Parental age is a well known contributing factor to autism in children. But a new study analyzing more than five million births has found that maternal age is far more important than paternal age. “Although fathers’ age can contribute risk, the risk is overwhelmed by maternal age,” University of California at David research Janie Shelton, the study’s lead author, told the Today Show.
Mother’s older than forty were about fifty percent more likely to have a child with autism than those in their twenties, while fathers in their forties only raise their risks by thirty six percent.
These finding contradict previous research that suggested that father’s age was the bigger factor, though paternal age does seem to have an increased influence when older fathers are paired with younger mothers. Children born to mothers under twenty five with fathers over the age of forty have twice the chance of being autistic than they would if their father was in his twenties as well.
Autism experts find this latest study more convincing than previous ones, partly because it’s larger. Maternal age is also well known to be the stronger contributing factor in other genetic disorders, so it makes sense that this also be the case in autism.
Maureen Durkin, a University of Wisconsin research who studies the link between parental age and autism, points out that it’s important to note that the increased risks are small and that most older mothers give birth to perfectly healthy children. In fact, even this latest study suggests that the risk of a woman over forty having an autistic child is still less than four in one thousand.
