Emerging evidence on oral contraceptives and arterial disease.

A number of case-control studies published in recent years have shown an apparent increase in the risk of venous thromboembolism (VTE) associated with the use of third-generation oral contraceptives (OCs) compared with second-generation OCs. However, it is thought that these studies were subject to a number of biases that would have increased the risk estimates for third-generation OCs while lowering those for second-generation preparations. Data on the risk of ischemic stroke and myocardial infarction (MI) show no such difference between generations of OCs, with a statistically significant reduction in the risk of acute MI from first- to third-generation in one major study. Available results indicate that there is no significant increase in the risk of ischemic stroke or acute MI associated with the use of low-dose estrogen OCs in young women who are properly screened before use, and who have no pre-existing cardiovascular risk factors, such as smoking and hypertension, for these conditions. These findings should be taken into account when interpreting the results of studies on the risk of VTE in women taking combined OCs.