How is anemia in pregnancy typically managed?

Management of Anemia in Pregnancy

All pregnant women should receive 30 mg/day of oral iron starting at the first prenatal visit for prevention, and if anemia is diagnosed, treat with 60-120 mg/day of elemental iron orally. 1

Screening and Diagnosis

• Screen all pregnant women for anemia at the first prenatal visit and again at 24-28 weeks gestation using hemoglobin (Hb) or hematocrit (Hct) testing 1, 2
• Anemia is defined as Hb <11.0 g/dL in the first trimester and <10.5 g/dL in the second or third trimester 2
• If screening is positive, confirm with repeat Hb or Hct before initiating treatment 1
• In non-acutely ill pregnant women, make a presumptive diagnosis of iron deficiency anemia and begin treatment immediately without waiting for additional testing 1, 3

Treatment Algorithm

Primary Prevention (All Pregnant Women)

• Start 30 mg/day of oral elemental iron at the first prenatal visit 1
• Counsel on iron-rich foods and dietary factors that enhance iron absorption 1, 3

Treatment of Confirmed Anemia

Mild to Moderate Anemia (Hb ≥9.0 g/dL):

• Prescribe 60-120 mg/day of elemental iron orally 1, 3
• Provide dietary counseling on iron-rich foods 1, 3
• Recent evidence suggests intermittent dosing (every other day or three times weekly) may be as effective as daily dosing with fewer gastrointestinal side effects 2

Severe Anemia (Hb <9.0 g/dL or Hct <27.0%):

• Refer to a physician experienced in managing anemia during pregnancy for further evaluation 1
• Continue oral iron 60-120 mg/day unless contraindicated 1, 3

Monitoring Response to Treatment

• Reassess Hb/Hct after 4 weeks of treatment 1, 3
• Expected response: Hb increase of ≥1 g/dL or Hct increase of ≥3% 1
• If no response after 4 weeks despite compliance and absence of acute illness, perform additional testing: MCV, RDW, and serum ferritin 1, 3
• In women of African, Mediterranean, or Southeast Asian ancestry, consider thalassemia minor or sickle cell trait if anemia is unresponsive to iron 1

Dose Adjustment

• Once Hb/Hct normalizes for gestational age, reduce iron dose to 30 mg/day for maintenance 1
• If Hb >15.0 g/dL or Hct >45.0% in second or third trimester, evaluate for poor blood volume expansion and potential pregnancy complications 1

Intravenous Iron Therapy

Indications for IV iron:

• Severe anemia with clinical need for rapid correction (e.g., advanced pregnancy) 4
• Intolerance to oral iron 4
• Lack of response to oral iron after 4 weeks despite compliance 3, 5
• Malabsorption 4

Before switching to IV iron:

• Confirm compliance with oral iron regimen 3, 5
• Rule out other causes of iron-refractory anemia (thalassemia, sickle cell trait, hemoglobinopathies) 3, 5

IV iron options:

• Ferric carboxymaltose is preferred due to rapid effectiveness and better tolerability 5
• Iron sucrose (200 mg per dose over 10 minutes) is an alternative 5
• Iron dextran has higher risk of anaphylaxis and should be avoided if other options available 5
• Administer IV iron only in settings with resuscitation facilities available 5

Special Considerations

• Vegetarian women may require nearly double the iron supplementation due to lower absorption of non-heme iron 3
• Gastrointestinal side effects (nausea, constipation, diarrhea) are common with oral iron but generally self-limited 1, 6
• Higher oral iron doses correlate with increased adverse effects; consider lower doses or intermittent dosing if side effects are problematic 6, 2

Postpartum Management

• Screen women at risk for anemia at 4-6 weeks postpartum using Hb or Hct 1, 3
• Risk factors include: anemia persisting through third trimester, excessive blood loss at delivery, multiple birth 1
• Continue iron supplementation throughout pregnancy and postpartum period to prevent recurrence 3
• If no risk factors present, stop supplemental iron at delivery 1

Critical Pitfalls to Avoid

• Do not use folic acid doses >0.1 mg until vitamin B12 deficiency is ruled out or adequately treated, as folic acid can mask B12 deficiency while allowing neurologic damage to progress 7
• Do not assume all anemia in pregnancy is iron deficiency—macrocytic anemia, very low MCV, or moderate-to-severe anemia requires investigation for other causes 2
• Do not continue oral iron indefinitely without reassessing response at 4 weeks 1, 3
• Avoid assuming IV iron is safer than oral iron without considering venous thrombosis and allergic reaction risks 6