Pregnant women with venous thromboembolism are traditionally managed with anticoagulation, but inferior vena cava filters are an alternative. We balanced risks and benefits of an inferior vena cava filter in a decision analysis.

We constructed a decision model to compare in pregnant women with VTE the outcome of (1) inferior vena cava filter and anticoagulant treatment versus (2) anticoagulant treatment only.

Assuming a 63% risk reduction from an inferior vena cava filter (baseline mortality rate of venous thromboembolism of 0.5%), 318 women would need to be treated with inferior vena cava to prevent one venous thromboembolism related maternal death. Sensitivity analyses indicated that at a mortality rate of 0.5% the risk reduction from inferior vena cava needed to be 80%, while at a mortality rate of 2% a risk reduction of 20% would justify inferior vena cava.

In view of their potential morbidity, inferior vena cava filters should be restricted to pregnant woman at strongly increased risk of recurrent venous thromboembolism.