When we talk about a biological clock, the conversation often centers on the pressures women face regarding pregnancy and age. This is linked to the natural decline in egg quantity and quality as women age. However, male fertility also declines with age, and increasingly, experts recognize that when a couple experiences difficulty conceiving, male factors are just as likely to contribute as female factors. Historically, however, the focus has often been on testing the woman first.
That’s beginning to change. New male infertility guidelines released in Australia recommend that both partners undergo investigation simultaneously when facing fertility challenges. This shift acknowledges the significant role men play in conception and the importance of assessing male reproductive health.
A growing body of research underscores the impact of a man’s age and overall health on fertility. Let’s examine the evidence.
Semen and Sperm Health Decline with Age
Sperm production begins at puberty and continues throughout a man’s life, but sperm count typically begins to decline in the early twenties. Men over 55 often have sperm counts nearing or below the threshold considered for infertility, as defined by the World Health Organization.
However, quantity isn’t the only factor. Healthy sperm must be alive, exhibit good motility – the ability to move effectively – and possess a normal shape to successfully reach and fertilize an egg.
Adequate semen volume – the fluid carrying sperm – is also crucial, providing nourishment and support for the sperm.
From around age 30, there’s a decline in sperm motility, shape, and semen volume, alongside an increase in the number of non-viable sperm. The most significant changes generally occur around 35 years of age.
This age-related decline in sperm and semen quality directly impacts male fertility. One study involving over 2,000 couples found that men older than 45 took five times longer to conceive compared to men younger than 25. Another study showed a 20% lower chance of pregnancy within a year for men aged 45 compared to those at age 30.
Genetic Damage and Miscarriage Risk Increase with Age
Even if a sperm successfully fertilizes an egg, genetic integrity is paramount. As men age, their sperm accumulate more genetic damage, including alterations to DNA and chromosomes.
This accumulation is due to the repeated replication of sperm stem cells throughout a man’s life – each replication carries a risk of genetic errors. From around age 30, the rate of these genetic changes increases.
Genetic damage to sperm can lead to embryo development failure and miscarriage. Studies suggest a roughly 30% higher risk of miscarriage in men over 40 compared to those aged 25-29.
New techniques demonstrate that chromosomal abnormalities in sperm also increase with age, potentially leading to birth defects and chromosomal syndromes like Down syndrome and Klinefelter syndrome.
Beyond Age: Lifestyle and Environmental Factors
Beyond age, several lifestyle and environmental factors can impact semen and sperm health, and therefore fertility. Oxidative stress – an imbalance between damaging chemicals and antioxidants – disrupts sperm production and increases DNA damage, and is strongly linked to male infertility.
Oxidative stress is exacerbated by exposure to environmental toxins like pollution, heavy metals, pesticides, and certain chemicals.
Lifestyle factors such as smoking, excessive alcohol consumption, illicit drug use, a diet high in processed foods and sugar, obesity, and a sedentary lifestyle also contribute to oxidative stress.
Underlying medical conditions, such as erectile dysfunction or structural issues within the male reproductive tract, can also cause infertility. A varicocele (enlarged veins in the scrotum) is a common and often treatable cause of male infertility. In some cases, men may be born without the tubes that transport sperm, resulting in the absence of sperm in their semen.
However, in approximately one in three cases of male infertility, the cause remains unknown.
The New Guidelines and Maintaining Sperm Health
The World Health Organization recognizes the importance of addressing infertility in all individuals. Australia’s new male infertility guidelines reflect this by recommending simultaneous investigation of both partners in heterosexual couples. For men, this includes a physical examination and analysis of semen and blood samples.
For the one in nine couples in Australia facing fertility issues, these guidelines offer a pathway to earlier diagnosis and treatment options.
If you are planning to conceive, age is a factor, but not the only one. To optimize sperm health, consider:
- Adopting a healthy diet rich in vitamins A, C, E, and D.
- Quitting smoking.
- Moderating alcohol consumption.
- Maintaining a healthy weight.
- Engaging in regular exercise.
- Managing stress.
- Minimizing exposure to environmental toxins and pollutants.
Reducing unnecessary stress surrounding conception is also beneficial. In Australia, the majority of pregnancies result in healthy babies, regardless of parental age.
