Male infertility: causes, diagnostics and modern treatment options

Author photo
Zappelphilipp Marx•
Andrologist examining a sperm sample in a modern fertility laboratory

Unfulfilled desire to have children is for many couples one of the most stressful phases in life – and yet the image that the problem “is usually the woman’s” persists. Large analyses show that male factors are wholly or partly involved in about half of cases; organisations such as the World Health Organization estimate that around one in six people worldwide will experience infertility at some point in their lives. This article focuses on the male side: what exactly does “male infertility” mean, which causes are possible, how is a thorough assessment carried out and what treatment options are realistically available – from lifestyle changes to IVF and ICSI – so you can better judge the next steps for you or you as a couple.

What is male infertility?

The WHO defines infertility as the failure to achieve a pregnancy after at least twelve months of regular, unprotected sexual intercourse. This definition applies to all genders – the cause may lie with the man, the woman, both partners or remain unexplained despite investigation.

In male infertility the central issue is that sperm quality or quantity is insufficient for conception to occur or to be maintained naturally. Clinicians distinguish:

  • Primary infertility: you have not fathered a child to date.
  • Secondary infertility: conception has occurred previously but is now not possible despite a desire to have children.

Important: a single mildly abnormal semen analysis is not a diagnosis. Sperm parameters fluctuate, and they 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 the same time.

Problems with sperm production

Sperm are produced in the testes. If production is disturbed, this can lead to too few sperm (oligozoospermia), poor motility (asthenozoospermia) or abnormal shape (teratozoospermia). Common triggers include undescended testicle in childhood (cryptorchidism), testicular injury, chemotherapy or radiotherapy, severe infections or hormonal disorders.

Varicocele (dilated veins in the scrotum)

A varicocele is a varicose-type enlargement of the veins in the scrotum. It can cause heat retention and thus impair sperm maturation. Many men have a varicocele without symptoms – it becomes clinically relevant mainly when sperm quality is reduced and there is a desire to have children.

  • Diagnosis: Palpation and Doppler ultrasound by a urologist or andrologist.
  • Treatment: Microsurgical ligation or embolisation when there is a clear indication.

Obstruction of the sperm ducts

If the vas deferens or other conduits are blocked, scarred or congenitally absent, sperm may not appear in the ejaculate or do so in markedly reduced numbers. Causes include previous surgery, inflammation, congenital anomalies or vasectomy.

In some cases the blockage can be reconstructed. If this is not possible, sperm can often be retrieved directly from the testes or epididymis and used with ICSI.

Hormonal disorders

Testicular function is closely regulated by hormones from the brain and pituitary gland. Disorders of this axis – for example due to tumours, trauma, genetic conditions or medications – can cause sperm production to collapse or fail to start.

  • Typical constellations: testosterone deficiency, altered LH/FSH levels, elevated prolactin, thyroid disorders.
  • Treatment: treat the underlying condition, possibly with 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 in men with absent vas deferens can severely limit or prevent sperm production. Detailed clinical genetics counselling is important alongside diagnostic testing.

Infections and inflammation

Inflammation of the testes, epididymis or prostate can damage sperm and cause scarring of the sperm ducts. Sexually transmitted infections such as chlamydia or gonorrhoea, but also mumps orchitis, are often involved.

  • Diagnosis: Urine and swab tests, possibly antibody tests and ultrasound.
  • Treatment: Appropriate antibiotic or antiviral therapy according to guidelines, with partner treatment where indicated.

Lifestyle, environment and work

Smoking, heavy alcohol use, recreational drugs, obesity, lack of exercise, poor sleep and chronic stress can significantly worsen sperm count and quality. Environmental toxins, heat exposure (saunas, tight clothing, laptop on the lap) and workplace chemicals also contribute.

Idiopathic infertility

Despite modern diagnostics, in a proportion of men the cause remains unclear. This is referred to as idiopathic male infertility. In these cases lifestyle optimisation, realistic counselling and an individualised fertility strategy are especially important.

