Prescrire international
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Prescrire international · Jun 2009
Intrauterine devices: an effective alternative to oral hormonal contraception.
(1) Intrauterine devices (IUDs) are placed in the uterine cavity with the objective of providing long-term contraception, mainly by preventing fertilisation. The best-known IUDs contain copper, but there is also an IUD delivering levonorgestrel, a progestin; (2) How effective are these devices, and what are their adverse effects? To answer these questions, we analysed the literature using the standard Prescrire methodology; (3) T-shaped copper IUDs, with a copper surface area of 380 mm2 on 3 arms, and the levonorgestrel-releasing device, have similar contraceptive efficacy as combined oral contraceptives that are used correctly. In contrast, IUDs are more effective than oral contraception used incorrectly; (4) Among IUD users, there are on average about 6 pregnancies per 1000 woman-years. ⋯ Women must be warned that IUDs do not protect them from sexually transmitted diseases; (11) Menstrual bleeding is often heavier in women with cooper IUDs than in women who do not use IUDs, and may be associated with menstrual pain; (12) The levonorgestrel IUD is associated with a marked reduction in menstrual blood loss and irregular bleeding; amenorrhoea occurs in 35% of women after 2 years of use. The levonorgestrel IUD also has hormonal adverse effects such as headache, acne, breast tension and functional ovarian cysts; (13) IUDs can safely be used in breastfeeding women, immediately after a pregnancy, in cases of diabetes or HIV infection, during nonsteroidal antiinflammatory drug therapy, and after an ectopic pregnancy. The only problems occurring in women who have never had children are pain during insertion and more frequent expulsions; (14) A copper IUD is a first-line contraceptive method for women with a history of deep venous thrombosis, pulmonary embolism, or coronary events; (15) It is better to postpone IUD insertion when the woman has a genital tract infection or unexplained vaginal bleeding; (16) IUD insertion is an effective alternative to "morning-after" hormonal contraception.