title: Unexplained differences in first stage labor duration in primiparas at North American and European hospitals.
authors.forename: M
authors.initials: M
authors.lastname: Thomson
mesh_terms: D002584:Cervix Uteri / Q000502:physiology; D005060:Europe; D005260:Female; D006801:Humans; D007747:Labor Stage, First / Q000187:drug effects / Q000502:physiology*; D007743:Labor, Obstetric / Q000502:physiology*; D010121:Oxytocin; D011247:Pregnancy; D044469:Racial Groups; D013997:Time Factors; D014481:United States
chemical_list: D010121:Oxytocin