CLINICAL AND SUBCLINICAL DEFICITS AT 8 YEARS IN A GEOGRAPHICALLY DEFINED COHORT OF LOW-BIRTH-WEIGHT INFANTS

Objective - To determine the prevalence of subclinical deficits in cog nitive and motor function in low birthweight infants. Design - Childre n of birth weight less than or equal to 2000 g born to mothers residen t in Merseyside in 1980-1 assessed using the Wechsler Intelligence Sca le for Children (WISC), the Neale analysis of reading ability, and the Stott-Moyes-Henderson test of motor impairment (TOMI). Children atten ding normal schools assessed with controls matched for age, sex, and c lass in school. Children attending special schools were assessed unmat ched. Subjects - 233 matched index case-control pairs attending normal primary schools and 46 unmatched children attending special schools. Setting - Primary and special schools. Main outcome measures - IQ scor e, reading age in months, and TOMI score. Results - Index cases when c ompared with controls had a lower WISC score (mean IQ difference 8.8; 95% confidence interval (CI) 6.8 to 10.7), a lower reading age (mean d ifference 6.5 months; 95% CI 4.0 to 9.0), and poorer motor performance as shown by the TOMI score (mean difference 1.4; 95% CI 1.1 to 1.8). Of the children attending special schools, 23/46 (50%) had a WISC scor e less than or equal to 50. Conclusions - Low birthweight children hav e significant subclinical deficits of cognitive and motor function and extra resources, especially in education, may be required to meet the ir needs.