severe anaemia (haemoglobin concentration <100 g/L), recruited 6-48 h after birth, from 20 health facilities across Nigeria. Nurses randomly assigned participants (1:1) to either a single intravenous dose (20 mg/kg up to a maximum of 1000 mg) of ferric carboxymaltose or oral ferrous sulphate (one 200 mg tablet containing 65 mg of elemental iron) twice per day until 6 weeks postpartum. Laboratory staff and the statistician were masked to the treatment. The primary outcome was anaemia (haemoglobin <110 g/L) at 6 weeks postpartum, and analysis was done by intention to treat. The trial was registered in the International Standard Randomised Controlled Trial registry (ISRCTN51426226) on March 10, 2022. FINDINGS: Between Dec 7, 2022, and June 21, 2024, 1400 women gave consent and were randomly assigned: 701 to the ferric carboxymaltose group and 699 to the ferrous sulphate group. The primary outcome was assessed in 655 women in the ferric carboxymaltose group and 662 in the ferrous sulphate group. At 6 weeks, the prevalence of anaemia in the ferric carboxymaltose group was 18% (115 of 655) versus 32% (214 of 662) in the ferrous sulphate group (risk ratio 0·54, 95% CI 0·44-0·66, p<0·001). Adverse events were less common in the ferric carboxymaltose than the ferrous sulphate group (53 8% vs 143 20%). In the ferric carboxymaltose group, headache (12 participants 2%) was the most common adverse event, whereas dark stools (76 participants 11%) were the most common adverse event among the ferrous sulphate group. INTERPRETATION: In treating postpartum moderate-to-severe anaemia, ferric carboxymaltose was more effective than ferrous sulphate and well tolerated. FUNDING: Bill & Melinda Gates Foundation.