Sex, thrombosis and inherited thrombophilia.

The incidence of venous thromboembolism (VTE) is two-fold higher in women than in men during reproductive age, which is likely explained by the use of hormonal contraceptives and by pregnancy in this phase of life. After adjustment for these factors, men have a two-fold higher risk of developing a first VTE compared with women, which is in line with earlier observations that men have a two-fold higher risk of recurrent VTE. These findings indicate that the intrinsic risk of VTE is higher in men than in women. Hormonal contraceptives increase the risk of VTE and the risk varies per type, dose, and administration route. In women with a high baseline risk of VTE, avoidance of some hormonal contraceptives should be considered, as well as thrombosis prophylaxis during pregnancy. Presence of hereditary thrombophilia increases the risk of a first VTE episode. This review focuses on the differences in risk of VTE between men and women, hormonal risk factors for women, and how these interact with common types of hereditary thrombophilia.