What is the best treatment for a pregnant woman at 14 weeks gestation (GA) with mild anemia (Hb 9.4)?

Treatment of Anemia at 14 Weeks Gestation with Hemoglobin 9.4 g/dL

The best treatment is oral ferrous sulfate (or equivalent oral iron) at 60-120 mg of elemental iron daily, taken twice daily if tolerated. 1, 2, 3

Rationale for Oral Iron as First-Line Treatment

This patient has mild anemia (Hb 9.4 g/dL at 14 weeks gestation, which is below the 11.0 g/dL threshold for first trimester anemia). 1, 3 The American College of Obstetricians and Gynecologists recommends making a presumptive diagnosis of iron deficiency anemia in non-acutely ill pregnant women and beginning oral iron treatment immediately without waiting for additional testing. 1, 2

• Oral iron at 60-120 mg/day of elemental iron is the recommended first-line treatment for mild to moderate anemia in pregnancy. 1, 2, 3
• The Centers for Disease Control and Prevention specifically recommends this dosing range for pregnant women with anemia. 1, 2
• Iron deficiency is the most common cause of anemia in pregnancy (approximately 75% of cases), making empiric oral iron therapy both diagnostic and therapeutic. 3, 4

Why Not Blood Transfusion?

Blood transfusion is not indicated for this patient because:

• Hemoglobin of 9.4 g/dL represents mild anemia, not severe anemia requiring transfusion. 3
• Severe anemia requiring consideration of transfusion is defined as hemoglobin 4.0-6.9 g/dL. 3
• This patient is clinically stable at an antenatal clinic visit with no evidence of acute hemorrhage or hemodynamic compromise.
• Blood transfusion carries risks of infection, transfusion reactions, and alloimmunization that are not justified for mild anemia responsive to oral therapy.

Why Not IV Iron Initially?

Intravenous iron is reserved for specific circumstances that do not apply to this patient:

• The American College of Obstetricians and Gynecologists recommends IV iron only for severe anemia, intolerance to oral iron, or lack of response to oral iron after 4 weeks despite compliance. 1, 2
• This patient should first receive a trial of oral iron therapy. 1, 2, 3
• IV iron (particularly ferric carboxymaltose) is preferred when oral iron fails, but starting with oral therapy is the standard approach. 1

Treatment Protocol

Initial dosing:

• Prescribe 60-120 mg of elemental iron daily (ferrous sulfate 325 mg twice daily provides approximately 130 mg elemental iron). 1, 2, 5
• Counsel the patient about gastrointestinal side effects (nausea, constipation, diarrhea) which are common but generally self-limited. 1, 5
• Provide dietary counseling on iron-rich foods and foods that enhance iron absorption. 1, 2

Monitoring:

• Reassess hemoglobin or hematocrit after 4 weeks of treatment. 1, 2
• An adequate response is defined as hemoglobin increase ≥1 g/dL or hematocrit increase ≥3%. 1, 2
• If no response after 4 weeks despite compliance, perform additional testing including mean corpuscular volume, red cell distribution width, and serum ferritin. 1

Dose adjustment:

• Once hemoglobin normalizes for gestational age, reduce to maintenance dose of 30 mg/day elemental iron. 1
• Continue iron supplementation throughout pregnancy and the postpartum period. 1

Important Caveats

• Do not take iron within 2 hours of tetracycline antibiotics due to absorption interference. 5
• New evidence suggests intermittent dosing may be as effective as daily dosing with fewer side effects, though guidelines still recommend daily therapy. 3
• Vegetarian women may require nearly double the iron supplementation due to lower absorption of non-heme iron. 1
• Screen again at 24-28 weeks gestation and at 4-6 weeks postpartum if anemia persists through third trimester. 1, 2