A small study that examined brains from children who died found abnormal patterns of cell growth in autistic children. The research bolsters evidence that something before birth might cause autism, at least in some cases.
The authors said the clusters are likely defects that occurred during the second or third trimesters of pregnancy.
Scientists have been working for decades to find the cause of autism, and they increasingly believe its origins begin before birth. In addition to genetics, previous research suggests other factors might include infections during pregnancy, preterm birth and fathers’ older age at conception.