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 sexes — the cause may be male, female, both, or remain unexplained despite evaluation.
In male infertility the central issue is that sperm quality or quantity is insufficient for achieving or maintaining a pregnancy naturally. Clinicians distinguish:
- Primary infertility: You have not previously fathered a child.
- Secondary infertility: A pregnancy occurred before, but conception no longer happens despite trying.
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 comorbidities, and the fertility status of your partner.
Common causes of male infertility
The current guideline of 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. When production is disturbed, this can lead to too few sperm (oligozoospermia), poor motility (asthenozoospermia), or abnormal shape (teratozoospermia). Common triggers include childhood cryptorchidism, testicular injury, chemotherapy or radiotherapy, 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 increased heat and impair sperm maturation. Many men have a varicocele without symptoms — it becomes relevant mainly when semen quality is reduced and there is a desire to have children.
- Diagnosis: Palpation and Doppler ultrasound by urology or andrology specialists.
- Treatment: Microsurgical ligation or embolization when there is a clear indication.
Obstructions of the reproductive tract
If the vas deferens or other ducts are blocked, scarred, or congenitally absent, sperm may be absent from the ejaculate or present only in very low numbers. Causes include prior surgeries, infections, congenital anomalies, or vasectomy.
In some cases the obstruction can be surgically reconstructed. If that is not possible, sperm can often be retrieved directly from the testis or epididymis and used with ICSI.
Hormonal disorders
Testicular function is closely regulated by hormones from the brain and pituitary gland. Disturbances in this axis — for example from tumors, trauma, genetic conditions, or medications — can result in severely reduced or absent sperm production.
- Typical scenarios: Testosterone deficiency, altered LH/FSH levels, elevated prolactin, thyroid disorders.
- Treatment: Treat the underlying condition; if appropriate, hormonal stimulation (e.g., hCG, FSH) under close monitoring.
Genetic causes
Genetic changes such as Klinefelter syndrome (47,XXY), Y-chromosome microdeletions, or CFTR mutations in cases of absent vas deferens can severely limit or prevent sperm production. Alongside diagnostics, detailed genetic counseling is essential.
Infections and inflammation
Inflammation of the testes, epididymis, or prostate can damage sperm and cause scarring of the ducts. Sexually transmitted infections such as chlamydia or gonorrhea, as well as mumps orchitis, are frequently involved.
- Diagnosis: Urine and swab tests, possibly antibody tests and ultrasound.
- Treatment: Appropriate antibiotic or antiviral therapy according to guidelines, including partner treatment when indicated.
Lifestyle, environment and work
Smoking, heavy alcohol use, recreational drugs, obesity, physical inactivity, poor sleep and chronic stress can significantly worsen sperm count and quality. Additional factors include environmental toxins, heat exposure (saunas, tight clothing, laptops on the lap) and workplace chemicals.
Idiopathic infertility
Despite modern diagnostics, the cause remains unclear for some men. This is called idiopathic male infertility. In these cases, lifestyle changes, realistic counseling and an individualized fertility strategy are particularly important.
Lifestyle & sperm quality: what you can do yourself
You cannot control everything — but you can influence much more than many people think. Professional societies and health authorities 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-training sessions per week is a good target.
- Smoking & alcohol: Quitting smoking is one of the single most important measures; limit alcohol if possible.
- Sleep: 7–8 hours of sleep with a relatively consistent schedule supports hormones and recovery.
- Stress: Exercise, relaxation techniques, coaching or psychotherapy can help reduce chronic stress.
Supplements can be useful when true deficiencies are present (e.g., vitamin D, zinc, folic acid). “Miracle” products without diagnostic justification rarely deliver what they promise.
Evaluation in men: how the workup proceeds
A thorough evaluation of male fertility follows a clear plan. Ideally it is performed by an andrology-experienced urologist or in a fertility clinic.
- Detailed history: Duration of trying to conceive, partner’s cycle information, prior pregnancies, medical history, surgeries, infections, medications, drugs, occupation, lifestyle.
- Physical examination: Testicular volume, epididymis, spermatic cords, varicoceles, congenital anomalies, pain or indurations.
