The value of serial cervical length measurements for the prediction of threatened preterm labour

ObjectivesTo assess the predictive performance of cervical length measurement at presentation and 24 h later in women with symptoms of preterm labour.Study designCervical length was measured transvaginally at presentation and 24 hours later in 122 women presenting with threatened preterm labour between 23 and 33 + 6 gestational weeks.ResultsSix women delivered within 1 week of presentation. The sensitivity and specificity of a cervical length <15 mm at admission for delivery within one week was 83.3 and 95.8%, respectively. A reduction of >20% in cervical length 24 h after admission predicted 50% of preterm deliveries within 1 week, with a specificity of 92.7%; in combination with cervical length at presentation it did not improve the prediction. The same was observed for birth before 32 weeks (N = 9) and birth before 35 weeks (N = 15).ConclusionsWomen with threatened preterm labour and a cervical length of <15 mm at presentation are at high risk of delivering preterm. Cervical change in the following 24 hours does not seem to improve the prediction.