The Contribution of Bleeding Assessment Score and Pictorial Blood Loss Assessment Chart to the Diagnosis of Von Willebrand Disease in Adolescent Girls With Iron Deficiency Anemia

Background: Heavy menstrual bleeding (HMB) is common among adolescents and is an important driver of iron deficiency anemia. However, clinicians under-recognize inherited bleeding disorders. Iron deficiency transiently elevates von Willebrand factor (VWF) and factor VIII levels, both of which are acute-phase reactants, thereby masking quantitative VWF deficiency. Methods: This prospective cross-sectional study enrolled iron-deficient adolescent girls at a single center. We used a structured bleeding history (ISTH-BAT), menstrual blood loss quantification (PBAC), and coagulation testing after iron repletion to detect VWD-spectrum abnormalities. Results: A total of 235 girls aged 11 to 18 years with iron deficiency anemia completed the International Society on Thrombosis and Hemostasis Bleeding Assessment Tool and the Pictorial Blood Loss Assessment Chart and were stratified into 3 prespecified groups: high ISTH-BAT score with PBAC-defined HMB (n=23), low ISTH-BAT score with PBAC-defined HMB (n=131), and low ISTH-BAT score without PBAC-defined HMB (n=78). VWF: Ag, VWF: RCo, and FVIII:C levels were measured after iron repletion. Among 232 participants with complete data, VWD-screen positivity was defined as VWF: Ag and/or VWF: RCo <50 IU/dL. Overall, 40.9% (95/232) were VWD-screen-positive, with a significant group gradient (65.2%, 40.5%, 34.6%; P =0.033), preserved under stricter 2021-aligned thresholds (<30 IU/dL; 34.8%, 6.1%, 3.8%; P <0.001). Lower VWF:Ag and VWF:RCo levels drove these differences (both P <0.001), suggesting quantitative VWF abnormalities. FVIII:C levels were lower in patients who screened positive ( P =0.005). Routine coagulation tests and PFA-100 closure times did not differ between the groups. Conclusion: Combined ISTH-BAT and PBAC stratification enriches for postrepletion VWD-screen positivity; a 2-step triage strategy following iron repletion warrants prospective validation in this population.