Case Presentation: A 20-year-old female, nonsmoker, G1P0 at 25 weeks, presented to the ED with left leg swelling. Ultrasound confirmed a left femoral DVT. CBC and CMP were unremarkable. She started enoxaparin 80mg twice daily and followed with OB/GYN. Her hypercoagulable workup showed a prolonged aPTT and DRVVT, which corrected with mixing, indicating absence of [...]