title: Interrelations between four antepartum obstetric interventions and cesarean delivery in women at low risk: a systematic review and modeling of the cascade of interventions.
abstract: OBJECTIVE
  To critically appraise the literature on the relations between four intrapartum obstetric interventions-electronic fetal monitoring (EFM), epidural analgesia, labor induction, and labor acceleration; and two types of delivery-instrumental (forceps and vacuum) and cesarean section.
  
  
  METHODS
  This review included meta-analyses published between January 2000 and April 2012 including at least one randomized clinical trial published after 1995 and presenting results on low-risk pregnancies between 37 and 42 weeks of gestation, searched in the databases Medline, Cochrane Library, and EMBASE with no language restriction.
  
  
  RESULTS
  Of 306 documents identified, 8 fulfilled the inclusion criteria and presented results on women at low risk. EFM at admission (vs intermittent auscultation) was associated with cesarean delivery (odds ratio [OR] = 1.20, 95% confidence interval [CI] 1.00-1.44) and epidural analgesia (OR = 1.25, 95% CI 1.09-1.43). Epidural on request was associated with cesarean delivery (OR = 1.60, 95% CI 1.18-2.18), instrumental delivery (OR = 1.21, 95% CI 1.03-1.44), and oxytocin use (OR = 1.20, 95% CI 1.01-1.43) when compared with epidural on request plus nonpharmacological labor pain control methods such as one-to-one support, breathing techniques, and relaxation. Induction and acceleration of labor showed heterogeneous patterns of associations with cesarean delivery and instrumental delivery.
  
  
  CONCLUSIONS
  Complex patterns of associations between obstetric interventions and modes of delivery were illustrated in an empirical model. Intermittent auscultation and nonpharmacological labor pain control interventions, such as one-to-one support during labor, have the potential for substantially reducing cesarean deliveries.
authors.affiliation: Institut national d'excellence en santé et en services sociaux (INESSS), QC, Canada; Department of Epidemiology, Biostatistics and Occupational Health, McGill University, Montreal, QC, Canada.
authors.forename: Michel
authors.initials: M
authors.lastname: Rossignol
authors.forename: Nils
authors.initials: N
authors.lastname: Chaillet
authors.forename: Faiza
authors.initials: F
authors.lastname: Boughrassa
authors.forename: Jean-Marie
authors.initials: JM
authors.lastname: Moutquin
mesh_terms: D015360:Analgesia, Epidural / Q000706:statistics & numerical data*; D016362:Analgesia, Obstetrical / Q000706:statistics & numerical data; D002585:Cesarean Section / Q000706:statistics & numerical data*; D005113:Extraction, Obstetrical / Q000706:statistics & numerical data*; D005260:Female; D005323:Fetal Monitoring / Q000706:statistics & numerical data*; D006801:Humans; D007751:Labor, Induced / Q000706:statistics & numerical data*; D016017:Odds Ratio; D010120:Oxytocics; D011247:Pregnancy
chemical_list: D010120:Oxytocics
keywords: cesarean delivery; electronic fetal monitoring; epidemiology; epidural analgesia; instrumental delivery; labor acceleration; labor induction; obstetrics