Infertility is a deeply challenging issue faced by many families today, and in nearly half of such cases, male factors are involved. Among the most common male factors are zero sperm count (azoospermia) and low sperm count (oligospermia). These conditions directly affect a man’s ability to father children, yet they are often misunderstood.

Understanding the causes of zero or low sperm count is vital because it provides insight into both prevention and possible treatment. In this article, we will explore the main causes and explain how each one affects male fertility.

1. Hormonal Imbalances

Hormones are the body’s messengers that regulate sperm production. The hypothalamus in the brain sends signals to the pituitary gland, which in turn stimulates the testes to produce sperm through the action of testosterone, follicle-stimulating hormone (FSH), and luteinising hormone (LH).

When there is a disruption in this chain such as low testosterone, pituitary gland malfunction, or thyroid disorders—sperm production is reduced or completely halted. For example, men with very low levels of FSH and LH may fail to stimulate the testes to make sperm.

Effect on fertility: Without balanced hormones, sperm production is either slowed down, reduced drastically, or stopped entirely, leading to low or zero sperm count.

2. Genetic Disorders

Some men are born with genetic conditions that interfere with normal sperm development or transport. Examples include:

• Klinefelter syndrome, where an extra X chromosome affects testicular growth.
• Y chromosome microdeletions, which remove key genes needed for sperm formation.
• Congenital absence of the vas deferens, often linked to cystic fibrosis genes, where sperm cannot travel out of the testes.

Effect on fertility: Genetic problems usually cause permanent sperm production failure or block the natural pathway, resulting in little to no sperm being found in semen.

3. Testicular Problems

The testes are the factory of sperm production, so any damage to them directly affects fertility. Common issues include:

• Undescended testes: if the testes fail to descend during childhood, the heat inside the body damages sperm-forming cells.
• Varicocele: enlarged veins in the scrotum increase temperature and disrupt sperm production.
• Infections: mumps orchitis and sexually transmitted infections can scar or damage testicular tissue.
• Injury or surgery: trauma to the testes may destroy sperm-producing ability.

Effect on fertility: These conditions reduce both the quality and quantity of sperm, sometimes leading to permanent infertility if not corrected early.

4. Obstruction in the Reproductive Tract

Even if sperm are produced normally, they may not appear in semen if there is a blockage along the pathway. Blockages can occur in the vas deferens, epididymis, or ejaculatory ducts due to:

• Infections such as chlamydia or gonorrhoea, which cause scarring.
• Past surgeries, including hernia repairs.
• Congenital defects in the ducts.

Effect on fertility: Men with blocked ducts may ejaculate semen that contains no sperm, making conception impossible without medical intervention.

5. Medical Conditions and Treatments

Certain health problems interfere with male fertility. Chronic diseases such as diabetes can damage the nerves needed for ejaculation, while liver or kidney diseases disrupt hormone balance. Cancer treatments, including chemotherapy and radiation, are known to severely harm sperm cells, sometimes permanently.

Effect on fertility: Depending on the condition, medical issues may either reduce sperm production temporarily or cause long-term infertility.

6. Lifestyle Factors

Everyday habits play a significant role in sperm health. Smoking, alcohol consumption, and drug abuse all reduce testosterone and increase oxidative stress, which damages sperm DNA. Obesity raises oestrogen levels and lowers testosterone, creating an unfavourable environment for sperm production. Heat exposure, from hot baths, saunas, or placing laptops directly on the lap, can also reduce sperm count.

Effect on fertility: Over time, unhealthy lifestyle choices steadily lower sperm count and reduce sperm quality, making conception harder.

7. Medications and Toxins

Certain drugs, whether prescribed or abused, can harm sperm production.

• Anabolic steroids used for bodybuilding suppress natural testosterone and reduce sperm count.
• Chemotherapy drugs target rapidly dividing cells, which include sperm cells.
• Radiation therapy damages sperm DNA and testicular tissue.

Effect on fertility: These substances either temporarily shut down sperm production or cause permanent infertility, depending on dose and duration of exposure.

8. Chemicals, Pesticides and Insecticides

One of the growing concerns in modern times is the effect of environmental chemicals on fertility. Men working in agriculture, factories, or chemical industries are at high risk of exposure to toxins such as:

• Pesticides and herbicides, which disrupt reproductive hormones.
• Heavy metals like lead, cadmium, and mercury, which poison sperm-forming cells.
• Plastics (BPA, phthalates), which mimic oestrogen and interfere with hormone balance.
• Insecticides such as organophosphates and pyrethroids, which directly damage sperm DNA, lower testosterone, and reduce sperm motility.

Effect on fertility: Chemical and insecticide exposure weakens sperm production, reduces sperm quality, and may cause long-term infertility if exposure is repeated and unprotected.

Conclusion

Zero or low sperm count is not caused by one single factor but by a combination of internal and external influences. Hormonal imbalances, genetic disorders, testicular damage, blockages, chronic illnesses, lifestyle habits, medications, and exposure to toxins or insecticides all play a role. The common effect is the same: fewer or no sperm available to fertilise the egg, making conception difficult.

The good news is that many of these causes can be prevented or managed. Healthy lifestyle choices, protection from toxins, and timely medical care go a long way in preserving fertility. Above all, men and families must remember that science has its limits, but God’s power is unlimited. The Bible assures us: “For with God nothing shall be impossible” (Luke 1:37, KJV).