Prospective validation of a perinatal bacterial vaginosis screening risk score

Objective: Prospectively validate an antenatal bacterial vaginosis (BV) risk score at two public health department obstetrics clinics. Study Design: Women (n = 409) entering prenatal care received a BV risk score (range 0 to 16) at their first visit and at 24 to 28 weeks' gestation. BV was measured with Gram-stained vaginal smears. Normal discharge was used as a surrogate for being asymptomatic. Results: Approximately half of the women scored ≥3 at each assessment. In total 29% had true BV at the first assessment (13% at the second assessment). The BV risk score, (≥3) had 9% sensitivity and 63% specificity, and the BV risk score (≥5) had 88% sensitivity and 76% specificity. Among true cases, 42% were asymptomatic, of which 77% had risk scores ≥3. All symptomatic BV cases had risk scores ≥3. Conclusion: In practice, the risk score identified both asymptomatic and symptomatic cases. Asymptomatic women are of particular interest because they are not screened for BV under current practice guidelines.