CD40LG and Venous thrombosis: This is also associated with obstetric complications, the diagnosis being based on the Sydney criteria: one clinical criteria (pregnancy morbidity or arterious or venous thrombosis) and one laboratory criteria (high value of lupus anticoagulant, of anticardiolipin antibodies IgM/IgG or of anti-beta 2 glicoprotein-I antibodies IgM/IgG) [40,49,54,55].