Male Infertility Causes

The Causes of Male Infertility, Explained

Male fertility depends on three main things. The testes need to produce healthy sperm, hormones need to support sperm production, and sperm need a clear path to leave the body. A problem with any of these can affect fertility.

1. Problems With Sperm Production

Problems with sperm production are one of the most common causes of male infertility.

• Varicocele:Varicocele is a condition in which the veins around the testicles become enlarged. It can increase the temperature around the testicles and affect sperm production. It is found in about 15% of men and around 40% of men with abnormal semen results. Treatment can improve sperm quality over several months.
• Undescended testes: Sometimes one or both testicles do not move into the scrotum during childhood. This can affect sperm production later in life. Early treatment generally gives better results.
• Infections and inflammation: infections such as mumps after puberty, epididymitis, orchitis, tuberculosis of the genital tract, and some sexually transmitted infections can damage the testicles or block the passage of sperm.
• Injury, torsion and surgery: Testicular injuries, untreated testicular torsion and some previous hernia or scrotal surgeries can affect sperm production or sperm transport.
• Cancer treatment: Chemotherapy and radiotherapy can reduce or stop sperm production. Men who are about to undergo cancer treatment should discuss sperm freezing with their doctor before treatment begins.
• Testicular failure: In some men, the testes do not produce sperm normally, even though no specific cause can be identified after testing.

2. Hormonal and Endocrine Causes

Hormones from the brain, including FSH and LH, help control sperm production. Testosterone produced by the testes also plays an important role. Problems with these hormones can reduce sperm production.

Possible causes include low testosterone, high prolactin levels, thyroid problems, poorly controlled diabetes and problems affecting the pituitary gland.

Testosterone supplements and anabolic steroids need special attention. External testosterone can tell the brain to reduce the signals that control the testes. As a result, sperm production can decrease or stop. Although sperm production may recover after stopping these medicines, recovery can take several months. Men should speak to a fertility specialist before taking testosterone or anabolic steroids.

3. Genetic Causes

Some cases of male infertility are caused by genetic changes.

• Klinefelter syndrome: This condition occurs when a man has an extra X chromosome, usually written as 47,XXY. It is one of the most common genetic causes of male infertility and may be diagnosed during a fertility evaluation.
• Y chromosome microdeletions: Small missing sections of the Y chromosome can affect sperm production. These changes are more common in men with very low or absent sperm counts.
• CFTR Gene Mutations: changes in the CFTR gene can cause congenital absence of the vas deferens. The testes may produce sperm normally, but the tubes that carry sperm are missing or not properly developed. Sperm can often be collected directly from the testicles or epididymis.

Genetic testing may be recommended when sperm counts are very low, or no sperm are found. The results can help doctors choose the right treatment and explain possible genetic risks.

4. Blockages and Sperm Transport Problems

In some men, the testes produce sperm normally, but the sperm cannot leave the body because of a blockage. Possible causes include previous vasectomy, congenital absence of the vas deferens, infections, scarring, ejaculatory duct blockage and cysts.

This type of infertility can often be treated. Sperm may be collected directly from the epididymis or testicle using procedures such as PESA, TESA or testicular sperm retrieval and then used with ICSI.

5. Sexual and Ejaculation Problems

Problems such as erectile dysfunction, premature ejaculation, painful intercourse and low sexual desire can make conception difficult, even when sperm quality is normal. Retrograde ejaculation happens when semen moves into the bladder instead of leaving through the penis. It can occur in men with diabetes, after some prostate surgeries or while taking certain medicines.

A post-ejaculation urine test can help identify this problem. In some cases, sperm can be collected from the urine and used for fertility treatment. These problems can be difficult to discuss, but many are treatable. That is why fertility specialists ask about them during a private consultation.

6. Immune-Related Causes and Sperm DNA Damage

Sometimes the immune system produces anti-sperm antibodies. These antibodies can affect sperm movement and their ability to interact with the egg. They may develop after an injury, infection or vasectomy. A man can also have a normal semen analysis but still have high sperm DNA fragmentation. This means there are breaks or damage in the genetic material inside the sperm.

