Uterine Cervical Length Measurement by Transvaginal Ultrasonography for Prediction of Preterm Delivery

Chang, Y J; Lee, M H; Joo, S H; Ko, K S

Abstract

OBJECTIVE
The purpose of this study was to evaluate the diagnostic accuracy through uterine cervical length measurement by transvaginal ultrasonography for prediction of preterm delivery in patients with preterm labor. Materials and
METHODS
Vaginal ultrasonography was performed in 64 patients admitted with preterm labor(24 to 36 weeks) and cervical dilatation of <3 cm. Comparison between the patients with cervical length 18 mm or less(short cervical length group) and the patients with cervical lenght more than 18 mm (long cervical length group) was performed for prediction of the preterm delivery and the admission-to-delivery interval.
RESULTS
The admission-to-delivery interval of short cervical length group was significantly shorter than that of the long cervical length group (p<0.001). The newborns of short cervical length group were admitted to NICU longer than that of the long cervical length group (p<0.05). Diagnostic accuracy of the cervical length(cutoff value: 18 mm) and the occurrence of preterm delivery was sensitivity of 58.6%, specificity of 80.0%, positive and negative predictive value of 91.9% and 33.3%, respectively. The admission-to-delivery interval in the patients with funneling of cervix was significantly shorter than that in the patients without funneling of cervix (p<0.05).
CONCLUSION
The short cervical length group and cevical funneling group in patient with preterm labor showed shortened admission-to-delivery interval. The short cervical length group (18 mm or less) shows high positive predictive value (91.9%) for prediction of preterm delivery. Therefore, it is useful to measure the cervical length and cervical funneling by vaginal ultrasonography to predict preterm delivery for patients with preterm labor.