EPIDEMIOLOGY OF ORAL-CONTRACEPTIVES AND CARDIOVASCULAR-DISEASE

Purpose: To review the association between combined oral contraceptive s and cardiovascular disease, with emphasis on oral contraceptives con taining low doses of estrogen (low-dose oral contraceptives). Data Sou rces: A systematic search of the MEDLINE database was done for all rel evant articles published between 1967 (when low-dose oral contraceptiv es were introduced in the United States) and June 1997. Textbooks, mee ting proceedings, and reference lists were also searched. Study Select ion: All English-language human epidemiology studies of oral contracep tives that used cardiovascular disease as an end point were reviewed. Animal and metabolic studies were reviewed only if they were especiall y relevant to the mechanism of action of oral contraceptives. Data Ext raction: Descriptive and analytic data from each study were collected. Data Synthesis: Data were organized by cardiovascular end point, study design, estrogen dose, and type of progestogen. Data on relative and absolute risk are presented to address current prescription guidelines . Conclusions: The risk for cardiovascular disease is lower with curre nt preparations of oral contraceptives, including those that contain t he new progestogens, than with older oral contraceptives containing hi gh doses of estrogen. Among users of low-dose oral contraceptives, car diovascular diseases occur mainly in smokers and women with predisposi ng factors. Every effort should be made to encourage smoking cessation among potential users of oral contraceptives.