Research published over the last decade suggests that babies born to older men have an increased risk of arriving prematurely or developing birth defects, certain cancers or neurodevelopmental disorders, though the overall risk is still low.

"Older guys have been having babies since biblical days. It’s not a new phenomenon. What we didn’t understand was they might be producing kids with a higher risk of problems," said Arthur Caplan, a professor of medical ethics at NYU's Grossman School of Medicine.

The medical community does not have a consistent definition of so-called advanced paternal age, but the American Urological Association and American Society for Reproductive Medicine jointly recommend that doctors talk to men ages 40 and up about the increased risk of adverse health outcomes in their offspring.

"Men should be aware that they, too, go through the same reproductive aging cycle as women, despite the fact that they don't have menopause," said Dr. Gloria Bachmann, associate dean for women’s health at Rutgers Robert Wood Johnson Medical School.

A 2019 study determined that a father's age has a significant impact on a child's health and development. The study found that babies born to older fathers had an increased risk of cleft lip or palate, heart defects, autism, schizophrenia and bipolar disorder. Additional research suggests that advanced paternal age is moderately associated with the most common form of childhood leukemia and linked to a slightly elevated risk of pediatric non-Hodgkin lymphoma.

In 2018, researchers at Stanford University found that babies born to fathers ages 45 or older were 18% more likely to have seizures and 14% more likely to be born premature compared with babies born to fathers ages 25 to 34.

That study also noted a risk to pregnant people: The partners of men ages 45 and older were 28% more likely to develop gestational diabetes than those of men ages 25 to 34.

"The absolute risk does remain relatively low. For an individual, it may not be as meaningful. But certainly on a population level, if we're looking at societal changes where parents are getting older, then it may be this measurable increase in some of these disorders," said Dr. Michael Eisenberg, an author of that study and a urology professor at Stanford University School of Medicine.

Eisenberg said men, on average, accumulate about two mutations in their sperm’s DNA every year, which may help explain why health risks for their babies increase as they age.

But men are, on average, procreating later in life in the U.S.

Fifty years ago, around 4% of infants were born to fathers over age 40, according to Eisenberg’s analysis of data from the Centers for Disease Control and Prevention. By 2015, that number had risen to around 9%.

"We've seen basically doubling rates of older fathers," Eisenberg said.

Considerations for older fathers

Caplan said many older men who are considering having kids don't receive the same reproductive counseling that older women do.

"There’s a whole system set up to sort of deal with older women who want to have children and the risks that they pose to the children that isn’t set up for men," he said.

The disparity is rooted in sexism, he said, and amplified by lighthearted news coverage of older male celebrities having kids.

"There’s an attitude: 'This guy’s 80. He’s still reproducing. That’s cool,'" Caplan said. But the decision to have a child later in life, he added, should be made carefully with a doctor and take into account a man's individual health status and economic situation.

Even then, he added, there's the ethical concern that an older father won't live long enough to participate in much of his child's life.

"It’s not great for offspring to only have one parent, even if they’re rich," Caplan said.

However, Bachmann said age should be one of many factors that men weigh when deciding whether to reproduce. Some men are better listeners, role models and teachers in their older years, she said.

"They may actually be a better father at 61 than they would have been at 21," Bachmann said.

She recommended that men who want to delay having kids consider sperm banking at younger ages if they have the financial means to do so. Older men considering fatherhood should prepare for the possibility of not raising their child to adulthood, she added.

"If an individual who is advanced age is going to become a parent, the child should have a community that is going to be comforting, that's going to be supportive and that will be there if something should happen to one or both parents," Bachmann said.