Male Infertility: Causes, Treatment, and Modern Solutions

Male factor alone contributes to approximately 30% of cases of delayed pregnancy, and combines with female factors in another 20% — meaning sperm-related issues play a role in roughly half of all infertility cases, according to the World Health Organization. The good news is that most of these cases can be diagnosed and treated, and many can be overcome with modern assisted reproductive techniques.

Understanding the semen analysis

The semen analysis is the cornerstone of male fertility evaluation. Normal values are based on the WHO 2021 (6th edition) criteria:

• Volume: 1.4 mL or more
• Total count: 39 million or more per ejaculate
• Concentration: 16 million or more per mL
• Total motility: 42% or more
• Progressive motility: 30% or more
• Normal morphology: 4% or more (strict Kruger criteria)
• Vitality: 54% or more

A single abnormal result does not equal infertility. The analysis should be repeated after 6 to 12 weeks for confirmation, because sperm production takes approximately 74 days and is affected by fever, stress, and illness.

Types of sperm abnormalities

Oligospermia (low count)

Concentration below 16 million/mL, classified as:

• Mild: 10–15 million/mL
• Moderate: 5–10 million/mL
• Severe: less than 5 million/mL

Asthenospermia (poor motility)

Progressive motility below 30%. Good motility is essential for penetrating cervical mucus and reaching the egg.

Teratospermia (abnormal morphology)

Less than 4% normal forms. Abnormalities may be in the head, midpiece, or tail.

Azoospermia (absent sperm)

Complete absence of sperm in the ejaculate. Subclassified as:

• Obstructive: production is normal but ducts are blocked
• Non-obstructive: a problem with sperm production in the testes

DNA fragmentation

Elevated sperm DNA fragmentation can affect fertilisation quality and embryo development, even with a normal routine semen analysis. It is tested when fertilisation fails or with recurrent miscarriage.

Main causes

Varicocele

The most common, treatable cause. Found in approximately 40% of primary infertility and 80% of secondary infertility. It raises testicular temperature and affects sperm production.

Hormonal disorders

• Hypogonadism (testosterone deficiency)
• Pituitary dysfunction (low FSH and LH)
• Hyperprolactinaemia
• Thyroid dysfunction

Genetic factors

• Klinefelter syndrome (47,XXY) — accounts for approximately 5% of azoospermia cases
• Y chromosome microdeletions
• CFTR mutations associated with cystic fibrosis and congenital absence of the vas deferens

Infections and inflammation

• Epididymitis
• Mumps after puberty
• Untreated sexually transmitted infections

Environmental and lifestyle factors

• Smoking (reduces sperm concentration and motility by 13–22%)
• Alcohol
• Recreational drugs including cannabis
• Occupational heat exposure (drivers, bakers, foundry workers)
• Pesticides and heavy metals
• Use of anabolic steroids or exogenous testosterone

Obesity and chronic disease

Obesity (BMI greater than 30) is associated with reduced sperm concentration and motility. Uncontrolled diabetes affects erectile function and semen quality.

Medical treatments

• Chemotherapy and radiotherapy
• Some medications: SSRIs, beta blockers, certain antibiotics, methotrexate

Comprehensive diagnosis

Full male fertility evaluation includes:

• Detailed medical and surgical history
• Physical examination of the testes, vas deferens, and epididymis
• Two semen analyses with a 6 to 12 week interval
• Hormonal tests: testosterone, FSH, LH, prolactin, estradiol, TSH
• Scrotal ultrasound (for varicocele diagnosis)
• DNA fragmentation testing when indicated
• Genetic testing in azoospermia or severe oligospermia
• Semen culture when infection is suspected

Treatment options

Lifestyle modification

The simplest and often the most impactful treatment:

• Complete smoking cessation
• Weight loss if BMI exceeds 25
• Avoiding heat exposure (hot tubs, saunas, laptop on lap)
• Regular moderate exercise
• A balanced diet rich in antioxidants
• Supplements: zinc, selenium, vitamins C and E, CoQ10, L-carnitine, folate

Medical treatment

• Management of thyroid disorders
• Prolactin reduction with agents such as cabergoline
• Treatment of infections with appropriate antibiotics
• Hormonal therapy for FSH/LH deficiency (in selected cases)

Surgical treatment

• Microscopic varicocele repair: improves semen parameters in 60–70% of cases per ASRM
• Microscopic testicular sperm extraction (Micro-TESE): for non-obstructive azoospermia
• Epididymal sperm aspiration (PESA/MESA): for obstructive azoospermia
• Vasectomy reversal

Assisted reproductive techniques

• Intrauterine insemination (IUI): effective in mild to moderate cases
• Conventional IVF: for moderate cases
• ICSI: the gold standard for severe male factor — a single sperm is injected directly into each egg, working even with less than 1% of normal sperm counts
• IMSI and PICSI: advanced techniques for selecting the best sperm with high-magnification microscopy
• Surgically retrieved sperm combined with ICSI for azoospermia

Success rates

• Lifestyle modification improves semen parameters by 20–50% over 3 to 6 months
• Varicocele surgery raises natural pregnancy rates by 30–50% on average
• ICSI achieves fertilisation rates of 60–80% regardless of sperm severity
• Live birth rates with ICSI broadly match conventional IVF

Sperm-healthy lifestyle

Every improvement takes 3 months to show:

• Complete smoking cessation
• Losing 5–10% of body weight if overweight
• 150 minutes of moderate weekly activity (but avoid excessive cycling)
• 7 to 8 hours of sleep
• Stress reduction through relaxation techniques
• A Mediterranean-style diet with oily fish, nuts, and leafy greens
• Avoiding direct heat exposure to the testes

When to consult a specialist

See a fertility specialist if:

• Conception has not occurred after 12 months (or 6 months if the female partner is 35 or older)
• There is a history of undescended testes, post-pubertal mumps, or previous surgery
• Previous use of steroids or exogenous testosterone
• Previous chemotherapy or radiation
• You want to preserve fertility before medical treatment

Frequently asked questions

Can sperm quality be improved?

Yes. Lifestyle modification, treatment of underlying causes, and antioxidant supplementation can substantially improve parameters within 3 to 6 months.

Do anabolic steroids affect fertility?

Severely. Steroids and exogenous testosterone shut down sperm production, and recovery can take months to years.

Does cycling cause infertility?

Excessive cycling (more than 5 hours per week) may affect fertility through pressure and heat. Moderate cycling is safe.

Does advanced paternal age affect fertility?

Yes. Sperm quality and DNA fragmentation increase with age, particularly after 45, with a small increase in the risk of certain genetic disorders.

Sources

• World Health Organization (WHO). Laboratory manual for the examination and processing of human semen, 6th edition.
• American Society for Reproductive Medicine (ASRM). Diagnostic evaluation of the infertile male.
• European Association of Urology (EAU). Guidelines on male infertility.
• National Institute for Health and Care Excellence (NICE). Fertility problems, Clinical Guideline CG156.
• American Urological Association (AUA). Male infertility evaluation guideline.
• Cochrane Database of Systematic Reviews. Antioxidants for male subfertility.

Medical disclaimer

This article provides general medical information for educational purposes only. It is not a substitute for personal medical advice, diagnosis, or treatment from a qualified healthcare professional. Every patient's situation is different. Please consult Dr. Haytham Ibrahim before making any decisions about evaluation or treatment of male infertility.