Significance of positive Chlamydia serology in women with normal-looking Fallopian tubes

Chlamydia trachomatis poses a potential threat to the fertility of women by causing tubal damage. Many women with serological evidence of past Chlamydia infection have normal tubal appearances on laparoscopic assessment. The aim of this study was to assess if serological evidence of past chlamydial infection affects the likelihood of conception in women with normal tubes. Infertile couples in which the female partner was under the age of 40 years, with normal ovulatory function and a male partner with normal sperm function were studied. All women had normal tubes as assessed by laparoscopy. Serum Chlamydia antibody titres were assayed using the immunofluorescence test. Pregnancy rates were related to grouped Chlamydia antibody titres (<64, 64-256 and ⩾512). A total of 174 women were studied. The cumulative pregnancy rates (SE) according to these titres were 45.1% (6.2), 42.6% (9.3), 59.1% (11.8) and the risk ratios (95% confidence interval) were 1, 1.59 (0.82-3.07) and 1.04 (0.52-2.08) respectively. The differences were not statistically significant. Therefore, in women with normal-looking tubes, serological evidence of past chlamydial infection does not appear to have an adverse effect on pregnancy rates. These findings suggest that laparoscopic findings and not Chlamydia serological titres are the key to prognosis.