ABSTRACT
Introduction 413 What is the risk for venous thromboembolism with
different types of contraceptive? 414 What is the effect of the duration of oral contraceptive
use on the risk for venous thromboembolism? 415 What is the mechanism for the association between oral
contraceptive use and venous thromboembolism? 415
What is the effect of prothrombotic blood abnormalities on the risk for venous thromboembolism in women using oral contraceptives? 416
Clinical management scenarios 416 Conclusions and priorities for future research 418 References 418
The oral contraceptive (OC) is one of the most widely used drugs worldwide. It is estimated that 100 million women use a typical OC consisting of an estrogen and a progestin component, which is available in an oral and, more recently, transdermal preparations.1 Approximately 13 million women use a progestin-only contraceptive, which has comparable contraceptive efficacy as the combined estrogenprogestin formulations, and is available in an oral, intramuscular, intrauterine, and subdermal formulations.2
