Background: To asses the role of a copper intrauterine device (IUD) per se in the development of pelvic inflammatory disease (PID) and complicated PID in women considered at low risk of PID.
Methods: Cases were 51 women admitted to hospital with a diagnosis of acute PID, and controls were 50 healthy women attending an outpatient clinic for routine gynecological check-up. The women were 25-45 years old. Data were analyzed and compared between groups using the statistical program package sas.
Results: IUD use was not associated with an increased risk of PID in general, but in women > or =35 years, IUD use was associated with a risk of PID [odds ratio (OR) = 4.2, confidence interval (CI) 1.1-16.3]. When adjusting for smoking, educational level, employment, and microbial findings in women with PID, IUD use was associated with complicated PID in women > or =35 years (OR = 33.9, CI 1.2-959.6), but not in younger women. When adjusting age and IUD use duration for each other in IUD users, age > or =35 years was a significant risk factor for PID (OR = 4.9, CI 1.3-19.2), but not long (> or =5 years) duration. In IUD users with PID, age > or =35 years was a risk factor for a PID to be complicated in both the unadjusted and adjusted analysis (OR = 12.7, CI 1.6-102.3; OR = 12.1, CI 1.4-104.7), whereas long duration of IUD use was not. When adjusting for significant endocervical microbial findings, long duration of IUD use and age, only age > or =35 years, remained significantly associated with both PID and complicated PID (OR = 5, CI 1.1-21.9; OR = 36, CI - 1.9-670).
Conclusions: IUD use was not associated with PID in low-risk younger women, but in women > or =35 years, IUD use was associated with an increased risk of PID. The study also demonstrates an association between IUD use and complicated PID in women > or =35 years.