Impact of a man's age on fertility and pregnancy outcome

The average age that couples start having children has been rising steadily for the past several decades. Since menopause eventually prevents natural conception and pregnancy in women, female fertility is typically the focus of this increase in age. Also, we've all seen and heard stories about men becoming fathers well into their 70s. if you didn’t know better, you’d think that a man’s fertility stays steady throughout his life and that as long as he can continue to produce sperm, he can do his part in the conception process. However, many studies show a decline in fertility as a man gets older. In addition, recent studies have confirmed that pregnancy complications are higher when the father is older.

Male fertility changes with age

In actuality, there are a number of significant changes that happen in a man’s physiology as he ages, which can dramatically impact fertility and reproduction. Some of the major changes in male fertility include:

• Lower sperm count: While you’ll most likely continue to produce sperm throughout your life cycle, you’re going to produce less as you age. In fact, once you pass the age of 35, your sperm count (and semen volume) will both decline a little bit each year.
• Lower testosterone levels: Part of the reason for your declining sperm count has to do with lower levels of the male hormone testosterone. Testosterone plays an important role in sperm production, and its decline can impact you in other areas, such as lower energy levels as you age.
• More abnormal sperm: Unlike women who have a set number of eggs that last throughout her reproductive years, men continue to regenerate sperm. As this happens through the years, however, the new sperm are more likely to have genetic mutations. For example, a 2003 study in The Journal of Urology found that in about 50% of cases where a baby was born with Down syndrome to older parents, the man’s sperm was the primary cause. Another study showed that children born to men between the ages of 45 and 49 were twice as likely to have schizophrenia when compared with men 25 and under. That risk tripled when the men hit the age of 50.

Slowing the decline in male fertility

There are a number of things you can do in terms of your lifestyle, however, to slow your declining fertility. For example:

• Reach and maintain an optimal weight
• Avoid the use of recreational drugs
• Quit smoking
• Reduce cholesterol (which can also help reduce erectile dysfunction)
• Ask your doctor to check your testosterone levels

If you and your partner are trying to conceive and having a hard time, don’t be afraid to get fertility testing. A fertility specialist can help to rule out certain male infertility causes. Additionally, you may be able to uncover an underlying problem that’s affecting your fertility, such as testicular cancer.

How pregnancy outcomes increase as men age 

Not many studies have explored pregnancy outcomes in aging men. Recent evidence suggests that in addition to a decrease in fertility, there is also an increase in pregnancy complications as men get older such as:

• gestational diabetes
• intrauterine growth restriction
• preterm birth.
• the offspring of fathers of advanced paternal age also have increased risks of chromosomal and non-chromosomal birth defects and an increased incidence of childhood autism and cancers.

In a 2019 study, researchers reported that in couples with unexplained infertility, "analyses for age categories showed a gradual worsening of clinical outcomes with increasing male age, with a significantly worse live birth and clinical pregnancy outcomes in males aged older than 50 years compared to males younger than 40 years (P < 0.05)."

Be proactive

Let your doctor know how old the baby's father is so you can get checked regularly for any complications. Get informed counseling before pregnancy so you understand the risks. You may also discuss with your doctor if you should consider storing sperm at a younger age.