Intrauterine devices & infection: review of the literature.

The relationship between use of an intrauterine device (IUD) and pelvic inflammatory disease (PID) has been studied extensively over the past 50 years. Previous research has led to considerable controversy and debate. Numerous limitations in the studies make it difficult to draw any firm conclusions from the past research or to design new approaches to study the topic. The main research barriers include uncertainty of infection/diagnoses, and inappropriate comparison groups for IUD users. Natural history studies of the aetiology of disease and observational research among IUD users suggest that the risk of PID is very low. Research linking previous IUD use to the more distant endpoint of tubal infertility reveals that the risks may be even lower than the risks of PID.