How Age Affects Male Fertility
Fertility in males decreases with age, and although this is not as dramatic as the decrease in women, it is still true. So if you and your partner are considering starting a family and one or both of you is over the age of 35, it is worth knowing about the effects of age on fertility.
Floralia Wellness is a naturopathic fertility clinic that works with men and couples at every step of their fertility journey, integrating naturopathic fertility care with conventional fertility treatments. The focus is on achieving optimal sperm quality and fertility results. If you have concerns, a consultation is a great place to start.
When does male fertility start to decline?
While women are born with all the eggs they will ever have, men are constantly producing sperm, which gives the impression that their fertility has no expiration date. However, the quality of their sperm is a different story altogether.
Most evidence suggests that the ageing process begins at the age of 35. This is when the parameters of sperm motility and morphology start changing, as well as the integrity of the DNA. According to a 2025 study published in the journal Frontiers in Aging, which analysed 6,805 sperm samples from men aged 20 to 63, the volume of the sperm, as well as the progressive and total motility, significantly reduced with age, while the DNA fragmentation increased. This process is not immediately noticeable, but the decline in the quality of the sperm is gradual, with the process picking up speed from the age of 40. By the time the man is 45, the changes are considerable enough to affect conception rates as well as the outcome of the pregnancy and the health of the offspring.
The fertility rate in men 40 and older has risen by almost 30 per cent since 1980, meaning more men are attempting conception in a time when these declines are already in progress. Infertility due to age is no longer a dialogue limited to one gender; it’s a dialogue both partners can have.
What happens to sperm quality as you age
Semen analysis divides the quality of your sperm into several distinct parameters. These parameters change with your age in different ways. Knowing the individual parameters can help you understand your results and where to focus.
Sperm count and motility
The two most important aspects of semen analysis that most people tend to look at first are count and motility. In other words, they want to know how many sperm are present in the sample and how well these sperm are moving. Both of these aspects are essential for conception. First of all, a sperm cell has to reach the egg, and then it has to have enough forward motion to penetrate it.
In males, the concentration of the sperm may decrease with time, although this is not as dramatic as the changes seen in other parameters. It is the motility, however, which is affected by the advancement of age. At the age of 40 to 45 years, the motility of the sperm is decreased to such an extent that it affects the time it takes to conceive. It is one of the first parameters to be assessed by a naturopath.
Sperm morphology
Each sperm cell also has a unique shape profile, including the size of the heads, the length of the tails, the proportionate size of the midpieces, and the overall structure.
As the male gets older, the percentage of abnormal morphology increases. It does not mean it is impossible to conceive, it is just less likely to happen in one cycle. It is worth investigating lifestyle factors and oxidative stress if the morphology results come back outside the reference ranges.
Semen volume
The total amount of fluid present in ejaculation is more significant than most men understand. It determines the total number of sperm present, even though concentration per millilitre is sufficient.
Semen volume also decreases with age, especially in men aged 45 and above. Low semen volume can also be caused by changes in the prostate and/or seminal vesicles, so it is important to note this if your readings show low semen volume.
Sperm DNA fragmentation
This factor is not usually included in a routine semen analysis, but it can be the most clinically significant factor. If the genetic material carried in the sperm cell is damaged, it can impair fertilisation, even if the other counts are satisfactory. If there is a high level of fragmentation in the sperm, there can be decreased fertilisation potential and decreased development of embryos, and there can also be a risk of miscarriage, even though other semen parameters are satisfactory.
Oxidative stress is a significant factor here. As men grow older, more reactive oxygen species (ROS) accumulate in their systems and cause more damage to their sperm DNA. A 2024 review in Human Reproduction discusses how oxidative stress contributes to DNA mutations and disrupts base excision repair mechanisms, as well as epigenetic modifications in sperm cells during the process of aging. The more divisions a sperm cell undergoes in a man’s lifetime, the greater the risk of genetic mutations occurring. The percentage of sperm DNA fragmentation increases linearly with paternal age, which is what Floralia’s practitioners directly correct in clients.
The hormonal shift most men don't notice
Testosterone gets a lot of attention, but a single figure on a blood test will not reveal what is going on inside your body. What happens with age is a gradual disruption of the entire system of hormones that controls sperm production.
