title: Changing Dutch approach and trends in short-term outcome of periviable preterms.
abstract: BACKGROUND
  In 2006, the Dutch guideline for active treatment of extremely preterm neonates advised to lower the gestational age threshold for active intervention from 26 0/7 to 25 0/7 weeks gestation.
  
  
  OBJECTIVE
  To evaluate the association between the guideline modification and early neonatal outcome.
  
  
  METHODS
  National cohort study, using prospectively collected data from The Netherlands Perinatal Registry.
  
  
  METHODS
  The study population consisted of 9713 infants with a gestational age between 24 0/7 and 29 6/7 weeks, born between 2000 and 2011. Three gestational age subgroups were analysed: 24 0/7 to 24 6/7 weeks (n=269), 25 0/7 to 25 6/7 weeks (n=852) and 26 0/7 to 29 6/7 weeks (n=8592).
  
  
  METHODS
  Neonatal intensive care unit (NICU) admission, live births, neonatal in-hospital mortality, morbidity and favourable outcome (no mortality or morbidity) before (2000-2005; period 1) and after (2007-2011; period 2) introduction of the modified guideline, using χ(2) tests and univariable and multivariable logistic regression analyses.
  
  
  RESULTS
  In the second period, the proportion of live births and NICU admissions increased and the proportion of neonatal and in-hospital mortality decreased significantly in all subgroups. Morbidity in surviving infants of 25 weeks increased significantly, although the association between guideline modification and morbidity became non-significant after case-mix adjustment. Overall, favourable outcome did not change significantly after guideline modification in all subgroups when adjusted for variation in case-mix.
  
  
  CONCLUSIONS
  Overall, the trend in mortality gradually declined at all gestational ages, starting before 2006. This suggests that the guideline modification was a formalisation of already existing daily practice.
authors.affiliation: Department of Neonatology, Radboud University Medical Centre, Nijmegen, The Netherlands.
authors.forename: Maria J
authors.initials: MJ
authors.lastname: Zegers
authors.affiliation: The Netherlands Perinatal Registry, Utrecht, The Netherlands.
authors.forename: Chantal W P M
authors.initials: CW
authors.lastname: Hukkelhoven
authors.affiliation: Julius Center for Health Sciences and Primary Care, University Medical Center, Utrecht, The Netherlands.
authors.forename: Cuno S P M
authors.initials: CS
authors.lastname: Uiterwaal
authors.affiliation: Department of Neonatology, Radboud University Medical Centre, Nijmegen, The Netherlands.
authors.forename: Louis A A
authors.initials: LA
authors.lastname: Kollée
authors.affiliation: Wilhelmina Children's Hospital, Utrecht, The Netherlands.
authors.forename: Floris
authors.initials: F
authors.lastname: Groenendaal
mesh_terms: D000066491:Clinical Decision-Making; D005865:Gestational Age; D019983:Guideline Adherence; D017052:Hospital Mortality / Q000639:trends; D006801:Humans; D007223:Infant; D007226:Infant Mortality / Q000639:trends*; D062071:Infant, Extremely Premature; D007363:Intensive Care Units, Neonatal / Q000706:statistics & numerical data; D015931:Intensive Care, Neonatal / Q000706:statistics & numerical data*; D009426:Netherlands / Q000453:epidemiology; D017410:Practice Guidelines as Topic; D028761:Withholding Treatment
keywords: Epidemiology; Mortality; Neonatology