Cerebral palsy following term newborn encephalopathy: a population-based study

Cerebral palsy (CP) can occur in term infants with or without preceding newborn encephalopathy, We compared the type and severity of CP and associated disability in these two groups. Participants from a population-based case-control study of term newborn encephalopathy were followed up for 6 years and linked to the Western Australian Cerebral Palsy Register. The remaining term infants with CP for the same period were also identified from the Cerebral Palsy Register. 13% of neonatal survivors of term newborn encephalopathy had CP, a rate of 116 per 1000 term live births. Overall, 24% of term infants with CP followed newborn encephalopathy. CP following newborn encephalopathy was more likely to: affect males (72% vs 56%); be severe (47% vs 25%); and be of spastic quadriplegia or dyskinetic types. Cognitive impairment was more common (75% vs 43%) and severe (41% vs 16%), as was epilepsy (53% vs 29%) in survivors of encephalopathy. These children were also more likely to: be non-verbal (47% vs 22%); have a severe composite disability score (47% vs 26%); and die between time of diagnosis of CP and age 6 years (5-year cumulative mortality 19% vs 5%). Children born at term who develop CP following newborn encephalopathy have a poorer prognosis than those with CP who were not encephalopathic in the first week of life. Cerebral palsy (CP) remains a common and disabling condition in which the diagnosis may not be confirmed until the age of 5 years. Although some cases of CP follow newborn encephalopathy, for many the neonatal period was uneventful (Nelson and Ellenberg 1987). With the exception of the study by Gaffney et al. (1994), there have been few studies of CP that have examined the differences between these two groups of children in terms of the type and severity of CP and the range of associated disabilities. In the mid-1990s we performed a population-based case-control study in Western Australia to investigate the aetiology of moderate to severe newborn encephalopathy (Badawi et al. 1998a,b). We have subsequently followed up both case and control children to the age of 5 years to determine their developmental outcome including the presence of CP Using the Western Australian Cerebral Palsy Register we have also reviewed the details of all patients with CP born at term in the same period who did not have newborn encephalopathy. Before a detailed causal pathway analysis is carried out, in this paper we compare the type and severity of CP and the pattern of associated disability in these two groups of children with CP who were born at term.