Hormonal contraception

When used correctly, hormonal contraception--oral contraceptives (OCs), injectable progestins, and subdermal implants, in particular--can offer the most effective reversible method of pregnancy prevention available. The availability of OCs with lower hormonal dosages and more careful screening of OC acceptors have apparently eliminated the increased risk of vascular disease documented among OC users in the 1970s. Lower-dose OCs also have a lesser adverse effect on lipids and glucose metabolism. In fact, use of low-dose OCs may have a beneficial impact from the standpoint of lipid changes. The association between OC use and breast cancer remains unresolved, although recent studies suggest that the apparently increased risk among women 20-44 years of age is followed by a decreased risk among nulliparous women 45-54 years old. The reduced androgenic potency of 3 new progestins--gestodene, desogestrel, and norgestimate--is expected to increase further the safety of OC use and reduce side effects such as withdrawal bleeding. The most important recent development in the field of hormonal contraception has been the use of antiprogesterones such as RU-486. These agents not only have numerous therapeutic uses (e.g., as abortifacients or inhibitors of ovulation), but also offer insight into the mechanisms of steroid hormone action. Less productive has been research into steroidal contraception for men, although early trials of weekly injections with long-acting androgens have produced promising results.