Oral Contraceptives and the Occurrence of Disease

Abstract

Use of oral contraceptives (OCs) increases women's risk of acquiring a cardiovascular disease, especially stroke, venous thromboembolism (VTE), and myocardial infarction. For example, in 1 study, the incidence rate for a VTE in a site other than a superficial leg vein in women who had never has a VTE before and were current OC users stood at 11/10,000 while it was 3 in nonusers (attributable risk=8/10,000). Both progestogen and estrogen content contribute to this risk. Even though the risk is strongest in current users, it continues somewhat in women who used OCs for a long time in the past. The risk is especially high in older women and cigarette smokers. The estrogens in OCs decrease AT III activity and the progestogens in some OCs decrease the high density lipoprotein-cholesterol concentrations more than the estrogens can increase them. Even though women who have used OCs for a long time have an increased risk of hepatocellular adenoma, the attributable risk is insignificant. These women also are increased risk of acquiring cervical cancer, cervical dysplasia, and malignant melanoma. On the other hand, research indicate that OCs are not associated with pituitary adenoma and breast cancer. Combined OCs prevent 5 hospitalizations for endometrial cancer/100,000 ever users and 4 hospitalizations for ovarian cancer/100,000 ever users. Further, OCs decrease the risks of acquiring benign breast disease, pelvic inflammatory disease, functional ovarian cysts, iron deficiency anemia, and ectopic pregnancy. They may also play a role in preventing rheumatoid arthritis. Overall, their beneficial effects reduce 500-600 hospitalizations/100,000 current and past users/year.