Infertility is more widespread than most people believe, and in about half of all cases male factors are responsible. Yet male infertility tends to receive far less attention than female infertility. Consequent upon this, a large number of men have no clear idea of what is going on or of the steps they can take. Male factors are found in as many as 50 to 70 % of infertile couples, and male infertility contributes to 20 to 30 % of all infertility cases. This guide outlines the most common causes, diagnostic methods, and available treatment options. It aims to help you feel informed and confident as you move forward.
What Is Male Infertility?
Male infertility refers to a man’s inability to cause pregnancy in a fertile female partner after 12 months of regular unprotected intercourse.
There are several underlying causes, each affecting fertility through a different mechanism:
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Low sperm count (oligospermia): Producing too few sperm to fertilise an egg. The WHO 2021 sixth edition lower reference limit is 16 million sperm per millilitre of semen.
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Poor sperm motility (asthenospermia): sperm that do not move properly. At least 42% of sperm should show total motility per WHO 2021 reference values.
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Abnormal sperm morphology (teratospermia): sperm that are misshapen or abnormally formed. At least 4% of a man’s sperm should have normal shape and form.
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Blockages or obstructions: blockages in the male reproductive tract that prevent the delivery of sperm. Conditions like varicocele or ejaculatory duct obstruction can cause blockages.
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Hormone imbalances: problems with the hypothalamus, pituitary gland, or testicles that cause low testosterone or other hormonal imbalances.
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Genetic disorders: conditions such as Klinefelter syndrome that involve the improper development of the male reproductive organs and/or sex chromosomes.
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Sperm DNA fragmentation: damage to the genetic material inside sperm. This damage can lead to failed fertilisation, poor embryo development, or repeated miscarriages, even if a standard semen analysis looks completely normal.
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Unknown causes: in some men, the underlying cause of their infertility remains unexplained. This is known as idiopathic infertility.
Common Causes of Male Infertility
As a male, several factors can contribute to infertility and issues with sperm production or quality. Some of the most common causes of male infertility include:
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Varicocele: An enlargement of the veins in the scrotum, known as a varicocele, is the most common cause of male infertility that can be corrected. Varicoceles occur in about 40% of men who have primary infertility and as high as 80% of those who have secondary infertility. The enlarged veins raise scrotal temperature and lead to oxidative stress, which directly damages sperm count, motility, morphology, and DNA integrity. Microsurgical varicocelectomy remains the accepted standard of treatment and has been shown to improve sperm characteristics and greatly reduce sperm DNA fragmentation.
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Sperm DNA Fragmentation: Sperm DNA fragmentation is becoming more and more widely recognised as a major cause of male infertility, which is often overlooked. Nowadays, new diagnostic methods such as testing for sperm DNA fragmentation are being suggested in cases where the results of a standard semen analysis are normal, but fertility problems still exist. Men with varicocele have considerably higher levels of sperm DNA fragmentation than men without varicocele, and repairing the varicocele has been shown to reduce fragmentation significantly. Testing is especially advised in cases involving recurrent miscarriage, repeated failure of IVF, or when the standard parameters are normal but conception does not take place.
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Infection: Infections such as chlamydia, gonorrhoea, and herpes can cause sperm abnormalities and blockage of the reproductive tract. Treatment with antibiotics may help improve fertility, but untreated infections can cause permanent scarring.
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Ejaculation Issues: Problems with ejaculation, such as retrograde ejaculation where semen flows into the bladder rather than exiting normally, can impact fertility. Treatment may involve medications or surgical correction depending on the underlying anatomical cause.
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Hormonal Imbalance: Improper levels of testosterone, FSH, and LH may contribute to infertility. A morning blood draw assessing the full hormonal axis, including prolactin and TSH, identifies where the disruption is occurring and guides appropriate treatment.
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Unknown Causes: In some men, the underlying cause of infertility remains unexplained. ART procedures are often the best treatment option in these cases.
Symptoms of Male Infertility
Difficulty Conceiving
If you and your partner have been trying to conceive for over a year without success, it could indicate male infertility. The most common symptom is difficulty getting a woman pregnant, but watch for other signs too.
