Correlation Between Head Perineum Distance Measured by Trans-périneal Ultrasound and Delivery Mode in Patient in the Second Stage of Labor

Head-perineum distance measured by transperineal ultrasound is a simple and well-known tool to help diagnose the fetal head engagement and predictive value to instrumental extraction succeeds.

It is performed in labor room and is a non-invasive test, realized on a healthy skin.

The investigators performed a systematical measure of head perineum distance at the beginning of the expulsive labor phase. The investigators made the hypothesis, based on our clinical experience, that starting expulsive labor phase with head perineum distance greater than forty five millimeters, lead to an increased risk of instrumental extraction and therefore an increase in materno-fetal morbidity and mortality.

The investigators sought to evaluate the optimal head perineum distance at the beginning of expulsive efforts.