Intrapartum Ultrasonography in Evaluation of the Progress of Labor

The optimal management of the second stage of labor is a subject of an ongoing debate. It is well established that prolonged second stage of labor is associated with increased maternal and neonatal morbidity.

Diagnosing the onset of labour is one of the most critical and complex judgments made by care providers in the delivery room. Measurement of cervical dilatation is considered the most crucial parameter for labour progress during childbirth and the main reason for doing digital vaginal examination (DVE) in women with signs of labour onset.

DVE was the most common method for measuring cervical dilatation in the past and has been the gold standard for assessing labour progress. However, it can be subjective, inaccurate, and uncomfortable for women. Also, only 50% of assessments are accurate, and there is an increased risk of infection with frequent DVE. Therefore, vaginal examination cannot be a correct scale for measuring cervical dilatation, mainly when done by different examiners. Because of the poor reliability and pain associated with DVE, the use of intrapartum ultrasound to measure cervical dilation has been suggested as an alternative method. Abdominal, vaginal, trans-labial, and trans-perineal 2D and 3D ultrasounds have been used to measure cervical dilatation during labour.