Low Sperm Count
A low sperm count, known as oligospermia, is a decrease in the number of sperm present in a man’s semen. A healthy sperm count is typically 15 million sperm per milliliter of semen or more. Under 10 million is considered low and may make conceiving naturally difficult. Sperm count can be tested through a semen analysis.
A low sperm count, known as oligospermia, is a decrease in the number of sperm present in a man’s semen. The WHO 2021 lower reference limit is 16 million/mL; results below this threshold warrant further investigation. Sperm count is tested through a semen analysis.
Abnormal Sperm Shape and Movement
Infertile men may have a high percentage of sperm with abnormal morphology and motility. Healthy sperm should have an oval head and long tail that propels forward movement. Misshapen sperm and sperm with slow or no movement may have trouble reaching and fertilising an egg. A semen analysis can detect these issues.
Other Symptoms
Additional symptoms of male infertility to be aware of include:
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Pain or swelling in the testicles
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Decreased facial or body hair
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Erectile dysfunction or premature ejaculation
Semen Analysis
A semen analysis measures several factors of semen and sperm health. Based on the WHO 2021 sixth edition reference values:
| Parameter | Lower Reference Limit (WHO 2021) |
| Sperm concentration | 16 million/mL |
| Total motility | 42% |
| Progressive motility | 30% |
| Normal morphology | 4% |
| Semen volume | 1.4 mL |
| pH | 7.2 or 8.0 |
Two separate analyses are recommended; sperm parameters vary week to week, and a single result is rarely sufficient for clinical decision-making.
Additional Tests
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Blood tests include a hormone panel that measures testosterone, FSH, LH, prolactin, and TSH.
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A physical examination checks for varicocele, testicular size, and any structural abnormalities.
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A scrotal ultrasound can identify subclinical varicocele or structural issues that a physical exam may miss.
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A sperm DNA fragmentation test is recommended if standard results are normal, but fertility problems continue, or in cases of repeated miscarriage or failed IVF.
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Genetic testing, such as karyotyping and Y-chromosome microdeletion analysis, is used when sperm count is very low or absent.
Treatment Options for Male Infertility
Medications Medications may be used to treat hormone imbalances or infections that contribute to infertility. Hormonal medications including FSH, LH, and clomiphene citrate can stimulate sperm production. Antibiotics can treat infections like prostatitis that may impair fertility.
Surgery
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Varicocele repair: microsurgical varicocelectomy is the gold standard, improving sperm parameters and reducing DNA fragmentation
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Vasectomy reversal: success rates depend significantly on how long ago the vasectomy was performed
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Epididymostomy: correcting blockages in the epididymis
Assisted Reproductive Technology (ART)
IUI has a success rate of about 10 to 15 % per cycle for male factor infertility. IVF with ICSI has different success rates depending on the woman’s age. For women under 35, the rate is around 40 to 50% per cycle, but it drops to below 15% for women over 40. Since each case is unique, your specialist will provide success rates that apply to your situation. For men with azoospermia, using TESA or micro-TESE to retrieve sperm, together with ICSI, can still offer a chance to become parents.
Lifestyle Changes
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Reducing stress levels through exercise, meditation, or yoga
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Quitting smoking and limiting alcohol consumption, both of which can damage sperm
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Avoiding hot tubs, saunas, and sources of heat which can temporarily reduce sperm count
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Eating a healthy, balanced diet with plenty of nutrients like vitamin C, zinc, and folate, which support sperm health and production
Lifestyle Changes to Improve Male Fertility
There are several lifestyle changes you can make to improve male fertility and increase your chances of conceiving a child. Healthy adjustments to your daily habits can significantly affect sperm health and viability.
Exercise Regularly Regular exercise improves circulation, releases hormones, reduces stress, and supports overall health, all of which boost fertility. Aim for 30 to 60 minutes of moderate exercise most days. Activities like walking, jogging, biking, and strength training are excellent options. However, avoid intense exercise that could raise testicular temperature.
Eat a Balanced, Nutritious Diet
A well-balanced, nutrient-rich diet supports sperm health and male fertility. Choose whole foods such as fruits and vegetables, whole grains, lean proteins, and healthy fats. Key fertility nutrients include zinc, folate, vitamin C, and antioxidants. Avoid processed foods, sugar, red meat, and unhealthy fats, as they can negatively affect sperm health.
