(CNN) William Hudson has yet to meet the future Mrs. William Hudson, and so he's not taking any chances: When he was 28, he froze his sperm.
Hudson has read the science suggesting that older men are less fertile than younger men and that when they do father a child, that child is more likely to have a whole host of health problems.
"I'm not getting any younger," said Hudson, now 30. "I banked my sperm because I wanted to have the option of using younger sperm later in life."
Hudson is one of a small but growing group of single young men who've chosen to store their sperm, just as single young women have stored their eggs.
A few dozen men like him have ponied up $450 a year to store their sperm at California Cryobank out of fear of advanced paternal age, according to Scott Brown, the bank's communications director.
"It's still pretty rare at this point," Brown said. "But it is a small trend."
Hudson's "aha moment" came when he was a producer for CNN.
"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," he said.
That study, of 2.6 million Swedish children, found that children of older fathers were more likely to have certain psychiatric disorders.
When the fathers were 45 and older, their children were three times more likely to have an autism spectrum disorder, 13 times more likely to have attention deficit hyperactivity disorder and 25 times more likely to have bipolar disorder than the children of fathers 20 to 24.
Later, Hudson got even more steeped in the study of sperm.
He left CNN to go to Yale Law School, where he wrote an award-winning article about sperm storage for the Food and Drug Law Journal.
In it, he chronicles more than half a decade's worth of research linking older sperm to health problems.
According to the Mayo Clinic, studies show that the offspring of men older than 40 might face an increased risk of autism and schizophrenia as well as birth defects, such as the bone growth disorder achondroplasia.
One explanation is that as sperm age, they develop more genetic mutations. Researchers in Iceland looking at 78 families found that 20-year-old fathers passed on an average of 25 mutations, but 40-year-old fathers passed on 65 mutations, an increase of two new mutations per year.
The Mayo Clinic also points out that older men have a slightly more difficult time conceiving a child.
That finding is not surprising given that semen volume, sperm motility -- how well the sperm swim -- and morphology -- the percentage of sperm that are normal -- decrease with age, according to researchers at the Institute of Reproductive Medicine in Germany at the University of Münster.
For all these reasons, Dr. Harry Fisch had advised his two sons to father children in their late 20s or early 30s.
But Fisch, a clinical professor of urology and reproductive medicine at Weill Cornell Medical College, said he wouldn't go so far as to tell his sons to bank their sperm if they arrived at their early 30s without any marriage prospects.
Fisch, author of the book "The Male Biological Clock: The Startling News About Aging, Sexuality, and Fertility in Men," said he thinks that what Hudson and other men are doing "may be excessive."
Though studies do suggest that there is an increased risk with advanced paternal age, he said, the risk of any man having a problem is "extremely small," so the increased risk for older fathers is "a very low number."
Plus, he said, there's no data telling us at what age a man's sperm might start becoming problematic, so it wouldn't be clear when he should use his stored sperm instead of fathering a child naturally.
"Does it begin at 40? Does it begin at 50? Some other age? We just don't know," he said.
Others think banking sperm at a young age isn't "excessive" at all.
Writing in the journal Nature, Alexey Kondrashov, a biologist at the University of Michigan, said that if advanced paternal age leads to substantial health problems for children, "then collecting the sperm of young adult men and cold-storing it for later use could be a wise individual decision."
Kevin Smith, a bioethicist at Abertay University in Scotland, took it one step further, suggesting that storing sperm should "become the norm." His suggestion was roundly criticized by his colleagues, according to the BBC.
Hudson doesn't know whether he'll ever use his stored sperm; he'll figure that out with his future wife, when he meets her.
In the meantime, he said, it's nice to know it's there, waiting for him at a cryobank in New York.
He calls it "an insurance policy."
"I felt like it was better to be safe," he said. "This might not be for everybody, but for me, it makes sense."