The use of OCs is associated with an increased risk of CVT,200 a risk that is increased significantly in women with an underlying hereditary prothrombotic fac- tor, such as factor V Leiden or prothrombin gene mutation.203 Pregnancy and OC use are considered transient risk factors and do not necessarily indicate a higher risk for recurrence. Most pregnancy-related CVT occurs in the third trimester or Treatment and Recurrence The standard therapy for acute CVT is anticoagulation with intravenous unfractionated heparin or subcutaneous low- molecular-weight heparin (LMWH) followed by oral antico- There are no large studies of the use of newer anticoagulants that are currently only approved for use in patients with nonvalvular AF or deep venous thrombosis205 ; therefore, warfarin is usually recommended. Management and imaging recommendations are provided in detail in prior and are summarized below. There are no second- ary prevention trials of duration of anticoagulation in adults with CVT; therefore, guidelines are based solely on observa- tional data. Recurrence rates range from 2% to 5% in most studies, although many of these studies did not provide long- term follow-up of patients, and the level of anticoagulation at the time of recurrence was often not reported. In the International Study on CerebralVein and Dural Sinus Thrombosis (ISCVT), recurrence of CVT was seen in 2.2% of patients, and other recurrent thrombotic events were seen in 4.3%, with a mean (Table 7). A recent large, ret- rospective, multinational study performed follow-up of 706 patients for a median of 40 months and tracked prespecified risk factors and conditions such as infections, trauma, OC use, pregnancy, puerperium, HT, recent neurosurgical proce- dures, and the presence of myeloproliferative neoplasms.199 Significantly more women than men had at least 1 risk factor Table 7. 