Incidence of neonatal seizures, perinatal risk factors for epilepsy and mortality after neonatal seizures in the province of Parma, Italy.

OBJECTIVE: Information about the incidence of neonatal seizures (NS) is scarce. Previous studies relied primarily on a clinical diagnosis of seizures. This population-based, retrospective study evaluated the incidence of electroencephalography (EEG)-confirmed seizures in neonates born in the province of Parma and the perinatal risk factors for mortality and epilepsy.

METHODS: All neonates with suspected seizures or with medical conditions at high risk for seizures from the study area were recorded in the neonatal intensive care unit (NICU) of the Parma University Hospital. NS were EEG confirmed. Perinatal risk factors for mortality and epilepsy after NS were evaluated with Cox's proportional hazards models.

RESULTS: In a 13-year period, 112 patients presented with NS: 102 newborns had electroclinical seizures (46 full-term and 56 preterm), whereas 10 presented only electrical seizures. The incidence was 2.29/1000 live births (95% confidence interval [CI] 1.87-2.72), with higher rates in preterm neonates (14.28/1000 in preterm vs 1.10/1000 in full-term infants). The incidence increased with decreasing gestational age (31-36 weeks of gestation: 5.01/1000, 28-30: 54.9/1000, and <28: 85.6/1000) and with decreasing birth weight (≥2500 g: 1.19/1000, <1000 g: 127.57/1000). Twenty-eight patients (25%) died, 16 (14.3%) had a diagnosis of epilepsy, 33 (29.5%) had cerebral palsy, and 39 (34.8%) had a developmental delay. Among the perinatal risk factors considered, the multivariate analysis showed an association between a 5-minute Apgar score of 0-7 and etiology with increased mortality and between female gender and status epilepticus with epilepsy.

SIGNIFICANCE: The incidence of NS is inversely associated with gestational age and birth weight. The etiology and a low Apgar score are strongly related to mortality; female gender and status epilepticus are risk factors for the development of epilepsy.