Related Experiment Video
Updated: Jul 13, 2026
External Cephalic Version: Is it an Effective and Safe Procedure?
Published on: June 6, 2020
Progressive cervical length changes versus single cervical length measurement by transvaginal ultrasound for
Talat Umut Kutlu Dilek1, Gurkan Yazici, Ayfer Gurbuz
1Department of Obstetrics and Gynecology, Mersin University School of Medicine, Mersin, Turkey. umutdilek@gmail.com
Background:
To evaluate cervical length changes as predictors of preterm delivery.
Methods:
Two hundred and fifty-seven pregnant women underwent transvaginal ultrasound examination at 16 and 24 weeks of gestation. Cervical length was measured and the difference between the 2 measurements was calculated. The sensitivity, specificity, positive predictive value and negative predictive value of cervical length and cervical length changes were calculated and these methods were compared by receiver-operating characteristic (ROC) curve analysis.
Results:
Preterm delivery (before 37 weeks of gestation) occurred in 19 patients (7.4%). The mean cervical length was shorter in the preterm group, the area under the ROC curve for prediction of preterm delivery was 0.914, ultrasound had a sensitivity of 84.2% to predict preterm delivery with a false-positive rate of 18.5%, and the relative risk was 4.56 at the 34.3-mm cutoff value at 24 weeks of gestation. In contrast, a cervical length change on transvaginal ultrasound had a sensitivity of 73.3% to predict preterm delivery with a false-positive rate of 18.1%, and the relative risk was 4.08 at the 6.6-mm cutoff value.
Conclusion:
A single cervical length measurement obtained at 24 weeks of gestation can predict preterm delivery as accurately as cervical length change.
