ABSTRACT
Power, passenger, and passage; this is the triad that controls the birth process. Unaected by the ebbs and tides of modern technology, the dimensions of the bony pelvis remain constant. erefore, it is of utmost importance to understand the role of the pelvis and to commit to memory the types, the dimensions, and prognosis for birth of the basic pelvic types, since the practitioner will be making decisions regarding the route of birth that may have signicant consequences for mother and infant. erefore, this chapter will focus on the bony pelvic structures, the best predictors of birth outcomes. Knowledge of pelvic adequacy is an essential component in the decision to allow a trial of labor and plan for a vaginal birth.
