[Neonatal arterial ischemic stroke in term or near-term newborns: prevalence and risk factors]

The general designation ischemic perinatal stroke includes several disease states that differ in pathophysiology, timing of occurrence and presentation. While it seems logical to assume that their prevalence and their risk factors depend primarily on the considered type of stroke, most studies used inconsistent definitions or included heterogeneous populations, which limits their accuracy. Given these biases, the French Society of Neonatology and the French Centre for Paediatric Stroke wished to update the knowledge in this domain, focusing on a specific form of perinatal stroke, i.e neonatal arterial ischemic stroke (NAIS) in term or near term newborns. A comprehensive analysis of published epidemiological data was dedicated to the following issues: Is the prevalence of NAIS well defined from epidemiological studies? What are the best recognized risk factors and is it possible to delineate a maternal and fetal population at risk for this condition? On July 31, 2015 a total of four hospitalized-based and five population-based studies, and six case-control studies were found. The conclusions are the following: The prevalence of NAIS in term or near term newborns varies from 6 to 17/100,000 live births (level of evidence 2). NAIS represents a half of total ischemic perinatal strokes (i.e. including those with delayed presentation as well) and one fourth of perinatal strokes (i.e. including cerebral haemorrhage stroke as well). Four sets of risk factors are consistent across different studies (level of evidence 3): (1) male sex, (2) obstetrical determinants (first pregnancy, caesarean section), and two peripartum complications: (3) intrapartum hypoxia and (4) materno-fetal/neonatal infection. Bacterial meningitis, cardiac disorders/procedures and invasive care such as extra-corporeal circulation carry a risk of NAIS as well. A registry could help refining epidemiological descriptive data. It could also be used to develop etiological studies focusing on pathophysiological hypotheses derived from the identified aforementioned risk factors.