A Rare Case of Postpartum-acquired Hemophilia A Presenting with Deep Vein Thrombosis.

Acquired hemophilia A (AHA) is a rare autoimmune disorder (1.5 per million) caused by autoantibodies against factor VIII, leading to coagulopathy. Postpartum AHA is uncommon, accounting for only 1-5% of cases, and typically presents with mucocutaneous or vaginal bleeding, while deep vein thrombosis (DVT) is an extremely rare manifestation. We report a case of a 33-year-old postpartum female presenting with left lower limb DVT and spontaneous bleeding. Initial management with heparin and direct oral anticoagulants (DOACs) exacerbated bleeding, prompting treatment revision. Persistently elevated activated partial thromboplastin time (aPTT) with normal platelet count and prothrombin time (PT) raised suspicion of AHA. A Bethesda assay confirmed high-titer factor VIII inhibitor (35.2 BU/mL). Immunosuppressive therapy with rituximab, corticosteroids, and cyclophosphamide successfully led to remission. This case highlights an unusual presentation of AHA with DVT in a postpartum patient. The combination of thrombosis and bleeding necessitates careful diagnosis and individualized management. Prompt recognition of prolonged aPTT, uncorrected mixing study, and confirmatory Bethesda assay are crucial for early intervention. Postpartum AHA, though rare, should be considered in postpartum females presenting with coagulopathy or thrombosis. Early diagnosis and tailored treatment improve outcomes and reduce mortality.