Prevention of postpartum venous thrombosis with low doses of heparin.

Postpartum superficial and deep venous thrombosis were found in 22.3% and 5.3% of women with varicose veins who delivered vaginally, or by cesarean section. The preventive use of low doses of heparin (5,000 U every 12 h injected subcutaneously) in 116 parturients with varicose veins reduced significantly the incidence of postpartum venous thrombosis. None of the 26 women with previous thrombosis who received preventive treatment, developed such an event.