Does iron supplementation improve pregnancy outcomes?

Although iron is typically prescribed during pregnancy to prevent IDA,^[1][2] regardless of the mother’s iron levels, more studies should be conducted to verify its benefits throughout pregnancy and after childbirth.

One meta-analysis has assessed the effect of daily iron supplementation in pregnant iron-replete women and found that it may reduce both maternal IDA and maternal ID at term (i.e., at 37 weeks gestation or later). The results also suggested that daily oral iron supplementation may decrease the risk of newborns being small for gestational age (SGA) (i.e., having a birth weight below the 10th percentile for their gestational age) or low birthweight (LBW) (i.e., having a birth weight lower than 2500 g).^[2] Another meta-analysis, which included pregnant and non-pregnant women of reproductive age with IDA, found a significant increase in hemoglobin and ferritin levels following iron supplementation.^[1] However, both meta-analyses presented high heterogeneity, risk of bias, and low to moderate levels of evidence, leaving some questions about the benefits and safety of preventative iron supplementation unanswered.