Male fertility: the basics

Understanding how male reproduction works provides the foundation for understanding fertility:

Sperm production (spermatogenesis):

Sperm are produced in the testes through a process that takes approximately 74 days (about 2.5 months). This means lifestyle changes made today can affect sperm quality in 2-3 months.

The sperm's journey:

1. 1.Production: Sperm develop in the seminiferous tubules within the testes
2. 2.Maturation: They move to the epididymis where they mature over about 2 weeks
3. 3.Storage: Mature sperm are stored in the epididymis until ejaculation
4. 4.Ejaculation: During ejaculation, sperm mix with seminal fluid from the prostate and seminal vesicles
5. 5.Travel: After intercourse, sperm swim through the cervix, uterus, and into the fallopian tubes

Key hormones:

• Testosterone: Essential for sperm production and sexual function
• FSH (Follicle Stimulating Hormone): Stimulates sperm production
• LH (Luteinising Hormone): Stimulates testosterone production

Daily sperm production:

A healthy adult male produces approximately 100-200 million sperm per day. Despite this high number, only one sperm will fertilise an egg, and the journey is challenging - most sperm don't survive the trip.

What makes a sperm healthy:

• Motility: Ability to swim properly
• Morphology: Normal shape and structure
• DNA integrity: Undamaged genetic material

Many factors can influence sperm production and quality:

Age:

While men produce sperm throughout life, quality declines with age:

• Sperm volume, motility, and morphology decrease
• DNA fragmentation increases
• Fertility declines more gradually than in women but still matters

Lifestyle factors:

Heat exposure: The testes hang outside the body because sperm production requires temperatures slightly below body temperature.

• Avoid hot tubs and saunas
• Don't use laptops directly on your lap
• Avoid tight underwear
• Limit prolonged sitting

Smoking: Reduces sperm count, motility, and increases DNA damage. Quitting improves sperm health over 3-6 months.

Alcohol: Excessive consumption affects testosterone and sperm production. Moderate consumption is less clear-cut but generally best limited when trying to conceive.

Weight: Obesity affects hormone levels and sperm quality. Losing weight can improve fertility.

Diet: A healthy diet supports sperm health. Mediterranean-style diets rich in antioxidants are beneficial.

Medications and drugs:

• Certain medications can affect sperm (discuss with your doctor)
• Cannabis use is associated with reduced sperm count
• Anabolic steroids can severely impact or stop sperm production

Occupational and environmental:

• Exposure to toxins, pesticides, heavy metals
• Radiation exposure
• Prolonged occupational heat exposure

Testing male fertility is straightforward and should be part of any fertility investigation:

Semen analysis:

The primary test for male fertility, evaluating:

Sperm count (concentration):

• Normal: ≥15 million sperm per mL
• Lower counts may reduce fertility but don't rule out conception

Total sperm count:

• Normal: ≥39 million sperm per ejaculate
• Indicates overall production capacity

Motility (movement):

• Normal: ≥40% moving, ≥32% progressive motility
• Sperm need to swim effectively to reach the egg

Morphology (shape):

• Normal (strict criteria): ≥4% normal forms
• Shape affects ability to penetrate the egg

Volume:

• Normal: ≥1.5 mL
• Very low volume may indicate blockage or hormonal issues

Other factors: pH, liquefaction time, white blood cell count

How to provide a sample:

• Abstain from ejaculation for 2-5 days before
• Collect by masturbation into a sterile container
• Keep the sample at body temperature
• Deliver to the lab within 1 hour

Additional tests (if needed):

• Hormone testing: Testosterone, FSH, LH levels
• Sperm DNA fragmentation: Assesses genetic integrity
• Antisperm antibodies: May affect sperm function
• Ultrasound: Evaluates testes and reproductive structures
• Genetic testing: For very low counts

The good news is that many aspects of sperm health can be improved:

Timeline:

Because sperm take about 3 months to develop, give lifestyle changes at least 3 months to show effect. Be patient and consistent.

Lifestyle modifications:

Quit smoking: One of the most impactful changes. Improvements seen within 3-6 months.

Limit alcohol: Moderate consumption or less is recommended when trying to conceive.

Maintain healthy weight: If overweight, losing even 5-10% body weight can improve hormones and sperm.

Exercise moderately: Regular moderate exercise is beneficial. Excessive intense exercise may temporarily reduce sperm count.

Manage stress: Chronic stress affects hormones and sperm production.

Prioritise sleep: Poor sleep is associated with lower sperm quality.

Dietary improvements:

• Eat plenty of fruits and vegetables (antioxidants)
• Include healthy fats (omega-3s from fish, nuts)
• Choose whole grains over refined carbohydrates
• Limit processed foods
• Stay well hydrated

Supplements (evidence varies):

Some supplements may support sperm health (discuss with your doctor):

• Zinc
• Selenium
• Vitamin C
• Vitamin E
• CoQ10
• L-carnitine
• Folic acid

Environmental changes:

• Keep phones out of pockets when possible
• Avoid prolonged laptop use on lap
• Limit hot bath/sauna use
• Review workplace exposures

When lifestyle changes aren't sufficient, medical treatments are available:

Hormonal treatments:

If hormone imbalances are identified:

• Clomiphene: Can increase testosterone and sperm production
• HCG/FSH injections: Stimulate sperm production in certain conditions
• Treating thyroid or other hormonal disorders

Surgical treatments:

Varicocele repair: Varicoceles (enlarged veins in the scrotum) are the most common correctable cause of male infertility. Surgery can improve sperm parameters.

Vasectomy reversal: For men who've had vasectomies and now want children.

TESE/micro-TESE: Surgical sperm extraction directly from the testes when no sperm are present in ejaculate.

Assisted reproduction:

IUI (Intrauterine Insemination):

Washed, concentrated sperm are placed directly in the uterus. Helpful for mild male factor issues.

IVF with ICSI:

ICSI (Intracytoplasmic Sperm Injection) involves injecting a single sperm directly into an egg. This can achieve fertilisation with very low sperm counts or poor sperm quality.

Donor sperm:

An option when:

• No sperm are present and can't be retrieved
• Severe genetic conditions
• Personal choice

Success rates:

Many male fertility issues are very treatable:

• Lifestyle improvements alone can restore fertility
• Hormonal treatments work well for specific conditions
• ICSI allows fertilisation with very few sperm
• Most couples with male factor eventually achieve pregnancy with appropriate treatment