What is the recommended treatment for iron deficiency anemia in pregnant women?

Iron Deficiency Anemia Treatment in Pregnancy

For confirmed iron deficiency anemia in pregnancy, prescribe 60-120 mg of elemental iron daily as oral therapy and begin treatment immediately without waiting for additional confirmatory testing if the patient is not acutely ill. 1, 2

Initial Treatment Approach

First-Line Oral Iron Therapy

• Start 60-120 mg elemental iron daily for all pregnant women with confirmed iron deficiency anemia 1, 2
• Begin treatment immediately upon diagnosis without waiting for additional testing in non-acutely ill patients 1, 2
• Continue treatment throughout pregnancy and into the postpartum period 1, 2

Optimizing Absorption and Tolerability

• Take iron supplements at bedtime to reduce gastrointestinal side effects 1
• Separate calcium supplements and antacids from iron doses by several hours, as they significantly decrease absorption 1, 2, 3
• Consider taking with vitamin C-containing foods to enhance absorption 1, 3
• Recent evidence suggests alternate-day dosing may improve adherence while maintaining efficacy 3

Monitoring Treatment Response

Four-Week Reassessment

• Recheck hemoglobin or hematocrit after 4 weeks of treatment 1, 2
• Expected response: hemoglobin should increase by ≥1 g/dL or hematocrit by ≥3% 1, 2
• Once hemoglobin normalizes for gestational age, decrease iron dose to 30 mg/day for maintenance 1, 2

Non-Response Protocol

If anemia does not respond after 4 weeks despite compliance:

• Obtain MCV, RDW, and serum ferritin concentration 1, 2
• Consider alternative diagnoses including thalassemia minor or sickle cell trait, particularly in women of African, Mediterranean, or Southeast Asian ancestry 1
• Assess for ongoing blood loss or malabsorption syndromes 3

When to Escalate to Intravenous Iron

Consider intravenous iron therapy for:

• Severe anemia (hemoglobin <9.0 g/dL or hematocrit <27.0%) 1
• Intolerance to oral iron with significant gastrointestinal side effects 2, 4
• Lack of response to oral iron after 4 weeks despite confirmed compliance 2, 4
• Advanced pregnancy requiring rapid correction 4

Ferric carboxymaltose is the preferred intravenous formulation due to rapid effectiveness and better tolerability 2, 4

Special Population Considerations

High-Risk Groups Requiring Closer Monitoring

• Vegetarian women may require nearly double the iron supplementation due to lower absorption of non-heme iron from plant sources 1, 3
• Non-Hispanic Black and Mexican American women have higher prevalence of iron deficiency 1
• Women with short interpregnancy intervals or gastrointestinal conditions affecting absorption need higher-dose prophylaxis 1, 3

Postpartum Management

Screening and Treatment

• Screen for anemia at 4-6 weeks postpartum only if risk factors are present: anemia continued through third trimester, excessive blood loss at delivery, or multiple birth 1, 2
• If no risk factors exist, discontinue iron supplementation at delivery 1
• For postpartum iron deficiency anemia, treat with 60-120 mg elemental iron daily and continue for 2-3 months after hemoglobin normalizes 1

Common Pitfalls to Avoid

• Failing to separate calcium supplements and antacids from iron doses by several hours, which is the most common cause of treatment failure due to reduced absorption 1, 3
• Not identifying higher-risk women (vegetarians, certain ethnic groups, short interpregnancy intervals) who need increased supplementation from early pregnancy 1, 3
• Discontinuing treatment too early before iron stores are adequately replenished 1, 3
• Assuming gastrointestinal symptoms are solely from iron when they may overlap with normal pregnancy symptoms 5

Expected Side Effects

Common gastrointestinal effects include nausea, constipation, or diarrhea, though these often overlap with normal pregnancy symptoms 1, 5. Darkening of stool or urine is expected and harmless 1. Possible staining of teeth and gums may occur 1. Lower doses or alternate-day dosing may reduce side effects while maintaining efficacy 3, 5.