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.
Continue reading this article in the New York Times.