What is the recommended management for a pregnant woman with anemia?

Management of Anemia in Pregnancy

All pregnant women should receive 30 mg/day of elemental iron starting at the first prenatal visit, and those diagnosed with anemia should be treated with 60-120 mg/day of oral elemental iron as first-line therapy. 1, 2

Screening Protocol

• Screen all pregnant women for anemia at the first prenatal visit and again at 24-28 weeks gestation using hemoglobin or hematocrit testing. 1, 2

• Anemia is defined as hemoglobin <11 g/dL in all trimesters, with severity classified as: 2, 3

  • Mild: 10-10.9 g/dL
  • Moderate: 7-9.9 g/dL
  • Severe: <7 g/dL

• If screening is positive, confirm with a repeat hemoglobin or hematocrit test before initiating treatment. 1

• For non-acutely ill pregnant women with confirmed anemia, make a presumptive diagnosis of iron deficiency anemia and begin treatment immediately without waiting for additional iron studies. 1

• Refer to a physician familiar with anemia in pregnancy if hemoglobin is <9.0 g/dL or hematocrit is <27.0%. 4

Treatment Algorithm

Universal Prophylaxis

• Start 30 mg/day of oral elemental iron at the first prenatal visit for ALL pregnant women, regardless of anemia status. 4, 1, 2

• Provide dietary counseling on iron-rich foods and foods that enhance iron absorption. 4, 1

Treatment of Confirmed Anemia

• Prescribe 60-120 mg/day of oral elemental iron for mild to moderate anemia (hemoglobin 7-10.9 g/dL). 4, 1, 2

• Take iron on an empty stomach to maximize absorption, though this may increase gastrointestinal side effects. 5

• Consider taking iron with vitamin C to improve absorption, though evidence is limited. 5

• Avoid taking iron with food, antacids, or proton pump inhibitors as they significantly decrease absorption. 5

Monitoring Response

• Reassess hemoglobin or hematocrit after 4 weeks of treatment. 4, 1

• The expected response is an increase of ≥1 g/dL in hemoglobin or ≥3% in hematocrit. 4, 1

• If anemia does not respond after 4 weeks despite confirmed compliance and absence of acute illness, perform additional testing including mean corpuscular volume (MCV), red cell distribution width (RDW), and serum ferritin. 4, 1

• In women of African, Mediterranean, or Southeast Asian ancestry, mild anemia unresponsive to iron therapy may be due to thalassemia minor or sickle cell trait. 4

Dose Adjustment

• Once hemoglobin or hematocrit normalizes for gestational age, reduce iron dose to 30 mg/day for maintenance through pregnancy and the postpartum period. 1, 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. 4, 1

Intravenous Iron Therapy

Consider intravenous iron for severe anemia, intolerance to oral iron, or lack of response to oral iron after 4 weeks despite confirmed compliance. 1, 6

• Before switching to intravenous iron, confirm compliance with the oral iron regimen and rule out other causes of iron-refractory anemia. 1

• Ferric carboxymaltose is the preferred intravenous iron option due to rapid effectiveness and better tolerability. 1, 2

• Intravenous iron sucrose is safe after the first trimester, with no adverse maternal or fetal outcomes reported in published studies. 7

• Be aware that severe adverse reactions including circulatory failure and severe hypotension may occur with parenteral iron products, potentially causing fetal bradycardia, especially during the second and third trimester. 7

Special Populations

• Vegetarian women may require nearly double the iron supplementation due to lower absorption of non-heme iron from plant sources. 1, 5

Postpartum Management

• Screen women at risk for anemia at 4-6 weeks postpartum using hemoglobin or hematocrit, applying non-pregnant anemia criteria (hemoglobin <12 g/dL). 4, 1, 2

• Risk factors for postpartum anemia include anemia persisting through the third trimester, excessive blood loss at delivery, and multiple birth. 4, 2

• Continue iron supplementation throughout pregnancy and the postpartum period to prevent recurrence. 1, 2

• Monitor breastfed infants for gastrointestinal toxicity (constipation, diarrhea) if the mother is receiving intravenous iron. 7

Common Pitfalls

• Do not assume compliance without verification, as gastrointestinal side effects (constipation, nausea, abdominal discomfort) are common and frequently lead to treatment discontinuation. 1, 5

• Hemoglobin or hematocrit measurement alone can be imprecise for detecting iron deficiency in pregnancy due to physiologic hemodilution, but remains the primary screening tool. 4

• Serum ferritin has limited use during pregnancy as it often decreases in late pregnancy despite adequate iron stores and increases during inflammation. 4