What is the best management approach for a 22-week pregnant patient with severe anemia who has received 2 units of Packed Red Blood Cells (PRBCs) and has a normal platelet count?

Management of Severe Anemia at 22 Weeks Gestation After Transfusion

After receiving 2 units of PRBCs for hemoglobin 6.6 g/dL at 22 weeks gestation, immediately initiate therapeutic oral iron at 60-120 mg elemental iron daily, investigate the underlying cause of severe anemia, and administer corticosteroids for fetal lung maturity given the viable gestational age and potential need for preterm delivery. 1

Immediate Post-Transfusion Actions

Verify Transfusion Response

• Recheck hemoglobin within 24-48 hours to confirm adequate response, expecting approximately 1.5 g/dL rise per unit transfused (total expected rise of 3 g/dL from baseline 6.6 to approximately 9.6 g/dL). 1, 2
• Do not obtain serum iron studies, ferritin, or transferrin saturation within 24 hours of transfusion, as packed red blood cell transfusion artificially elevates these values and will mask iron deficiency. 3

Initiate Iron Supplementation Immediately

• Start therapeutic oral iron at 60-120 mg elemental iron daily immediately after transfusion, without waiting for laboratory confirmation of iron deficiency. 1
• Iron deficiency accounts for 79-90% of severe anemia cases in pregnancy, making empiric treatment appropriate. 4
• Counsel on iron-rich foods and absorption enhancers (vitamin C) while avoiding absorption inhibitors (calcium, tea, coffee). 1

Diagnostic Workup (After 24 Hours)

Essential Laboratory Testing

• Obtain complete blood count with mean corpuscular volume (MCV) and red cell distribution width (RDW) after 24 hours post-transfusion. 1
• If patient is of African, Mediterranean, or Southeast Asian ancestry, obtain hemoglobin electrophoresis to rule out thalassemia or sickle cell trait. 1, 4
• Perform peripheral blood smear to evaluate red blood cell morphology and identify hemoglobinopathies. 1

Interpretation of Results

• If MCV is low (<80 fL) with elevated RDW: confirms iron deficiency anemia, continue therapeutic iron. 1
• If MCV is low with normal RDW in at-risk ethnic groups: suspect thalassemia trait, which will not respond to iron therapy. 4
• If anemia fails to respond after 4 weeks of iron therapy: perform serum ferritin at that time and consider alternative diagnoses including occult bleeding, malabsorption, or hemoglobinopathy. 1, 4

Obstetric Management Considerations

Fetal Lung Maturity

• Administer betamethasone 12 mg intramuscularly for two doses, 24 hours apart, for fetal lung maturity given the viable gestational age (22 weeks) and increased risk of preterm delivery with severe maternal anemia. 1
• This is critical because severe anemia increases the risk of hemodynamic compromise requiring emergency delivery. 1

Monitoring Requirements

• Continuous fetal heart rate monitoring should have been performed during transfusion given the viable gestational age. 1
• Schedule close follow-up with hemoglobin testing in 1-2 weeks to assess response to iron therapy, expecting at least 1 g/dL increase after 4 weeks of treatment. 1
• Plan for increased antenatal surveillance given the severity of anemia and potential for preterm delivery. 1

Delivery Planning

• Ensure delivery occurs at a facility with immediate operating room capabilities and blood bank access. 1
• Consider timing of delivery based on maternal response to treatment and fetal well-being, balancing prematurity risks against maternal anemia severity. 1

Follow-Up Iron Management

Expected Response Timeline

• Hemoglobin should increase by at least 1 g/dL after 4 weeks of therapeutic iron supplementation. 1
• Continue therapeutic dose (60-120 mg daily) throughout pregnancy until hemoglobin normalizes for gestational age. 1
• Once hemoglobin normalizes, decrease to maintenance dose of 30 mg elemental iron daily for remainder of pregnancy. 1

Management of Treatment Failure

• If hemoglobin does not increase by at least 1 g/dL after 4 weeks of oral iron, consider intravenous iron (ferric carboxymaltose 800-1500 mg) as first-choice alternative due to rapid effectiveness and better tolerability. 4
• Intravenous iron should be administered in settings with resuscitation facilities available due to rare but serious hypersensitivity reactions. 4

Critical Pitfalls to Avoid

Common Errors

• Do not perform extensive workup before initiating iron therapy in otherwise well pregnant women with severe anemia—begin treatment immediately. 1, 4
• Do not obtain iron studies within 24 hours of transfusion, as this will falsely elevate serum iron and transferrin saturation, potentially missing iron deficiency diagnosis. 3
• Do not overlook ethnic-specific hemoglobinopathies in women of African, Mediterranean, or Southeast Asian descent if anemia is unresponsive to iron after 4 weeks. 1, 4
• Do not delay corticosteroids for fetal lung maturity at this viable gestational age with severe maternal anemia. 1

Monitoring Considerations

• The elevated platelet count (526,000/mm³) is likely reactive thrombocytosis secondary to severe anemia and iron deficiency, and should normalize with treatment. 1
• Ensure patient has established care at a facility capable of managing high-risk pregnancy and potential preterm delivery. 1