The hypothalamic-pituitary-testicular (HPT) axis is a system by which your brain and testicles communicate. It is a chain of signals by which your hypothalamus sends messages to your pituitary gland, which then sends messages to your testicles telling them to make sperm and testosterone. As you get older, these signals become weaker. It takes longer for your testicles to react to these signals. As a result, your pituitary gland sends louder and louder signals in response, but the volume of these signals decreases as you get older. A clinical review by the Universities of Dundee and Edinburgh describes how the hormone system is affected by age: semen volume and total sperm count decrease after age 35; sperm motility decreases from age 30; and DNA fragmentation is significantly increased in men aged 40 years and above.
As we age, our testosterone levels drop by 1 to 2 per cent every year past the age of 30. This is not a dramatic change, but over the course of ten to twenty years, the result is significant. This means that the sex drive, the ability to get an erection, the energy level, and the efficiency with which the sperm is made are all impacted. This is known as late-onset hypogonadism, but it is not the same as the hormonal shift that occurs in women during menopause. This is not an instantaneous change, but rather a gradual one, which is exactly the reason that men do not even realise the change is happening until they are trying to conceive and something is not working.
In practice, the naturopaths at Floralia work with men in their late 30s and 40s who feel normal but whose blood work indicates that their testosterone is significantly lower than what it was 10 years ago. If you think your hormones might be off, testosterone testing can help you start with a clear baseline. The symptoms of sexual dysfunction might be slight, such as less frequent morning erections, less sex drive that is dismissed as stress, or longer time between ejaculations, or all of the above. All of these are signs that the HPT axis is shutting down, often accompanied by declining sperm counts.
The interest in this lies in the fact that the decrease in hormones is not entirely predetermined by age. There are specific ways in which one can help support the HPT axis, and these can help slow down the rate of decline. This is where naturopathy can play a role, because the conventional approach often overlooks the fact that testosterone therapy, which is often recommended, can, in fact, decrease sperm counts rather than increase them.
How paternal age affects pregnancy outcomes
Much of the age-related fertility debate is centred around the female partner, but the statistics regarding paternal age have a different narrative. The risks are well-documented and are worth being acknowledged.
Time to conception
The time it takes for the female partner of a man over 45 to conceive is almost five times longer than for those whose partners are less than 25 years of age. Advancing age in men has been shown to increase the time it takes for conception to occur, in addition to reducing the chances of conception even for young women without any fertility problems.
This is partly because of the changes in the quality of the sperm cells discussed above, and partly because of the high incidence of erectile dysfunction among aging males, which affects the frequency of intercourse during the fertile window. These two factors can add up if the female is also above the age of 35, because her age affects the quality of the egg cells.
Miscarriage risk
The risk of miscarriage also increases with the age of the father, especially when the father is 35 years old or above. This is because the father's age increases the risk of chromosomal disorders as well as DNA damage in the sperm cells. When the damaged DNA is present in the sperm cell, the embryo formed will not develop properly even if the egg is fertilised.
Miscarriage can already be an emotional time. Learning that paternal age is a contributing factor can be confronting, but it can also be helpful knowledge. It means there are things that can be done to help reduce sperm DNA fragmentation and improve embryo quality prior to conception or an IVF cycle.
Risks to offspring health
While the data is not as commonly discussed, it is worth understanding. There is research indicating that autism spectrum disorders, as well as schizophrenia, are more prevalent in children born to older fathers, with the risk increasing significantly beyond the age of 45. There is also an association with childhood leukaemia, as well as the likelihood of the infant requiring an intensive care unit stay.
These are not certainties. Most babies conceived by older dads are perfectly healthy. However, the risk does exist, and it is due to the fact that there is a gradual build-up of genetic mutations in sperm. Cell division in sperm creation is a constant risk of replication error, and this error builds up over time. Understanding this allows you to balance your choices: whether to have a child sooner, whether to have a child through genetic screening, whether to work on reducing oxidative damage to sperm DNA before conception, or all of the above.
Why age hits male fertility differently to female fertility
The total number of eggs that women are born with (which will be their total lifetime quota) varies between one and two million. However, by puberty, this quota has already been reduced to 300,000. Every month, 1,000 eggs are lost, and only one, or sometimes two, mature and get ready to be released. This means that female fertility has a hard and fast clock, and by the mid-30s, the rate of decline accelerates, and in the early 40s, chances of natural conception are low.
