HealthDay News — Parents’ ages may play a role in a child’s risk of developing autism spectrum disorders, according to research published in Molecular Psychiatry.
“The associations between older paternal age and autism spectrum disorders (ASD) is now well established. A risk increase with advancing maternal age has also been shown,” wrote Sven Sandin, PhD, a statistician in the department of medical epidemiology and biostatistics at the Karolinska Institute in Stockholm, and colleagues.
“There are, however, important issues to resolve. It is still not clear whether paternal and maternal ages represent independent risk factors.”
To test if advancing paternal and maternal ages are independently associated with ASD risk and estimate the functional form of the associations, the investigators culled data from 30,902 children with ASD and 5,766,794 without ASD in five countries.
Similar to the findings of past research, this study found the risk of having a child with ASD was 66% greater in fathers aged over 50 years compared with fathers aged 20 to 29 years. The risk for children of fathers in their 40s was 28% higher than for children of fathers in their 20s. Compared with mothers who had children in their 20s, children of women in their 40s were 15% more likely to have ASD.
Past research finding a higher risk of ASD among children with older fathers has suggested that genetic mutations from aging sperm may be related to development of ASD, but this study raises more questions, according to the researchers.
“This study cannot determine what the mechanisms are,” Sandin told HealthDay. “But it does suggest that degrading sperm is not likely to be the only mechanism that explains the relation between age of parents and autism. Other mechanisms are likely to be involved.”