title: Lack of analgesic effect of systemically administered morphine or pethidine on labour pain.
authors.forename: M J
authors.initials: MJ
authors.lastname: Lucas
authors.forename: S M
authors.initials: SM
authors.lastname: Ramin
authors.forename: S
authors.initials: S
authors.lastname: Sharma
mesh_terms: D000701:Analgesics, Opioid / Q000008:administration & dosage*; D005260:Female; D006801:Humans; D008614:Meperidine / Q000008:administration & dosage*; D009020:Morphine / Q000008:administration & dosage*; D007744:Obstetric Labor Complications / Q000517:prevention & control*; D010147:Pain Measurement; D011247:Pregnancy
chemical_list: D000701:Analgesics, Opioid; D009020:Morphine; D008614:Meperidine