Residues of pelvic inflammatory disease in intrauterine device users: a result of the intrauterine device or Chlamydia trachomatis infection?

It is currently believed that intrauterine devices cause pelvic inflammatory disease and tubal infertility. To investigate this concept further, we evaluated 245 infertile patients for inflammatory residues by laparoscopy or laparotomy; 176 patients had not used an intrauterine device and 69 had used one. Chlamydial antibody titers were performed on all patients. Although users had a higher overall prevalence of inflammatory residues than nonusers, there was no difference in residue prevalence for either group at the same titer level. No specific type of device appeared to be associated with either an increased or decreased residue frequency. "Silent" chlamydial infections occurred with equal frequency in both users and nonusers. We conclude that inflammatory residues and tubal infertility in intrauterine device users are not caused by the intrauterine device but by both overt and silent chlamydial infections.