The safety of intrauterine devices.

Mortality and morbidity associated with the IUD -- already relatively low -- can probably be reduced to a minimum with greater awareness of the risks of IUD use. This assessment focusses on 4 main areas of concern: 1) Consequences of contraceptive failure. A unique feature of intrauterine contraception is that the morbidity of pregnancies due to failure of the method is increased by the method itself. When pregnancy occurs with the IUD in place, incidence of extrauterine pregnancy, spontaneous abortion, bleeding, and prmature and still births are increased, with the miscarriage rate up to 50% (compared to 10 to 20% in the general population). This latter incidence is steeply reduced if the IUD can be removed. 2) Pelvic infection. Many studies have shown increased incidence among IUD users, the consistency of reports indicating a causal relationship, especially worrying in that the highest risk is among young nulliparas. A variety of causes has been suggested. While infection cannot be completely eliminated, strict attention to antisepsis at insertion, recognition of early warning signals, and avoidance of use by high risk groups, should minimize the dangers. 3) Problems associated with insertion. A major concern is avoidance of perforation. Special care is needed when inserting a device up to 8 weeks after pregnancy. A perforated IUD should be removed -- copper-bearing devices may be especially risky. Laparotomy or minilap may be preferable to laparoscopy for removal of bioactive devices. Risks at insertion should be considered when prescribing medicated devices which require more frequent replacement. 4) Anemia. All IUDs have some effect on bleeding, most causing increased bleeding during menstruation and some intermenstrual bleeding and spotting. This has primarily been seen as a cause for discontinuation, but may have medical consequences in developing countries where iron loss cannot be easily made up nutritionally. A small but real risk from therapeutic practices (use of drugs and antibiotics to reduce side effects, and surgical procedures for removal of perforated IUDs) is also noted.