What are the treatment options for iron deficiency anemia (IDA) in pregnancy?

From the Guidelines

Iron deficiency anemia in pregnancy should be treated with oral iron supplementation, typically ferrous sulfate 325 mg (containing 65 mg elemental iron) taken once or twice daily between meals with vitamin C to enhance absorption. Alternative formulations include ferrous gluconate or ferrous fumarate if sulfate isn't tolerated. Treatment should continue throughout pregnancy and for at least 3 months after hemoglobin normalizes to replenish iron stores. For severe anemia (hemoglobin <7 g/dL) or when oral therapy fails, intravenous iron may be necessary, with options including iron sucrose or ferric carboxymaltose. Common side effects of oral iron include constipation, nausea, and dark stools; these can be managed by taking iron with food (though this reduces absorption), using stool softeners, or reducing dosage. Iron supplementation is crucial during pregnancy as maternal iron demands increase significantly to support fetal development, placental growth, and expanded maternal blood volume. Untreated iron deficiency anemia in pregnancy is associated with preterm birth, low birth weight, and impaired cognitive development in the infant. Regular monitoring of hemoglobin levels is recommended to assess treatment response, with follow-up testing 2-4 weeks after starting therapy 1.

Some key points to consider:

• The usual dose of elemental iron per day is 60 to 120 mg 1.
• Prenatal vitamins often include a low dose of iron; the usual dose prescribed in early pregnancy is 30 mg of elemental iron per day 1.
• Higher doses (60 to 100 mg of elemental iron per day) are sometimes prescribed in populations at increased risk for iron deficiency anemia 1.
• The Institute of Medicine recommends a Recommended Dietary Allowance for iron in pregnant women of 27 mg per day 1.
• Iron supplementation is crucial during pregnancy to support fetal development, placental growth, and expanded maternal blood volume 1.

Overall, the treatment of iron deficiency anemia in pregnancy is similar to that in nonpregnant women and includes additional iron intake through oral iron pills, prenatal vitamins, and diet 1.

From the FDA Drug Label

Iron deficiency anemia during pregnancy should be treated. Untreated IDA in pregnancy is associated with adverse maternal outcomes such as post-partum anemia Adverse pregnancy outcomes associated with IDA include increased risk for preterm delivery and low birth weight Published data from randomized controlled studies and prospective observational studies on the use of Venofer in pregnant women have not reported an association of Venofer and adverse developmental outcomes.

Treating iron deficiency anemia in pregnancy is recommended.

• Iron sucrose (IV) can be used to treat iron deficiency anemia in pregnant women after the first trimester, as studies have not shown adverse maternal or fetal outcomes 2.
• Ferric carboxymaltose (IV) may also be used, but it is not known if it is safe and effective in pregnant women 3. It is essential to weigh the risks and benefits of treatment and consider the potential consequences of untreated iron deficiency anemia in pregnancy.

From the Research

Treating Iron Deficiency Anemia in Pregnancy

• Iron deficiency anemia is a prevalent cause of nutritional deficiency anemia in pregnant women, and oral iron is the first line of treatment 4.
• Untreated iron deficiency anemia in pregnancy can result in complications for the mother and fetus 4.
• Hemoglobin response at day 14 of oral iron may be useful in assessing whether and when to transition patients from oral to intravenous (IV) iron 5.
• A ≥1.0-g/dL increase in hemoglobin on day 14 most accurately predicted satisfactory overall hemoglobin response to oral iron on day 42/56 5.

Intermittent vs Daily Iron Supplementation

• Intermittent iron supplementation may be a feasible alternative to daily iron supplementation among pregnant women who are not anemic and have adequate antenatal care 6.
• Women receiving intermittent supplementation had fewer side effects and were at lower risk of having high hemoglobin concentrations during the second or third trimester of pregnancy 6.
• Daily oral iron supplementation during pregnancy reduces maternal anemia at term by 70% and iron-deficiency anemia at term by 67% 7, 8.

Benefits and Risks of Iron Supplementation

• Iron supplementation during pregnancy probably reduces maternal iron-deficiency anemia at term and may reduce maternal iron deficiency at term 8.
• Women taking iron supplements are probably less likely to have infants with low birthweight 8.
• The evidence is very uncertain for adverse effects, severe anemia, and maternal death 8.
• Daily oral iron supplementation during pregnancy may reduce maternal anemia and iron deficiency at term, but the positive effect on other maternal and infant outcomes is less clear 7, 8.