Abstract 51: The Incidence of Perinatal Stroke is 1:1200 Live Births: A Population-Based Study in Alberta Canada

Abstract

Introduction: Perinatal stroke encompasses six cerebrovascular syndromes which occur between the 20 th week of gestation and the 28 th post-natal day. Morbidity is significant including motor, language, behavioral, and cognitive challenges, as well as epilepsy. Acute presentations include neonatal arterial ischemic stroke (NAIS), neonatal cerebral sinovenous thrombosis (CSVT), and neonatal hemorrhagic stroke (NHS). Delayed presentations include arterial presumed perinatal ischemic stroke (APPIS), periventricular venous infarction (PVI), and presumed perinatal hemorrhagic stroke (PPHS). Inconsistent terminology and lack of population-based cohorts has limited accurate measurement of disease-specific perinatal stroke incidence. Our objective was to define the incidence of the subtypes of perinatal stroke using a population-based cohort. Methods: The Alberta Perinatal Stroke Project is a research cohort established in 2008 in Southern Alberta, Canada (population ~2.1 million). Leveraging universal health care at a single tertiary care pediatric center facilitated true population-based epidemiology. Patients included had neuroimaging-confirmed perinatal stroke. Case acquisition included exhaustive retrospective hospital and ICD code searches (1990-2008) and prospective enrollment from all NICU and neurology/stroke clinics (2008-2018). Live birth rate denominators were determined from the provincial census. Results: The overall incidence of perinatal stroke in Southern Alberta from 2008-2018 was 81 cases per 100,000 live births, or 1 case per approximately 1200 live births. The incidence of NAIS was 31 per 100,000 (~1/3000), APPIS was 11 per 100,000 (~1/9000), PVI was 18 per 100,000 (~1/5500), and CSVT was 10 per 100,000 (~1/9800). The incidence of NAIS increased after implementing prospective case identification, from 8.5 (95% CI 5.3-11.6) per 100,000 to 31 per 100,000 (95% CI 24.4-38.2), p<0.00001, the remainder of stroke subtypes were stable over time. Conclusions: The overall incidence of perinatal stroke in Southern Alberta is 1:1200 live births. Population-based sampling of disease-specific states may explain why this rate is much higher than previous estimates.