Venous thrombosis during pregnancy.

Venous thrombosis during pregnancy can present a difficult diagnostic and therapeutic dilemma. To prevent pulmonary embolism, an early, accurate diagnosis of deep venous thrombosis must be made and appropriate heparin therapy must be instituted. Contrast and radionuclide venography are valuable diagnostic techniques. Prophylactic, subcutaneously administered heparin is useful in preventing deep venous thrombosis in the high-risk pregnant patient. Warfarin is not recommended because of its effect on the fetus.