Measurement of pubic symphysis width in different birthing positions using ultrasound

Pubic symphysis width is measured using 3D freehand ultrasound in different birthing positions: supine, lithotomy position, standing and squatting. The relative position of the pubic bones would also be analysed. Preliminary results show that the motion at pubic symphysis in different positions includes rotation and translation and vertical positions tends to have a larger motion compared to lying down. The results may determine whether some positions may present a biomechanical advantage to ease birth.