Sorg AL, von Kries R, Klemme M, et al. - In this large case-control study, researchers identified maternal, obstetric, and neonatal risk factors associated with perinatal arterial ischaemic stroke (PAIS) diagnosed within 28 days after birth and analyzed the underlying pathophysiology. Active surveillance was used in 345 paediatric hospitals and a population-based perinatal database for quality assurance of hospital care for case and control ascertainment. Using logistic regression, complete cases of PAIS was analysed. One hundred thirty-four people with PAIS and 576 comparison people were analyzed after exclusion of records with missing data. Male sex, preterm birth (< 37 wk gestational age), small for gestational age (SGA), low umbilical artery pH (< 7.1), low 5-minute-Apgar score (< 7), multiple pregnancies, hypoxia, intubation/mask ventilation, nulliparity, Caesarean section, vaginal-operative delivery, chorioamnionitis, and oligohydramnios were linked to an increased risk in univariate analysis. The mutual adjustment resulted as independent risk factors in the male gender, multiple birth, chorioamnionitis, preterm birth, and SGA. They confirmed the role of chorioamnionitis and SGA for PAIS, highlighting the importance of inflammatory processes and fetal-placental insufficiency. Additional risk factors have been identified as multiple births and preterm birth.