The quality of evidence is downgraded by study quality (unclear allocation concealment, blinding, incomplete outcome data, and selective reporting) and by indirectness (the improvement in laboratory parameters is not sufficient to make conclusions on clinical benefit).
A Cochrane review included 44 studies with a total of 43 274 subjects. 23 studies were conducted in countries that in 2011 had some malaria risk in parts of the country. There were significant heterogeneity across most prespecified outcomes. There was no clear difference in low birthweight babies (RR 0.84; 95% CI 0.69 to 1.03; 11 trials, n=17 613, low quality evidence) with iron supplements compared to controls. They appeared to deliver slightly heavier babies (mean difference (MD) 23g; 95% CI -3.02 to 50.51; 15 trials, n=18 590), but this was non-significant. There were no clear differences between groups for neonatal death or congenital anomalies. Maternal anaemia at term was reduced (RR 0.30; 95% C) 0.19 to 0.46; 14 trials, n=2199, low quality evidence). Women receiving iron were on average more likely to have higher haemoglobin (Hb) concentrations at term and in the postpartum period, but were at increased risk of Hb concentrations greater than 130 g/L during pregnancy, and at term.
Date of latest search: 10 January 2015