Clinical efficacy of cervical length and volume for prediction of labor onset in VBAC candidates

Abstract

Background: The purpose of this research is to discover whether measurement of cervical length and cervical volume at term is helpful in predicting the onset of labor in VBAC can-didates. Methods: Transvaginal sonographic evaluations of the cervixes of pregnant women who desired to undergo VBAC were performed between 36 - 40 weeks gestation. Clinical in-formation such as labor onset time, gestational age at delivery and delivery mode was gath-ered from medical records. Results: A total of 514 pregnant women participated in this study. Cervical length was sig-nificantly longer in the group that delivered 7 days or more after measurement than in the group that delivered within 7 days of measurement (43±0.77 cm vs. 2.99±0.72 cm, p< 0.001). Cervical volume was significantly larger in the group that delivered at and after 7 days than in the group that delivered within 7 days (29.21±11.62 cm3 vs. 34.07±13.41 cm3, p=0.014). The cervical length ROC curve was significantly more predictive than the cervical volume ROC curve (AUC: 0.711 vs 0.594, p= 0.001). There were no significant differences between the combined cervical length/volume ROC curve and the cervical length ROC curve alone (p= 0.565). The AUC of the cervical length ROC curve to predict postterm pregnancy was 0.729. Conclusion: Measuring cervical length is helpful in predicting the onset of spontaneous labor within 7 days and posterm delivery in VBAC candidates. © Ivyspring International Publisher.