Venous thromboembolism (VTE) is a common disorder, and oral contraceptives (OC)  are   well-known   risk   factors   associated   with   venous thromboembolism(VTE)^(2,15,44,49).

The individual risk of VTE varies as a result of a complex interaction between congenital and transient or permanent acquired risk factors. 

Risk factors can be either intrinsic as age,  overweight,  previous VTE, thrombophilia or related to surgical procedures, and/ or to medical disorders such as neoplastic diseases ^(61,62).

Inherited thrombophilia is a very important risk factor of venous thromboembolism (VTE) however, there are only few studies on the   risk   of   VTE   in   women   with   inherited   thrombophilia   who   use   oral contraceptives ^(63,64).

Retrospective family cohort studies revealed the absolute risk of venous thromboembolism in women with single or multiple thrombophilic defects taking hormonal contraceptives ^(64,65,66).
Because of the high prevalence of the carriers of the G20E10A mutation of the prothrombin gene (PT20210A) (6.5%) and the carriers of the factor V Leiden mutation (FVL) (2%) (a hereditary disorder in which activated factor V is inactivated by activated protein C) in the Spanish population, a retrospective family cohort study of 325 women, belonging to 97 families with inherited thrombophilia, was performed to determine   the   risk   of   VTE   associated   with   hormonal   contraceptives (HCs) intake.

The results of this study showed for carriers of the PT20210A mutation, the risk of VTE in HC users was 3-fold higher than that in non-carriers.

Carriers of FVL (FactorV Leiden) mutation taking HCs showed an OR of 1.4, indicating a tendency to increase the risk of VTE ⁽⁶⁷⁾.

Genetic screening for these mutations should   be   considered   in   potential   OC   users   belonging   to   families   with thrombophilia ⁽⁶⁸⁾. Women with hereditary deficiencies of protein S, protein C or antithrombin are at high risk of VTE when taking hormonal contraceptives, particularly if other thrombophilic defects are present ^(69,70,71).

Generally, they have VTE at a younger age,  and sometimes this event may be dramatic but the overall risk is not increased by HCs ^{(72,73,74,75)}.

In addition,  rare cases of thromboembolism in young women caused from the increase of coagulation factor VIII were reported ^(76,77).