Objective: To study the incidence, clinical features, etiologic distribution, and day of seizure onset by etiology in neonates with seizures.
Design: Prospective, population-based study involving all the obstetric and neonatal units across the province of Newfoundland, Canada. All units were given educational sessions on neonatal seizure symptomatology.
Subjects: Detailed questionnaires were prospectively collected for all infants with probable neonatal seizures for a period of 5 years.
Results: The incidence rate was 2. 6 per 1000 live births, 2.00 for term neonates, 11.1 for preterm neonates, and 13.5 for infants weighing <2500 g at birth. Seizures lasting 30 minutes or longer were present in 5%, and the neonatal death rate among infants with seizures was 9%. Hypoxic-ischemic encephalopathy was the presumed cause in 40%, infections in 20%, and metabolic abnormalities in 19%.
Conclusions: Clinical neonatal seizures occur 6 times more often in preterm infants than in term infants. Hypoxic-ischemic encephalopathy continues to be a major marker of the likelihood of seizures.