Causes of Male Infertility | Complete Guide | Mother Hospitals Hyderabad

Q: What is the most common cause of male infertility?

The most common cause of male infertility is varicocele — dilated varicose veins within the scrotum — found in 35–40% of infertile men. Varicocele raises scrotal temperature and generates oxidative stress, damaging sperm production, motility, and DNA. It is the most common correctable cause. Other common causes include oligospermia (low count), azoospermia (no sperm), asthenospermia (poor motility), high sperm DNA fragmentation, hormonal imbalances, and lifestyle factors.

Q: Can male infertility be caused by lifestyle factors?

Yes — lifestyle is a major and modifiable cause of male infertility. Key lifestyle factors: (1) Smoking — reduces count by 20–40%, damages motility and DNA. (2) Heavy alcohol — lowers testosterone. (3) Anabolic steroids — severely suppresses sperm production, sometimes to zero. (4) Obesity — raises scrotal temperature and converts testosterone to oestrogen. (5) Scrotal heat — laptops, hot baths, saunas, tight underwear. (6) Stress — chronic stress elevates cortisol, suppressing testosterone. Most lifestyle-related causes are reversible within 3 months.

Q: Can genetic problems cause male infertility?

Yes. Genetic causes include: Klinefelter's syndrome (47,XXY) — the most common genetic cause, causing azoospermia. Y-chromosome microdeletion (AZFa, AZFb, AZFc regions) — causes severe oligospermia or azoospermia. Cystic fibrosis gene mutation (CFTR) — causes congenital bilateral absence of vas deferens (CBAVD), a form of obstructive azoospermia. These are identified with karyotyping and Y-deletion testing, and influence decisions about sperm retrieval and donor sperm.

Q: Does age affect male fertility?

Yes — male fertility declines with age, though less sharply than female fertility. After 45, sperm DNA fragmentation increases significantly, sperm motility and morphology decline, and testosterone levels fall. Children fathered by older men (45+) have a modestly higher risk of certain genetic conditions (though absolute risk remains small). The decline in male fertility with age accelerates after 50. However, many men father children well into their 50s and 60s with ICSI.

Causes of Male Infertility by Category

Diagnosed at Mother Hospitals & IVF Center with semen analysis, hormone panel, ultrasound, and genetic testing

🔬

Sperm Parameter Causes

Most Common

Oligospermia — Low Sperm Count

Sperm count <16 million/mL

The most common sperm parameter abnormality. Grades from mild to severe. Treated with IUI (mild) or ICSI (moderate/severe). Even 1 sperm is enough for ICSI.

Azoospermia — No Sperm

Affects 1 in 100 men

Complete absence of sperm. Obstructive type (blocked ducts) treated with TESA + ICSI. Non-obstructive (production failure) may yield sperm with micro-TESA.

Asthenospermia — Poor Motility

Total motility <42%

Sperm cannot swim effectively. ICSI bypasses motility completely — the embryologist injects sperm directly into the egg. Even immotile-but-alive sperm can be used.

Teratospermia — Abnormal Shape

Normal morphology <4% (Kruger)

High proportion of abnormally shaped sperm affects fertilisation ability. ICSI selects the best-shaped available sperm. Even 0% normal morphology can be treated.

High Sperm DNA Fragmentation

DFI above 30%

Invisible on routine semen analysis — causes IVF failure and miscarriage even with normal count. Treated with PICSI, TESA, antioxidants. DFI test must be specifically requested.

🩺

Anatomical & Structural Causes

Often Correctable

Varicocele

Present in 35–40% of infertile men

Dilated varicose veins in the scrotum raise testicular temperature and generate oxidative stress. The most common correctable cause. Varicocelectomy significantly improves sperm parameters.

Obstructed Vas Deferens

Causes obstructive azoospermia

Blockage in the vas deferens (tube carrying sperm from testis to ejaculatory duct). Causes: vasectomy, infection, injury, surgery. Treated with TESA + ICSI or surgical reversal.

Congenital Absence of Vas Deferens (CBAVD)

Associated with CFTR gene mutation

The vas deferens is absent from birth — sperm is produced but has no exit route. Treated with PESA (epididymal sperm aspiration) + ICSI. CFTR mutation testing is recommended.

Undescended Testes (Cryptorchidism)

Early surgical correction reduces impact

Testes that did not descend into the scrotum during development. Raises testicular temperature, impairing sperm production. Risk increases with delayed surgical correction in childhood.

Retrograde Ejaculation

Sperm goes backward into bladder

Semen flows backward into the bladder instead of out through the urethra. Associated with diabetes, spinal injury, prostate surgery, certain medications. Treated by retrieving sperm from urine or TESA.

⚗️

Hormonal Causes

Treatable

Hypogonadotropic Hypogonadism

Low FSH + low testosterone

The pituitary gland fails to produce FSH and LH that stimulate the testes. Testes are functional but not stimulated. Treatable with FSH + hCG injections — can stimulate sperm production to normal levels.

Elevated Prolactin (Hyperprolactinaemia)

Suppresses testosterone production

High prolactin (from a pituitary adenoma or medication) suppresses testosterone and LH, reducing sperm production. Treated with dopamine agonists (cabergoline, bromocriptine). Highly treatable.

Anabolic Steroid Use

Suppresses sperm production — often severely

Anabolic steroids (bodybuilding) suppress pituitary FSH and LH, stopping sperm production — sometimes to zero azoospermia. Recovery can take 6–24 months after stopping. Must be disclosed to the fertility specialist.

