Comparison of cervical characteristics assessed by TVUS (with and without saline) with digital method in prediction of labor induction outcome: a prospective study

Background: Objective: To compare digital and transvaginal sonographic cervical assessment (pre & post vaginal saline) in predicting the outcome of induction of labor.Methods: Study design was prospective study, setting at medical college and research institute. Hundred pregnant women with singleton pregnancies admitted for induction of labor between 37-42 weeks of gestation. Digital and TVUS (Transvaginal ultrasonography) assessment of cervix was made with and without saline instillation and the statistical comparative data was derived. The primary outcome was initiation of active labor and the secondary outcomes were mode of delivery, active labor within 12 hours, induction to delivery interval, and the duration of active laborResults: No ultrasound or digital cervical characteristics predicted the initiation of active labor (P>f; >0.05), mode of delivery and the duration of active labor; however, TVUS assessment of cervical length but not cervical width is significantly better than digital assessment of cervical length (P <0.001); it independently discriminates and predicts active labor within 12 hours. Conclusions: TVUS measurement of cervical length is a better predictor of active labor within 12 hours than digital assessment. Visualization of cervix by TVUS was enhanced with saline administration but the difference between the measurements with and without saline was not statistically significant.