Iron deficiency anemia--a lack of iron in the blood--occurs in about 20 percent of pregnant women in the United States. Iron is an important nutrient during pregnancy, so it's important to be sure you have an adequate intake.

There are three primary reasons that a sufficient iron intake to prevent anemia is important. First, iron is necessary for the formation of maternal and fetal hemoglobin, the oxygen-carrying component of blood. Since a woman's blood volume increases by 25 to 40 percent during pregnancy, and the baby is manufacturing blood cells, too, the need for iron increases putting the mother at risk for anemia. Second, during the last trimester, the baby draws from the mother some of the iron reserves that it will need during the first four to six months of life. Third, the increased blood volume and iron stores help your body adjust, to some degree, to the blood loss that occurs during childbirth.

Maternal iron deficiency anemia is associated with an increased incidence of anemia in the baby during the first year of life, as well as anemia and decreased iron stores in the mother. Pregnant women with iron deficiency anemia, particularly in the first and second trimesters, have an increased risk for premature delivery and for delivering a low-birth weight infant.

Most doctors recommend iron supplements for their pregnant patients. Typically, a daily 60 milligram iron supplement is prescribed to prevent anemia, even though the recommended amount of iron during pregnancy is 30 milligrams a day. That's because iron from supplements is not fully absorbed. Taking 60 milligrams of iron a day will ensure that you actually absorb the recommended daily amount of iron.

Iron supplements are best absorbed if taken with foods rich in vitamin C, such as orange, grapefruit, or tomato juice. Absorption is impaired if you take them with antacids or calcium- containing foods, such as milk and cheese. Iron supplements sometimes cause upset stomach, constipation, or nausea. If that is the case for you, remember you can get much of the iron you need from iron-rich foods, such as organ meats, (liver, for example), red meat, egg yolks, and legumes (dried peas and beans). Be sure to consult your doctor, though, before you stop taking an iron supplement.

Iron deficiency anemia in pregnant women and in infants after delivery is easily preventable by eating a balanced, nutritious, iron-rich diet and taking iron supplements as prescribed by your doctor.