A changing panorama of cerebral palsy? A population-based study of children born during the 20-year period 1970-89
Tidsskr Nor Laegeforen, 116 (26):
3118--3123 (October 1996)Abstract
In a population-based study cerebral palsy was diagnosed in 110 cases (2.4 per 1,000) among live born children with birth weight > or = 500 g (N = 45,976) during the 20-year period 1970-89 (cerebral palsy cases with a postneonatal etiology excluded). The incidence of cerebral palsy showed a linear declining trend from 2.8 per 1,000 in the first five-year cohort born 1970-74 to 2.0 per 1,000 in children born 1985-89 (p = 0.17). 15.9\% of the decline in incidence of cerebral palsy from the first to the second ten-year cohort could be explained by a decreasing rate of low birth weight (500-2,499 g) in the population, from 4.2\% 1970-79 to 3.8\% 1980-89 (p < 0.05). The neonatal mortality rate declined significantly from 7.2 per 1,000 in the first to 3.9 per 1,000 in the last ten-year cohort respectively (p < 0.01). More children with cerebral palsy born in the ten-year period 1980-89 were treated with mechanical ventilation in the neonatal period (13/46; 28.3\%) than such children born in the ten-year period 1970-79 (4/64; 6.3\%) (p < 0.01). The results contrast with the traditional findings of a higher incidence of cerebral palsy incidence following improved survival of infants with low birth weight. Our results may reflect a more integrated development of perinatal care. Research on ways of preventing low birth weight may allow us to lower the incidence of cerebral palsy still further.