Senior author Dr. Harvey Kliman, research scientist in the Department of Obstetrics, Gynecology & Reproductive Sciences at the Yale School of Medicine, and colleagues at the MIND Institute at the University of California, Davis, said the finding allows for earlier diagnosis and treatment.
The researchers found abnormal placental folds and abnormal cell growths called trophoblast -- cells which provide nutrients to the embryo and develop into a large part of the placenta -- inclusions are key markers to identify newborns who are at risk for autism.
Kliman and his team examined 117 placentas from infants of at-risk families, those with one or more previous children with autism. These families were participating in a study called Markers of Autism Risk in Babies -- Learning Early Signs. Kliman compared these at-risk placentas to 100 control placentas collected by researchers at the University of California, Davis, from the same geographic area.
The at-risk placentas had as many as 15 trophoblast inclusions, while none of the control placentas had more than two trophoblast inclusions.
The study, published in the journal Biological Psychiatry, said a placenta with four or more trophoblast inclusions conservatively predicted an infant with a 96.7 percent probability of being at risk for autism.