title: Biological and Social Influences on Outcomes of Extreme-Preterm/Low-Birth Weight Adolescents.
abstract: OBJECTIVE
  The importance of biological versus social influences on long-term outcomes of extremely preterm children is debatable. The goal of this study was to determine the relative contributions of biological and social exposures to outcomes into adolescence in extremely preterm survivors, hypothesizing that biological exposures would be more important early, but social exposures would dominate later.
  
  
  METHODS
  The study included 298 consecutive survivors born at <28 weeks' gestation or weighing <1000 g in Victoria, Australia (during 1991-1992), and 262 normal birth weight (>2499 g) control subjects who were used to standardize outcomes for the preterm group. Cognitive ability was assessed at 2, 5, 8, and 18 years of age. Academic achievement was assessed at 8 and 18 years of age.
  
  
  RESULTS
  The differences between the preterm and control groups for cognitive and academic scores remained relatively constant over time. The biological variables most associated with worse outcomes within the extremely preterm group were intraventricular hemorrhage and postnatal corticosteroid therapy. Of the social variables, being reared in a multilingual household was disadvantageous early, with social class and maternal education becoming more important for later outcomes. The strength of the biological associations mostly equaled or exceeded those of social exposures, even in late adolescence.
  
  
  CONCLUSIONS
  Contrary to expectations, several perinatal biological exposures had large and persistent adverse associations with cognitive and academic outcomes among extremely preterm survivors. As expected, some social variables assumed increasing importance in later years but mostly did not diminish or exceed the important biological associations.
authors.affiliation: Departments of Obstetrics and Gynaecology, and Paediatrics, University of Melbourne, Melbourne, Australia; Royal Women's Hospital, Melbourne, Australia; Murdoch Childrens Research Institute, Melbourne, Australia; and lwd@unimelb.edu.au.
authors.forename: Lex W
authors.initials: LW
authors.lastname: Doyle
authors.affiliation: Departments of Obstetrics and Gynaecology, and Royal Women's Hospital, Melbourne, Australia; Murdoch Childrens Research Institute, Melbourne, Australia; and.
authors.forename: Jeanie L Y
authors.initials: JL
authors.lastname: Cheong
authors.affiliation: Paediatrics, University of Melbourne, Melbourne, Australia; Royal Women's Hospital, Melbourne, Australia; Murdoch Childrens Research Institute, Melbourne, Australia; and.
authors.forename: Alice
authors.initials: A
authors.lastname: Burnett
authors.affiliation: Murdoch Childrens Research Institute, Melbourne, Australia; and Royal Children's Hospital, Melbourne, Australia.
authors.forename: Gehan
authors.initials: G
authors.lastname: Roberts
authors.affiliation: Paediatrics, University of Melbourne, Melbourne, Australia; Murdoch Childrens Research Institute, Melbourne, Australia; and.
authors.forename: Katherine J
authors.initials: KJ
authors.lastname: Lee
authors.affiliation: Paediatrics, University of Melbourne, Melbourne, Australia; Murdoch Childrens Research Institute, Melbourne, Australia; and.
authors.forename: Peter J
authors.initials: PJ
authors.lastname: Anderson
mesh_terms: D000124:Achievement; D000293:Adolescent; D016022:Case-Control Studies; D002648:Child; D002675:Child, Preschool; D003071:Cognition; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D052577:Infant, Extremely Low Birth Weight; D062071:Infant, Extremely Premature; D007231:Infant, Newborn; D007235:Infant, Premature, Diseases / Q000628:therapy; D015931:Intensive Care, Neonatal; D008297:Male; D065840:Protective Factors; D012307:Risk Factors; D012931:Social Environment; D012959:Socioeconomic Factors