PRENATAL EVENTS AND THE RISK OF CEREBRAL-PALSY IN VERY-LOW-BIRTH-WEIGHT INFANTS

The purpose of this study was to analyze associations between prenatal factors and cerebral palsy in a geographically based cohort of very l ow birth weight infants. Cases (n = 80) and controls had birth weights of 500-1,500 g and were born in 1978-1989, to a resident of one of 17 counties in northwest North Carolina. Medical records were reviewed f or data about prenatal and neonatal factors. Associations were analyze d separately for three clinical forms of spastic cerebral palsy (hemip legia, diplegia, and quadriplegia) and for cerebral palsy with and wit hout antecedent major cranial ultrasound abnormalities. The following factors were associated most strongly with an increased risk of cerebr al palsy: multiple gestation, chorioamnionitis, maternal antibiotics, antepartum vaginal bleeding, and labor lasting less than 4 hours. Pree clampsia and delivery without labor were associated with a decreased r isk. Evidence of confounding was found for each of these associations, except for those with chorioamnionitis and labor lasting less than 4 hours. The association with chorioamnionitis was stronger for diplegia (compared with hemiplegia and quadriplegia) and for cerebral palsy wi thout major cranial ultrasound abnormalities. Associations with antepa rtum vaginal bleeding (increased risk) and preeclampsia (decreased ris k) were stronger for cerebral palsy occurring with major cranial ultra sound abnormality.