496 Association of placental pathology and autism spectrum disorders

Emerging findings suggest that perinatal factors may influence the risk of developing autism spectrum disorders (ASD). Abnormal placentation has been proposed as a potential factor. We aimed to evaluate association between placental pathology and gross morphology with ASD. conducted matched case-control study children confirmed who were born 2000 2017 at one three university-affiliated hospitals in Montreal, Quebec. Cases, identified through Montreal Children’s Hospital Autism Spectrum Disorders Program, babies (1:5) on same day hospital. Multi-fetal births excluded. Data pregnancy characteristics pathologies collected from maternal infant hospital charts by abstractors blind diagnoses. This is analysis data single-site had reports available. Pearson chi-squared Wilcoxon rank-sum tests used estimate p-values. During period, 107 this area later diagnosed Mothers cases controls similar parity, gravidity, BMI, no differences frequency chronic hypertension, gestational diabetes, clinical chorioamnionitis. slightly older age more frequently smokers. Cases likely male (78% vs 52%), earlier, heavier weight. There abnormalities controls, 18% each group possessing least abnormality, including chorioamnionitis, vasculitis, decidual inflammation, chorionitis, funisitis, villitis. Placental hypermaturity was common among (p=0.002). No weight, thickness, umbilical cord length, insertion found controls. suggests placentation, infections, or do not increase development