Respiratory distress syndrome in preterm infants and risk of epilepsy in a Danish cohort

Infant respiratory distress syndrome (IRDS) may be complicated by intracerebral hemorrhage, a known trigger of epilepsy. However, few data exist on long term epilepsy risk following IRDS. We therefore examined the association between IRDS in preterm infants and childhood epilepsy. We conducted a population-based cohort study using individual-level data linkage among nationwide registries. All infants born at 32-36 weeks of gestation in 1978-2009 were identified in the Medical Birth Registry. We identified children with IRDS and those with epilepsy using the Danish National Patient Registry. We computed the cumulative incidence of epilepsy with follow-up from birth until epilepsy, emigration, death, age 15, or December 31, 2014. We used Cox's regression analysis to compute hazard ratios comparing children with and without IRDS, adjusting for sex, birth year, gestational age, multiplicity, major malformations, and maternal age. We identified 95,026 infants, of whom 6426 (6.8%) had IRDS. The cumulative incidence of epilepsy was 3.4% by age 15 in children with IRDS and 2.1% in children without IRDS. The adjusted hazard ratio of epilepsy among children with IRDS compared to those without was 1.4 (95% CI 1.2-1.6). When we restricted the IRDS cohort to children with no simultaneous morbidities that had clinical symptoms overlapping with IRDS, the overall adjusted HR was 1.1 (95% CI 0.9-1.4). In children born preterm at 32-36 weeks' gestation, IRDS was associated with increased risk of childhood epilepsy.