In the case of males, the pattern is different. While males produce sperm from the time they reach puberty, there is no point at which the supply dries up. The quality of newly manufactured sperm declines with time, as does the hormonal process that controls the manufacture. This means that male fertility declines but not suddenly.
This is important because the cumulative result of the diminished egg quality as well as the diminished sperm quality is greater than the sum of the two individual elements. When the female is over 35, the male is also more likely to be over 35, which increases the difficulty. The probability is different for the couple where the male is 42, and the female is 38, than for the couple where the male is significantly younger than the female. For couples in this situation, consulting with a fertility naturopath who evaluates both partners can help determine where the greatest opportunities for improvement exist.
Lifestyle factors that accelerate the decline
The rate at which the quality of sperm is impaired is not related to the individual’s age. A 2024 narrative review published in the journal Human Fertility investigated the effects of diet, exercise, drug use, stress, sleep, and weight control on the reproductive health of males. It concluded that lifestyle factors affect sperm parameters.
Smoking is one of the most damaging. Oxidative stress is increased, while sperm count and motility are reduced. DNA fragmentation is also accelerated. Also, even moderate amounts of alcohol consumption can inhibit the production of testosterone, resulting in reduced sperm count over time.
Weight is also an essential factor. When there is too much body fat, particularly in the abdominal region, hormonal balance is interfered with through a process known as aromatisation. During this process, testosterone turns into oestrogen. Men who are overweight tend to have lower levels of testosterone compared to those who are not overweight, regardless of their age. The former also have poor-quality sperm.
Dietary quality has a quantifiable effect on sperm quality. A healthy diet includes antioxidants, zinc, selenium, omega-3 fatty acids, and folate. These nutrients play a crucial role in the production of healthy sperm and in protecting against DNA damage. A clinical nutritionist can assist you in developing a diet based on your results. Processed foods and high sugar content in food can have a negative effect on sperm quality, as can a diet lacking in fruits and grains.
Environmental toxins are more difficult to manage but are still included in the discussion. Exposure to pesticides, heavy metals, solvents, and endocrine disruptors in the workplace can interfere with sperm production. Heat exposure from saunas, hot baths, and tight clothing can also play a role in sperm quality; however, this is a reversible condition.
Sexually transmitted diseases, if left untreated, can result in inflammation and scarring in the reproductive system, which in turn affects fertility. This is another reason why regular health checkups are important as you get older.
The good news is, sperm development takes around 72 days from start to finish, so three months of lifestyle changes can result in noticeable improvements in your semen analysis results.
What a semen analysis can actually tell you
Most men are given their results in a sheet of numbers with reference ranges, but no information on what these numbers mean in terms of their likelihood of conceiving.
The basic principle of the test is quite simple. You supply a semen sample, usually after two to five days of abstinence, and various sperm parameters, such as concentration (number of sperm per millilitre), total count, motility (percentage of forward-moving sperm), morphology (percentage of normally shaped sperm), and volume, are analysed and compared to reference ranges set up by the World Health Organisation.
Here is where it gets more useful. Just because your result falls within the 'normal' range does not mean that everything is perfect for conception. The reference values provided by the WHO are the 5th percentile of men who have succeeded in achieving pregnancy. So these are the bare minimum, not the best. Having a sperm count of 16 million per millilitre is technically within the range, but having 60 million per millilitre gives you a much better chance of success per cycle. At Floralia, your results are interpreted in this way. Not just whether you pass or fail, but where you are in the range. You can learn more about the full scope of what is explored in male fertility tests.
A standard analysis has some blind spots, too. It doesn’t check sperm DNA fragmentation. This is a significant factor in some cases when everything else is perfectly normal. If you are having trouble conceiving for a while or have suffered miscarriages several times in a row, you should insist on a DNA fragmentation analysis. It’s more expensive than a standard analysis and may not come as part of the standard package, but it can completely turn your treatment around.
