Mr Mammy
What’s at stake for older dads?
“It’s very well-documented: Men are having children later into life,”
Actor George Clooney, 55, will soon to be a father to twins with his wife, human rights lawyer Amal Clooney, 39 — reigniting a conversation about what it means to be an older dad.
Despite growing awareness of in-vitro fertilization and aging mothers — such as Janet Jackson, who gave birth last month at 50 — some of the science and social impacts of aging fathers are less clear. But that isn’t deterring hopeful dads from growing their families.
“It’s very well-documented: Men are having children later into life,” said Dr. Mary Samplaski, a male-fertility specialist at Keck Medicine of the University of Southern California. “It’s become so much more mainstream.”
Men’s fertility does not drop as sharply as women’s as they age, said Samplaski; many can have biological children long after they’re old and gray without the need for technology to intervene. But some of Samplaski’s patients have questions about the risks of fathering later in life.
Knowing the risks
A Swedish study in 2014 added to the evidence that dads older than 45 are more likely to have children with schizophrenia, autism and other psychiatric disorders. Still, even for these fathers, the absolute risk was found to be very low — well below 1% for certain conditions.
For one man who saw the study, the findings pushed him into action.
“I reported on a big study that came out in 2014, and I thought a lot about it, and a few months later, I went and banked my own sperm,” former CNN producer William Hudson said in August.
“I banked my sperm because I wanted to have the option of using younger sperm later in life.”
To explain the link between mental illness and paternal age, researchers have pointed to the mutations that accumulate in sperm DNA as men get older, which may be inherited by their sons and daughters.
There are no genetic tests for psychiatric illnesses such as autism spectrum disorder and schizophrenia, Samplaski said.
However, last year, another study in Nature Genetics took an opposing view: Spontaneous mutations in sperm DNA were not largely to blame for the increased risk of psychiatric illness. The researchers found that genes might contribute to this risk, but only a small portion of it — about 10% to 20%.
A closer look at the data shows that mental illness isn’t just linked to older fathers; there’s a risk among younger fathers, too. Some researchers say the focus on mutations could be a red herring. According to the authors of the Nature Genetics study, fathers with a heritable mental illness may simply be more likely to have children at the extremes of age — perhaps because they socialize or take risks differently.
