Chlamydial Antibody Test in Screening of Tubal Infertility: Specificity and Sensitivity Analysis

Sexually transmitted infection is a frequent cause of tubal factor abnormality. Chlamydia trachomatis is a common causative organism for sexually transmitted infection. There are studies indicating association of chlamydial antibodies in serum with tubal abnormalities. In many centers chlamydial antibody test is done as part of routine work up for infertility. The objective of the study was to evaluate the sensitivity and specificity of chlamydial antibody test in screening infertile women for tubal factor infertility. This cross-sectional observational study was performed for one year from January 2019 to December 2019 in the Department of Reproductive Endocrinology and Infertility of Bangabandhu Sheikh Mujib Medical University (BSMMU), Bangladesh. The infertile women having laparoscopy as part of infertility work up were enrolled in the study. The women had their serum tested for chlamydial antibody IgG by enzyme linked immune-sorbent assay. The sero-positivity for chlamydial antibody was tested against the findings of laparoscopy and dye test as gold standard for diagnosing tubal factor infertility. Statistical analysis was done to find out the sensitivity and specificity of the chlamydial antibody test in screening infertile women for tubal factor infertility. The study population included 163 infertile women with mean age 29.8±5.8 years. The tubal factor infertility was present in 56.4% of the women. The sero-positivity of Chlamydia trachomatis IgG was 36.6%. Sensitivity and specificity of Chlamydial antibody test (IgG positive) in detecting tubal factor infertility is 47.8% and 70.4% respectively. Positive predictive value of chlamydial antibody test in detecting tubal factor infertility is 41.5% and negative predictive value is 72.4%. Positive likelihood ratio is 1.59. Negative likelihood ratio is 0.74. Accuracy is 57.67%. In conclusion, the chlamydial antibody test may not be an appropriate screening test for tubal factor infertility in women of Bangladesh because of low sensitivity and moderately high specificity.