lacental Trophoblast Inclusions in Autism pectrum Disorder

ackground: Microscopic examination of placental tissue may provide a route to assessing risk and understanding underlying iology of autism. ethods: Occurrence of a distinctive microscopic placental morphological abnormality, the trophoblast inclusion, was assessed using rchived placental tissue. The rate of occurrence of trophoblast inclusion-positive slides observed for 13 individuals with autism pectrum disorder (ASD) was compared to the rate in an anonymous consecutive birth cohort. esults: The occurrence of inclusion positive slides was significantly greater in the ASD group compared to the control group (6/27 lides, 22.2% vs. 12/154, 7.8%; Fisher Exact Test, two-tailed p .033; relative risk 2.85). The proportion of positive cases was also reater in the ASD group (5/13 cases, 38.5% vs. 8/61, 13.1%; Fisher Exact, two-tailed p .044; relative risk 2.93). Behavioral severity cores did not differ across groups of inclusion positive (N 4) and negative (N 8) ASD individuals. onclusions: Although probably not functionally detrimental or causative, the greater occurrence of placental trophoblast inclusions bserved in ASD individuals may reflect altered early developmental processes. Further research is required to replicate the basic inding, to understand the basis for the trophoblastic abnormality, and to determine the utility of the measure in early detection of ASD.