Written By NICHOLAS BAKALARA at the New York Times

A large review of studies concludes that taking iron supplements during pregnancy reduces the risk for maternal anemia and for having a baby with low birth weight.

The analysis covered 92 studies involving almost two million subjects. Some of the studies tested iron alone and others iron in combination with folic acid, which is routinely used to reduce the risk for birth defects.

Over all, the researchers found a significant inverse relationship between the dose of iron and the risk for maternal anemia in the third trimester. For every increase of 10 milligrams of iron, up to 66 milligrams, there was a 12 percent decrease in the risk for anemia.