Women with thrombophilia (all other thrombophilias, except homozygous factor V Leiden and mutation of prothrombin 20210), with no previous venous thromboembolism event, and with family history of thrombosis, should perform clinical surveillance during pregnancy, and antithrombotic prophylaxis in the puerperium: 94% agreement. The gene discussed is F2; the disease is thrombophilia.