Using a clinical vignette of a healthy, non-smoking 35-year-old woman who wants information about oral contraceptive pills (OCPs), Petitti reviews the risks and benefits that figure into each decision about the use of these agents.

The noncontraceptive benefits reviewed by the author include decreasing the risk for ovarian cancer by one half. This reduction is apparent after five years of use and persists for 10 to 20 years after OCPs are discontinued. Risk of endometrial cancer also is reduced within five years of use, and the protection persists over the long term. The occurrence of acne is decreased by all combination OCPs, but only a few formulations have been allowed to make this specific claim. Menstrual blood flow is reduced, which is associated with lower rates of anemia and reduced severity of dysfunctional uterine bleeding.

Making a decision about using OCPs also requires consideration of the known risks (see accompanying table). Older contraceptives with higher estrogen doses were associated with increased risks of myocardial infarction and ischemic stroke. Interpretation of older studies was complicated by the higher prevalence of smoking and undiagnosed hypertension in women in that era. More recent studies of lower-estrogen OCPs have not shown consistent or statistically significant increases in ischemic events. The type of progestin used did not alter the risk of heart attack or stroke in patients using lower-estrogen pills.

The risk of venous thromboembolism is increased threefold to fourfold, and patients taking pills containing so-called third-generation progestins (desogestrel or gestodene) have an even higher risk of blood clot. The risk for clot formation is highest in the first year of pill use. The author notes that screening for thrombophilia (i.e., factor V Leiden, prothrombin gene mutations, and protein C or S deficiency) has been suggested, but it is not recommended routinely and has not been demonstrated to be cost-effective.

Uncontrolled hypertension, diabetes, and hyperlipidemia are associated with increased risk for ischemic events in patients using OCPs, but whether any elevated risk remains when these conditions are controlled is not clear. The degree of any association between OCPs and breast cancer also remains unclear, despite more than 60 epidemiologic studies. The most recent and largest studies have shown no increased risk or a slight increase in risk (relative risk of 1.24).

The author notes that several estrogen-progestin combinations are available, but no particular formulation has been shown to be superior in contraceptive effectiveness, cycle control, bleeding pattern, or prevalence of minor side effects, such as weight gain.