What is the protocol for managing anemia in pregnant women?

Management of Anemia in Pregnant Women

Screen all pregnant women for anemia at the first prenatal visit and again at 24-28 weeks gestation using hemoglobin or hematocrit, then treat with oral iron 60-120 mg/day of elemental iron as first-line therapy, escalating to intravenous ferric carboxymaltose if oral therapy fails after 4 weeks, is not tolerated, or if rapid correction is needed. 1, 2

Screening Protocol

• Screen at first prenatal visit using hemoglobin or hematocrit measurements 2
• Screen again at 24-28 weeks gestation to detect anemia developing later in pregnancy 2
• Define anemia as hemoglobin <11.0 g/dL in the first trimester 1
• If screening is positive, confirm with repeat testing before initiating treatment 2
• In non-acutely ill pregnant women, make a presumptive diagnosis of iron deficiency anemia and begin treatment immediately without waiting for additional confirmatory testing 1, 2

First-Line Treatment: Oral Iron

• Prescribe 60-120 mg/day of elemental iron orally for mild to moderate anemia 1, 2
• Take iron between meals (not with food) to maximize absorption, though this may reduce tolerability 1
• Consider taking iron with ascorbic acid (vitamin C) to enhance absorption 1
• Counsel patients about consuming iron-rich foods including meat, poultry, certain fruits and vegetables, and iron-fortified grain products 1
• Universal prophylaxis: All pregnant women should receive 30 mg/day of oral elemental iron starting at the first prenatal visit 2

Common Pitfall: Verify Compliance

• Do not assume compliance—actively verify that patients are taking the medication, as gastrointestinal side effects frequently lead to discontinuation 1
• Side effects are common but generally self-limited 2

Monitoring Response to Oral Iron

• Reassess hemoglobin after 4 weeks of treatment 1, 2
• Expected response: hemoglobin increase of ≥1 g/dL or hematocrit increase of ≥3% 1, 2
• If no response occurs 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 1, 2
• Once hemoglobin normalizes for gestational age, reduce iron dose to 30 mg/day for maintenance 2

When to Escalate to Intravenous Iron

Switch to intravenous iron therapy if: 1, 2, 3

• Patient fails oral therapy after 4 weeks despite confirmed compliance
• Patient cannot tolerate oral preparations due to side effects
• Rapid correction of anemia is required (e.g., advanced pregnancy)
• Hemoglobin is <9.0 g/dL or hematocrit is <27.0%

Intravenous Iron: Preferred Agent and Dosing

• Ferric carboxymaltose (Injectafer) is the preferred intravenous iron option due to rapid effectiveness, better tolerability, and clinical trial evidence in pregnancy populations 2, 3
• Dosing: 15 mg/kg body weight up to maximum 750 mg per dose, administered on two occasions separated by at least 7 days, for cumulative dose up to 1,500 mg 3
• Administration time: 15-minute infusion, which is significantly more convenient than older preparations 3
• Alternative preparations include iron sucrose (Venofer) with maximum 200 mg per dose and 10-minute infusion, or iron dextran (Cosmofer) which can give total dose in single 6-hour infusion but carries 0.6-0.7% risk of serious reactions including anaphylaxis 3

Safety Considerations for IV Iron

• Advise pregnant women about the risk of hypersensitivity reactions which may have serious consequences for the fetus 4
• Patients should report signs of hypersensitivity such as rash, itching, dizziness, lightheadedness, swelling, and breathing problems 4
• Patients should report signs of hypophosphatemia such as fatigue, muscle weakness or pain, bone and joint pain, or bone fractures 4
• Question patients regarding any prior history of reactions to parenteral iron products before administration 4

Monitoring Response to IV Iron

• Reassess hemoglobin and ferritin at appropriate intervals to confirm response 3
• Expected response: hemoglobin should increase by ≥1 g/dL within 2-4 weeks 3
• Once hemoglobin normalizes for gestational age, decrease to maintenance dose of 30 mg/day oral iron 3

Referral Criteria

• Refer to a physician familiar with anemia in pregnancy if hemoglobin is <9.0 g/dL or hematocrit is <27.0% 1, 3
• Consider alternative diagnoses in women of African, Mediterranean, or Southeast Asian ancestry, where thalassemia minor or sickle cell trait may present as mild anemia unresponsive to oral iron 3

Additional Diagnostic Considerations

• Perform coeliac serology as part of the evaluation, particularly if there is a family history of gastrointestinal neoplasia or coeliac disease 1
• Do not attribute iron deficiency anemia to aspirin, warfarin, or proton pump inhibitors without completing appropriate investigations, as these medications do not reduce the likelihood of underlying gastrointestinal pathology 1
• Upper gastrointestinal endoscopy and duodenal biopsy can be performed safely in pregnancy if coeliac disease is suspected 1

Postpartum Management

• Screen women at risk for anemia at 4-6 weeks postpartum using hemoglobin or hematocrit 2
• Risk factors include anemia persisting through the third trimester, excessive blood loss at delivery, and multiple birth 2
• Continue iron supplementation throughout pregnancy and postpartum period to prevent recurrence 2

Special Populations

• Vegetarian women may require nearly double the iron supplementation due to lower absorption of non-heme iron 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 2

Safety of Oral Iron in First Trimester

• There is no evidence that oral iron supplementation in the first trimester causes harm to mother or fetus 1