Progressive cervical length changes versus single cervical length measurement by transvaginal ultrasound for prediction of preterm delivery.
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.


CONCLUSIONS
A single cervical length measurement obtained at 24 weeks of gestation can predict preterm delivery as accurately as cervical length change.
Department of Obstetrics and Gynecology, Mersin University School of Medicine, Mersin, Turkey. umutdilek@gmail.com
Talat Umut Kutlu
TU
Dilek
Gurkan
G
Yazici
Ayfer
A
Gurbuz
Bahar
B
Tasdelen
Sitki
S
Gulhan
Burcu
B
Dilek
Saffet
S
Dilek
D000328:Adult; D002584:Cervix Uteri / Q000000981:diagnostic imaging*; D005260:Female; D006801:Humans; D007752:Obstetric Labor, Premature / Q000000981:diagnostic imaging*; D011237:Predictive Value of Tests; D011247:Pregnancy; D011262:Pregnancy Trimester, Second; D012372:ROC Curve; D012680:Sensitivity and Specificity; D016216:Ultrasonography, Prenatal