Initial evaluation of DVT in pregnancy and postpartum: Alternative approach

DVT: deep vein thrombosis; CUS: compression ultrasound.

* In our practice, we typically determine the probability of DVT based on gestalt clinical suspicion since standard, objective pretest probability tools are of limited or no value during pregnancy and postpartum.

¶ We have a preference for whole-leg CUS (images both the proximal and calf veins) rather than proximal vein CUS (does not image the calf); however, choosing between them may beinstitution-dependent. Clinicians should be aware of which type of CUS is performed at the bedside. In advanced pregnancy, CUS should be performed with the patient in the left lateral decubitus position.

Δ Empiric anticoagulation should be initiated if a delay in obtaining CUS is anticipated; this is discussed in related UpToDate content.

◊ D-dimer level ≥500 ng/mL is not diagnostic of DVT and can be elevated in pregnancy and in many other conditions (eg, infection).

§ D-dimer level may also be obtained, if not already performed. In most patients, empiric anticoagulation is not needed while awaiting additional testing.

¥ Magnetic resonance venography is an alternative if Doppler is inconclusive. Empiric anticoagulation should be administered in this population while waiting for testing.

‡ This choice should be individualized. Alternative imaging modalities include magnetic resonance venography. Notably, the suspicion for calf vein DVT should be very low if whole-leg CUS was performed as the initial test.

† For patients with a low to moderate clinical suspicion for DVT in whom the D-dimer is <500 ng/mL, CUS is not typically needed. However, some experts have a low threshold to perform CU S.