How does age impact male fertility?

It’s pretty widely known that it becomes much more difficult for women to become pregnant as they get older. A woman is born with all the eggs she will ever use in her lifetime, and over time (especially after the age of 32), those eggs start to become damaged until a woman is no longer able to reproduce (i.e. menopause). On the contrary, men can produce somewhere between 100 million and 200 million new sperm every day – but that doesn’t necessarily mean that male fertility remains constant over time.

Just as in women, men can (and will) see a fertility decline as they age. However, that isn’t stopping people from having children later in life: since 1980, the fertility rate for men in their 30s has increased by 21% and by nearly 30% for men aged 40 years and older. In contrast, the fertility rate in men younger than age 30 years has decreased by 15%.

How does fertility decline with age in men?

Men typically have changes in semen quality as they get older. Sperm concentration, motility, and morphology all typically decrease over time. This is partly caused by men’s natural decline in testosterone levels: on average a guy’s testosterone dips by 1-2% per year once he hits age 30. Since testosterone plays such a strong role in spermatogenesis, it makes sense that sperm quality would see a similar decline.

Research has also shown that sperm’s DNA integrity tends to decline with age. Older men tend to have higher levels of DNA fragmentation which can lead not only  to fertility difficulties, but also to higher rates of newborn birth defects. Studies have found that advanced paternal age (older men having children) has been correlated with a slightly increased risk of birth defects, autism, cancer, and schizophrenia.

As couples age, they are also more likely to partake in decreased levels of sexual activity, which is directly correlated with decreased chances of conception. The chance of erectile dysfunction also increases with age, though ED is typically not associated with the frequency of sex.

Testicular size is a marker of the production of sperm. Though the size of the testis do not change during prime reproductive years, it usually does decline such at around age 80, testicular volume has been shown to decrease to around 69% of its original size.

What does age-related fertility decline mean for couples trying to conceive?

Studies conclude that men start to contribute to reduced fertility in their late thirties and early forties. While sperm quality doesn’t decline as quickly as women’s egg quality, it does drop and it can take older men longer to conceive than younger men. For men pursuing fertility treatment,  the risk of not having a baby after IVF is more than five times higher if the male partner is 41 years old or older. Children fathered by men older than 40 are more than five times as likely to have an autism spectrum disorder than those

fathered by men under 30. Finally, the risk of the woman having a miscarriage is twice as high with a male partner over the age of 45 as it is with a male partner under 25.

Like it or not, age is a barrier when it comes to starting a family, and the first step to making sure that you can become a dad is understanding what the risks and rewards are to have a child at any age. Becoming a father is one of the most amazing experiences a man can have. Getting yourself educated, involved, and tested early in the process can greatly improve your chances of success.

As always, we’re here to help you no matter where you are in your journey.

 

References

Harris, Isiah D, et al. “Fertility and the Aging Male.” Reviews in Urology, vol. 13, no. 4, 2011, pp. e184–e190.

Kennard, Jerry. “How Male Fertility Declines With Age.” Verywell Health, 2 July 2019.

Kerslake, Risa. “How Does Fertility Really Change with Age?” Modern Fertility Blog, Modern Fertility, 18 Mar. 2019.

Miller, Zoë. “How Your Fertility Changes throughout the Years.” Insider Health, INSIDER, 22 Apr. 2019.

“The Truth about Male Fertility Decline.” Extend Fertility, 18 July 2018.