[Ultrasonographic score for predicting vaginal delivery within 24h of induction: a pilot study]

Evaluate if a score based on ultrasound measurements (cervical length, perineal-fetal presentation distance, fetal occiput position) before the induction of labour is a good predictive test of vaginal delivery within 24h and compare it to Bishop score.

From January to April 2014, we included in a monocentric prospective study 45 patients who underwent a labour induction in the department of obstetrics and gynecology at Croix-Rousse Hospital. Ultrasound measurements of the distance between the perineum and the foetal presentation (with transperineal ultrasound), of the cervical length (with transvaginal ultrasound) and of the position of the occiput were collected before induction. Bishop score was also calculated for these patients, without receiving ultrasound data (and vice versa), in order to determine the mode of induction. Receiver Operating Characteristics (ROC) curves were used to evaluate performance of the ultrasonographic score and the Bishop score for predicting vaginal delivery within 24h.

The area under the ROC curve for ultrasonographic score was 84.5% (IC95% 64,6-100%). The area under the ROC curve for Bishop score was 73.2% (IC95% 64,2-82,2%). The comparison of these areas under the curve has shown a difference of 11.3% with a P-value of 0.055 in a two-tailed test.

Ultrasonographic score made with a combination of these ultrasound measurements appears to be an effective test to predict the chances of vaginal delivery within 24h of induction.