This leaflet is to help you understand the use of ultrasound in the assessment of fetal head descent in labor.

What defines fetal head descent during labor?
In normally progressing labor, the lowermost presenting fetal part (usually the fetal head) gradually descends into the maternal birth canal till vaginal delivery. Evaluation of fetal head descent in the birth canal is of importance in the labor ward because it provides information on  whether labor  is progressing normally  and can help  decide  the safest mode of delivery and whether an assisted birth ( vacuum, forceps or operative delivery) may be required. 
How to evaluate the fetal head station in the birth canal?
The degree of descent of the fetal head from high in the  pelvis, through  the length of the birth canal is traditionally assessed by digital vaginal examination, a somewhat subjective method. Ultrasound has been proposed as a less invasive, objective, and reproducible method for assessing fetal head descent compared to vaginal digital examination. By placing a ultrasound transducer on the maternal perineum, the fetal head can be visualized and various measures can be assessed  over time that  correlate  with  the degree of fetal head descent in the birth canal. Depending on the clinical scenario, clinicians can utilize the values obtained from one or more transperineal ultrasound parameters to determine whether fetal head progression down the birth canal is normal or aberrant. Moreover, transperineal ultrasound can also  assist clinicians in selecting the optimal mode of delivery, particularly when expedited delivery is warranted for fetal health concerns.

What other questions should I ask my doctor?
•    Is my labor progressing normally?
•    Are my contractions efficient?
•    Is the size of my baby appropriate for vaginal delivery?
•    Can ultrasound be used to check the position of my baby’s head and descent into the birth canal?
•    Are there signs that my baby is “stuck” in my pelvis? 
•    Will I need assistance with vaginal delivery?

Assessment of fetal head descent in labor

Last updated March 2024