Lifestyle & sperm quality: what you can do yourself

You cannot influence everything – but significantly more than many think. Professional societies and organisations such as the NHS and ESHRE emphasise 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 when overweight can improve hormones and sperm parameters.
  • Diet: plenty of vegetables, fruit, wholegrains, 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 reasonable target.
  • Smoking & alcohol: quitting smoking is one of the most important single measures; keep alcohol to small amounts if possible.
  • Sleep: 7–8 hours of sleep with a relatively regular schedule supports hormones and recovery.
  • Stress: exercise, relaxation techniques, coaching or psychotherapy can help reduce chronic stress.

Supplements can be useful if there are true deficiencies (e.g. vitamin D, zinc, folic acid). “Miracle cures” without investigation rarely deliver the promised benefits.

Diagnostics for men: how assessment proceeds

A good assessment of male fertility follows a clear pathway. Ideally it is performed by an andrologically experienced urologist or in a fertility clinic.

  1. Detailed history (anamnesis): duration of trying to conceive, partner’s cycle data, previous pregnancies, medical history, operations, infections, medications, recreational drugs, occupation, lifestyle.
  2. Physical examination: testicular volume, epididymis, spermatic cords, varicoceles, malformations, pain or indurations.
  3. Semen analysis according to WHO standards: assessment of volume, concentration, motility and morphology. A sample is usually recommended after 2–7 days of abstinence, and if abnormal a second sample is typically taken after several weeks. The procedure is based on, among other things, the current WHO laboratory manual for the examination of human semen.
  4. Hormone profile: testosterone, LH, FSH, and where indicated prolactin and thyroid function to assess endocrine control of testicular function.
  5. Infection screening: urine and swabs for sexually transmitted and other pathogens, possibly prostatic secretions or blood tests.
  6. Genetic tests: with markedly abnormal semen analysis, azoospermia or malformations: karyotype, Y-microdeletions, CFTR mutations and others as indicated.
  7. Imaging: ultrasound of the testes and scrotum, and further imaging if findings are unclear.

Important: the aim is not to find someone to blame, but to gain clarity. The more precisely the baseline situation is known, the more targeted the treatment can be.

Treatment & fertility care

The optimal treatment depends on your situation: cause, age, duration of trying to conceive, partner’s fertility, previous treatments and family plans. Reputable fertility clinics use a stepped approach.

Treat the underlying cause where possible

  • Varicocele: microsurgical repair or embolisation if sperm quality is impaired and there is a desire to have children.
  • Hormonal disorders: treatment of hypogonadism or other endocrine disorders with targeted hormone therapies.
  • Infections: antibiotic or antiviral therapies, partner treatment and follow-up testing.
  • Medication changes: where possible switch drugs that impair fertility.
  • Erectile and ejaculatory disorders: a combination of medication, sexual and couples counselling and, where necessary, technical aids.

Sustainably improve lifestyle

Even the best medical therapy can be limited by an unhealthy lifestyle. Many centres recommend working consistently on weight, exercise, sleep, substance use and stress for at least three to six months before or alongside treatment – sperm maturation takes roughly three months.

Assisted reproduction (IVF, ICSI & co.)

When sperm quality and other factors require it, assisted reproductive techniques are used. A useful overview is provided by the ESHRE information pages for patients.

  • IUI (intrauterine insemination): prepared sperm are placed directly in the uterus around ovulation – suitable for mild male factor infertility.
  • IVF (in vitro fertilisation): eggs are collected and placed in the laboratory with many sperm; fertilisation occurs in the culture 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, radiotherapy or surgery that may threaten fertility.

Chances & prognosis

Prognosis depends on many factors: the cause of infertility, duration of trying to conceive, the ages of both partners, the partner’s ovarian reserve, sperm quality and the chosen treatments.

  • Treatable causes (e.g. varicocele, hormonal imbalance, infections) can often be substantially improved.
  • Lifestyle changes take time but can have measurable effects on testosterone levels and semen analysis results.
  • With genetic causes or severe azoospermia options are more limited, but TESE/ICSI or donor sperm remain possible routes to parenthood.
  • Sometimes multiple treatment attempts do not produce the desired result – then it may be sensible to consider alternatives such as donor sperm, adoption or a life without genetically related children.

Structured counselling in fertility clinics can help assess realistic success probabilities for different strategies.

Psychosocial aspects: masculinity, shame and communication

Male infertility is more than a lab result. Many men experience the thought “it might be me” as deeply wounding. Fertility is still strongly linked with masculinity in society – this creates pressure and shame, even though infertility is a medical condition.

