title: Induction of labor in a contemporary obstetric cohort.
abstract: OBJECTIVE
  We sought to describe details of labor induction, including precursors and methods, and associated vaginal delivery rates.
  
  
  METHODS
  This was a retrospective cohort study of 208,695 electronic medical records from 19 hospitals across the United States, 2002 through 2008.
  
  
  RESULTS
  Induction occurred in 42.9% of nulliparas and 31.8% of multiparas and elective or no recorded indication for induction at term occurred in 35.5% and 44.1%, respectively. Elective induction at term in multiparas was highly successful (vaginal delivery 97%) compared to nulliparas (76.2%). For all precursors, cesarean delivery was more common in nulliparas in the latent compared to active phase of labor. Regardless of method, vaginal delivery rates were higher with a ripe vs unripe cervix, particularly for multiparas (86.6-100%).
  
  
  CONCLUSIONS
  Induction of labor was a common obstetric intervention. Selecting appropriate candidates and waiting longer for labor to progress into the active phase would make an impact on decreasing the national cesarean delivery rate.
authors.affiliation: Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD, USA.
authors.forename: S Katherine
authors.initials: SK
authors.lastname: Laughon
authors.forename: Jun
authors.initials: J
authors.lastname: Zhang
authors.forename: Jagteshwar
authors.initials: J
authors.lastname: Grewal
authors.forename: Rajeshwari
authors.initials: R
authors.lastname: Sundaram
authors.forename: Julie
authors.initials: J
authors.lastname: Beaver
authors.forename: Uma M
authors.initials: UM
authors.lastname: Reddy
mesh_terms: D000293:Adolescent; D000328:Adult; D020070:Cervical Ripening; D002585:Cesarean Section / Q000706:statistics & numerical data*; D015331:Cohort Studies; D017558:Elective Surgical Procedures; D005260:Female; D006801:Humans; D053208:Kaplan-Meier Estimate; D007745:Labor Onset; D007751:Labor, Induced / Q000379:methods / Q000706:statistics & numerical data*; D010298:Parity; D011247:Pregnancy; D011248:Pregnancy Complications; D012189:Retrospective Studies; D014481:United States; D055815:Young Adult