title: Perinatal outcomes following an earlier post-term labour induction policy: a historical cohort study.
abstract: OBJECTIVE
  To assess the changes in perinatal outcomes in children born from 37 weeks of gestation after implementation of a more proactive labour induction practice from 2009.
  
  
  METHODS
  Register-based cohort study.
  
  
  METHODS
  Denmark, 2000-12.
  
  
  METHODS
  Newborns from 37 weeks of gestation.
  
  
  METHODS
  Perinatal outcomes were estimated using a logistic regression analysis with adjustment for gestational age, maternal age, parity, plurality, smoking and body mass index.
  
  
  METHODS
  Perinatal outcomes.
  
  
  RESULTS
  A total of 770 926 infants were included. Labour induction from 37 weeks increased from 9.7% in 2000-02 to 22.5% in 2011-12. From 2003-05 to 2011-12, the risk of umbilical cord pH < 7.0 decreased by 23%; odds ratio (OR) 0.77 (95% confidence interval 0.67-0.89), and the adjusted OR of Apgar score < 7 at 5 minutes was unchanged. The risk of admission to neonatal intensive care units increased by 56%; OR 1.56 (1.47-1.66), whereas the risk of neonatal deaths decreased by 44%; OR 0.56 (0.45-0.70). The risk of cerebral palsy was from 2000-02 to 2009-10 reduced by 26%; OR 0.74 (0.60-0.90). The proportion of infants born with fetal weight ≥ 4500 g decreased by one-third; OR 0.68 (0.65-0.71). However, the risk of shoulder dystocia increased by 32%; OR 1.32 (1.21-1.44), whereas the risk of peripheral nerve injuries was reduced by 43%; OR 0.57 (0.45-0.73).
  
  
  CONCLUSIONS
  The results suggest an overall improvement in perinatal outcomes as a result of a more proactive post-term labour induction practice.
authors.affiliation: Department of Gynaecology, Rigshospitalet, Faculty of Health Science, University of Copenhagen, Copenhagen, Denmark.
authors.forename: M
authors.initials: M
authors.lastname: Hedegaard
authors.affiliation: Department of Gynaecology, Rigshospitalet, Faculty of Health Science, University of Copenhagen, Copenhagen, Denmark.
authors.forename: Ø
authors.initials: Ø
authors.lastname: Lidegaard
authors.affiliation: Department of Gynaecology, Rigshospitalet, Faculty of Health Science, University of Copenhagen, Copenhagen, Denmark.
authors.forename: C W
authors.initials: CW
authors.lastname: Skovlund
authors.affiliation: Department of Gynaecology, Rigshospitalet, Faculty of Health Science, University of Copenhagen, Copenhagen, Denmark.
authors.forename: L S
authors.initials: LS
authors.lastname: Mørch
authors.affiliation: Department of Obstetrics, Rigshospitalet, Faculty of Health Science, University of Copenhagen, Copenhagen, Denmark.
authors.forename: M
authors.initials: M
authors.lastname: Hedegaard
mesh_terms: D000328:Adult; D001720:Birth Injuries / Q000453:epidemiology / Q000209:etiology; D015331:Cohort Studies; D003718:Denmark; D005260:Female; D005865:Gestational Age; D006801:Humans; D007223:Infant; D007226:Infant Mortality; D007231:Infant, Newborn; D007232:Infant, Newborn, Diseases / Q000453:epidemiology / Q000209:etiology / Q000517:prevention & control*; D007233:Infant, Postmature; D015931:Intensive Care, Neonatal / Q000706:statistics & numerical data; D007751:Labor, Induced / Q000379:methods*; D016015:Logistic Models; D017063:Outcome Assessment, Health Care; D011247:Pregnancy; D012042:Registries
keywords: Asphyxia; birth induction; misoprostol; perinatal outcome; post-term labour