Pharmacogenetic aspects of the use of oral contraceptives and the risk of thrombosis

Abstract

Oral contraceptives are currently used by more than 100 million women in developed countries and are a highly efficacious method to prevent undesired pregnancies. However, oral contraceptives are associated with an increased risk of venous and arterial thrombosis, through changes in blood coagulation and fibrinolysis. In order to reduce such complications, the composition of oral contraceptives has changed over the past decades, both for the dose of oestrogen and the type of progestagen. However, the risk for venous thromboembolism remains, particularly for women who are carriers of inherited thrombophilia. In these women, prescription of oral contraceptives should be carried out on an individual basis. This review illustrates the risk of thrombosis, particularly venous thromboembolism, associated with the use of oral contraceptives, underlines the crucial role of the interaction of these drugs with other risk factors for the disease, and gives suggestions on the utility of thrombophilia screening before prescription.