Combined oral contraceptives increase risk of venous thrombosis according to oestrogen dose and type of progestogen

Commentary on: de Bastos M, Stegeman BH, Rosendaal F, et al. Combined oral contraceptives: venous thrombosis. Cochrane Database Syst Rev 2014;3:CD010813. There is compelling evidence that use of combined oral contraceptives (COCs) is associated with a two-to-fourfold increased risk of venous thrombosis (ie, either deep venous thrombosis or pulmonary embolism).1 Although the risks have been assessed for various combinations of oestrogen dose and type of progestogen in COCs, the findings of these assessments have been debated and a comprehensive comparison of the commonly used COCs has not …