"By the end of their reproductive years, more than 80% of US women will have used oral contraceptives (OCs), for an average of about 5 years. The pill has had a dramatic impact on social life in the US, affecting women's health, fertility trends, laws and policies, religion, interpersonal relations, family roles, women's careers, gender relations, and premarital sexual practices. The emergence of the women's rights movement of the 1960s and 1970s was significantly related to the availability of the pill and the control over fertility it enabled. This capability allowed women to make choices about other life arenas, especially work. Over the past 40 years, both the content and dose of the steroid components of OCs have changed significantly, with consequent reduced health effects. This improved safety profile has been further bolstered by the identification of women with risk factors such as smoking, high blood pressure, history of cardiovascular disease, and diabetes with vascular disease. In recent years, the emphasis has shifted from the health risks of OC use to the noncontraceptive health benefits."