Oral progestogen-only contraceptives and cardiovascular risk: results from the Transnational Study on Oral Contraceptives and the Health of Young Women.

BACKGROUND: The risk of cardiovascular disease associated with progestogen-only pills has rarely been studied so far. METHODS: In the Transnational case-control study we were looking for a potential cardiovascular disease risk with oral progestogen-only pills in women aged 16-44 years. A total of 1058 cases of myocardial infarction, thromboembolic cerebrovascular accident or venous thromboembolism, and 3808 controls unaffected by these diseases, were enrolled. The group of women who had either used oral progestogen-only pills or no oral contraceptives included 394 cardiovascular disease cases (123 cases of myocardial infarction, 90 cases of thromboembolic cerebrovascular accident and 181 cases of venous thromboembolism) and 2366 controls. RESULTS: The adjusted (matched) odds ratio (OR) for all cardiovascular diseases combined for women using progestogen-only pills compared with non-users of oral contraceptives was 0.84 (95% confidence interval (CI), 0.45-1.58). The adjusted ORs for myocardial infarction, thromboembolic cerebrovascular accidents and venous thromboembolism for users of progestogen-only pills were 0.94 (95% CI, 0.31-2.91), 1.60 (95% CI, 0.24-0.72) and 0.68 (95% CI, 0.28-1.66), respectively. Hence, there was no significant increase in cardiovascular disease risk associated with progestogen-only pill use. The association between cardiovascular disease and established risk factors (smoking and hypertension) was confirmed. CONCLUSION: Although limited by the small number of exposed cases, our data suggest that there is no convincing evidence for an increased risk of cardiovascular disease associated with progestogen-only pill use.