For men over the age of 35 who are considering starting a family, semen analysis can provide you with the facts to work with. You will know where you stand, and what areas need to be improved to avoid problems down the track. If the results indicate that things are not in an optimal state, then there is a clear plan to follow to rectify the situation. If the results indicate a more serious problem, then your naturopath can refer you to a fertility specialist or a urologist.
How naturopathic support can help protect male fertility
Traditional male fertility services have traditionally centred on two outcomes: the semen analysis outcome and, in the event of poor results, assisted reproductive technologies like ICSI and IVF. There appears to be a gap between "your results were below average" and "you need IVF," during which men are not offered much in the way of advice.
This is where naturopathic care can really help fill a need. The approach at Floralia Wellness is to start with your semen analysis and blood work, and then work backwards to determine what might be driving your results, and then work to correct those issues. You can learn more about this approach by reading about male infertility support.
If oxidative stress and DNA fragmentation are high, antioxidant therapy should take priority. This is not about going to the health food store and purchasing a generic "men's multivitamin" type of supplement. Instead, practitioner-grade supplements contain therapeutic levels of nutrients such as CoQ10, zinc, selenium, NAC, and vitamin C, which have been shown to reduce DNA fragmentation and increase sperm parameters. In fact, a systematic review published in the journal Antioxidants in 2023 found that multi-antioxidant supplementation has shown effective results in improving sperm quality. Among these, carnitines, coQ10, selenium, zinc, vitamin C, vitamin E, and lycopene have been found to have the most beneficial effects on sperm quality.
The dosage of the supplements is important. Just because a supplement may have 50mg of zinc on a health food store shelf does not mean that it will have the same benefits as a supplement protocol designed for your pathology results and presentation.
Herbal medicine is well documented in the history of male reproductive health. Certain herbs can help with the manufacture of testosterone, promote blood flow to the male reproductive system, reduce inflammation, and help regulate the stress response. Your naturopath chooses these herbs according to your individual picture, not as a generic formula.
Hormonal support is another area where naturopathic care provides value. Should blood work indicate a decrease in testosterone and an increase in oestrogen due to aromatisation, or problems with HPT axis signalling, there are strategies to correct each of these imbalances without shutting off your own production of hormones. This is an important difference from testosterone replacement therapy, which actually shuts off the production of FSH, the hormone that stimulates the production of sperm. Comprehensive hormone testing can also help to determine which hormone imbalances are at work.
Lifestyle and dietary advice is integrated into every treatment plan. Our naturopaths work with you to tailor the changes you can make to maximise the benefits based on your results, your lifestyle, and what is realistic for you to achieve. That might be a diet plan to help with weight loss and insulin resistance, exercise advice, stress management if cortisol is a factor, or any combination of these. A 2023 network meta-analysis published in Aging compared non-pharmaceutical interventions for sperm quality. Omega-3 fatty acids, lycopene, exercise, zinc, CoQ10, and acupuncture were all shown to have significant advantages over the different parameters.
For couples considering IVF or ICSI, naturopathic preconception care for the male can optimise the sperm sample for the procedure. Small improvements in sperm DNA fragmentation or motility can have a significant impact on the fertilisation rates and quality of embryos, thus improving the success of the procedure. Floralia works in collaboration with your fertility specialist to ensure that your naturopathic care complements your medical treatment.
When to get your fertility checked
Having a semen analysis and blood work at 35 gives you time to act on the results before you are under any pressure to conceive. Waiting until you have been trying for 12 months and are already stressed about this situation puts you on the back foot.
If you have not been successful in conceiving within six months, and either of you is over 35, then fertility testing for both partners could be considered. Male factor infertility causes half of all cases of couples who have difficulty conceiving, but men are often the last to be tested.
If you have a known medical condition that can impact fertility, such as a varicocele, a history of testicular injury, an enlarged prostate, or chemotherapy and/or radiation, early evaluation is warranted at any age. Floralia's approach to functional medicine employs advanced testing to identify underlying causes of complex or multiple system health issues.
And if you are not yet ready to have kids but want to reserve your options, then freezing your sperm is a viable option. It allows you to bank your sperm at your current quality level, which might be considerably better than the quality of your sperm in five or ten years.
Floralia Wellness provides male fertility consultations that comprise a case history, the interpretation of semen analysis, relevant blood tests, and a tailored treatment plan.
