Anemia in pregnancy.

Anemia is the most common hematologic complication of pregnancy and is associated with increased rates of premature birth, low birth weight and perinatal mortality. Iron deficiency is the most common cause of anemia, and most pregnant women benefit from daily supplementation of 30 to 60 mg of elemental iron. Folic acid deficiency, the most common cause of megaloblastic anemia in pregnancy, is associated with open neural tube defects and other complications. It is recommended that daily supplementation with 4 mg of folic acid be started at least one month before conception and continued through the first trimester. Other less common causes of anemia include glucose-6-phosphate dehydrogenase deficiency, sickle cell trait and disease, and the thalassemias. The primary care provider should emphasize risk evaluation, dietary and preconceptual counseling, testing and appropriate treatment.