What is male infertility?
The WHO defines infertility as the failure to achieve a pregnancy after at least twelve months of regular, unprotected intercourse. This definition applies to all genders — the cause can be the man, the woman, both partners, or remain unclear despite diagnostics.
With male infertility the central issue is that sperm quality or quantity are insufficient for achieving or maintaining a pregnancy naturally. Clinicians distinguish:
- Primary infertility: you have not previously fathered a child.
- Secondary infertility: a pregnancy occurred in the past but later attempts to conceive are unsuccessful despite desire for children.
Important: a single mildly abnormal semen analysis is not a diagnosis. Sperm parameters fluctuate and must always be considered together with your medical history, age, any pre-existing conditions and your partner’s fertility.
Common causes of male infertility
The current guideline from the European Association of Urology describes a range of typical causes. Often several factors contribute at once.
Problems with sperm production
Sperm are produced in the testes. If production is disturbed, there may be too few sperm (oligozoospermia), poor motility (asthenozoospermia) or abnormal morphology (teratozoospermia). Common triggers include undescended testis in childhood, testicular injury, chemotherapy or radiation, severe infections or hormonal disorders.
Varicocele (varicose veins in the scrotum)
A varicocele is a varicose-like enlargement of the veins in the scrotum. It can cause heat build-up and impair sperm maturation. Many men have a varicocele without symptoms — it becomes relevant mainly when sperm quality is reduced and there is a desire for children.
- Diagnosis: palpation and Doppler ultrasound by urology or andrology.
- Treatment: microsurgical ligation or embolisation when clearly indicated.
Obstruction of the sperm ducts
If the vas deferens or other ducts are blocked, scarred or congenitally absent, sperm may not appear or appear in very low numbers in the ejaculate. Causes include prior surgeries, infections, congenital anomalies or vasectomy.
In some cases the obstruction can be reconstructed. When this is not possible, sperm can often be retrieved directly from the testis or epididymis and used with ICSI.
Hormonal disorders
Testicular function is tightly linked to hormones from the brain and pituitary gland. Disturbances in this axis — for example due to tumours, injury, genetic disorders or medications — can lead to a collapse of sperm production or prevent it from starting.
- Typical constellations: low testosterone, altered LH/FSH levels, elevated prolactin, thyroid disorders.
- Treatment: treat the underlying condition, possibly hormonal stimulation (e.g. hCG, FSH) under close supervision.
Genetic causes
Genetic changes such as Klinefelter syndrome (47,XXY), Y chromosome microdeletions or CFTR mutations associated with absent vas deferens can severely limit or prevent sperm production. Alongside diagnostics, detailed clinical genetic counselling is essential.
Infections and inflammation
Inflammation of the testes, epididymis or prostate can damage sperm and cause scarring of the ducts. Sexually transmitted infections (STIs) such as chlamydia or gonorrhoea are often involved, as can mumps orchitis.
- Diagnosis: urine and swab tests, possibly antibody tests and ultrasound.
- Treatment: appropriate antibiotic or antiviral therapy according to guidelines, partner treatment and follow-up checks.
Lifestyle, environment and work
Smoking, high alcohol consumption, recreational drugs, overweight, lack of exercise, poor sleep and chronic stress can significantly worsen sperm count and quality. Environmental toxins, heat exposure (sauna, tight clothing, laptop on the lap) and workplace chemicals also contribute.
Idiopathic infertility
Despite modern diagnostics, the cause remains unclear in a portion of men. This is called idiopathic male infertility. In these cases lifestyle measures, realistic counselling and an individual fertility strategy are particularly important.
Lifestyle & sperm quality: What you can do yourself
You cannot influence everything — but much more than many think. Professional societies and organisations such as the NHS or ESHRE emphasize that lifestyle factors have a measurable effect on sperm quality and hormones.
- Weight: a BMI in the normal range and even a 5–10% weight loss in overweight individuals can improve hormones and sperm parameters.
- Diet: plenty of vegetables, fruit, whole grains, legumes, nuts and healthy plant oils; limit highly processed foods, sugar and trans fats.
- Exercise: at least 150 minutes of moderate aerobic activity plus one to two strength sessions per week is a good target.
- Smoking & alcohol: quitting smoking is one of the most important single measures; limit alcohol where possible.
- Sleep: 7–8 hours of sleep with a relatively consistent sleep pattern supports hormones and recovery.
- Stress: exercise, relaxation techniques, coaching or psychotherapy can help reduce chronic stress.
Supplements can be useful when true deficiencies exist (e.g. vitamin D, zinc, folate). "Miracle cures" without diagnostics rarely deliver what they promise.
Male diagnostic work-up: How the assessment is carried out
A good assessment of male fertility follows a clear plan. Ideally it is performed by an andrologically experienced urologist or at a fertility clinic.
- Detailed history: duration of the fertility attempt, partner’s cycle data, previous pregnancies, medical history, surgeries, infections, medications, drugs, occupation, lifestyle.
- Physical examination: testicular volume, epididymis, spermatic cords, varicoceles, malformations, pain or nodules.
- Semen analysis according to WHO standard: analysis of volume, concentration, motility and morphology. A sample after 2–7 days of abstinence is usually recommended and, if abnormal, a second semen analysis after several weeks. This is based in part on the current WHO laboratory manual for the examination of human semen.
