Iron deficiency anemia: pregnancy outcomes with or without iron supplementation.

To estimate the efficacy of iron supplementation in anemic pregnant women on the basis of occurrence of pregnancy complications and birth outcomes. Comparison of the occurrence of medically recorded pregnancy complications and birth outcomes in pregnant women affected with medically recorded iron deficiency anemia and iron supplementation who had malformed fetuses/newborns (cases) and who delivered healthy babies (controls) in the population-based Hungarian Case-Control Surveillance System of Congenital Abnormalities. Of 22,843 cases with congenital abnormalities, 3242 (14.2%), while of 38,151 controls, 6358 (16.7%) had mothers with anemia. There was no higher rate of preterm births and low birth weight in the newborns of anemic pregnant women supplemented by iron. However, anemic pregnant women without iron treatment had a significantly shorter gestational age at delivery with a somewhat higher rate of preterm births but these adverse birth outcomes were prevented with iron supplementation. The rate of total and some congenital abnormalities was lower than expected and explained mainly by the healthier lifestyle and folic acid supplements. The secondary findings of the study showed a higher risk of constipation-related hemorrhoids and hypotension in anemic pregnant women with iron supplementation. A higher rate of preterm birth was found in anemic pregnant women without iron treatment but this adverse birth outcome was prevented with iron supplementation. There was no higher rate of congenital abnormalities in the offspring of anemic pregnant women supplemented with iron and/or folic acid supplements. Copyright © 2011 Elsevier Inc. All rights reserved.