ASSESSING THE CONTRIBUTION OF BIRTH ASPHYXIA TO CEREBRAL-PALSY IN TERM SINGLETONS

In a geographically-based study, we investigated the risk of cerebral palsy following intrapartum asphyxia at term, and the contribution of intrapartum asphyxia at term to the overall rate of cerebral palsy. We used stringent criteria for identifying intrapartum asphyxia, while r ecognising that the initial hypoxial insult might have occurred in the antenatal period. In the first part of the investigation, a cohort of 160 term, singleton infants, with a low (less than or equal to 3) 1-m inute Apgar score, was followed to the age of 5 years. Six infants in the cohort had presumed intrapartum asphyxia, of whom two died in the neonatal period, three had spastic quadriparesis, profound development al delay and visual impairment, and one was unimpaired. The frequency of cerebral palsy associated with birth asphyxia was estimated as one in 3700 full-term livebirths. To assess the impact of birth asphyxia o n the overall rate of cerebral palsy, all cases of cerebral palsy born in the study period were identified. Of the 30 cases, the three ident ified in the follow-up study were the only ones whose impairment could be attributed to birth asphyxia in a fullterm birth. Birth asphyxia a t term therefore was associated with 10% [95% confidence interval (CI) 2.1,26.5] of all cases of cerebral palsy and with 20% (95% CI 4.3,48. 1) of the 15 cases of cerebral palsy in children born at term.