Abstract T MP64: Placental Pathology in Neonatal and Presumed Perinatal Arterial Ischemic Stroke

Abstract

Objectives: Arterial ischemic stroke (AIS) occurring around birth presents in the neonatal period (NAIS) or manifests later with evidence of remote stroke (presumed perinatal, PPAIS). Both likely result from fetal/neonatal, placental, and maternal risk factors. Few studies have focused upon placental abnormalities in NAIS/PPAIS. We hypothesized that placental pathology would reveal patterns of abnormality in NAIS/PPAIS. Methods: We retrospectively reviewed patients with neonatal or presumed perinatal stroke in a large children’s hospital since January 2005. Placental specimens requested for all cases of neonatal stroke were reviewed by one pathologist. Clinical data were collected on maternal and infant risk factors. Stroke type was determined by consensus neuroimaging review. Results: We identified 30 cases with placental specimens, including 20 (67%) AIS, 9 (30%) venous infarction, and 1 arterial and venous (both). Four cases were presumed perinatal, all AIS. Of AIS/both cases, 13 (65%) involved the middle cerebral artery territory, 2 (9.5%) involved perforators, and 6 (28%) were multifocal. Clinical risk factors were identified in 17 (57%). Of placental specimens, 28/30 (93%) showed abnormalities including uteroplacental malperfusion, fetal vascular flow restriction or thrombosis, chorioamnionitis, non-specific chronic villitis, and large placenta with chorangiosis. Fourteen cases (47%) had chorioamnionitis, 11 AIS and 3 venous, of which all AIS and 1 venous showed both maternal and fetal inflammation. In 15 cases (50%) meconium was found, including 13 AIS (62%) and 2 venous (22%). Two or more abnormalities appeared in 14 cases (47%). Meconium and chorioamnionitis with fetal-side inflammation were significantly more common in AIS than in venous cases (p = 0.047 and p = 0.003, respectively). Conclusions: Placental abnormality was common in NAIS/PPAIS even in the absence of clinical risk factors. Meconium and chorioamnionitis with fetal-side inflammation were especially prevalent in arterial cases. All findings were subacute to chronic and could reflect intrauterine stressors that may predispose to acute ischemic stroke in the perinatal period.