(704) Cerebral Venous Thrombosis and Pulmonary Embolism From Etonogestrel/Ethinyl Estradiol Vaginal Ring

Introduction: Contraceptive vaginal rings (CVRs) are a relatively new form of contraception which includes etonogestrel/ethinyl estradiol that delivers 120 µg of etonogestrel and 15 µg of ethinyl estradiol/24 hours.
Hormonal contraceptive pills increases risk of venous thromboembolism (VTE) including deep venous thrombosis (DVT) and pulmonary embolism (PE). Similar risk may be associated with CVRs.
Cerebral venous sinus thrombosis (CVST) due to contraception has been described but its occurrence with CVRs is very rare.
We describe a case of concomitant CVST and PE in a patient due to etonogestrel/ethinyl estradiol CVR.

Description: A 39 y-o female presented with headache and emesis. She had 3 days of headaches and neck pain. Her past medical history was unremarkable. Etonogestrel/ethinyl estradiol CVR was her only current medication. She had no personal or family history of thrombophilia.
CT head was concerning for venous sinus thrombosis, small area of intracerebral hemorrhage and empty delta sign. CT angiography and MR venogram confirmed extensive right transverse and sigmoid sinus thrombosis extending to the right internal jugular vein. She was started on heparin drip and CVR was removed.
Hypercoagulable workup including evaluation for anti-phospholipid syndrome (APAS), factor V leiden & prothrombin gene mutations, protein C, S & anti-thrombin III levels and connective tissue disease was negative. CT scans and Doppler ultrasound to rule out any additional venous thrombosis or malignancy revealed a right pulmonary embolus. No DVT or cancer was found. She recovered clinically and was transitioned from heparin to oral anticoagulation prior to discharge.

Discussion: CVST risk factors include inherited thrombophilia, APAS, pregnancy, malignancy, immobilization and hormonal contraceptive use. The risk may depend on the formulation of hormonal contraceptives and may be more pronounced with the use of third-generation formulations like CVRs. Etonogestrel alters the balance between anti and procoagulant factors. It causes resistance to protein C, decreases protein S levels, and increases prothrombin and factor VII.
Our case illustrates that CVRs have prothrombotic potential. Extensive CVST and de novo PE in our patient are a very rare manifestation of hormonal contraceptive vaginal ring associated VTE.