Oral contraceptives are a reliable and convenient method of birth control. Nevertheless, physicians are reluctant to use them in women over 35 because of concerns about increased risks of cardiovascular disease, stroke and cancer despite evidence to the contrary. Well-designed studies have shown that the incidence of thromboembolic disease is related to the estrogen dose and that the risk of thromboembolism is highest in women who smoke. With current oral contraceptive formulations, there is no increased risk of cardiovascular disease or stroke in women without other risk factors. Oral contraceptives have been shown to protect against endometrial and ovarian cancer. The risk of breast cancer appears to be increased only minimally among current oral contraceptive users. Thus, oral contraceptives offer a safe and effective means of birth control in women over 35, especially in the absence of other risk factors.
PIP: No one has yet conducted a definitive, prospective, controlled study in 35-50 year old women that examines the relationship between oral contraceptive (OC) use and thromboembolism, myocardial infarction (MI), stroke, and cancers of the breast and genital organs. The available data derive from large studies on women in all age groups. These studies, mostly from the US and the UK, demonstrate that older women are somewhat more likely to be at risk of thromboembolism, MI, and stroke. Yet, the risk does not tend to be limited to OC users and is likely associated with other risk factors for cardiovascular disease. The risk of thromboembolism is greatest in smokers. It is also associated with the estrogen dose, which is lower today than it was in the past (= or 50 mcg vs. = or 100 mcg). The relationship between breast cancer and OC use is not clear, but the data suggest that the risk of breast cancer is elevated slightly among current OC users. The data confirm, however, that OCs protect against endometrial and ovarian cancer. Since many women older than 35 years old need safe, reversible contraception, the US Food and Drug Administration Advisory Committee concluded that healthy older women with no risk factors can safely use OCs. Women who should avoid OCs include those with a hormone-related history of thromboembolism, coronary artery disease, hypertension, diabetes, and other conditions that might cause adverse effects. Women with a clear family history of endometrial or ovarian cancer could likely benefit from OC use. Prospective studies of such women who do use OCs should be conducted to determine whether the protective effects of OCs can be extended. If the results are favorable, providers can emphasize OC benefits rather than risks. OCs are safe and effective for women over 35 who have no risk factors.