Abstract / Summary
Abnormal bleeding is experienced by many hemophilia carrier females. Since 2021, women and girls with residual factor 8 or 9 clotting activity levels <40 IU/dL are given a diagnosis of hemophilia similar to men and boys. Despite the increased recognition, barriers to diagnosis persist for women and girls with hemophilia. Among these are the limitations of two widely used assays for hemophilia diagnosis—the one stage clotting assay (OSA) and two-stage chromogenic substrate assay (CSA). Discrepant results between these assays may lead to missed diagnosis and incorrect severity classification which result in inadequate treatment and bleeding complications. International guidelines recommend that both assays be performed and repeated for confirmation in hemophilia diagnosis. However, the availability of both assays is not universal due to resource limitations. Methods for laboratory diagnosis of hemophilia, the limitations associated with laboratory diagnosis in women and girls, and potential solutions to these challenges are discussed.