Lithotomy position for vaginal birth

If the woman cannot be placed in lithotomy position because a suitable bed with stirrups is not available, a stack of towels or an upside down bedpan is placed under the mother's hips and back to raise the perineum above the surface of the bed/stretcher. This provides additional room to maneuver when guiding the infant posteriorly to ease his/her shoulder under the symphysis pubis.