Ultrasound parameters and clinical examination to assess fetal head station in labor

Purpose: Different ultrasound methods such as intrapartum translabial ultrasound (ITU) head station, angle of progression (AOP), head-perineum distance (HPD) and head-symphysis distance (HSD) have been proposed to examine the progress of labor. We analyzed the relationship between these ultrasound parameters and compared them with digital palpation. Patients and methods: Stored volume dataset pairs that had been acquired from nulliparous women at term with prolonged first stage of labor were studied. The volumes had been acquired with a three-dimensional transducer placed between the labia majora in a mid-sagitt…