Outcomes after Neonatal Seizures in Infants Less Than 29 Weeks' Gestation: A Population-Based Cohort Study

OBJECTIVE: The aim of this study was to evaluate the association between neonatal seizure and neurodevelopmental impairment (NDI) at 18 to 24 months in extremely preterm neonates. The association between anticonvulsants use and NDI was also assessed. STUDY DESIGN: In this retrospective cohort study of infants born at <29 weeks' gestation from the Canadian Neonatal Network and Canadian Neonatal Follow-Up Network databases, we compared mortality and neurodevelopmental outcomes in infants who had neonatal seizures with those without seizures after adjusting for confounders. RESULTS: Of the 2,762 eligible neonates, 133 (4.8%) had seizures. Infants who had seizures were of lower gestation (25.2 vs. 26.2 weeks) and birth weight (819 vs. 920 g) and had higher rates of adverse outcomes. Neonatal seizure was associated with higher odds of composite outcome of death or significant NDI (74 vs. 27%; adjusted odds ratio [OR]: 3.4; 95% confidence interval [CI]: 2.2-5.4). Death or significant NDI was higher in infants with seizures treated with anticonvulsants than those without treatment (89 vs. 70%); however, when adjusted for confounders, it was not significantly different (adjusted OR: 3.5; 95% CI: 0.83-14.6). CONCLUSION: Neonatal seizures were independently associated with higher odds of death or significant NDI at 18 to 24 months of age. Relationship of anticonvulsant and neurodevelopmental outcomes needs further studies.