Venous Thromboembolism in Young Female While on Oral Contraceptives: High Frequency of Inherited Thrombophilia and Analysis of Thrombotic Events in 400 Czech Women (Clinical and Applied Thrombosis/Hemostasis)

Oral contraceptive use is a common risk factor for venous thromboembolism in women of reproductive age. The presence of inherited thrombophilia further increases this risk. Methods: We analyzed a large group of 400 Czech women with venous thromboembolism in association with oral contraceptive with regard to duration of use at the time of manifestation of venous thromboembolism, the frequency of inherited and acquired thrombophilia, the frequency of eliciting risk factor for thrombosis including immobilization, surgery, administration of plaster cast, long travel, and so on, and the type of thrombosis. The mean age of the women was 26 years, and the average duration of use was 45 months at the onset of thrombosis. Results: Venous thrombosis solely due to the pill occurred in 57% of the women, and in the other 43%, an additional transient eliciting factor was recognized. Among the clinical manifestation, distal thrombosis prevailed (N = 231, 58%) followed by proximal deep vein thrombosis (N = 65, 16%), pulmonary embolism (N = 21, 5%), and thrombosis in unusual sites (N = 20, 5%). Inherited or acquired thrombophilia was diagnosed in 195 (49%) women: factor V Leiden mutation in 35%, congenital deficiency of antithrombin in 1.8%, protein C in 0.8%, protein S in 1%, F IIG20210A in 5%, and antiphospholipid syndrome (APS) in 5.3%. Among the most common risk factors were immobilization of lower limb, minor and major surgery, and trauma. Conclusion: The results confirm that venous thromboembolism is a multifactorial disease in which thrombophilia screening is needed in young symptomatic women on the pill with thrombosis. The results also emphasize the value of proper thromboprophylaxis in women while on oral contraceptive in situations of increased risk for venous thromboembolism.