Do Men Have a Biological Clock that Impacts Their Fertility?

You may have heard that women are born with all the eggs they’ll ever have, and that egg quality declines with age, but what about male fertility?

Various things can impact male fertility, including medical issues or injuries, environmental and medical history factors, lifestyle choices, and last but not least, age. With all these contributors to fertility issues, you may be surprised how little men’s “biological clock” is discussed. 

Infertility does not come from women alone; men must also be aware of their own “biological clock” and how age can impact the number and quality of sperm just as it does for women’s egg quantity and quality. 

While many factors can contribute to the decline in fertility health for men, below, we dive a little deeper into the realities of men’s age and its impact on fertility. 

Men’s “Biological Clock”

Studies have indicated that male fertility does indeed decrease with age. It’s not as drastic of a change as you see with women’s age-related fertility decline, but it still needs to be addressed all the same. 

Decrease in Sperm Motility and Morphology

Motility refers to the sperm's ability to move and swim toward the egg, while Morphology refers to the size and shape of the sperm. As a man ages, there is a decrease in sperm Motility and Morphology. Research has shown a decrease of 0.8% per year for motility, which is believed to be due to the decline in function of the prostate gland and epididymis. As for morphology, studies have shown a decline of 0.2-0.9% yearly resulting in a lower number of normally shaped sperm, causing a decline in male fertility. 

Decrease in Semen Volume

There is not a lot of data to show any major decreases in semen volume over time, but some research indicates a small decrease over time. This, combined with lower sperm motility and morphology, can contribute to fertility issues for men. 

Additional Factors Involving Paternal Age

It’s important to also note there is an increased risk of miscarriage due to genetic abnormalities as men age. The age for men where this seems to be a bigger concern is after age 50. 

In addition to concerns with genetic abnormalities that can lead to miscarriage, there is also a higher chance of birth defects and certain conditions. There have been links to increased risk of children with schizophrenia and even autism due to paternal age. 

Why is Men’s Age Left Out of The Conversation

There are many facts about women’s declining fertility with age, and we know that women nearing age 40 will see a greater decline in their fertility. Still, evidence shows that men’s fertility declines as they age, yet we see so little that is discussed about it. Why is that?

While studies are being done on men to learn more, we don’t know all there is to know about the male sperm. Many other factors impact male fertility unrelated to age, making it more challenging to narrow down the impacts directly related to age. Sperm is also regenerated approximately every 60-75 days, so there’s no limit to how many sperm can be created in one lifetime, whereas women are born with all the eggs they will ever have. 

Male Fertility Testing

Men are waiting longer to have children in recent decades, so it’s important to be mindful of the impact age has on men’s fertility. Their “biological clocks” are also ticking, so getting tested is a great way to get ahead of the game and ensure everything looks good.

Here at Nova IVF, we offer a full workup on male fertility, including semen analysis. In this non-invasive test, a semen sample is produced by the male and examined under a microscope to determine the quantity and quality of sperm. 

Whether you’re ready to start your family or looking to see what your future fertility potential looks like, we can help you figure out what your options are and help you learn more about the importance of early review of fertility needs.