Prediction of pelvic pathology in subfertile women with combined Chlamydia antibody and CA-125 tests

ObjectivesChlamydia antibody test (CAT) has been proposed to predict tubal disease. A correlation between CA-125 and the extent of endometriosis has been found by others. In this study we explored whether a combination of the two tests adds to the predictive value of the individual tests for predicting tubal disease or endometriosis. We also used the combination of tests as a new index test to screen for severe pelvic pathology.Study designThis retrospective study compares the findings of 240 laparoscopies with the serological test results. Findings were classified according to the existing ASRM scoring systems for adnexal adhesions, distal tubal occlusion and endometriosis. Severe pelvic pathology was defined as the presence of ASRM classes III and IV tubal disease or ASRM classes III and IV endometriosis. The predictive value was calculated for both tests separately and for the combined test. The combined test was positive if at least one test result was abnormal (CAT positive and/or CA-125 ≥35 IU/ml).Results67/240 women had tubal disease, 81/240 had some degree of endometriosis. The odds ratios (ORs) of the CAT and the combined test to diagnose severe tubal disease were 6.6 (2.6–17.0) and 7.3 (2.9–19.3), respectively. The ORs of the CA-125 and the combined test to diagnose severe endometriosis were 15.6 (6.2–40.2) and 3.0 (1.2–8.0), respectively. Severe pelvic pathology was present in 65/240 women (27%). The ORs for severe pelvic pathology of the CAT, CA-125 and the combined test were 2.5 (1.4–5.3), 4.9 (1.9–9.6) and 6.6 (3.3–13.4), respectively. If the combined test was normal 15 out 131 women (11%) were shown to have severe pelvic pathology.ConclusionsThe combined test adds hardly anything to the predictive value of CAT alone to diagnose severe tubal disease. The combined test is better than the CAT to predict severe pelvic pathology, but is not significantly better than the CA-125. If both the CAT and CA-125 are normal one could consider not performing a laparoscopy.