Iron supplements in pregnancy may not be without risks. Iron deficiency anemia is common among women of childbearing age, so physicians recommend daily iron supplements for pregnant women to guard against premature birth and low-birth-weight babies. Iron supplements, however, may raise the risks of gestational diabetes, hypertension, and metabolic syndrome in some women. Researchers compared 500 pregnant women diagnosed with gestational diabetes in mid-pregnancy (24 to 28 weeks) with 500 pregnant women with normal blood glucose levels. Among all 1,000 women, 212 took daily iron supplements. Women who used iron had two-to-three-fold higher rates of gestational diabetes, hypertension, and metabolic syndrome. Also, iron supplements were associated with higher values on oral glucose tolerance tests in both the women with normal glucose levels and those with gestational diabetes. The study, reported in the August issue of the American Journal of Obstetrics and Gynecology, adds to growing evidence that iron supplementation in pregnancy may have negative consequences. The study authors suggest monitoring blood glucose levels in pregnant women who are taking iron supplements and call for larger studies to confirm their results.