Update on oral contraception

Abstract

Oral contraceptives (OCs) were first introduced more than 30 years ago. OC manufacturers have reduced the dosage of synthetic estrogens (e.g., ethinyl estradiol, 100-150 mcg to 20-35 mcg) and progestins to limit their metabolic effects on lipoproteins, carbohydrates, and hemostasis. In addition to protection from pregnancy, OC benefits include lower incidence of painful periods, excessive bleeding, and iron deficiency anemia; reduction of ovarian cysts, benign breast tumors, and pelvic inflammatory disease; and protection against endometrial and ovarian cancers. The risk of a cardiovascular event (myocardial infarction, cerebrovascular events, venous thromboembolism, and deep vein thrombophlebitis) in OC users is 1-2/100,000 women years. Cardiovascular risk factors include smoking, hypertension, lipid disorders, severe obesity, diabetes mellitus, and cardiovascular events in first degree relatives before age 40. Thus, women with any of these risk factors should not use OCs. OCs do not increase the risk of breast cancer in women less than 59 years old. They may increase this risk if used over a long duration before the first fullterm pregnancy. OCs may cause a modest increase in cervical neoplasia. Low-dose OCs have a small effect on lipid metabolism. OCs increase serum triglycerides 30-50%. OCs increase insulin secretion and hyperinsulinemia increases the cardiovascular risk. Practitioners should evaluate clients before prescribing OCs. They should not prescribe OCs to women with hypertension, diabetes mellitus, lipid disorders, gynecological cancers, and previous cardiovascular disorders. Practitioners should tell clients that smoking is a leading risk factor and about OC's side effects (e.g., menstrual disturbances). The physical exam should include a cervical PAP smear, gynecological exam of the uterus and the ovaries, and a breast exam. Practitioners should test cholesterol and triglycerides before and during OC use. Premenopausal healthy women with no risk factors can use low-dose OCs.