Prevalence of cervicovaginal infections during gestation and accuracy of clinical diagnosis.

OBJECTIVES: The aim of this study was to establish the prevalence of cervicovaginal infections in normal third-trimester pregnant women and evaluate the accuracy of clinical diagnosis. METHOD: A total of 328 pregnant women were followed at the Prenatal Outpatient Clinic of the Department of Obstetrics and Gynecology at the School of Medical Sciences, Universidade Estadual de Campinas (UNICAMP), Brazil, from October 1991 to February 1993. The clinical diagnosis was based on the characteristics of the vaginal discharge, and the etiological diagnosis was based on bacterioscopy of the vaginal secretion and direct immunofluorescence for Chlamydia trachomatis. The data were analyzed statistically, determining the sensitivity, specificity, and positive and negative predictive value of the clinical diagnosis related to the laboratory diagnosis of the different infections. RESULTS: The prevalence of infection was 39.6% (Candida albicans, 19.2%; bacterial vaginosis, 9.5%; intermediate vaginal flora, 6.7%; Chlamydia trachomatis, 2.1%; and vaginal trichomoniasis, 2.1%). The accuracy of clinical diagnosis was low, with sensitivity between 50% and 65% and specificity around 60%, with the exception of trichomoniasis, which showed a sensitivity of 100% and chlamydia, with a sensitivity of 0% and a specificity of 100%. CONCLUSION: The accuracy of the clinical diagnosis of infections was low, specifically with respect to the positive predictive value. The results demonstrate the need for specific testing of cervicovaginal infections at prenatal visits. Reliance on simple vaginal examination results in a low yield for detection of vaginal infections.