Vaginal pH versus cervical length in the mid-trimester as screening predictors of preterm labor in a low-risk population

Abstract Objective To assess the accuracy of a sign of bacterial vaginosis and a sign of cervical insufficiency in predicting preterm labor (PTL, occurring in the 37th week or earlier) and early PTL (occurring in the 34th week or earlier) in a low-risk cohort of 316 pregnant women. Method Vaginal pH was assessed using test gloves and cervical length (CL) was measured by transvaginal ultrasound. A pH value less than 5.0 (the 95th-percentile threshold) and a CL greater than 26 mm (the 5th-percentile threshold) were considered normal. Results There were 14 participants (4.4%) with an elevated vaginal pH and 15 (4.7%) with a shortened CL. The incidence of PTL ( Conclusion An elevated vaginal pH was a better predictor of early PTL than a shortened CL in this cohort of pregnant women at low risk.