IUDs safe and effective at nine years of continuous use.
The WHO Special Programme of Research, Development and Research Training in Human Reproduction has conducted long term studies on 2 copper releasing IUDs (TCu220C and TCu380A) in almost 2800 women which show that they are effective for 9 years. The pregnancy rates for TCu220C at 7 and 9 years are 4.9 and 5.4/1000 woman years respectively. Thus the annual risk of pregnancy is about 1%. The pregnancy rates for TCu380A are even lower (1.7 and 2.1 respectively), an annual rate of less than 0.5%. As a result of these studies, the US Food and Drug Administration sanctioned TCu380A use for 8 years up from 6 years. More than 80 million women worldwide, especially in developing countries (e.g., about 74 million in China), use the IUD. Researchers have analyzed data on 22,908 insertions from 12 trials to see whether IUD use is related to pelvic inflammatory disease (PID) and whether long term use causes more severe PID. They learned that the overall PID rate is 1.6/1000 woman years. The first 20 days after insertion carry a 7 times higher risk of PID, but the risk falls considerably thereafter and stays low for at least 8 years. Further, duration of IUD use does not increase the severity of PID. WHO is supporting research at 28 centers which are evaluating a new IUD which has copper sleeves hanging from a nylon suture (frameless IUD). During insertion, the clinician embeds the suture superficially into the top of the uterus so the IUD and the copper sleeves are suspended. WHO is also supporting research at up to 6 centers on 2 modified frameless IUDs designed to be inserted after delivery. The research want to determine whether the high expulsion rate of IUDs inserted during the postpartum period can be reduced.