Male Infertility — Causes, Symptoms & Treatment Guide — Symptoms, Causes & Treatment | MyMedicPlus

Male infertility is defined as the inability to achieve pregnancy in a fertile female partner after 12 months of regular unprotected intercourse, attributable to a male factor. It contributes to approximately 50% of all infertility cases globally — as a sole factor in 30% and as a contributing factor in a further 20%. Male infertility affects approximately 7% of men of reproductive age, making it one of the most common medical conditions in men under 50. The male contribution to fertility is primarily through sperm — its quantity (sperm count), motility (forward progressive movement), and morphology (normal shape) as assessed by semen analysis (seminogram). Causes range from anatomical (varicocele — the most common correctable cause), hormonal (hypogonadotropic hypogonadism), genetic (Klinefelter syndrome, Y-chromosome microdeletion), testicular (non-obstructive azoospermia), and obstructive (vasectomy, epididymal obstruction). Modern assisted reproductive technology (ART), particularly intracytoplasmic sperm injection (ICSI), has transformed outcomes even for men with severely abnormal semen parameters.

Pre-testicular causes (hormonal): hypogonadotropic hypogonadism (HH) — deficiency of FSH and LH causing inadequate testicular stimulation — congenital (Kallmann syndrome — HH with anosmia) or acquired (pituitary tumour, hyperprolactinaemia, anabolic steroid or exogenous testosterone use — suppresses FSH/LH by negative feedback). Testicular causes: varicocele (abnormal dilation of pampiniform venous plexus — present in 40% of infertile men; causes scrotal hyperthermia impairing spermatogenesis); cryptorchidism (undescended testes — if uncorrected by age 2, causes testicular damage); Klinefelter syndrome (47,XXY — most common chromosomal cause of male infertility, azoospermia in 90%); Y-chromosome microdeletion (AZF — azoospermia factor loci on Y chromosome — found in 10–15% of azoospermic men); orchitis (viral — mumps — causes testicular atrophy; bacterial); testicular torsion (ischaemic damage if not corrected within 6 hours); chemotherapy or radiotherapy (gonadotoxic — cyclophosphamide, alkylating agents); primary testicular failure (idiopathic — most common cause of non-obstructive azoospermia). Post-testicular causes (obstructive): obstructive azoospermia from vasectomy, epididymal obstruction (congenital bilateral absence of the vas deferens — CBAVD — associated with CFTR mutations/cystic fibrosis carrier status), ejaculatory duct obstruction. Lifestyle risk factors: tobacco smoking (reduces sperm motility and morphology by 20%); excessive alcohol (disrupts FSH/LH); obesity (aromatisation of testosterone to oestradiol); heat exposure (hot baths, saunas, occupational heat — testicular temperature 1–2°C above body required for spermatogenesis); anabolic androgenic steroid (AAS) misuse (suppresses the hypothalamic-pituitary-testicular axis — azoospermia in most users); cannabis, cocaine.

Male infertility is usually asymptomatic — most men have no symptoms and the diagnosis is made during infertility investigation when a couple cannot conceive. The only symptom of infertility is failure to achieve pregnancy. However, associated conditions may cause recognisable symptoms. Varicocele: a dull dragging ache or heaviness in the left scrotum (varicocele is left-sided in 85% of cases) — worse with prolonged standing or exercise; palpable 'bag of worms' swelling in the scrotum; may be impalpable (subclinical varicocele detected on scrotal ultrasound). Hypogonadism: reduced libido, erectile dysfunction, fatigue, depression, reduced muscle mass, loss of body and facial hair, gynaecomastia (breast tissue enlargement from elevated oestrogen). Klinefelter syndrome: tall stature, small testes (orchidometer volume <15 mL), reduced body hair, gynaecomastia, cognitive and learning difficulties. Infection (prostatitis, epididymitis): testicular or scrotal pain, swelling, fever, dysuria, urethral discharge. Ejaculatory disorders: retrograde ejaculation (low volume ejaculate, post-ejaculation urine shows sperm) in diabetes, following TURP or bladder neck surgery; anejaculation in spinal cord injury.

Semen analysis (seminogram) is the cornerstone investigation — performed after 2–5 days of sexual abstinence, two samples collected at least 4 weeks apart for accuracy. WHO 2021 reference values for normal semen: volume ≥1.4 mL, total sperm count ≥39 million per ejaculate, total motility ≥42% (progressive motility ≥30%), morphology ≥4% normal forms (Kruger strict criteria). Terminology: azoospermia (no sperm), oligospermia (<16 million/mL), asthenospermia (low motility), teratospermia (abnormal morphology), oligoasthenoteratozoospermia (OAT — combined defect). Hormonal profile: FSH, LH, testosterone (total and free), oestradiol, prolactin, AMH — elevated FSH suggests testicular failure; low FSH/LH suggests HH. Genetic testing: karyotype (Klinefelter 47,XXY), Y-chromosome microdeletion (AZFa, AZFb, AZFc), CFTR mutation analysis (CBAVD). Scrotal and testicular ultrasound: varicocele detection (venous diameter >3 mm with Valsalva; reflux on Doppler), testicular volume assessment, masses. Anti-sperm antibodies (ASA) test: indicated if sperm clumping on semen analysis. Transrectal ultrasound (TRUS): ejaculatory duct obstruction assessment. Testicular biopsy: for azoospermia — distinguishes obstructive (normal spermatogenesis) from non-obstructive (impaired spermatogenesis); therapeutic sperm extraction (TESE, micro-TESE) simultaneously.

