Does midtrimester Nugent score or high vaginal pH predict gestational age at delivery in women at risk for recurrent preterm birth?

Abstract

Objective: To estimate whether bacterial vaginosis, as defined by either Nugent score or vaginal pH, predicts gestational age at delivery in women at risk for recurrent preterm birth.

Study design: Planned secondary analysis of a randomized cerclage trial in women with prior spontaneous preterm birth 17⁰(/)⁷-33⁶(/)⁷ weeks. Vaginal Gram stain and pH were collected at the initial study visit. Women not assigned to cerclage, either because they did not experience cervical shortening <25 mm or because they were randomly assigned to no cerclage, were studied.

Results: Seven hundred eighty-six women had complete delivery gestational age, Gram stain, and pH results. The diagnosis of bacterial vaginosis by either Nugent score ≥ 7 or by pH ≥ 5 was not associated with earlier birth.

Conclusion: The presence of bacterial vaginosis at 16-21⁶(/)⁷ weeks does not predict gestational age at birth in women at risk for recurrent preterm birth.