title: Evaluation of the INTERGROWTH-21st project newborn standard for use in Canada.
abstract: OBJECTIVE
  To evaluate the performance of the INTERGROWTH-21st Project newborn standard vis-a-vis the current Canadian birth weight-for-gestational age reference.
  
  
  METHODS
  All hospital-based singleton live births in Canada (excluding Quebec) between 2002 and 2012 with a gestational age between 33 and 42 weeks were included using information obtained from the Canadian Institute for Health Information. Small- and large-for gestational age centile categories of the INTERGROWTH standard and Canadian reference were contrasted in terms of frequency distributions and rates of composite neonatal morbidity/mortality.
  
  
  RESULTS
  Among 2,753,817 singleton live births, 0.87% and 9.63% were <3rd centile and >97th centile, respectively, of the INTERGROWTH standard, while 2.27% and 3.55% were <3rd centile and >97th centile, respectively, of the Canadian reference. Infants <3rd centile and >97th centile had a composite neonatal morbidity/mortality rate of 46.4 and 12.9 per 1,000 live births, respectively, under the INTERGROWTH standard and 30.9 and 16.6 per 1,000 live births, respectively, under the Canadian reference. The INTERGROWTH standard <3rd centile and >97th centile categories had detection rates of 3.14% and 9.74%, respectively, for composite neonatal morbidity/ mortality compared with 5.48% and 4.60%, respectively for the Canadian reference. Similar patterns were evident in high- and low-risk subpopulations.
  
  
  CONCLUSIONS
  The centile distribution of the INTERGROWTH newborn standard is left shifted compared with the Canadian reference, and this shift alters the frequencies and neonatal morbidity/mortality rates associated with specific centile categories. Further outcome-based research is required for defining abnormal growth categories before the INTERGROWTH newborn standard can be used.
authors.affiliation: Maternal, Child and Youth Health, Surveillance and Epidemiology Division, Centre for Chronic Disease Prevention, Public Health Agency of Canada, Ottawa, Canada.
authors.forename: Shiliang
authors.initials: S
authors.lastname: Liu
authors.affiliation: Department of Obstetrics and Gynecology, University of Calgary, Calgary, Canada.|Department of Community Health Sciences, University of Calgary, Calgary, Canada.
authors.forename: Amy
authors.initials: A
authors.lastname: Metcalfe
authors.affiliation: Maternal, Child and Youth Health, Surveillance and Epidemiology Division, Centre for Chronic Disease Prevention, Public Health Agency of Canada, Ottawa, Canada.
authors.forename: Juan Andrés
authors.initials: JA
authors.lastname: León
authors.affiliation: Department of Community Health Sciences, University of Calgary, Calgary, Canada.|Department of Pediatrics, University of Calgary, Calgary, Canada.
authors.forename: Reg
authors.initials: R
authors.lastname: Sauve
authors.affiliation: Departments of Pediatrics and of Epidemiology, Biostatistics and Occupational Health, McGill University, Montreal, Canada.
authors.forename: Michael S
authors.initials: MS
authors.lastname: Kramer
authors.affiliation: Department of Obstetrics and Gynaecology and the School of Population and Public Health, University of British Columbia and the Children's and Women's Hospital and Health Centre of British Columbia, Vancouver, Canada.
authors.forename: K S
authors.initials: KS
authors.lastname: Joseph
mesh_terms: D001724:Birth Weight / Q000502:physiology*; D002170:Canada; D016208:Databases, Factual; D005260:Female; D005865:Gestational Age; D006801:Humans; D007223:Infant; D007226:Infant Mortality / Q000639:trends*; D007231:Infant, Newborn; D007236:Infant, Small for Gestational Age; D050498:Live Birth; D008297:Male; D012016:Reference Values; D012189:Retrospective Studies