Cervical consistency index and risk of cesarean delivery after induction of labor at term.

OBJECTIVE: To evaluate the association between cervical consistency index (CCI) and the risk of cesarean delivery after planned induction of labor (IOL).

METHODS: We designed an observational prospective study, including women admitted for IOL at term. Ultrasonographic images were obtained before IOL and CCI was calculated offline once recruitment was completed. Main outcome was defined as cesarean delivery due to failed IOL or due to arrest of labor. Univariate statistical analysis was performed using Fisher's exact test for categorical variables and Student's T-test for continuous characteristics. Multivariate analysis was performed using logistic regression, including CCI and other variables related to the outcome. Intraclass correlation coefficients were used to estimate intra- and interobserver agreement.

RESULTS: We included a total of 510 women admitted for IOL. After excluding 46 women for emergent cesarean deliveries, 464 pregnancies were analyzed. Main outcome occurred in 100/464 (21.6%) pregnancies. We did not find differences between mean CCI between the cesarean and the vaginal delivery groups (70.2% ± 12.3% vs 70.0% ± 13.1%; p=0.94). Multivariate analysis also showed absence of statistical association between CCI and the mode of delivery. Intra-class correlation coefficients for intra and inter-observer's agreement were 0.81 (0.66-0.89) and 0.86 (0.75-0.92), respectively.

CONCLUSIONS: CCI does not seem to be associated with the risk of cesarean delivery after IOL. This article is protected by copyright. All rights reserved.