What is the management of iron deficiency anemia (IDA) in pregnancy?

From the Guidelines

Iron deficiency anemia in pregnancy should be treated promptly with oral iron supplementation, typically 60 to 120 mg of elemental iron per day, as recommended by the U.S. Preventive Services Task Force 1. The treatment of iron deficiency anemia in pregnant women is similar to that in nonpregnant women and includes additional iron intake through oral iron pills, prenatal vitamins, and diet.

• The usual dose of elemental iron per day is 60 to 120 mg, which can be achieved through oral iron pills or prenatal vitamins 1.
• Prenatal vitamins often include a low dose of iron, with the usual dose prescribed in early pregnancy being 30 mg of elemental iron per day, but higher doses may be prescribed in populations at increased risk for iron deficiency anemia 1.
• Dietary iron is also an essential component of treatment, with the Recommended Dietary Allowance for iron in pregnant women being 27 mg per day, and natural food sources of iron including certain fruits, vegetables, meat, and poultry 1.
• It is also important to note that nonheme iron, found in vegetarian diets, may be less well-absorbed than heme iron, found in diets containing meat, and therefore the iron requirement may be almost twice as much in women who eat a purely vegetarian diet 1. The prevention of iron deficiency anemia in pregnancy includes routine screening at the first prenatal visit and again at 24-28 weeks, with prophylactic iron supplementation recommended for all pregnant women even without anemia.
• Screening tests typically involve measurement of serum hemoglobin or hematocrit levels, which is often the first step used in primary care practice 1.
• Treatment should continue throughout pregnancy and for at least 3 months after hemoglobin normalizes to replenish iron stores, and common side effects can be managed by taking iron with food if necessary, increasing dietary fiber, and using stool softeners.
• For severe anemia or poor tolerance of oral supplements, intravenous iron formulations may be needed, and iron deficiency anemia in pregnancy increases risks of preterm birth, low birth weight, and postpartum hemorrhage, while adequate treatment improves maternal and fetal outcomes 1.

From the Research

Definition and Diagnosis of Iron Deficiency Anemia in Pregnancy

• Iron deficiency anemia is defined as a low red blood cell count, a low hematocrit, or a low hemoglobin concentration, with a hemoglobin concentration of less than 11.0 g/dL in the first trimester and less than 10.5 or 11.0 g/dL in the second or third trimester 2.
• Serum ferritin is a helpful adjunct for the diagnosis of iron deficiency anemia, with a threshold value of < 30 μg/L indicating iron deficiency 3.
• Screening for iron deficiency anemia is recommended in every pregnant woman, with serum ferritin-level screening in the first trimester and regular hemoglobin checks at least once per trimester 3.

Treatment of Iron Deficiency Anemia in Pregnancy

• Oral iron therapy is the first-line treatment for iron deficiency anemia in pregnancy, with intermittent dosing being as effective as daily or twice-daily dosing with fewer side effects 2, 4.
• Intravenous iron therapy is recommended for patients with severe iron-deficiency anemia, intolerance of oral iron, lack of response to oral iron, or in the case of a clinical need for rapid and efficient treatment of anemia 3, 2.
• Intravenous iron therapy is also preferred for pregnant people with iron deficiency anemia in the third trimester, with newer generations of intravenous iron demonstrating shorter infusion times and improved safety profiles 5.

Monitoring and Prevention of Iron Deficiency Anemia in Pregnancy

• Regular monitoring of hemoglobin levels and serum ferritin is essential to prevent and treat iron deficiency anemia in pregnancy 4.
• Early screening for iron deficiency before the onset of anemia is highlighted as a beneficial approach, with the use of intravenous iron to expedite treatment 4.
• The American College of Obstetricians and Gynecologists recommends screening for anemia with a complete blood count in the first trimester and again at 24 0/7 to 28 6/7 weeks of gestation 2.

Risks and Benefits of Treatment Options

• Oral iron supplementation is associated with adverse gastrointestinal effects, which can decrease adherence and lead to subtherapeutic treatment 4.
• Intravenous iron therapy is generally safe, with rare allergic reactions, but close surveillance during administration is recommended 3, 2.
• The optimal route of iron repletion remains uncertain, with ongoing large, randomized trials aiming to define the optimal route of iron treatment for pregnant patients diagnosed with iron deficiency anemia 6.