A new study conducted at the University of Wisconsin School of Medicine and Public Health, Madison showed that the risk of autism increases for older parents. Researchers analyzed the data of 253 347 children born in 1994. They had the information of both parent's age of 1251 children diagnosed with autism at age 8.
It was found that mothers aged 35 and older were 30 percent more likely to have autistic child than mothers aged between 25 and 29. Fathers aged over 40 years old were also at greater risk of having a child diagnosed with autism.
The findings also showed that first child born from two older parents was three times more likely to have autism than third child or a child born from younger mother and father. Previous research showed that there is a link between mother's educational level and the risk of autism in children. Dr Maureen Durkin, the leading researcher of the study said that it might actually be mother's age that contributed to the development of autism in her child than educational level, because more educated women tend to be older.
Scientists think that the link between parental age and autism in children can be due to several factors. One of these factors is genetic damage, occurring more often in older parents. Also, older parents have more risk of accumulating pollutants from the environment in their bodies, which increases the risk of developing autism disorder for their children.
Other possible explanations refer to the increased use of assisted reproductive technologies to treat infertility for older parents. From other point of view, psychological characteristics of older parents, who wait longer to have children, contribute to the increase of autism risk in children.
The findings were published in the American Journal of Epidemiology, the Reuters Health reported.