Research has found that a dad’s age at conceiving poses more risk to a baby’s health than the age of the mother, reports the BBC.
The results reveal that the sperm of older men affects the number of genetic mutations that can be passed on to a child.
Decode Genetics studied the DNA of 78 parents with children diagnosed with autism or schizophrenia and found that the father’s age was crucial to the genetic risk of such disorders.
Sperm from an older man has more DNA faults likely to lead to miscarriage, autism and mental illness, than that of a 20-year-old.
“The average age of fathers has been steeply rising since 1970. Over the same period there’s been an increase in autism,” said Dr Kari Stefansson, chief executive of Decode Genetics.
“It’s very likely that part of that rise is accounted for by the increasing age of the father.”
A young father passes on average 25 mutations to his child while a 40-year-old can pass on around 65.
The study suggests that mutations increase with age, with men risking passing on two more mutations to children every year they delay fatherhood.
It’s the first study to link a dad’s age with possible health risks to children after decades of research emphasising the age of mums.
“Society has been very focused on the age of the mother. But apart from [Down’s Syndrome] it seems that disorders such as schizophrenia and autism are influenced by the age of the father,” says Dr Kari.
One researcher has suggested men should consider freezing their sperm if they wanted to have a family later in life.