title: Decline in stillbirths and perinatal mortality after implementation of a more aggressive induction policy in post-date pregnancies: a nationwide register study.
abstract: BACKGROUND
  In 2011 Danish national guidelines were changed towards a more aggressive induction and fetal surveillance policy from (1) induction of labor at gestational age (GA) of 42+0weeks and (2) no fetal surveillance after 40+0weeks to (1) induction of labor between 41+2and 41+6weeks, (2) earlier induction at 41+0weeks in the case of maternal age >40 years or body mass index (BMI) >35 kg/m2and (3) fetal surveillance at GA 41+0weeks.
  
  
  METHODS
  This national cohort study included all pregnancies that reached 41+0weeks of gestation in 2008-2014 (n = 102 167). Multivariate logistic regression analyses were used to estimate risks in the years after (2012-2014) vs. before (2008-2010) new national guidelines, adjusted for maternal age, BMI, and parity.
  
  
  RESULTS
  We observed a decline in stillbirths from 0.9‰ to 0.5‰ [odds ratio (OR)adjusted0.50, 95% CI 0.29-0.89, p = 0.018]. Furthermore, a decline in perinatal deaths from 1.3‰ to 0.8‰ (ORadjusted0.62, 95% CI 0.39-0.96, p = 0.033) and vacuum extraction (ORadjusted0.86, 95% CI 0.82-0.90, p = 0.007) was observed. The risk of cesarean section (ORadjusted0.98, 95% CI 0.94-1.02, p = 0.251), Apgar score below 7 at five minutes (ORadjusted0.96, 95% CI 0.81-1.14, p = 0.0.678) and admissions to the neonatal department (ORadjusted1.04, 95% CI 1.00-1.14, p = 0.064) did not change, whereas induction of labor increased from 28.2 to 42.6% (ORadjusted1.89, 95% CI 1.84-1.95, p < 0.001).
  
  
  CONCLUSIONS
  This study showed a decline in stillbirths and perinatal mortality after implementation of new Danish guidelines for post-date pregnancies. The risk of interventions as cesarean section and vacuum extraction remained stable despite an increase in labor inductions.
authors.affiliation: Department of Obstetrics and Gynecology, Aarhus University Hospital, Skejby, Denmark.
authors.forename: Anne R
authors.identifier: http://orcid.org/0000-0003-0342-0708
authors.initials: AR
authors.lastname: Zizzo
authors.affiliation: Department of Obstetrics and Gynecology, Aarhus University Hospital, Skejby, Denmark.
authors.forename: Ida
authors.initials: I
authors.lastname: Kirkegaard
authors.affiliation: Department of Obstetrics and Gynecology, Copenhagen University Hospital, Hvidovre, Denmark.
authors.forename: Anja
authors.identifier: http://orcid.org/0000-0002-8340-104X
authors.initials: A
authors.lastname: Pinborg
authors.affiliation: Department of Obstetrics and Gynecology, Aarhus University Hospital, Skejby, Denmark.
authors.forename: Niels
authors.initials: N
authors.lastname: Ulbjerg
mesh_terms: D003718:Denmark / Q000453:epidemiology; D005260:Female; D005865:Gestational Age; D006801:Humans; D007231:Infant, Newborn; D007751:Labor, Induced; D008428:Maternal Mortality / Q000639:trends*; D000068101:Maternal-Child Health Services; D017063:Outcome Assessment, Health Care; D017410:Practice Guidelines as Topic; D011247:Pregnancy; D011256:Pregnancy Outcome; D011273:Pregnancy, Prolonged; D012042:Registries; D050497:Stillbirth
keywords: Stillbirth; epidemiology; induced labor; prolonged pregnancy