Thyroid Disease

Hypothyroidism or hyperthyroidism

Both underactive and overactive thyroid affect testosterone levels and sperm production. A routine thyroid function test (TSH) is included in the male fertility workup. Treated with medication.

🧬

Genetic Causes

Diagnosed with Karyotyping

Klinefelter's Syndrome (47,XXY)

Most common genetic cause of azoospermia

Extra X chromosome causes testicular failure and azoospermia. Present in ~1 in 660 men. Micro-TESA can retrieve sperm in 50–60% of cases. Identified with karyotyping.

Y-Chromosome Microdeletion

AZFa, AZFb, AZFc regions

Deletions in the AZF (azoospermia factor) regions of the Y chromosome cause severe oligospermia or azoospermia. AZFc deletion: TESA may succeed. AZFa/AZFb deletion: sperm retrieval very unlikely. Guides counselling before TESA.

CFTR Mutation

Causes absent vas deferens (CBAVD)

Mutations in the cystic fibrosis gene (CFTR) cause congenital bilateral absence of vas deferens — a form of obstructive azoospermia. CFTR testing is essential before PESA/ICSI. Partner must also be tested.

🌿

Lifestyle & Environmental Causes

Modifiable — Start Today

Smoking

Reduces sperm count by 20–40%

Smoking significantly reduces count, motility, and causes DNA fragmentation. The most impactful modifiable cause. Quitting for 3 months shows measurable improvement in all parameters.

Scrotal Heat Exposure

Laptops, hot baths, saunas, tight underwear

Sperm production requires scrotal temperature 2–4°C below body temperature. Chronic heat (laptops on lap, hot baths, saunas, tight underwear) impairs spermatogenesis. Reversible within 3 months of avoiding heat.

Obesity

Raises oestrogen, lowers testosterone

Excess fat converts testosterone to oestrogen (aromatisation), suppressing sperm production. Obesity also raises scrotal temperature. Weight loss of 5–10% significantly improves testosterone and sperm parameters.

Heavy Alcohol Use

Lowers testosterone, damages sperm

Chronic heavy alcohol use (>14 units/week) lowers testosterone, impairs liver function (which metabolises hormones), and directly damages sperm. Reducing alcohol improves parameters within 3 months.

Pesticide & Chemical Exposure

Endocrine disruptors

Organophosphate pesticides, heavy metals (lead, mercury, cadmium), and endocrine-disrupting chemicals (BPA in plastics, phthalates) reduce sperm count and quality. Occupational exposure requires protective measures.

🦠

Infections & Immunological Causes

Treatable

Mumps Orchitis

Permanent damage if bilateral

Mumps virus infection of the testes (orchitis) in post-pubertal males causes permanent testicular damage. Unilateral orchitis: usually some sperm production remains. Bilateral: often causes azoospermia. TESA + ICSI may help.

Epididymitis / Epididymo-Orchitis

Chlamydia, gonorrhoea, E. coli

Infection and inflammation of the epididymis can cause scarring and obstruction, causing obstructive azoospermia. Treated with antibiotics — early treatment prevents permanent damage. TESA available if blockage persists.

Antisperm Antibodies

Immune attack on sperm

The immune system produces antibodies that attach to sperm, reducing motility and preventing fertilisation. Common after vasectomy reversal, infection, or trauma. Identified by MAR (mixed agglutination reaction) test. ICSI bypasses antibody effects.

Frequently Asked Questions — Male Infertility Causes

What is the most common cause of male infertility?

The most common cause is varicocele — dilated varicose veins in the scrotum — found in 35–40% of infertile men. It raises scrotal temperature and generates oxidative stress, damaging sperm. Other common causes: oligospermia (low count), azoospermia (no sperm), asthenospermia (poor motility), high sperm DNA fragmentation, and lifestyle factors (smoking, heat, steroids).

Can male infertility be caused by lifestyle factors?

Yes — lifestyle is a major modifiable cause. Smoking reduces count by 20–40% and damages DNA. Anabolic steroids suppress production to zero. Obesity raises oestrogen. Scrotal heat (laptops, hot baths) impairs spermatogenesis. Heavy alcohol lowers testosterone. Most lifestyle causes are reversible within 3 months of correction.

Can genetic problems cause male infertility?

Yes. Klinefelter's syndrome (47,XXY) — the most common genetic cause, causing azoospermia. Y-chromosome microdeletion — causes severe oligospermia or azoospermia. CFTR mutation — causes absent vas deferens (CBAVD). Identified with karyotyping and Y-deletion testing, which influence decisions about sperm retrieval.

Does age affect male fertility?

Yes — after 45, sperm DNA fragmentation increases significantly, motility and morphology decline, and testosterone falls. However, many men father children into their 50s and 60s with ICSI. The decline is less abrupt than female fertility loss, but significant from age 50+.

Is male infertility treatable?

Yes — the vast majority of male infertility cases are treatable. Varicocele: surgical repair. Hormonal: medication. Obstructive azoospermia: TESA + ICSI. Oligospermia: ICSI. Lifestyle causes: reversible with changes + antioxidants. Even genetic causes (Klinefelter's) may yield sperm via micro-TESA in selected cases. The goal at Mother Hospitals is biological fatherhood through whatever route is possible.

Causes of Male Infertility — Complete Guide

Causes of Male Infertility by Category

Dr. E. Prashanthi Reddy

Frequently Asked Questions — Male Infertility Causes

Related Services