The rationale of primitive delivery positions.
D036861:Delivery, Obstetric; D005260:Female; D049690:History, Ancient; D049691:History, Medieval; D049711:History, Modern 1601-; D006801:Humans; D008519:Medicine, Traditional; D009774:Obstetrics / Q000266:history*; D010384:Pelvic Bones / Q000502:physiology; D011187:Posture; D011247:Pregnancy