Iron supplements in pregnant women with normal iron status: A systematic review and meta-analysis

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#pregnancy #infant-newborn #female #infant #humans

Iron supplements in pregnant women with normal iron status: A systematic review and meta-analysis

Hansen et al., 2023 | Acta Obstet Gynecol Scand | Meta Analysis

Citation

Hansen Rebecka, Sejer Emilie P F, ... Schroll Jeppe B. Iron supplements in pregnant women with normal iron status: A systematic review and meta-analysis. Acta Obstet Gynecol Scand. 2023-Sep;102(9):1147-1158. doi:10.1111/aogs.14607

Abstract

INTRODUCTION: Effects of daily iron supplementation in iron replete pregnancy are unclear. This systematic review aimed to assess benefits and harms of oral iron supplements in pregnant women without anemia and iron deficiency. MATERIAL AND METHODS: We predefined and registered a protocol in PROSPERO (CRD42020186210) and performed the review following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) methodology. We searched for randomized clinical trials (RCTs) and observational studies comparing daily oral iron supplementation with no iron supplements in non-anemic iron replete pregnant women. Searches were conducted in MEDLINE (by PubMed), EMBASE (by OVID), Cochrane Library, and ClinicalTrials.gov from inception to September 2022 without language restrictions. Two authors independently screened records, extracted data, and assessed risk of bias using the revised Cochrane risk of bias tool (RoB2). One author read full-texts, assessed certainty of evidence by GRADE and conducted meta-analyses using a random-effects model. Primary outcomes included iron deficiency anemia, iron deficiency, hemoglobin >130 g/L, elevated iron status, small for gestational age newborns, low birthweight newborns, preterm birth, and congenital anomalies. RESULTS: Eight RCTs (2822 women) but no observational studies were eligible for inclusion. Daily oral iron supplementation in pregnancy probably reduces iron deficiency anemia at term (risk ratio [RR]: 0.51, 95% confidence interval [CI]: 0.38-0.70; 4 RCTs, 1670 women; I2  = 13%; moderate-certainty evidence) and the incidence of low birthweight babies (RR: 0.30, 95% CI: 0.13-0.68; 2 RCTs, 361 infants; I2  = 0%; moderate-certainty evidence). In addition, it may reduce iron deficiency at term (RR: 0.74, 95% CI: 0.60-0.92; 4 RCTs, 1663 women; I2  = 58%; low-certainty evidence) and the incidence of small for gestational age babies (RR: 0.39, 95% CI: 0.17-0.86; 1 RCT, 213 infants; I2 not estimable; low-certainty evidence). CONCLUSIONS: Daily iron supplementation in iron replete non-anemic pregnant women probably reduces the risk of maternal iron deficiency anemia at term and low birthweight.

Key Findings

Eight RCTs (2822 women) but no observational studies were eligible for inclusion. Daily oral iron supplementation in pregnancy probably reduces iron deficiency anemia at term (risk ratio [RR]: 0.51, 95% confidence interval [CI]: 0.38-0.70; 4 RCTs, 1670 women; I2  = 13%; moderate-certainty evidence) and the incidence of low birthweight babies (RR: 0.30, 95% CI: 0.13-0.68; 2 RCTs, 361 infants; I2  = 0%; moderate-certainty evidence). In addition, it may reduce iron deficiency at term (RR: 0.74, 95%

Outcomes Measured

  • Requires manual extraction

Population

Field Value
Population pregnant women
Sample Size 4
Age Range See abstract
Condition deficiency

MeSH Terms

  • Pregnancy
  • Infant, Newborn
  • Female
  • Infant
  • Humans
  • Pregnant People
  • Anemia, Iron-Deficiency
  • Birth Weight
  • Dietary Supplements
  • Iron Deficiencies

Evidence Classification

  • Level: Meta Analysis
  • Publication Types: Meta-Analysis, Systematic Review, Journal Article
  • Vertical: iron

Provenance

Source extracted via PubMed E-utilities API on 2026-04-09