Does transvaginal sonographic measurement of cervical length before 14 weeks predict preterm delivery in high-risk pregnancies?
Article first published online: 21 FEB 2003
Copyright © 2003 ISUOG. Published by John Wiley & Sons, Ltd.
Ultrasound in Obstetrics & Gynecology
Volume 21, Issue 2, pages 140–144, February 2003
How to Cite
Berghella, V., Talucci, M. and Desai, A. (2003), Does transvaginal sonographic measurement of cervical length before 14 weeks predict preterm delivery in high-risk pregnancies?. Ultrasound Obstet Gynecol, 21: 140–144. doi: 10.1002/uog.28
- Issue published online: 21 FEB 2003
- Article first published online: 21 FEB 2003
- Manuscript Accepted: 12 JUL 2002
- first trimester;
- preterm birth;
- transvaginal ultrasonography
To determine whether high-risk patients manifest cervical length < 25 mm on transvaginal ultrasound before 14 weeks of gestation, and if this finding is predictive of preterm delivery.
Asymptomatic pregnancies at high risk for preterm birth were followed prospectively from 10 + 0 weeks to 13 + 6 weeks with transvaginal sonographic measurement of the cervix. A cervical length < 25 mm was considered a short cervix at this gestational age and at the follow-up ultrasound examinations, performed between 14 and 24 weeks. The primary outcome was preterm birth at < 35 weeks of gestation.
One hundred and eighty-three pregnancies met the study criteria and were included in the analysis. Only 10 (5%) patients had a cervix < 25 mm before 14 weeks. The sensitivity, specificity and positive and negative predictive values of a short cervix were 14%, 97%, 50%, and 82%, respectively (relative risk, 2.8; 95% confidence interval, 1.4–5.6). The mean transvaginal sonographic cervical length before 14 weeks of gestation was 33.7 ± 6.9 mm in pregnancies which delivered preterm (n = 36), and 35.0 ± 6.8 mm in those delivering at term (n = 147) (P = 0.3). Follow-up transvaginal ultrasound examination of the cervix to 24 weeks revealed that the average gestational age at which a short cervix was detected was 18.7 ± 2.9 weeks.
A cervical length < 25 mm on transvaginal sonographic assessment rarely occurs before 14 weeks even in high-risk patients destined to deliver preterm; in these patients cervical changes predictive of preterm birth develop mostly after this gestational age. Copyright © 2003 ISUOG. Published by John Wiley & Sons, Ltd.