Intrauterine devices: an update.

Three intrauterine devices (IUDs) are available in the United States: the copper T 380A and two levonorgestrel-releasing IUDs, one that releases 20 mcg of levonorgestrel per 24 hours, and one that releases 14 mcg per 24 hours. All are safe and effective methods of contraception that work predominantly by prefertilization mechanisms. The copper T 380A IUD may be placed in nonpregnant women at any time in the menstrual cycle. The prescribing information for the 20- and 14-mcg levonorgestrel-releasing IUDs advises that insertion occur during the first seven days of menses. Insertion immediately after vaginal or cesarean delivery may be considered with the copper T 380A and the 20-mcg levonorgestrel-releasing IUDs; however, expulsion rates are higher than with delayed postpartum insertion. The prescribing information for both levonorgestrel-releasing IUDs advises a waiting period of six weeks postpartum or following second-trimester pregnancy loss. Current guidelines indicate that IUDs are acceptable for use in nulliparous women, in adolescents, and in women who are breastfeeding. They may also be used in women who have a history of sexually transmitted infection, although screening is recommended. IUDs should not be inserted for at least three months after resolution of a sexually transmitted infection. Neither antibiotic prophylaxis nor misoprostol use before IUD insertion is beneficial. If pregnancy occurs, the IUD should be removed if feasible. Possible side effects of levonorgestrel-releasing IUDs include headaches, nausea, hair loss, breast tenderness, depression, decreased libido, ovarian cysts, oligomenorrhea, and amenorrhea. The main side effect of the copper T 380A IUD is increased menstrual bleeding, which may continue even with long-term use.