title: Neurologic and developmental disability at six years of age after extremely preterm birth.
abstract: BACKGROUND
  Birth before 26 weeks of gestation is associated with a high prevalence of neurologic and developmental disabilities in the infant during the first two years of life.
  
  
  METHODS
  We studied at the time of early school age children who had been born at 25 or fewer completed weeks of gestation in the United Kingdom and Ireland in 1995. Each child had been evaluated at 30 months of age. The children underwent standardized cognitive and neurologic assessments at six years of age. Disability was defined as severe (indicating dependence on caregivers), moderate, or mild according to predetermined criteria.
  
  
  RESULTS
  Of 308 surviving children, 241 (78 percent) were assessed at a median age of six years and four months; 160 classmates delivered at full term served as a comparison group. Although the use of test reference norms showed that cognitive impairment (defined as results more than 2 SD below the mean) was present in 21 percent of the children born extremely preterm (as compared with 1 percent in the standardized data), this value rose to 41 percent when the results were compared with those for their classmates. The rates of severe, moderate, and mild disability were 22 percent, 24 percent, and 34 percent, respectively; disabling cerebral palsy was present in 30 children (12 percent). Among children with severe disability at 30 months of age, 86 percent still had moderate-to-severe disability at 6 years of age. In contrast, other disabilities at the age of 30 months were poorly predictive of developmental problems at 6 years of age.
  
  
  CONCLUSIONS
  Among extremely preterm children, cognitive and neurologic impairment is common at school age. A comparison with their classroom peers indicates a level of impairment that is greater than is recognized with the use of standardized norms.
authors.affiliation: School of Human Development, University of Nottingham, Nottingham, United Kingdom. neil.marlow@nottingham.ac.uk
authors.forename: Neil
authors.initials: N
authors.lastname: Marlow
authors.forename: Dieter
authors.initials: D
authors.lastname: Wolke
authors.forename: Melanie A
authors.initials: MA
authors.lastname: Bracewell
authors.forename: Muthanna
authors.initials: M
authors.lastname: Samara
mesh_terms: D016022:Case-Control Studies; D002547:Cerebral Palsy / Q000453:epidemiology; D002648:Child; D003072:Cognition Disorders / Q000453:epidemiology*; D002658:Developmental Disabilities / Q000453:epidemiology*; D019988:Children with Disabilities / Q000145:classification; D005260:Female; D005500:Follow-Up Studies; D005865:Gestational Age; D006801:Humans; D007231:Infant, Newborn; D007234:Infant, Premature; D007360:Intelligence; D007361:Intelligence Tests; D008297:Male; D009422:Nervous System Diseases / Q000453:epidemiology*; D009483:Neuropsychological Tests; D012016:Reference Values