Chlamydial serologic characteristics among intrauterine contraceptive device users: does copper inhibit chlamydial infection in the female genital tract?

OBJECTIVE

Our objective was to assess the association between copper intrauterine contraceptive device use and the level of antichlamydial antibodies.

STUDY DESIGN

Fifty-four women (29 with history of ectopic pregnancy, 2 with non-tubal factor infertility, 1 with tubal factor infertility, and 22 with intact intrauterine pregnancies) with current or prior intrauterine contraceptive device use were compared with 60 prenatal control subjects with respect to antichlamydial antibodies.

RESULTS

When the intrauterine contraceptive device user group was subdivided into copper users and Lippes Loop device users, a significantly lower geometric mean serum antibody titer among copper intrauterine contraceptive device users was detected. The odds ratio estimates for past chlamydial exposure (> or = 1:64 immunoglobulin G, > or = 1:128 immunoglobulin G) in users of noncopper versus copper intrauterine contraceptive devices were 9.1 (95% confidence interval 1.9 to 43.0) and 10.5 (95% confidence interval 1.5 to 71.8), respectively.

CONCLUSIONS

The lower geometric mean serum antibody titer of antichlamydial antibody among copper versus Lippes Loop device users and the large association measured between past chlamydial infection and noncopper intrauterine contraceptive device use suggest that copper may have a protective effect against Chlamydia trachomatis infection or a suppressive effect on development of antichlamydial antibodies.