Potentially asphyxiating conditions and spastic cerebral palsy in infants of normal birth weight.

OBJECTIVE Our purpose was to examine the association of cerebral palsy with conditions that can interrupt oxygen supply to the fetus as a primary pathogenetic event. STUDY DESIGN A population-based case-control study was performed in four California counties, 1983 through 1985, comparing birth records of 46 children with disabling spastic cerebral palsy without recognized prenatal brain lesions and 378 randomly selected control children weighing > or = 2500 g at birth and surviving to age 3 years. RESULTS Eight of 46 children with otherwise unexplained spastic cerebral palsy, all eight with quadriplegic cerebral palsy, and 15 of 378 controls had births complicated by tight nuchal cord (odds ratio for quadriplegia 18, 95% confidence interval 6.2 to 48). Other potentially asphyxiating conditions were uncommon and none was associated with spastic diplegia or hemiplegia. Level of care, oxytocin for augmentation of labor, and surgical delivery did not alter the association of potentially asphyxiating conditions with spastic quadriplegia. Intrapartum indicators of fetal stress, including meconium in amniotic fluid and fetal monitoring abnormalities, were common and did not distinguish children with quadriplegia who had potentially asphyxiating conditions from controls with such conditions. CONCLUSION Potentially asphyxiating conditions, chiefly tight nuchal cord, were associated with an appreciable proportion of unexplained spastic quadriplegia but not with diplegia or hemiplegia. Intrapartum abnormalities were common both in children with cerebral palsy and controls and did not distinguish between them.