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Evidence summaries

Daily Oral Iron Supplementation during Pregnancy

Routine oral iron supplementation during pregnancy appears to be effective for maternal anaemia but not for infant outcomes. Level of evidence: "B"

The quality of evidence is downgraded by study quality (unclear allocation concealment, blinding, incomplete outcome data, and selective reporting).

Summary

A Cochrane review [Abstract] 1 included 57 studies with a total of 48 971 subjects. The trials were conducted in 27 countries around the world and many studies were conducted in countries that had some malaria risk in parts of the country. There were significant heterogeneity across most prespecified outcomes. Low birthweight was reduced (RR 0.84, 95% CI 0.72 to 0.99; 12 trials, n=18 290) with iron supplements compared to controls. Babys were slightly heavier (mean difference 25g), but this was non-significant. There were no clear differences between groups for neonatal death, preterm birth, or congenital anomalies. Maternal anaemia (Hb less than 110 g/L) at term was reduced (RR 0.30; 95% CI 0.20 to 0.40; 14 trials, n=13 543, low certainty evidence).

An overview of systematic reviews 5 summarized the evidence concerning oral iron-based interventions compared to placebo or no iron-based interventions to prevent critical outcomes in pregnancy or treat critical outcomes in the postpartum phase. Compared to placebo/no treatment, iron-based therapies reduced maternal anemia at term by 59% (RR 0.41, 95% CI 0.23 to 0.73; 7 trials, I² = 86%; moderate-quality evidence) and maternal iron deficiency anemia by 67% (RR 0.33, 95% CI 0.16 to 0.69; 7 trials, I² = 49%). There was no evidence of difference between iron-based therapies vs control in terms of side effects (RR 1.42, 95% CI 0.91 to 2.21), preterm delivery (13 studies: RR 0.93, 95% CI 0.84 to 1.03; low-quality evidence), low birthweight (RR 0.94, 95% CI 0.79 to 1.13; low-quality evidence) and infant mortality (RR 0.93, 0.72 to 1.20; low-quality evidence).

Clinical comments

Note

Date of latest search: 2024-11-22

    References

    • Finkelstein JL, Cuthbert A, Weeks J, et al. Daily oral iron supplementation during pregnancy. Cochrane Database Syst Rev 2024;8(8):CD004736. [PubMed]
    • Abraha I, Bonacini MI, Montedori A et al. Oral iron-based interventions for prevention of critical outcomes in pregnancy and postnatal care: An overview and update of systematic reviews. J Evid Based Med 2019;12(2):155-166. [PubMed]

Primary/Secondary Keywords