What helps many people:

  • Talk openly with your partner about feelings, concerns and limits.
  • Use information from reputable sources rather than myths and half-knowledge from forums.
  • Consider psychological support or couples therapy if trying to conceive dominates your life.
  • Share experiences with others affected – for example through support groups or online communities.

Important: reduced sperm quality does not make you “less of a man”. It does not reflect on your character, your sexuality or your 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 been having regular unprotected sex for about twelve months without pregnancy occurring.
  • You had an undescended testicle, testicular torsion or surgery in the groin or genital area.
  • You notice lumps, hardening, significant size differences or persistent pain in a testicle.
  • You can feel a palpable “bag of worms” of veins in the scrotum or notice a sensation of heaviness.
  • You have persistent erectile dysfunction or problems with ejaculation.
  • You have received or plan to receive chemotherapy or radiotherapy.
  • You have used anabolic steroids or unregulated testosterone products for a prolonged period.

Acute severe testicular pain is an emergency – you should seek medical help the same day (A&E, urology clinic).

Clinic checklist: well prepared for the fertility consultation

With a little preparation the first appointment at a fertility clinic or andrology clinic will be much more relaxed – and you will get more out of it:

  • Ask in advance how semen collection is organised and how many days of abstinence are recommended.
  • List all medications, supplements and any past hormone or anabolic steroid courses.
  • Bring existing records (semen analyses, hormone results, operation reports, clinic letters).
  • Check with your health insurer what investigations and treatments are fully or partially covered.
  • As a couple, consider which routes you would in principle consider (e.g. IVF/ICSI, TESE, donor sperm, adoption).
  • Write down concrete 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 natural conception, IVF or ICSI, donor sperm, adoption or another life path is best for you – without blame and with a realistic, compassionate view of yourselves.

Disclaimer: Content on RattleStork is provided for general informational and educational purposes only. It does not constitute medical, legal, or other professional advice; no specific outcome is guaranteed. Use of this information is at your own risk. See our full Disclaimer.

Frequently asked questions (FAQ)

Male infertility is usually considered when, despite regular unprotected intercourse for about twelve months, no pregnancy has occurred and no sufficient explanation has been found in the female partner.

Current analyses show that male factors are wholly or partly involved in about half of couples with infertility, which is why assessment should always include both partners.

When there are no particular risk factors, it is usually sufficient to start an assessment after about twelve months without pregnancy; earlier review may be sensible for older couples or when clear risks are present.

The semen analysis is the central laboratory test, but it does not replace a full assessment, which should also include history, physical examination, hormone tests, infection screening and, where appropriate, genetic testing.

Yes, mildly altered values do not rule out pregnancy, because semen analyses vary and factors such as age and the partner’s cycle also matter, so spontaneous conception may still be possible.

Smoking, heavy alcohol use, drugs, obesity, lack of exercise, poor sleep and chronic stress can significantly worsen sperm count and quality, while reducing these factors often leads to measurable improvements.

Supplements can help when deficiencies are proven, but they do not replace a healthy lifestyle, and without diagnostic guidance expensive combination products are often less effective than hoped.

A varicocele is a varicose-type enlargement of veins in the scrotum that can affect sperm quality, but it only needs treatment when there are symptoms or a desire for children combined with abnormal semen parameters.

In azoospermia the cause is investigated first and in some cases sperm can be retrieved from the testis or epididymis for use in ICSI, although success cannot be guaranteed in every case.

In IVF eggs are placed in the laboratory with many sperm and fertilisation occurs naturally in the culture medium, whereas in ICSI a single sperm is injected directly into the egg; ICSI is primarily used for severely impaired sperm quality.

As sperm maturation takes roughly three months, effects of weight loss, smoking cessation, increased exercise or improved sleep usually become visible in laboratory values only after several months.

Cost coverage depends on your insurer, age, marital status and the type of therapy, so it is worth checking early with your insurer and the fertility clinic about specific conditions and possible out-of-pocket costs.

Reduced sperm quality is a medical diagnosis and does not speak to character, worth or masculinity, even though it often feels different and many men initially experience shame or guilt.

Whether starting immediately with IVF or ICSI is sensible depends on cause, age, duration of trying to conceive and personal preferences and should be discussed carefully with a fertility clinic before choosing a path.