Do you test both Von Willebrand factor (VWF) antigen and factor VIII levels in a pregnant patient with known Von Willebrand disease (VWD)?

Testing in Pregnant Women with Known Von Willebrand Disease

Yes, both Von Willebrand factor (VWF) antigen and factor VIII levels should be tested in pregnant patients with known Von Willebrand disease (VWD) to guide management during pregnancy and delivery. 1

Rationale for Testing Both Parameters

• Pregnancy naturally increases VWF and FVIII levels, but this increase varies significantly between patients and VWD subtypes 2
• Women with baseline VWF and FVIII levels >30 U/dL typically achieve normal levels by delivery, while those with baseline levels <20 U/dL often show insufficient increases 3, 2
• The VWF:RCo/VWF:Ag ratio (which requires testing both parameters) remains abnormal throughout pregnancy in type 2 VWD patients, indicating persistent qualitative defects despite quantitative increases 2

Timing of Testing

• Initial testing should be performed early in pregnancy to establish baseline levels 4
• Follow-up testing should be conducted in the third trimester (32-34 weeks) to guide delivery planning 3
• Additional testing may be needed before invasive procedures (amniocentesis) or if bleeding complications occur 3

Clinical Decision-Making Based on Test Results

• If both VWF and FVIII levels are >50 IU/dL near term, specific hemostatic prophylaxis is rarely required 2
• If either VWF:RCo or FVIII remains <50 IU/dL, prophylactic treatment before delivery is indicated 5
• Type 2 VWD patients typically maintain an abnormal VWF:RCo/VWF:Ag ratio throughout pregnancy and require replacement therapy regardless of absolute levels 2

Special Considerations

• Sample handling is critical for accurate results - blood should be transported at room temperature and processed promptly 1
• Frozen samples should be stored at or below -40°C and carefully thawed at 37°C before testing 1
• Stress, exercise, and inflammatory conditions can falsely elevate VWF and FVIII levels 1

Post-Delivery Monitoring

• Delayed postpartum hemorrhage is a significant risk as VWF and FVIII levels return to baseline 6
• Continued monitoring of both parameters is recommended for at least 2 weeks after delivery 5
• Prophylactic treatment may need to be extended into the postpartum period based on test results 3

Treatment Options Based on Test Results

• For type 1 VWD with adequate response, desmopressin may be used 7, 4
• For type 2B, type 3, and non-responders to desmopressin, plasma-derived FVIII/VWF concentrates are indicated 4
• Tranexamic acid may be useful at discharge to prevent excessive bleeding during lochia 3, 2