Postpartum maternal and infant haematological effects of second-trimester ferric carboxymaltose versus standard-of-care oral iron in Malawi: longitudinal follow-up of a randomised controlled trial

Background: Anaemia is common in mothers and infants in the first year postpartum, especially in sub-Saharan Africa. We evaluated whether treating anaemia in the second trimester of pregnancy with a single dose of intravenous iron, ferric carboxymaltose, compared with standard-of-care oral iron could alleviate anaemia in postpartum women and their infants.

Methods: REVAMP (ACTRN12618001268235), an open-label, individually randomised, controlled trial done across nine urban and five rural health centres in Malawi, recruited women if they were in the second trimester of singleton pregnancy, had a capillary haemoglobin concentration of less than 10·0 g/dL, and had a negative malaria rapid diagnostic test. Once enrolled, women were randomly assigned (1:1) to receive intravenous ferric carboxymaltose (20 mg/kg up to 1000 mg) or standard of care (60 mg oral elemental iron twice daily for 90 days); all women received preventive malaria treatment. The primary endpoint of REVAMP was anaemia prevalence at 36 weeks of gestation, with follow-up of mothers and infants until 1 month postpartum. In REVAMP-EXTENDED, women from REVAMP who gave consent, and their infants, were followed up at 3, 6, 9, and 12 months postpartum, and venous blood was collected for haemoglobin, ferritin, and C-reactive protein measurement. Maternal postpartum outcomes comprised prevalence of anaemia (venous haemoglobin concentration <11 g/dL up to and including delivery and <12·0 g/dL postpartum) and haemoglobin concentration, as well as iron status (iron deficiency, defined as serum ferritin <15 μg/L, or <30 μg/L if C-reactive protein >5 mg/L, and iron deficiency anaemia [both iron deficiency and anaemia]). Infant outcomes comprised cord ferritin concentration, and haemoglobin and ferritin concentrations at 1, 3, 6, 9, and 12 months of age.

Findings: Between Nov 12, 2018, and March 2, 2021, 862 women were randomly assigned in REVAMP, of whom 793 (393 in the ferric carboxymaltose group [376 liveborn infants] and 400 [379 liveborn infants] in the standard-of-care group) provided consent for REVAMP-EXTENDED. At 12 months postpartum, ferritin concentrations were higher (geometric mean ratio 1·47 [95% CI 1·29-1·66], p<0·0001), and prevalence of iron deficiency was lower (prevalence ratio 0·65 [0·48-0·88], p=0·0050), in mothers receiving ferric carboxymaltose than in those receiving standard of care. Anaemia was less common in women who received ferric carboxymaltose than in those who received standard of care at 1 month (prevalence ratio 0·84 [95% CI 0·71-0·98], p=0·027), 3 months (0·75 [0·62-0·91], p=0·0029), and 6 months (0·78 [0·63-0·96], p=0·018) postpartum but not thereafter. There was no evidence of a difference between groups regarding cord ferritin, infant ferritin, or infant haemoglobin concentrations at any timepoint. Benefits on postpartum anaemia were restricted to mothers with baseline iron deficiency.

Interpretation: Ferric carboxymaltose treatment in the second trimester protected women from postpartum anaemia and iron deficiency but did not affect infant haematological or iron status.

Funding: Bill & Melinda Gates Foundation.

Translation: For the Chichewa translation of the abstract see Supplementary Materials section.