Autism Spectrum Disorders (ASD) may be associated with parental age during pregnancy. A Finnish study reports associations between various ASDs and parental age starting in the teenage years. Researchers evaluated parental age in 4,713 cases of ASD, including 1,796 cases of PDD (pervasive developmental disorder), 1,785 cases of Asperger's syndrome and 1,132 cases of autism. All data were pulled from a Finnish prenatal autism study.
Children born to teen mothers (19 and younger) were more likely to be diagnosed with PDD. PDD was also diagnosed more often in mothers ranging from 35 to younger than 40, as was Asperger's syndrome. Autism was most often detected in children born to mothers between 35 and 49 during pregnancy.
Source: Lampi KM, Hinkka-Yli-Salomäki S, Lehti V, Helenius H, Gissler M, Brown AS, Sourander A. Parental Age and Risk of Autism Spectrum Disorders in a Finnish National Birth Cohort. J Autism Dev Disord. 2013 Mar 12.