When people think about the “biological clock,” it’s usually in relation to women. But men aren’t completely off the hook when it comes to age and fertility. While it’s true that men remain capable of fathering children much later in life, research shows that male fertility does change with age — and those changes can affect pregnancy outcomes.

So, does age really matter for men? Let’s break it down.

Does male fertility decline with age?

Unlike women, men don’t experience a sudden drop-off in fertility at a certain age. However, studies show that male fertility gradually declines starting in the late 30s to early 40s.

Some of the changes seen include:

• Lower sperm count: The number of sperm decreases with age.
  
  
• Reduced motility: Sperm may not swim as efficiently.
  
  
• More DNA fragmentation: Genetic quality of sperm tends to decline.
  
  
• Longer time to pregnancy: Couples with older male partners often take longer to conceive, even with younger female partners.
  
  

Male age and miscarriage risk

Sperm quality doesn’t just affect conception — it can also influence pregnancy outcomes.

• Research shows that pregnancies fathered by men over 40 may carry a slightly higher risk of miscarriage, even when the mother is younger.
  
  
• This is likely due to increased rates of DNA fragmentation and chromosomal abnormalities in sperm.
  
  

Male infertility after 40: what the data shows

While every individual is different, studies suggest:

• Men over 40 are about 30% less likely to conceive naturally compared to men under 30.
  
  
• It can take longer than 12 months to achieve pregnancy as male age increases.
  
  
• Assisted reproductive technologies (like IVF or ICSI) can help, but older paternal age may still impact success rates.
  
  

How does male age compare to female age?

The impact of male age is real, but it’s generally less dramatic than female age. Egg quality and ovarian reserve decline sharply after 35, while sperm changes happen more gradually.

That said, when both partners are over 40, the combined effect can make conception more difficult and increase risks of miscarriage or genetic issues.

Can lifestyle improve male fertility after 40?

Yes — while age is something no one can control, lifestyle factors can help optimize sperm health. Recommendations include:

• Maintain a healthy weight
  
  
• Avoid smoking and excessive alcohol
  
  
• Exercise regularly
  
  
• Manage stress and sleep
  
  
• Limit heat exposure (e.g., saunas, hot tubs, laptops on laps)
  
  
• Eat a balanced diet rich in antioxidants (fruits, vegetables, nuts, whole grains)
  
  

Supplements (like CoQ10, vitamin C, and zinc) are sometimes suggested, but evidence is mixed — always check with a doctor before starting anything new.

The bottom line

Male fertility doesn’t disappear at 40, but age does matter. Sperm quality, time to pregnancy, and miscarriage risk can all be affected.

The good news? Unlike egg quality, sperm health is influenced by both age and lifestyle — meaning men can take steps to improve their chances of conception.

If you’re trying to conceive and concerned about male age, a fertility check-up and semen analysis can provide clarity and guide your next steps.

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