Measurement of serum CA-125 concentrations does not improve the value of Chlamydia trachomatis antibody in predicting tubal pathology at laparoscopy.

Chlamydia antibody testing (CAT) has been used to predict tubal pathology associated with Chlamydia infection, the leading cause of pelvic inflammatory disease (PID). Tubal pathology not related to C. trachomatis is unlikely to be identified by CAT alone. A correlation between serum CA-125 concentrations and the severity of adnexal inflammation during acute PID was demonstrated. The objectives of this study were to determine the prevalence of C. trachomatis infection in an Asian infertile population and to assess the role of a combination of serum CA-125 and CAT in the prediction of tubal pathology as shown by laparoscopy. A total of 110 consecutive women attending an infertility clinic for work-up were recruited. Blood was taken for CAT and CA-125 on the day of hospital admission and an endocervical swab was taken for culture of C. trachomatis prior to laparoscopy. Two (1.8%) women had C. trachomatis found in the endocervix and 28 (25.5%) women had CAT of > or = 1:32. Serum CA-125 concentrations were > 35 IU/ml in 11 (10%) women. The discriminative capacity of CAT in the diagnosis of tubal pathology including both proximal and distal obstruction was not improved by measuring serum CA-125, regardless of the threshold values of serum CA-125 concentration.