In 2006, the U.S. Preventive Services Task Force (USPSTF) recommended routine screening for iron deficiency anemia in asymptomatic, pregnant women but found insufficient evidence to recommend for or against routine iron supplementation for nonanemic pregnant women.
To systematically update the prior USPSTF reviews on screening and supplementation for iron deficiency anemia in pregnancy.
We searched Cochrane and Ovid MEDLINE® databases (1996 to August 2014) and reviewed the reference lists of relevant systematic reviews to identify studies published prior to 1996.
We included randomized, controlled trials and controlled observational studies of supplementation, screening, and related treatment on maternal and infant clinical outcomes; prevalence of iron deficiency anemia and iron deficiency; hematological indexes and ferritin levels; and harms.
One investigator abstracted details about each article's study design, patient population, setting, screening method, treatment regimen, analysis, followup, and results. A second investigator reviewed data abstraction for accuracy. Two investigators independently applied criteria developed by the USPSTF to rate the quality of each study. Discrepancies were resolved through a consensus process.
Eleven trials of routine maternal iron supplementation reported various clinical outcomes for women and infants. One study reported no differences in maternal quality of life. There was inconsistency among studies reporting an effect of maternal iron supplementation on rates of Cesarean delivery and infant outcomes, including small for gestational age and low birthweight. Studies reported no effect of maternal iron supplementation on infant gestational age, Apgar scores, preterm birth, and infant mortality. Twelve trials reported some improvement in maternal hematological indexes with variable doses of iron supplementation versus placebo at various timepoints, although not all were statistically significant. Pooled analysis of four trials reporting a lower incidence of iron deficiency anemia at term (two statistically significant and two with no difference) resulted in a statistically significant difference between groups favoring supplementation. One followup study reported no difference in infant iron status at 6 months. No study directly compared clinical outcomes between pregnant women screened and not screened for iron deficiency anemia. Evidence on the effects of prenatal iron therapy on long-term maternal or infant clinical outcomes remains sparse or unavailable.
Non–English-language articles were excluded. Studies conducted in developing countries were excluded, but some data from trials in countries with limited generalizability to U.S. populations were included. Studies were methodologically heterogeneous and possibly underpowered.
Evidence supports the effectiveness of routine iron supplementation during pregnancy for improving maternal hematological indexes, but the clinical significance for both pregnant women and infants remains unclear. No studies addressed the benefits or harms of screening for iron deficiency anemia during pregnancy. More research is needed to understand the clinical effects of routine screening for and treatment of iron deficiency anemia during pregnancy.
