Role of Intrapartum Ultrasound in Modern Obstetrics

Intrapartum ultrasound has become more popular over the last decade. It provides a more objective assessment of fetal head position and station than traditional digital vaginal examination, which is now known to be inaccurate. Correct identification of fetal head position is particularly useful before instrumental delivery, although it should not be used in the first stage of labour to predict successful vaginal delivery. Fetal head station can be assessed by determining the relationship between maternal and fetal structures transperineally, such as head-perineum distance and angle of progression. Intrapartum ultrasound has potential use before and during labour. Current evidence, however, shows it is most useful during the second stage of labour, especially when choice of optimal mode of delivery is not apparent. We believe that intrapartum ultrasound is a promising diagnostic tool that will ultimately improve the wellbeing of mothers and babies. Hong Kong J Gynaecol Obstet Midwifery 2017; 17(2):134-40