INTRAUTERINE-DEVICES AND PELVIC INFLAMMATORY DISEASE - AN INTERNATIONAL PERSPECTIVE

The risk of pelvic inflammatory disease (PID) associated with use of a n intrauterine device (IUD) has been an important concern that has dom inated decisions on its use throughout the world, especially in the US A. Early research that suggested such an association led to both a dra matic decline in use of the method and its withdrawal from the US mark et by two manufacturers. However, factors other than use of an IUD are now thought to be major determinants of PID risk. To address these co ncerns, we have reviewed the World Health Organisation's IUD clinical trial data to explore the incidence and patterns of PID risk with use of an IUD. The overall rate of PID among 22 908 IUD insertions and dur ing 51 399 woman-years of follow-up was 1.6 cases per 1 000 woman-year s of use. After adjustment for confounding factors, PID risk was more than six times higher during the 20 days after insertion than during l ater times (unadjusted rates, 9.7 vs 1.4 per 1 000 woman-years, respec tively); the risk was low and constant for up to eight years of follow -up. Rates varied according to geographical area (highest in Africa an d lowest in China) and were inversely associated with age. PID rates w ere lower among women who had IUDs inserted more recently. Our finding s indicate that PID among IUD users is most strongly related to the in sertion process and to background risk of sexually transmissible disea se. PID is an infrequent event beyond the first 20 days after insertio n. Because of this increased risk with insertion, IUDs should be left in place up to their maximum lifespan and should not routinely be repl aced earlier, provided there are no contraindications to continued use and the woman wishes to continue with the device.