TREND IN CEREBRAL-PALSY BIRTH PREVALENCE IN EASTERN DENMARK - BIRTH-YEAR PERIOD 1979-86

To investigate changes in cerebral palsy birth prevalence and perinata l mortality rate by different gestational age groups, 1979-86, cerebra l palsy cases in eastern Denmark were identified from the Danish Cereb ral Palsy Register, and information on birth and mortality rates was s ought in the Danish Medical Birth Register. From 1979-82 to 1983-86, t he birth prevalence of cerebral palsy increased from 2.6 to 3.0 per 10 00 (P < 0.05). The rate for infants of 31 weeks' gestation or more did not change, whereas a significant increase was observed in infants be low 31 weeks (85-123 per 1000, P < 0.05). In the same periods, perinat al mortality in eastern Denmark decreased significantly from 8.6 to 7. 8 per 1000. The decrease in stillbirth rate was significant in all sub groups of gestational ages except in those of 28-30 weeks' gestation. The early neonatal mortality rate decreased significantly only in infa nts below 31 weeks (282-239 per 1000, P < 0.05). Thus, in eastern Denm ark, cerebral palsy birth prevalence has increased from birth-year per iod 1979-82 to 1983-86 because of an increased rate in preterm infants below 31 weeks, who at the same time had a reduced risk of early neon atal death.