Screening for Chlamydia trachomatis in Low-Risk Obstetric Patients

OBJECTIVE The purpose of this study was to evaluate the prevalence of Chlamydia trachomatis in our rural obstetric population and assess the appropriateness of selective vs. universal prenatal screening. METHODS Between April 1, 1991 and May 1, 1993, 1,587 patients were screened at their first prenatal visit using a C. trachomatis antigen test. Patients who were unmarried, younger than 20 years of age, or had a history of a previous sexually transmitted disease (STD) were classified as being at high risk for C. trachomatis. All others were considered low risk for C. trachomatis. RESULTS The overall prevalence of C. trachomatis was 2.0%. There was a significant difference (P < 0.001) in the 1,128 patients considered low risk [0.5%, 95% confidence interval (CI) 0.2-1.2] compared to the 459 patients with one or more identifiable risk factors (5.7%, 95% CI 3.7-8.2). CONCLUSIONS Routine prenatal screening for C. trachomatis in our population is not appropriate for low-risk patients.