Bleeding Disorder Workup for Heavy Menstrual Bleeding in Young Women
Order a complete blood count (CBC), prothrombin time (PT), activated partial thromboplastin time (PTT), and the three von Willebrand disease tests (VWF antigen, VWF ristocetin cofactor activity, and Factor VIII activity) as your initial laboratory evaluation. 1
Initial Hemostasis Tests
Start with these basic coagulation studies to screen for common bleeding disorders:
- CBC - Identifies anemia from blood loss and evaluates platelet count (thrombocytopenia or thrombocytosis as potential bleeding causes) 1
- PT (Prothrombin Time) - Screens for coagulation factor deficiencies 1
- PTT (Activated Partial Thromboplastin Time) - Detects intrinsic pathway abnormalities 1
- Serum ferritin - Assesses iron stores, as low ferritin (<15 μg/L) occurs in 42.8% of women with heavy menstrual bleeding 2, 3
These tests do not diagnose von Willebrand disease but identify other coagulation abnormalities or thrombocytopenia that could explain bleeding 1.
Von Willebrand Disease Testing
If the bleeding history is strong (flooding, clots ≥1 inch, need to change pad/tampon hourly), order VWD assays with the initial visit rather than waiting for basic coagulation results. 1, 4
The three essential VWD tests are:
- VWF antigen (VWF:Ag) - Measures quantity of von Willebrand factor 1
- VWF ristocetin cofactor activity (VWF:RCo) - Assesses functional activity 1
- Factor VIII coagulant activity (FVIII) - Evaluates Factor VIII levels, which may be decreased in VWD 1
Von Willebrand disease is the most common inherited bleeding disorder, affecting up to 1% of the population and presenting with heavy menstrual bleeding in approximately 90% of affected women 1, 4. Recent data shows that 9.2% of women with heavy menstrual bleeding have VWF deficiency (VWF:GPAbR ≤50 IU/dL) 2.
When to Order Specialized Testing
Order VWF multimer analysis only if initial VWD tests show abnormal results - specifically if VWF:RCo is low or the ratio of VWF:RCo to VWF:Ag is below 0.5-0.7 1. Multimer analysis is technically complex, requires specialized interpretation, and helps determine VWD subtype but is not appropriate for initial screening 1.
Additional Considerations
Thyroid and Endocrine Evaluation
Screen for thyroid dysfunction and hyperprolactinemia, as these endocrine disorders commonly cause anovulatory bleeding patterns that present as heavy menstrual bleeding 3, 5.
Clinical History Red Flags
The NHLBI guidelines emphasize that bleeding disorders are more likely when patients report: 1
- Heavy menstrual bleeding since menarche
- Family history of bleeding disorders
- Bleeding with dental extractions or surgery
- Postpartum hemorrhage
- Easy bruising (>5 cm without trauma)
Common Pitfall
Do not rely on bleeding time or PFA-100 testing for screening - conflicting data exists regarding their sensitivity and specificity for von Willebrand disease, and current evidence does not support their routine use 1. The PT and PTT have universal support, but only 55% of providers consistently screen for associated conditions like hypermobility disorders 6.
Physical Examination Priorities
Look specifically for: 1
- Ecchymoses, hematomas, or petechiae suggesting active bleeding disorder
- Joint hypermobility (Ehlers-Danlos syndrome association)
- Telangiectasias (hereditary hemorrhagic telangiectasia)
- Signs of liver disease (jaundice, splenomegaly)
- Evidence of anemia (pallor)
Prevalence Context
Among women with heavy menstrual bleeding, 34.7% have overt anemia (hemoglobin ≤120 g/L), and 72.5% have ferritin <30 μg/L, indicating the high burden of iron deficiency in this population 2. The incidence of von Willebrand disease in adolescents with heavy menstrual bleeding is particularly high 7.