The predictive role of serial transperineal sonography during the first stage of labor for cesarean section.

Abstract

Objectives: Head to perineum distance (HPD) and angle of progression (AOP) are sonographic markers which have been investigated for the evaluation of labor progress. Here, we aimed to evaluate the predictive role of serially measured AOP and HPD during the first stage of labor in labor progress both in nulliparous and multiparous patients. Also, we firstly compared this role for labor progress.

Methods: This was a prospective longitudinal study including 299 patients. Patients were grouped as vaginal delivery (n=247) and cesarean section (n=52). Demographic and obstetric characteristics, HPD and AOP values, and vaginal examination findings were recorded and compared between groups.

Results: Slower changes in HPD and AOP values were detected in cesarean group. A HPD >38 mm predicted cesarean section with 86.9 % sensitivity and 59.2 % specificity (AUC=0.782, p<0.001) whereas AOP ≤117° predicted cesarean section with 93.5 % sensitivity and 65.1 % specificity in all patients (AUC=0.877, p<0.001). A HPD >37 mm predicted cesarean section with 84.2 % sensitivity and 55.2 % specificity (AUC=0.763, p<0.001) while AOP ≤110° predicted it with 82.7 % sensitivity and 73.3 % specificity in nulliparous patients (AUC=0.862, p<0.001). In multiparous patients, HPD>39 mm predicted cesarean section with 95.5 % sensitivity and 62.5 % specificity (AUC=0.824, p<0.001) and AOP ≤109° predicted cesarean section with 87.9 % sensitivity and 78.2 % specificity (AUC=0.909, p<0.001). AOP had superior predictive role than HPD in both nulliparous and multiparous groups (p<0.001 for both).

Conclusions: We suggest that differences in labor progress could be determined by using serial intrapartum sonography. However, more research is needed for the implementation of sonopartogram to the clinical obstetric practice.