title: A cohort study of low Apgar scores and cognitive outcomes.
abstract: OBJECTIVE
  To investigate the association of brief (0-5 minutes) and prolonged (>5 minutes) low Apgar scores (<7) in non-encephalopathic infants with educational achievement at age 15-16 and intelligence quotients (IQs) at age 18.
  
  
  METHODS
  Population-based record-linkage cohort study of 176 524 male infants born throughout Sweden between 1973 and 1976.
  
  
  METHODS
  Data from the Medical Birth Register were linked to Population and Housing Censuses, conscription medical records (IQ), and school registers (summary school grade). Infants were classified according to the time for their Apgar score to reach 7 or above. Premature infants and those with encephalopathy were excluded.
  
  
  RESULTS
  Infants with brief (OR = 1.14 (1.03-1.27)) or prolonged (OR = 1.35 (1.07-1.69)) low Apgar scores were more likely to have a low IQ score. There was an increased risk of a low IQ score (p = 0.003) the longer it took the infant to achieve a normal Apgar score. There was no association between brief (OR = 0.96 (0.87-1.06)) or prolonged (OR = 1.01 (0.81-1.26)) low Apgar scores and a low summary school grade at age 15-16, or evidence for a trend in the risk of a low school grade (p = 0.61). The estimated proportion with an IQ score below 81 due to transiently low Apgar scores was only 0.7%.
  
  
  CONCLUSIONS
  Infants in poor condition at birth have increased risk of poor functioning in cognitive tests in later life. This supports the idea of a "continuum of reproductive casualty", although the small individual effect suggests that these mild degrees of fetal compromise are not of clinical importance.
authors.affiliation: Clinical Science at North Bristol, Paul O'Gorman Lifeline Centre, Southmead Hospital, Bristol BS10 5NB, UK. mddeo@bristol.ac.uk
authors.forename: D E
authors.initials: DE
authors.lastname: Odd
authors.forename: F
authors.initials: F
authors.lastname: Rasmussen
authors.forename: D
authors.initials: D
authors.lastname: Gunnell
authors.forename: G
authors.initials: G
authors.lastname: Lewis
authors.forename: A
authors.initials: A
authors.lastname: Whitelaw
mesh_terms: D000293:Adolescent; D001034:Apgar Score; D003072:Cognition Disorders / Q000209:etiology*; D015331:Cohort Studies; D002658:Developmental Disabilities / Q000453:epidemiology / Q000523:psychology*; D004522:Educational Status; D005500:Follow-Up Studies; D006801:Humans; D007231:Infant, Newborn; D007360:Intelligence; D008297:Male; D015233:Models, Statistical; D011237:Predictive Value of Tests; D012959:Socioeconomic Factors; D013548:Sweden / Q000453:epidemiology