- Hormone profile: testosterone, LH, FSH, and where appropriate prolactin and thyroid tests to evaluate hormonal control of testicular function.
- Infection testing: urine and swab tests for sexually transmitted infections and other pathogens, possibly prostate secretions or blood tests.
- Genetic tests: for severely abnormal semen analyses, azoospermia or malformations: karyotype, Y microdeletions, CFTR mutations and others as indicated.
- Imaging: ultrasound of the testes and scrotum, and further imaging if findings are unclear.
Important: the goal is not to find someone to blame but to gain clarity. The more precisely the starting situation is known, the more targeted the treatment planning can be.
Treatment & fertility care
The optimal treatment depends on your situation: cause, age, duration of attempts, partner’s fertility, previous treatments and life plans. Reputable fertility centres use a stepwise approach.
Treat the underlying cause
- Varicocele: microsurgical repair or embolisation if sperm quality is impaired and there is a desire for children.
- Hormonal disorders: treatment of hypogonadism or other endocrine disorders with targeted hormone therapies.
- Infections: antibiotic or antiviral therapies, partner treatment and follow-up checks.
- Medication change: if possible, switch medications that impair fertility.
- Erectile and ejaculatory disorders: combination of medical therapy, sexual and couples counselling and, where appropriate, technical aids.
Improve lifestyle sustainably
Without a healthy lifestyle even the best medical therapy can be limited. Many centres recommend working consistently on weight, exercise, sleep, substance use and stress for at least three to six months before or alongside treatments — sperm maturation takes roughly three months.
Assisted reproduction (IVF, ICSI & Co.)
When sperm quality and other factors require it, techniques of assisted reproductive technology are used. A good overview is provided by the ESHRE information pages for patients.
- IUI (intrauterine insemination): processed sperm are placed directly into the uterus at ovulation — suitable for mild male factor infertility.
- IVF (in vitro fertilization): eggs are retrieved and placed in culture with many sperm; fertilization occurs in the medium.
- ICSI (intracytoplasmic sperm injection): a single sperm is injected directly into the egg. Standard for severely impaired sperm quality or after failed IVF.
- TESE/MESA: retrieval of sperm directly from the testis (TESE) or epididymis (MESA) when no or very few sperm are present in the ejaculate.
- Cryopreservation: freezing sperm before chemotherapy/radiation or surgeries that may endanger fertility.
Chances & prognosis
Outlook depends on many factors: the cause of infertility, duration of attempts, ages of both partners, the partner’s ovarian reserve, sperm quality and the treatments chosen.
- For treatable causes (e.g. varicocele, hormonal imbalance, infections) chances can often be substantially improved.
- Lifestyle changes take time but can have measurable effects on testosterone levels and semen analysis results.
- For genetic causes or severe azoospermia options are more limited, but TESE/ICSI or donor sperm remain possible paths to parenthood.
- Sometimes several treatment rounds do not achieve the desired result — then it may be sensible to consider alternatives such as donor sperm, adoption or a life without biological children.
Structured counselling at fertility clinics can help assess realistic success probabilities for different strategies.
Psychosocial aspects: masculinity, shame and communication
Male infertility is more than a lab finding. Many men experience the suspicion "it could be me" as a deep personal affront. Society still ties fertility closely to masculinity — this creates pressure and shame, even though infertility is a medical condition.
What helps many people:
- Talk openly with your partner about feelings, worries and boundaries.
- Use information from reliable sources rather than myths and hearsay from forums.
- Consider psychological support or couples counselling if the fertility issue dominates life.
- Connect with others affected — for example through support groups or online communities.
Important: reduced sperm quality does not make you "less of a man". It says nothing about your character, sexuality or worth.
When should you see a doctor?
It is sensible to start a urological or andrological assessment at least in the following situations:
- You have had about twelve months of regular unprotected sex without achieving pregnancy.
- You had undescended testis, testicular torsion or surgeries in the groin or genital area.
- You notice lumps, hardening, marked size differences or persistent pain in a testis.
- You can feel "worm-like" veins in the scrotum or notice a feeling of heaviness.
- You have persistent erectile dysfunction or problems with ejaculation.
- You have undergone or plan to undergo chemotherapy or radiation therapy.
- You have used anabolic steroids or uncontrolled testosterone preparations for a long time.
Acute severe testicular pain is an emergency — seek medical help the same day (emergency department, urology clinic).
Clinic checklist: Well prepared for the fertility appointment
With a little preparation the first appointment at a fertility clinic or andrology consultation will be much less stressful — and you’ll get more out of it:
- Ask in advance how semen collection is organised and how many days of abstinence are recommended.
- Write down all medications, supplements and past hormone or anabolic steroid courses.
- Bring any existing reports (semen analyses, hormone results, surgery reports, referral letters).
- Check with your insurer which tests and treatments are fully or partially covered.
- Discuss as a couple which options you would generally consider (e.g. IVF/ICSI, TESE, donor sperm, adoption).
- Note specific questions so nothing is missed during the consultation.
Conclusion
Male infertility is common but often remains in the shadows — medically and emotionally. The good news is that many causes can be treated or at least improved, especially if you pursue structured diagnostics early, honestly review your lifestyle and choose a reputable fertility clinic as a partner, so you can make an informed decision about whether a spontaneous pregnancy, IVF or ICSI, donor sperm, adoption or another path is best for you — without blame and with a realistic, compassionate view of yourselves.
