Male fertility myths and facts

Donors

When it comes to male fertility, there’s no shortage of confusion, and unfortunately, a lot of misinformation. This can make it feel difficult and overwhelming if you’re family planning, considering becoming a sperm donor, or want to make small lifestyle changes that will benefit your reproductive health.

In this article, we’ve addressed some of the most common male fertility myths and rebutted them with evidence-based insights. From sperm count to testicle temperature, we’re separating fertility facts from fiction to help you better understand your fertility.

Male fertility myths

Is it only men over 40 who have fertility issues?

Myth: Infertility is the result of ageing and isn’t influenced by any other factors.

Fact: People can face fertility issues at any age. A variety of factors, such as varicoceles, damage to the sex organs, and chronic diseases, can all affect men’s fertility. This common fertility myth probably came from well-intentioned advice, as several studies do indicate that older men are more susceptible to infertility, as age can result in lower sperm count, a less powerful ejaculation, lower motility, and poorer morphology of sperm cells (1). This does not mean, however, that young men are automatically excluded from having similar issues.

Male infertility can be caused by any of the following:

High levels of free radicals
Taking excessive alcohol
Too much smoking
Stress
Childhood infections like mumps or measles
Undescended testes
Genetic abnormalities
Obesity, causing testosterone/ oestrogen imbalance
Impotence
A medical history of prolonged illness, such as liver or kidney failure
Some drugs and medications, such as antibiotics, may affect hormones and the formation of sperm
Trauma to the groin due to accidents or sports injuries
Varicoceles: A congestion of veins on top of the testes, which increases the temperature of the testes, affecting sperm count
Scarring caused by a prolonged infection with chlamydia or gonorrhea
Prostate cancer
Anti-cancer chemotherapy
Retrograde ejaculation: When sperm flow backwards into the bladder instead of being ejaculated from the penis during an orgasm, which is then discharged next time the bladder is emptied

Do ‘old’ sperm cause birth defects?

Myth: Sperm that’s been stored in the testicles for too long becomes ‘bad’ or harmful to a future pregnancy.

Fact: Sperm are produced in a continuous cycle and typically take between 42 and 76 days to mature (2). If ejaculation doesn’t occur, older sperm are reabsorbed by the body, not stored indefinitely or released later. As sperm age, there is a slightly increased risk of DNA damage; however, studies have shown no statistical difference in birth defect rates in children born after ICSI (intracytoplasmic sperm injection) using non-ejaculated sperm compared to ejaculated sperm (3).

Very infrequent ejaculation may lead to a slightly lower percentage of motile (actively swimming) sperm (4), which could reduce the chances of conception, but this doesn’t mean the sperm are damaged or dangerous. A healthy ejaculation pattern (every 2–5 days) helps maintain optimal sperm quality.

Does too much sex cause low sperm count?

Myth: Having sex multiple times a day is the best way to increase your chances of conception.

Fact: Regular sexual intercourse actually decreases a couple’s ability to conceive. According to one small study, where participants ejaculated four times in a day at two-hour intervals, there was an overall decreasing trend noted in semen parameters after each ejaculation. Further, there was a significant reduction in sperm count and motility after the fourth ejaculation (5).

This fertility myth does seem sensible – more sex = more chance of conceiving, but there is a reason that we request abstinence before sperm donation from our donors. A 3-5 day period without ejaculation helps ensure optimal sperm count and quality.

Another fact: Want to increase your fertility? Try smart sex instead. Only have sex when your partner is ovulating (as determined by a physician) and have sex every other day, or even every other two days, to maximise sperm concentration and semen volume and optimise your reproductive potential during this period.

Does the cold kill sperm?

Myth: Keeping your testicles cold boosts sperm health.

Fact: This is based on some truth. Testicles hang outside the body because the human body temperature is 37°C, while the ideal temperature of the testicles for sperm production is 2 to 4 °C lower than this (6).

It is well documented that increased scrotal temperature decreases sperm quality (6), which is why advice for those trying to conceive is to avoid saunas and long, hot baths and to wear loose-fitting underwear so the testicles aren’t held too close to the body. However, this does not mean that especially cold temperatures improve fertility. While some studies have been conducted, a systematic review found that there was “insufficient evidence to draw any firm conclusions about the impact of scrotal cooling on male fertility” (7).

Does the amount of ejaculation affect fertility?

Myth: The more semen a man produces per ejaculation, the better the chance of pregnancy.

Fact: Many believe bigger volumes of semen increase the likelihood of conceiving, but this is actually a myth, with studies finding no relation between semen volume and pregnancy rates (8). The fact is that the quality of semen, including the concentration, motility, and morphology of sperm cells, is generally considered more important when it comes to male fertility.

Is infertility all in your head – can you just ‘relax’ and get pregnant?

Myth: Focusing too much on getting pregnant is what prevents it from happening.

Fact: This myth is believed by most couples. It is not true, however. Stress may have a small effect on hormone levels, but infertility is rarely psychological.

1 in 6 adults worldwide face fertility issues, and that number is rising (9). However, in 85-95% of cases, infertility can be treated with conventional medical therapies such as medication, assisted reproductive technologies, or surgery (10), so it is important not to ignore it if you are having difficulty trying to conceive.

Is infertility only a woman’s issue?

Myth: Only women have fertility problems.

Fact: Male infertility is just as common as female infertility. Around 7% of men worldwide experience fertility issues, and half of all fertility issues are the result of male infertility or fertility problems (11). Becoming aware of and understanding the information around male fertility is an important way to combat this.

Can tight trousers really lower your sperm count?

Myth: Tight clothing doesn’t affect your fertility.

Fact: Scrotal temperature affects sperm well-being, and it thrives in an environment that’s a few degrees cooler than our natural body temperature. Wearing tight trousers can raise the temperature of the testicles by not allowing cooler air to reach them, which can result in a decline of sperm count and motility (12).

Even environmental temperatures can have an impact on male fertility. For example, one study in Northern Italy found that sperm count was significantly lower in summer/autumn compared to winter (13).

Does the size of your testicles affect fertility?

Myth: The larger your testicles, the more fertile you are.

Fact: While testicle size does correlate to sperm-producing capacity to some extent (14), it’s not a reliable indicator of overall fertility. Many men with average or even smaller testicles produce healthy, high-quality sperm. What matters more are hormone levels, sperm motility, and overall testicular function, which can only be assessed with proper testing.

There’s a lot of misinformation out there about male fertility, but the truth is, your reproductive health is influenced by a wide range of factors, not just age or lifestyle clichés. Understanding how sperm is produced, what impacts fertility, and when to seek support can help you take control of your health and even help others start a family.

If you’re healthy, aged 18–46, and looking for a meaningful way to make a difference, you can apply to become a sperm donor.

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