Routine iron supplementation and screening for iron deficiency anemia in pregnancy: a systematic review for the U.S. Preventive Services Task Force

Ann Intern Med. 2015 Apr 21;162(8):566-76. doi: 10.7326/M14-2932.


Background: Routine screening and supplementation for iron deficiency anemia (IDA) in asymptomatic, nonanemic pregnant women could improve maternal and infant health outcomes.

Purpose: Update of a 2006 systematic review by the U.S. Preventive Services Task Force on screening and supplementation for IDA in pregnancy.

Data sources: MEDLINE and the Cochrane Library (1996 to August 2014) and reference lists of relevant systematic reviews to identify studies published since 1996.

Study selection: English-language trials and controlled observational studies about effectiveness of screening and routine supplementation for IDA in developed countries.

Data extraction: Data extraction and quality assessment confirmed and dual-rated by a second investigator using prespecified criteria.

Data synthesis: No study directly compared clinical outcomes or harms of screening or not screening pregnant women for IDA. Twelve supplementation trials were included, and no controlled observational studies met inclusion criteria. On the basis of 11 trials, routine maternal iron supplementation had inconsistent effects on rates of cesarean delivery, small size for gestational age, and low birthweight and no effect on maternal quality of life, gestational age, Apgar scores, preterm birth, or infant mortality. Twelve trials reported improvements in maternal hematologic indices, although not all were statistically significant. Pooled analysis of 4 trials resulted in a statistically significant difference in IDA incidence at term, favoring supplementation (risk ratio, 0.29 [95% CI, 0.17 to 0.49]; I2 = 0%). Maternal iron supplementation did not affect infant iron status at 6 months. Harms, none of which were serious or had long-term consequences, were inconsistently reported in 10 of the trials, with most finding no difference between groups.

Limitations: Data from trials in countries with limited generalizability to U.S. populations were included. Studies were methodologically heterogeneous, and some were small and underpowered.

Conclusion: There is inconclusive evidence that routine prenatal supplementation for IDA improves maternal or infant clinical health outcomes, but supplementation may improve maternal hematologic indices.

Primary funding source: Agency for Healthcare Research and Quality.

Publication types

  • Research Support, U.S. Gov't, P.H.S.
  • Review
  • Systematic Review

MeSH terms

  • Anemia, Iron-Deficiency / diagnosis
  • Anemia, Iron-Deficiency / drug therapy
  • Anemia, Iron-Deficiency / prevention & control*
  • Asymptomatic Diseases
  • Dietary Supplements* / adverse effects
  • Female
  • Hematologic Tests
  • Humans
  • Iron / administration & dosage*
  • Iron / adverse effects
  • Mass Screening* / adverse effects
  • Pregnancy
  • Pregnancy Complications, Hematologic / diagnosis
  • Pregnancy Complications, Hematologic / drug therapy
  • Pregnancy Complications, Hematologic / prevention & control*
  • Pregnancy Outcome


  • Iron