What is the management for a 30-year-old woman at 31 weeks gestation with severe anemia (hemoglobin of 4.2 mg/dl)?

Management of Severe Maternal Anemia at 31 Weeks Gestation

This patient requires immediate blood transfusion followed by investigation of the underlying cause and ongoing iron supplementation. A hemoglobin of 4.2 g/dL represents life-threatening severe anemia that poses immediate risk to both mother and fetus.

Immediate Management: Blood Transfusion

• Urgent packed red blood cell (PRBC) transfusion is mandatory for hemoglobin levels below 7.0 g/dL in pregnancy to prevent hemodynamic compromise and maternal mortality 1
• Transfuse 2-3 units of PRBCs initially, with each unit expected to raise hemoglobin by approximately 1.5 g/dL 1
• At Hb 4.2 g/dL, this patient will likely need 4-5 units to reach a safe hemoglobin level above 7.0 g/dL 1
• Establish IV access immediately and prepare for potential emergency delivery if fetal distress develops 2
• Perform transfusion in a location with immediate access to operating room capabilities given the viable gestational age 2

Critical Monitoring During Transfusion

• Continuous maternal vital signs and fetal heart rate monitoring throughout transfusion 2
• Monitor for signs of volume overload, particularly given the physiologic hypervolemia of pregnancy 3
• Severe anemia (Hb <7.0 g/dL) is associated with poor pregnancy outcomes including prematurity, spontaneous abortion, low birth weight, and fetal death 4

Post-Transfusion Evaluation

Investigate the underlying cause immediately through comprehensive laboratory testing 1, 3:

• Complete blood count with red cell indices (MCV, MCH, MCHC)
• Peripheral blood smear
• Serum ferritin (threshold <30 μg/L indicates iron deficiency) 5
• Red cell distribution width (RDW)
• Reticulocyte count
• Serum iron, total iron binding capacity, transferrin saturation
• Vitamin B12 and folate levels 6
• Hemoglobin electrophoresis if patient is of African, Mediterranean, or Southeast Asian ancestry to rule out thalassemia or hemoglobinopathy 2
• Direct antiglobulin test (Coombs) to evaluate for hemolysis 6
• Stool for occult blood if gastrointestinal bleeding suspected

Iron Supplementation

Initiate oral iron therapy at 60-120 mg elemental iron daily immediately after transfusion 2, 1:

• Continue this therapeutic dose throughout pregnancy 2
• Monitor hemoglobin response within 1-2 weeks; expect increase of at least 1 g/dL after 4 weeks of treatment 2, 1
• Once hemoglobin normalizes for gestational age (>10.5 g/dL in third trimester), decrease to maintenance dose of 30 mg/day 2, 1

If oral iron is not tolerated or ineffective after 4 weeks, switch to intravenous iron therapy 3, 5:

• Intravenous iron is preferred for patients who cannot tolerate, absorb, or do not respond to oral iron 3
• Ferric carboxymaltose is preferred in pregnancy due to well-controlled safety data 5
• IV iron is particularly indicated given advanced gestational age (31 weeks) requiring rapid correction 5

Obstetric Management Considerations

Administer corticosteroids for fetal lung maturity given the viable gestational age and potential need for preterm delivery 2:

• Betamethasone 12 mg IM x 2 doses 24 hours apart, or dexamethasone 6 mg IM every 12 hours x 4 doses
• This should be given regardless of transfusion status given the severity of maternal condition

Plan delivery timing 2:

• If maternal condition stabilizes and anemia corrects, plan delivery at 37-38 weeks per expert consensus 2
• Earlier delivery may be necessary if maternal condition deteriorates or fetal compromise develops
• Avoid prolonged pregnancy beyond 38 weeks given maternal anemia history

Nutritional counseling 2:

• Counsel on iron-rich foods (red meat, poultry, fish, legumes, fortified cereals)
• Advise on absorption enhancers (vitamin C-rich foods)
• Avoid tea and coffee with meals as they inhibit iron absorption

Common Pitfalls to Avoid

• Do not delay transfusion to pursue diagnostic workup; transfuse first, investigate simultaneously 1
• Do not assume iron deficiency without confirmation; at this severity, hemoglobinopathies, hemolysis, or bone marrow disorders must be excluded 2, 3
• Do not use only hemoglobin criteria for anemia diagnosis in pregnancy; physiologic hemodilution occurs normally, but Hb 4.2 g/dL is pathologic at any gestational age 6, 3
• Do not discharge without ensuring adequate response to treatment and close outpatient follow-up 1

Follow-Up Protocol

• Recheck hemoglobin 1-2 weeks post-transfusion 1
• If hemoglobin does not increase by at least 1 g/dL after 4 weeks of oral iron despite compliance, further evaluate with additional testing and consider IV iron 2, 1
• Weekly hemoglobin monitoring until stable in normal range for gestational age 2
• Increased antenatal surveillance with weekly non-stress tests given maternal condition 7
• Severe gestational anemia is associated with increased risk of severe acute maternal morbidity (adjusted OR 1.8) and postpartum hemorrhage (adjusted OR 1.7), requiring heightened vigilance 7