The planes of Hodge as an index of the progress of labor.
D001720:Birth Injuries / Q000517:prevention & control; D036861:Delivery, Obstetric; D005260:Female; D006801:Humans; D007743:Labor, Obstetric; D008722:Methods; D009772:Obstetrical Forceps; D010384:Pelvic Bones / Q000000981:diagnostic imaging*; D010387:Pelvimetry; D011247:Pregnancy; D011859:Radiography; D013997:Time Factors