Perinatal risk factors for SUDEP: A population-based case-control study

Sudden unexpected death in epilepsy (SUDEP) is a leading epilepsy-related cause of death. Researchers have highlighted the similarities between SUDEP and sudden infant death syndrome (SIDS), but perinatal risk factors such as those identified for SIDS have not been assessed previously for SUDEP. We conducted a population-based case-control study of 58 SUDEP individuals and 384 living epilepsy controls born after 1982, utilizing the Swedish Medical Birth Register together with other national health registers and individual medical records to examine if prenatal and perinatal factors are associated with SUDEP risk. We observed a 3-fold SUDEP risk increase for infants who were small for gestational age (SGA) (odds ratio [OR] 3.13; 95% confidence interval [CI] 1.05-9.30) and for those with an Apgar score of 0-6 compared to 9-10 at 10 min (OR 3.22; 95% CI 1.05-9.87). After adjusting for a number of known SUDEP risk factors, we observed that the Apgar score between 0 and 6 after 10 min had a 10-fold increased risk for SUDEP OR 10.37 (95% CI 1.49-72.01) and over a 2-fold risk for those born after the 40th gestational week (OR 2.42; 95% CI 1.03-5.65). The potential mechanisms linking low Apgar score, gestational age, and SGA to SUDEP risk remain to be explored.