title: Factors associated with higher oxytocin requirements in labor.
abstract: OBJECTIVE
  To identify clinical characteristics associated with high maximum oxytocin doses in women who achieve complete cervical dilation.
  
  
  METHODS
  A retrospective nested case-control study was performed within a cohort of all term women at a single center between 2004 and 2008 who reached the second stage of labor. Cases were defined as women who had a maximum oxytocin dose during labor >20 mu/min, while women in the control group had a maximum oxytocin dose during labor of ≤20 mu/min. Exclusion criteria included no oxytocin administration during labor, multiple gestations, major fetal anomalies, nonvertex presentation, and prior cesarean delivery. Multiple maternal, fetal, and labor factors were evaluated with univariable analysis and multivariable logistic regression.
  
  
  RESULTS
  Maximum oxytocin doses >20 mu/min were administered to 108 women (3.6%), while 2864 women received doses ≤20 mu/min. Factors associated with higher maximum oxytocin dose after adjusting for relevant confounders included maternal diabetes, birthweight >4000 g, intrapartum fever, administration of magnesium, and induction of labor.
  
  
  CONCLUSIONS
  Few women who achieve complete cervical dilation require high doses of oxytocin. We identified maternal, fetal and labor factors that characterize this group of parturients.
authors.affiliation: a Department of Obstetrics and Gynecology , Washington University in St. Louis , St. Louis , MO, Missouri , USA.
authors.forename: Heather A
authors.initials: HA
authors.lastname: Frey
authors.forename: Methodius G
authors.initials: MG
authors.lastname: Tuuli
authors.forename: Sarah K
authors.initials: SK
authors.lastname: England
authors.forename: Kimberly A
authors.initials: KA
authors.lastname: Roehl
authors.forename: Anthony O
authors.initials: AO
authors.lastname: Odibo
authors.forename: George A
authors.initials: GA
authors.lastname: Macones
authors.forename: Alison G
authors.initials: AG
authors.lastname: Cahill
mesh_terms: D000293:Adolescent; D000328:Adult; D016022:Case-Control Studies; D004305:Dose-Response Relationship, Drug; D005260:Female; D006801:Humans; D007231:Infant, Newborn; D007751:Labor, Induced / Q000379:methods* / Q000706:statistics & numerical data*; D007743:Labor, Obstetric / Q000187:drug effects / Q000502:physiology; D007744:Obstetric Labor Complications / Q000453:epidemiology; D010120:Oxytocics / Q000008:administration & dosage*; D010121:Oxytocin / Q000008:administration & dosage*; D011247:Pregnancy; D012189:Retrospective Studies; D012307:Risk Factors; D055815:Young Adult
chemical_list: D010120:Oxytocics; D010121:Oxytocin
keywords: Labor augmentation; labor induction; labor management