Duplex ultrasonography is the preferred diagnostic test to confirm which postpartum complication?

• A. Duplex ultrasonography
• B. D-dimer
• C. Venography
• D. CT angiography

Answer: (A)

Duplex ultrasonography is the go-to test for confirming a lower-extremity deep vein thrombosis in the postpartum period. After childbirth, the body is in a hypercoagulable state, so a suspected DVT needs a test that can safely and directly show the presence of a clot and how the vein is functioning. Ultrasound with Doppler assesses vein compressibility and blood flow; a clot makes a vein noncompressible and Doppler may show absent or abnormal flow, giving a clear confirmation of DVT without exposing the patient to radiation or contrast.

D-dimer, while useful in other settings, isn’t reliable in the postpartum period because levels are often elevated anyway, which can lead to false positives. Venography is more invasive and carries risks, and CT angiography is used primarily to evaluate suspected pulmonary embolism rather than to confirm a leg DVT.