Intrauterine devices: medicated and nonmedicated.

The main benefits of intrauterine devices (IUDs) are a lack of adverse systemic effects, excellent effectiveness, high continuation rates and the single act of motivation required for use. First year failure rates range from 2% to 3%, but decline steadily thereafter to a cumulative annual failure rate of less than 1% after six years. The risks of IUDs include increased blood loss, uterine perforation, pelvic infection and pregnancy-related complications. The incidence of perforation of the uterine fundus ranges from 1:1000 to 1:2500 insertions, while that of cervical perforation with the copper devices ranges from 1:600 to 1:1000. IUD use is associated with about a three-fold increased incidence of developing acute salpingitis in comparison with use of oral contraceptives and diaphragms. If pregnancy occurs with an IUD in place, there is a three-fold increased risk of spontaneous abortion, a ten-fold increased risk of ectopic pregnancy (5% of all IUD pregnancies) and a possible increased incidence of sepsis during the pregnancy.