Evaluation of the labour process with serial transperineal ultrasonography and prediction of the type of birth

OBJECTIVES: The purpose of this study is to follow the birth process with transperineal ultrasonography (TPU) and predict the delivery method using angle of progression (AOP). METHODS: The study included 134 patients. The AOP was examined with TPU in the lithotomy position applied at 4-h intervals, not at a time of straining or contractions. The relationship was examined between AOP and those who continued with vaginal delivery, and those who underwent caesarean section delivery. RESULTS: A total of 122 (91%) patients had vaginal delivery and 12 (9%) patients had cesarean delivery. In patients giving vaginal delivery, progress in AOP was observed in every 4-h measurement, but not in patients with cesarean section. In the ROC analysis, if 70% sensitivity and 75% specificity with AOP degree >132.5°, the patient was expected to have vaginal delivery with a probability of 77.5% (95% CI 0.62-0.93; p=0.002). CONCLUSIONS: Rather than repeating digital examinations, the labour process can be monitored with serial TPU and the type of delivery can be predicted. There is a need for further studies for the measurement of AOP with TPU to become a part of clinical practice in the monitoring of the whole labour process.