Cluster of perinatal events identifying infants at high risk for death or disability.

To determine the prognostic import of neonatal seizures according to the presence or absence of certain other postnatal characteristics, we studied a population of 39,000 infants with birth weight greater than 2500 gm. Children with clinically recognized neonatal seizures and 5-minute Apgar scores less than or equal to 5 and who had at least one of five signs compatible with neonatal encephalopathy had a risk for first-year death of 33%. Survivors of this cluster of events (low Apgar score-abnormal signs-seizures) had a risk for motor disability of 55%. In contrast, survivors of neonatal seizures who did not have poor Apgar scores or other abnormal signs had a risk for motor disability of only 0.13%. Thus, among infants with neonatal seizures the risk for cerebral palsy was 420 times greater if there had been a low 5-minute Apgar score and other neonatal signs. Low Apgar score-abnormal signs-seizures constituted a cluster of events that served to identify, within the first days of life, a tiny subgroup of term newborn infants in whom risk for chronic motor disability was 55%, and for death or disability was 70%.