- Semen analysis according to WHO standards: Assessment of volume, concentration, motility and morphology. A sample after 2–7 days of abstinence is usually recommended and, if abnormal, a repeat semen analysis after several weeks. The assessment is based in part on the current WHO laboratory manual for the examination of human semen.
- Hormone profile: Testosterone, LH, FSH, and when indicated prolactin and thyroid tests to assess 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: With severely abnormal semen analyses, azoospermia or congenital anomalies: 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 assign 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, prior treatments and life plans. Reputable fertility clinics use a stepwise approach.
Treat the cause where possible
- Varicocele: Microsurgical correction or embolization when semen quality is impaired and there is a desire to conceive.
- Hormonal disorders: Treatment of hypogonadism or other endocrine disorders with targeted hormone therapies.
- Infections: Antibiotic or antiviral treatment, partner treatment and follow-up testing.
- Medication changes: When possible, switch medications that impair fertility.
- Erectile and ejaculatory dysfunction: Combination of medication, sexual and couple counseling and, if needed, technical aids.
Improve lifestyle sustainably
Even the best medical therapy can be limited without a healthy lifestyle. Many clinics 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 technologies are used. A good overview is provided by the ESHRE patient information pages.
- IUI (intrauterine insemination): Prepared sperm are placed in the uterus at ovulation — suitable for mild male factor infertility.
- IVF (in vitro fertilization): Eggs are retrieved and placed in the lab with many sperm; fertilization 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 unsuccessful IVF.
- TESE/MESA: Retrieval of sperm directly from the testis (TESE) or epididymis (MESA) when none or very few sperm are present in the ejaculate.
- Cryopreservation: Freezing sperm before chemotherapy/radiation or surgeries that may threaten fertility.
Chances & prognosis
Chances depend on many factors: the cause of infertility, duration of trying to conceive, age of both partners, the partner’s ovarian reserve, sperm quality, and chosen treatments.
- With treatable causes (e.g., varicocele, hormonal imbalance, infections) chances can often be significantly improved.
- Lifestyle changes take time but can have measurable effects on testosterone levels and semen parameters.
- For genetic causes or severe azoospermia, options are more limited, but TESE/ICSI or sperm donation remain possible routes to parenthood.
- Sometimes several treatment cycles do not achieve the desired result — then it can be appropriate to consider alternatives such as sperm donation, adoption, or a life without biological children.
Structured counseling 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 suspicion “it might be my fault” as a severe blow. Fertility is still socially linked to masculinity, which creates pressure and shame, even though infertility is a medical condition.
What helps many people:
- Talk openly with your partner about feelings, worries and limits.
- Use information from reputable sources instead of myths and hearsay from forums.
- Consider psychological support or couple therapy if the desire to have children dominates your 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, your sexuality, or your worth.
When should you see a doctor?
It is sensible to start a urological or andrological evaluation at least in these situations:
- You have been having regular unprotected sex for about twelve months without pregnancy.
- You had cryptorchidism, testicular torsion, or surgery in the groin or genital area.
- You notice lumps, hardening, marked size differences or persistent pain in the 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 received or plan to receive chemotherapy or radiotherapy.
- You have used anabolic steroids or uncontrolled testosterone preparations for an extended period.
Acute severe testicular pain is an emergency — seek medical attention the same day (emergency department, urology clinic).
Clinic checklist: well prepared for the fertility appointment
A bit of preparation makes the first appointment at a fertility clinic or andrology consultation much less stressful — and helps you get more out of it:
- Ask in advance how sperm collection is organized and how many days of abstinence are recommended.
- Write down all medications, supplements, and any past hormone or anabolic steroid courses.
- Bring existing results (semen analyses, hormone levels, surgical reports, discharge letters).
- Check with your health 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, sperm donation, adoption).
- Note specific questions so nothing is forgotten during the appointment.
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 improved, especially if you pursue a structured evaluation early, honestly review your lifestyle, and choose a reputable fertility clinic as a partner so you can make an informed decision whether spontaneous conception, IVF or ICSI, sperm donation, adoption or another path is best for you — without blame and with a realistic, compassionate view of yourselves.
