Pre-induction translabial ultrasound measurements in predicting mode of delivery compared to bishop score: a cross-sectional study

Background: By increased concerns about the accuracy of the traditional methods to predict outcomes after induction of labor, developing new standards has a great clinical importance. Here, we compared the predictive value of translabial ultrasound measurements with Bishop Score to determine the suitability of induction of labor. Methods: A homogenous population of primigravid women was recruited. Induction of labor was performed with low-dose infusion of oxytocin. Translabial ultrasound and assessment of Bishop Score were performed by two different obstetricians. Receiver-operating characteristics curves were obtained to measure area under curve and subsequently, test sensitivity of each method. Results: One hundred women entered the investigation. Maternal body mass index was significantly higher among candidates of Cesarean section (P: 0.02). Maternal age and fetus weight, gender and occiput position were not determinants of outcomes of induction of labor. Cervical length and fetal head-pubis symphysis distance measured by translabial ultrasound had a test sensitivity of 90 and 88 %, respectively which were slightly higher than sensitivity of Bishop score (84 %). Conclusion: This study demonstrates that translabial measurements can be a suitable alternative method to monitor labor progress with an admissible predictive value compared with Bishop Score. It is a non-invasive method which provides valuable objective measurements and can be better accepted by women when considering the painful process which is required in evaluating Bishop Score.