Reduce Stress Chronic or long-term stress can damage sperm and testosterone production, impacting fertility. Try relaxation techniques like yoga, meditation, deep breathing, and journaling. Spend time with loved ones, engage in hobbies, and schedule downtime. Counselling or therapy can also help you develop coping strategies.
Limit Alcohol and Quit Smoking Both alcohol and tobacco use have been shown to reduce sperm health and fertility. Limit alcohol to 1 drink per day or avoid it completely when trying to conceive. Quit smoking immediately; your fertility may improve in as little as 3 months after quitting.
Facts and Statistics About Male Infertility
Prevalence of Male Infertility
Male factors are found in as many as 50 to 70 % of infertile couples around the world, which means that just as much attention should be paid to investigating male fertility as to assessing female fertility. Worldwide, about one in six couples will at some stage experience infertility.
Age Matters
Male fertility decreases gradually as a man gets older. Still, the most important change from a clinical point of view relates to sperm DNA integrity rather than sperm count alone. Sperm DNA fragmentation is considerably greater in men aged over 40 than in younger men, and a standard semen analysis usually cannot pick up on this. Men who are over 40 and who intend to start or continue having children should talk to their specialist about having sperm DNA fragmentation tested.
Lifestyle Choices Impact Fertility Certain lifestyle factors like smoking, heavy alcohol use, drug use, pollution or radiation exposure, overweight or obesity, and anabolic steroid use can negatively impact male fertility. Reducing or eliminating these harmful lifestyle choices can help improve sperm health and fertility.
Genetics Genetic abnormalities account for approximately 15–20% of confirmed male infertility cases. Conditions like Klinefelter syndrome, Y chromosome abnormalities, or cystic fibrosis gene mutations can contribute to infertility. Genetic testing and counselling may be recommended for some men to determine the cause of infertility and options for treatment.
Common Myths About Male Infertility
“Infertility is a woman’s problem”
Male factors are responsible for about half of all cases of infertility, whether on their own or in combination with female factors. Infertility is a medical condition that affects men and women to the same extent.
“Infertility only affects older men”
While fertility does decrease with age, infertility can affect men of all ages. In fact, one study found that about 9% of infertile men were under 25 years old. Infertility in younger men is often due to congenital or genetic problems, reproductive tract infections, or other issues.
“Lifestyle changes won’t help”
A healthy lifestyle that avoids harmful habits can significantly affect male fertility and sperm health. Things like limiting alcohol, quitting smoking, maintaining a healthy weight, reducing stress, and avoiding recreational drug use have been shown to improve sperm quality and increase fertility rates.
“Infertility is usually unexplained”
Some fertility cases remain unexplained after standard tests. But sperm DNA fragmentation testing now helps find answers in many of these situations. A standard semen analysis checks sperm count, movement, and shape. It does not look at the DNA inside the sperm. Even if your semen analysis is normal, you could still have high sperm DNA fragmentation. This can lead to repeated miscarriages or unsuccessful fertility treatments.
Conclusion:
Infertility in men is common, well understood, and in many instances can be treated. However, you need the right investigation to reach the correct diagnosis. A semen analysis is the most important initial procedure, but it doesn’t provide the full picture. Only by combining an assessment of sperm DNA fragmentation, hormonal testing, and a structural evaluation can you obtain the most comprehensive understanding of the situation. Whatever the cause, whether it’s a varicocele, a hormonal imbalance, a lifestyle factor, or something discovered through genetic testing, there is almost always a clear path forward. The best thing you can do is consult a urologist or reproductive specialist, and the earlier you do, the more options you’ll have.Frequently Asked Questions
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Anna Haotanto is the Founder of Zora Health and a passionate advocate for women’s empowerment. Anna’s personal experiences with egg-freezing, PCOS, perimenopause and the challenges of fertility have fueled her mission to provide high-quality information, financing, and support to help women and couples navigate their fertility journeys with confidence. She is also recognised for her achievements in finance, entrepreneurship, and women’s empowerment, and has been featured in various media outlets. You can also follow her on Linkedin or Instagram.
