Chlamydia trachomatis-induced cell-mediated and humoral immune response in women with unexplained infertility.

PROBLEM: What is the role of past Chlamydia trachomatis infection in unexplained infertility?

METHOD OF STUDY: This is a prospective study of the impact of past C. trachomatis infection on pregnancy rates in 96 women with unexplained infertility. Both humoral and cell-mediated immune responses (CMI) against C. trachomatis were studied. Serum C. trachomatis IgG antibodies were analyzed using major outer membrane protein (MOMP) peptide-based ELISA. CMI was studied by lymphocyte proliferation (LP) assay in vitro. Data on given fertility treatment, time to pregnancy, and pregnancy outcome were collected.

RESULTS: Altogether, 11.5% of the 96 women had C. trachomatis IgG antibodies. LP response to C. trachomatis was positive in 62.9% women. The overall pregnancy rate or live birth rate did not differ by the presence of antichlamydial antibodies or CMI against C. trachomatis. Time to spontaneous pregnancy was longer among C. trachomatis sero-positive women than among sero-negative women (2.9 years vs 2.0 years, P = .03).

CONCLUSION: Past chlamydial infection does not play a major role in unexplained infertility. Women with unexplained infertility and positive immune response to C. trachomatis do not have reduced pregnancy rates, but time to spontaneous pregnancy is longer among C. trachomatis IgG sero-positive women than among sero-negative women.