What is the recommended treatment for iron deficiency anemia in pregnancy?

Treatment for Iron Deficiency Anemia in Pregnancy

Treat iron deficiency anemia in pregnancy with oral elemental iron 60-120 mg daily as first-line therapy, monitoring response at 4 weeks with an expected hemoglobin increase of ≥1 g/dL. 1, 2

Screening and Diagnosis

• Screen all pregnant women for anemia at the first prenatal visit using hemoglobin or hematocrit measurements 3, 1, 2
• Confirm positive screening with a repeat hemoglobin or hematocrit test before starting treatment 3, 2
• In non-acutely ill pregnant women, make a presumptive diagnosis of iron deficiency anemia and begin treatment immediately without waiting for additional testing 1, 2
• Refer to a physician for further evaluation if hemoglobin is <9.0 g/dL or hematocrit is <27.0% 3

Treatment Algorithm

First-Line: Oral Iron Therapy

Prescribe 60-120 mg of elemental iron daily for documented iron deficiency anemia. 3, 1, 2 This is the standard treatment dose recommended by the CDC and ACOG, with evidence showing reduction in anemia incidence (risk ratio 0.38) compared to placebo 4.

• Counsel patients about consuming iron-rich foods (meat, poultry, fruits, vegetables, fortified grains) and foods that enhance iron absorption 3, 1, 2
• Advise patients not to take iron within 2 hours of tetracycline antibiotics due to absorption interference 5
• Warn patients about common gastrointestinal side effects (nausea, constipation, diarrhea), which overlap with normal pregnancy symptoms but are dose-dependent 3, 5, 6

Monitoring Treatment Response

• Reassess hemoglobin or hematocrit after 4 weeks of treatment 3, 1, 2
• An adequate response is defined as hemoglobin increase ≥1 g/dL or hematocrit increase ≥3% 3, 1, 2
• If no response after 4 weeks despite compliance and absence of acute illness, perform additional testing including mean corpuscular volume, red cell distribution width, and serum ferritin 3, 1, 2
• In women of African, Mediterranean, or Southeast Asian ancestry, consider thalassemia minor or sickle cell trait if anemia is unresponsive to iron therapy 3, 2

Dose Adjustment

• Once hemoglobin or hematocrit normalizes for gestational age, reduce iron dose to 30 mg daily for maintenance 3, 2
• If hemoglobin is >15.0 g/dL or hematocrit is >45.0% in the second or third trimester, evaluate for poor blood volume expansion and potential pregnancy complications 3, 2

Second-Line: Intravenous Iron Therapy

Consider intravenous iron for severe anemia, intolerance to oral iron, or lack of response to oral iron after 4 weeks despite compliance. 2, 7 A 2022 RCT demonstrated that IV iron significantly reduces anemia rates at delivery (40% vs 85%, p=0.039) compared to oral iron 8.

• Ferric carboxymaltose is the preferred intravenous option due to rapid effectiveness and better tolerability 2, 7
• Before switching to IV iron, confirm compliance with oral regimen and rule out other causes of iron-refractory anemia 2
• Close surveillance during administration is recommended for all intravenous iron products, though anaphylactic reactions are extremely rare with non-dextran products 7
• IV iron produces better haematological indices than oral iron, though concerns exist about venous thrombosis and allergic reactions 4

Prevention Strategy

• Start all pregnant women on low-dose (30 mg daily) oral elemental iron at the first prenatal visit, even without anemia 3, 1, 2
• The recommended daily iron intake for pregnant women is 27 mg per day 3, 1
• Vegetarian women may require nearly double the iron supplementation due to lower absorption of non-heme iron 2

Postpartum Management

• Screen women at risk for anemia at 4-6 weeks postpartum using hemoglobin or hematocrit 3, 2
• Risk factors include anemia persisting through the third trimester, excessive blood loss at delivery, and multiple birth 3, 2
• For mild postpartum iron deficiency anemia, prescribe oral iron therapy 3
• For moderate-to-severe postpartum anemia (hemoglobin <95 g/L), administer intravenous iron therapy 7
• If no risk factors for anemia are present, stop supplemental iron at delivery 3

Common Pitfalls

Daily oral iron dosing may provide better iron load delivery than alternate-day dosing, though adherence is lower (47% vs 62%) due to gastrointestinal side effects 6. Lower doses (60 mg) may be as effective as higher doses (120 mg) with fewer side effects, representing a reasonable balance between efficacy and tolerability 3, 4.