Obstetric analgesia with gas and oxygen.
D016362:Analgesia, Obstetrical; D005260:Female; D006801:Humans; D007743:Labor, Obstetric; D009609:Nitrous Oxide; D010100:Oxygen; D011247:Pregnancy; D014937:Work
D009609:Nitrous Oxide; D010100:Oxygen
LABOR; NITROUS OXIDE