Treat reversible causes first: varicocele repair (microsurgical varicocelectomy or laparoscopic approach) — meta-analyses show 40–60% spontaneous pregnancy rates post-repair in couples with no female factor; improves semen parameters in 60–70% of men. Hypogonadotropic hypogonadism: gonadotropin therapy (FSH + hCG injections) stimulates spermatogenesis — 80%+ achieve pregnancies; clomiphene or anastrozole (aromatase inhibitor) for mild idiopathic oligospermia with low testosterone. Azoospermia factor treatment: obstructive azoospermia — vasovasostomy (vasectomy reversal — best outcomes within 3 years), vasoepididymostomy, or sperm extraction. Non-obstructive azoospermia (NOA): microdissection testicular sperm extraction (micro-TESE) — identifying focal areas of active spermatogenesis in otherwise absent spermatogenesis — sperm retrieved in 50–60% of NOA cases; ICSI then performed on retrieved sperm. Assisted reproductive technology (ART): IUI (intrauterine insemination) — for mild oligospermia without female factor; IVF with ICSI (intracytoplasmic sperm injection — injection of single sperm into egg — gold standard for moderate-severe male factor; fertilisation rate 65–70% regardless of sperm count or motility — transformed male infertility treatment). Donor sperm: for severe NOA with failed sperm retrieval or genetic contraindications. Lifestyle: smoking cessation, alcohol reduction, achieving normal BMI, stopping anabolic steroids (recovery of spermatogenesis typically takes 12–18 months), avoiding excessive scrotal heat. Antioxidant supplementation: evidence-based combinations (CoQ10 200–400 mg, selenium, zinc, vitamin C, vitamin E, folic acid) improve semen parameters in oxidative stress-related oligospermia (meta-analysis evidence, Cochrane review 2019).

Psychological complications are significant and underrecognised — infertility causes depression, anxiety, reduced self-esteem, and relationship strain in both partners, but men's psychological distress is frequently under-supported. Sexual dysfunction (reduced libido, performance anxiety-related erectile difficulties) may develop during repeated timed intercourse and fertility investigation. Genetic risks: men with severe oligospermia or azoospermia due to Y-chromosome microdeletion (AZFc deletions) may transmit the deletion to male offspring through ICSI, causing infertility in the next generation — genetic counselling and karyotyping are essential before ICSI. Testicular cancer association: men with non-obstructive azoospermia have a modestly elevated risk of testicular germ cell tumours and should perform regular self-examination. Treatment complications include risks from surgical sperm retrieval (haematoma, infection, chronic pain, risk of further testicular damage) and from ICSI itself (slightly higher rates of sex chromosomal abnormalities in offspring — 0.5% vs. 0.2% with conventional IVF). Repeated failed ART cycles cause significant cumulative psychological burden requiring active mental health support.

Preserve future fertility: avoid tobacco smoking throughout reproductive years — smoking reduces sperm count, motility, and morphology by 20–25% and is associated with sperm DNA fragmentation. Maintain healthy body weight (BMI 18.5–24.9) — obesity significantly impairs testosterone production and semen quality. Avoid anabolic androgenic steroids absolutely — recovery of spermatogenesis after heavy AAS use may take 12–24 months and may be incomplete. Minimise scrotal heat exposure — wear loose, breathable underwear; avoid frequent hot baths, saunas, and laptop on lap for extended periods. Mumps vaccination in childhood prevents orchitis-related testicular damage (a rare but devastating cause of azoospermia). Cryptorchidism (undescended testes) should be surgically corrected (orchidopexy) by 12–18 months of age — delayed surgery significantly worsens future fertility and increases testicular cancer risk. Sperm banking (cryopreservation) before chemotherapy, radiotherapy, or vasectomy is recommended for all men of reproductive age — sperm can be stored for decades. Occupational chemical exposure: avoid pesticides (dibromochloropropane — DBCP), lead, cadmium, and endocrine disruptors.

See a doctor or fertility specialist after 12 months of unprotected regular intercourse without conception (or 6 months if the female partner is over 35 or has known reproductive issues — do not wait for a full year). Seek urgent urology review for: a painful swollen testis (testicular torsion — surgical emergency requiring orchidopexy within 6 hours to preserve fertility), or a painless testicular lump or mass (testicular cancer — most common cancer in men aged 20–35). See your GP for a semen analysis if: you have a history of undescended testis, previous testicular surgery or trauma, known varicocele, or you are planning chemotherapy or radiotherapy. Couples investigating infertility should assess both partners simultaneously from the outset — male factor investigation (semen analysis) is simpler and cheaper than female investigation and should always be done first or in parallel.