Menorrhagia Laboratory Panel
The initial laboratory work-up for menorrhagia should include: complete blood count (CBC), ferritin, PT/aPTT, von Willebrand factor antigen (VWF:Ag), von Willebrand factor ristocetin cofactor (VWF:RCo), factor VIII level, and fibrinogen 1, 2, 3.
Core Laboratory Tests
Hematologic Assessment
- CBC with peripheral smear - to assess for anemia from blood loss and evaluate platelet count/morphology
- Serum ferritin - iron deficiency is common and ferritin is the most sensitive marker 4
- Blood type - baseline documentation 1
Coagulation Screening
The following tests are essential because 11-16% of women with menorrhagia and normal gynecological evaluation will have von Willebrand disease 5:
- PT (prothrombin time) and aPTT - basic coagulation screening
- VWF:Ag (von Willebrand factor antigen)
- VWF:RCo (ristocetin cofactor activity)
- Factor VIII level
- Fibrinogen level
Additional Endocrine Tests
- TSH (thyroid-stimulating hormone) - thyroid dysfunction can cause menorrhagia 2, 3
- Serum creatinine - renal dysfunction assessment 2, 3
Extended Testing When Initial Work-up is Normal
If the above tests are normal but bleeding persists, consider:
- Platelet function testing (lumiaggregometer/platelet aggregation studies) - particularly if there is history of nose or gum bleeding, as an additional 20-30% may have platelet aggregation defects 1, 5, 2
- Factor XI level - can contribute to bleeding 2, 3
- Euglobulin clot lysis time - to assess for fibrinolysis disorders 2, 3
Important Clinical Caveats
PFA-100 testing has limited utility: While it has 80% sensitivity for von Willebrand disease, it only has 23% sensitivity for platelet aggregation defects and should not replace comprehensive testing 6. Similarly, bleeding time is not effective for screening 6.
In adolescents with no other bleeding history: Nearly 50% have dysfunctional and transient menorrhagia 1. Detailed coagulation assays can be postponed if there is no history of bleeding other than menorrhagia, no family history of bleeding, and no parental consanguinity 1. However, basic screening (CBC, ferritin, PT/aPTT) should still be performed 4.
Hemodynamic assessment is critical: In acute heavy menstrual bleeding, check orthostatic blood pressure and pulse measurements to assess stability 4.