Ironing Out Prenatal Supplements

Given that anemia affects 38% of pregnant women worldwide, prenatal iron supplements are commonly recommended. Observational studies have shown that antenatal anemia is associated with excess risk for preterm birth. However, evidence supporting the effects of prenatal iron supplementation on neonatal outcomes has been mixed. Investigators conducted a meta-analysis of 48 randomized trials of iron supplementation (collectively involving 17,793 women) and 44 cohort studies of maternal anemia and birth outcomes (involving almost 2 million women).

In the randomized trials, iron supplementation was associated with a significant reduction in risk for low birth weight (relative risk, 0.81; 95% confidence interval, 0.71 to 0.93); however, it did not …