The quality of preterm infants' spontaneous movements: an early indicator of intelligence and behaviour at school age

Abstract

BACKGROUND: The quality of very preterm infants' spontaneous movements at 11 to 16 weeks post-term age is a powerful predictor of their later neurological status. This study investigated whether early spontaneous movements also have predictive value for the intellectual and behavioural problems that children born very preterm often experience. METHODS: Spontaneous movement quality was assessed, using Prechtl's method, at 11 to 16 weeks post-term in 65 infants born at <or= 33 weeks of gestation in a single centre. Intelligence and behaviour were assessed with standardised tests at 7 to 11 years of age. Neurological status was assessed with Touwen's test. Multiple regression was used to determine the predictive value of movement quality for intelligence and behavioural problems. The Sobel test was used to determine if neurological status mediated associations found between early movement quality and outcome. RESULTS: Spontaneous movement quality at 11 to 16 weeks post-term was significantly, positively associated with later intelligence. The number of normal postural patterns displayed contributed most strongly to the association, which was not mediated by neurological status. Fidgety movements, strong predictors of later neurological dysfunction, were not associated with intelligence. Spontaneous movement quality was not associated with internalising or externalising problems but showed a trend to an association with attention problems. CONCLUSION: These findings suggest that, in children born preterm, early spontaneous movement quality has clear prognostic value for neurological and intellectual outcome, and to a lesser extent, for attentional outcome. However, cognitive outcome was associated with the presence of specific, age-appropriate postural patterns, while neurological outcome has been associated with the presence of global movement abnormalities. The presence of specific, age-appropriate postural patterns may reflect the integrity of areas of the brain involved in cognitive processing and the regulation of attention later in childhood. Alternately, it may facilitate cognitive and attentional development.