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Think Men Can Have Kids Forever? The Truth About Male Age and Fertility
By Masaya Jimbo, MD, PhD Fertility Urologist, RMA Philadelphia
People commonly believe that fertility is a woman’s issue and men can have children indefinitely into their 70s or 80s, without any meaningful consequences. Men can produce sperm throughout their lives. But it doesn’t mean male fertility—or reproductive risk—remains the same over time.
Male Infertility Is More Common Than People Think
One of the biggest misconceptions about fertility is how often men are involved. Infertility is always a couple’s problem, and statistically, male infertility factors are involved far more often than people realize. About 15 percent of all couples experience infertility—clinically defined as the failure to conceive within 12 months of attempted conception—and approximately half of those cases involve a male fertility component. In about 30 percent of couples experiencing infertility, the issue is primarily male. In another 20 percent, both partners contribute. Only about 30 percent of all infertility cases are strictly female, with the remaining unexplained.
Yes, Men Can Have Children Later in Life — But Age Still Matters
As men age, we routinely see measurable shifts in sperm quantity and quality, including:
- Lower semen volume
- Decreased sperm motility
- Reduced sperm concentration
These changes may not prevent conception outright, but they reflect a broader biological reality that male reproductive function evolves over time. And the conversation does not end with sperm count alone – paternal age can also affect the health of offspring.
Professional societies, including the American Society for Reproductive Medicine, emphasize that paternal age is not biologically neutral. The ASRM Ethics Committee Opinion On Assisted Reproduction With Advancing Paternal And Maternal Age notes that advancing paternal age is associated with increased new genetic mutations and offspring risks, further reinforcing that male reproductive health evolves over time.
The same ethics committee opinion notes that advanced paternal age (defined as age >40), has been connected to spontaneous abortion, pre-eclampsia, pre-term birth, low birth weight, and stillbirth. Advanced paternal age is linked to birth defects and neurodevelopmental conditions such as autism, schizophrenia, and Klinefelter syndrome. Some data suggest that offspring of older fathers may have shorter lifespans and higher rates of cognitive or behavioral challenges.
The absolute risk for any individual child is still small — but it is meaningfully higher than it is for younger fathers.
Why Genetic Risk Increases as Men Age
Men continue producing sperm throughout their lives, which means sperm cells are constantly dividing and replicating. Every time a cell divides, there’s an opportunity for copying errors — known as de novo mutations, or new mutations that weren’t present in either parent before conception.
Women are born with all their eggs, but men continually produce sperm, and new mutations accumulate with age.
A large review of germline mutation data from Oxford Academic, Male reproductive ageing: a radical road to ruin, shows that males contribute the vast majority of new mutations to the couple’s offspring, and the rate increases steadily with age because sperm are produced continuously throughout life. It notes, “Around 75 percent of all de novo mutations in humans occur in the male germ line and are strongly associated with paternal age.”
When Should Men Get Tested?
Men often wonder whether they should get their sperm tested proactively, especially as they age.
There’s no blanket rule. Some younger men come for counseling or baseline analysis; many are referred after an abnormal result in their partner’s fertility workup.
National guidelines recommend evaluating both partners at the same time. Focusing solely on the female partner can delay answers and prolong stress.
What Sperm Counts Actually Mean
- Total motile sperm count (TMSC) ≥40–50 million gives couples a good chance of conceiving naturally within a year.
- When TMSC is between 10 and 40 million, the couple may benefit from intrauterine insemination (IUI).
- When TMSC is <10 million, IVF is usually recommended.
Men with very low counts can still achieve parenthood, though cost and access may limit options.
Testosterone: A Major and Growing Fertility Risk
One of the most concerning trends I see is the widespread use of testosterone and anabolic steroids, often prescribed casually or obtained online. In a peer reviewed article in Translational Andrology and Urology, researchers conclude that exogenous testosterone makes men infertile.
When testosterone is introduced from outside the body through injections, gels, or pills, the testicles stop producing their own testosterone. Over time, they shrink and stop producing sperm entirely. Fertility can sometimes recover after stopping testosterone, but recovery may take months or years, and some men never regain normal sperm production.
Younger men who take testosterone, believing it will boost health or masculinity, may actually impair their fertility.
Understanding Male Fertility
Men can have children later in life — but fertility is not ageless. Sperm quality changes. Genetic risk increases. And lifestyle choices, medications and health conditions all matter.
Male age isn’t as limiting as female age — but it is absolutely relevant. Being informed early allows couples to plan better, intervene sooner, and avoid surprises when starting a family.
About the Author:
Masaya Jimbo, MD, Ph.D. Fertility Urologist, RMA Philadelphia
He completed his Urology residency at the Mayo Clinic and his subspecialty fellowship in men’s health, male infertility, and microsurgery at the University of Utah in Salt Lake City. He was drawn to Urology because it allows him to own his patients carefully—from the workup and medical management to necessary surgeries. 15% of couples are infertile, and in 50% of the cases, there is a male-related issue. His motivation is knowing he can help so many men overcome this hurdle.
Website: https://rmanetwork.com/staff/masaya-jimbo-md-fertility-urologist/
