title: Maternal and neonatal outcomes after induction of labor: a population-based study.
abstract: OBJECTIVE
  To evaluate maternal and neonatal outcomes at and beyond term associated with induction of labor compared to spontaneous onset of labor stratified by week of gestational age.
  
  
  METHODS
  In this retrospective cohort study, data form 402,960 singleton pregnancies from the Austria Perinatal Registry were used to estimate odds ratios of secondary cesarean delivery, operative vaginal delivery, epidural analgesia, fetal scalp blood testing, episiotomy, 3rd/4th-degree lacerations, retained placenta, 5-min APGAR <7, umbilical artery pH <7.1, and admission to neonatal intensive care unit. Multivariate logistic regression models based on deliveries with gestational age ≥37 + 0 were applied for adjustment for possible confounders.
  
  
  RESULTS
  Induction of labor was associated with increased odds for cesarean delivery (adjusted OR; 99% confidence interval: 1.53; 1.45-1.60), operative vaginal delivery (1.21; 1.15-1.27), epidural analgesia (2.12; 2.03-2.22), fetal scalp blood testing (1.40; 1.28-1.52), retained placenta (1.32; 1.22-1.41), 5-min APGAR <7 (1.55; 1.27-1.89), umbilical artery pH <7.1 (1.26; 1.15-1.38), and admission to neonatal intensive care unit (1.41; 1.31-1.51). In a subgroup of induction of labor with the indication, "post-term pregnancy" induction was similarly associated with adverse outcomes.
  
  
  CONCLUSIONS
  In Austria, induction of labor is associated with increased odds of adverse maternal and neonatal outcomes. However, due to residual confounding, currently, no recommendations for treatment can be derived.
authors.affiliation: University of Applied Sciences Tyrol, Innrain 98, 6020, Innsbruck, Austria. christoph.zenzmaier@fhg-tirol.ac.at.
authors.forename: Christoph
authors.initials: C
authors.lastname: Zenzmaier
authors.affiliation: Institute of Clinical Epidemiology, Tyrolean State Hospitals Ltd, Innsbruck, Austria.
authors.forename: Hermann
authors.initials: H
authors.lastname: Leitner
authors.affiliation: Department of Gynecological Endocrinology and Reproductive Medicine, Medical University of Innsbruck, Innsbruck, Austria.
authors.forename: Christoph
authors.initials: C
authors.lastname: Brezinka
authors.affiliation: Institute of Clinical Epidemiology, Tyrolean State Hospitals Ltd, Innsbruck, Austria.
authors.forename: Willi
authors.initials: W
authors.lastname: Oberaigner
authors.affiliation: University of Applied Sciences Tyrol, Innrain 98, 6020, Innsbruck, Austria. martina.koenig-bachmann@fhg-tirol.ac.at.
authors.forename: Martina
authors.initials: M
authors.lastname: König-Bachmann
mesh_terms: D000328:Adult; D015360:Analgesia, Epidural; D002585:Cesarean Section; D005260:Female; D005865:Gestational Age; D006801:Humans; D007231:Infant, Newborn; D007363:Intensive Care Units, Neonatal; D007751:Labor, Induced / Q000009:adverse effects*; D016015:Logistic Models; D011247:Pregnancy; D012189:Retrospective Studies
keywords: Cesarean section; Cohort study; Epidural analgesia; Induction of labor; Maternal outcomes; Neonatal outcomes