Higher sperm DNA fragmentation may be associated with unexplained infertility, repeated miscarriage, and some failed IVF cycles. Factors such as smoking, alcohol use, heat exposure, weight and age may also affect sperm DNA quality.

7. Lifestyle and Environmental Factors

Lifestyle factors may not always cause infertility on their own, but they can affect sperm quality and make other fertility problems worse.

• Tobacco: Smoking and chewing tobacco can reduce sperm count, movement and normal shape.
• Alcohol: Heavy or regular alcohol use can affect testosterone levels and sperm DNA.
• Weight: Being significantly overweight or underweight can affect semen quality and hormone levels.
• Heat: long hot baths, saunas, prolonged driving, hot work environments, and other sources of prolonged heat may affect sperm production.
• Stress and sleep: Long-term stress and poor sleep can affect the hormones involved in sperm production. workplace and environmental exposure: pesticides, heavy metals, industrial chemicals, paints,s and radiation can affect reproductive health.
• Medicines and substances: Steroids, opioids, some antidepressants, certain antifungal medicines and chemotherapy can affect sperm. Cannabis and other recreational drugs may also reduce sperm count and movement. Do not stop prescribed medicines without speaking to your doctor.

8. Age

Male fertility usually declines more gradually than female fertility, but age can still affect fertility. From the late thirties onwards, semen volume, sperm movement and DNA quality may gradually decline. It may also take longer to achieve pregnancy.

9. When No Cause Is Found

In some men, semen tests and other investigations do not identify a clear cause even though pregnancy does not occur. This is called unexplained or idiopathic male infertility. This does not mean treatment is impossible. Additional tests may provide more information, and treatments such as IUI, IVF and ICSI can help many couples.

Male infertility often has no clear symptoms. many men feel completely healthy, and the first sign is simply that pregnancy isn’t happening. See a fertility specialist if you have:

• No pregnancy after 12 months of regular unprotected intercourse, or after 6 months if your partner is over 35
• Swelling, pain or a lump in the scrotum
• A heavy or “bag of worms” feeling in the scrotum
• Difficulty with erections or ejaculation
• Reduced sexual desire
• Very low semen volume
• Cloudy urine after ejaculation
• Reduced facial or body hair
• Development of breast tissue
• A history of undescended testes, mumps after puberty, testicular injury, hernia surgery or cancer treatment

• Semen analysis: this is usually the first test. a semen sample is checked for volume, sperm count, motility, and morphology. The WHO 2021 reference values include a semen volume of 1.4 ml, sperm concentration of 16 million per ml, total sperm number of 39 million per ejaculate, total motility of 42%, progressive motility of 30%, vitality of 54% and normal morphology of 4%. One abnormal result does not always mean infertility. Fever, illness, stress and the period of abstinence before the test can affect semen results. The test may therefore need to be repeated.
• Clinical examination and medical history: the doctor checks the testes and scrotum and asks about previous illnesses, surgeries, infections, medicines, occupation, and lifestyle.
• Hormone tests: FSH, LH, testosterone, prolactin and thyroid tests may be recommended to identify hormone-related causes.
• Scrotal Doppler ultrasound: This can help identify varicocele, cysts and other structural problems.
• Sperm DNA fragmentation test: This may be considered in cases of repeated miscarriage, failed IVF or unexplained infertility.
• Genetic testing: Karyotyping and Y chromosome testing may be recommended when sperm counts are very low, or no sperm are found.
• Post-ejaculatory urine test: This can help diagnose retrograde ejaculation.

• Lifestyle and medical treatment: treatment may include stopping tobacco and anabolic steroids, treating infections, correcting hormone problems, managing diabetes and thyroid conditions, reducing heat exposure, and reaching a healthy weight. Since sperm take around three months to develop, improvements may take several months to appear.
• Surgery: Surgery may be recommended for varicocele, sperm blockages or vasectomy reversal in selected cases.
• Surgical sperm retrieval: When no sperm are found in the semen, sperm may sometimes be collected directly from the epididymis or testicle. Procedures include PESA, TESA, testicular sperm retrieval and micro-TESE. Micro-TESE is a specialised procedure used to find small areas of sperm production inside the testicle.
• Assisted reproduction: IUI may be considered for mild male-factor infertility. IVF may be recommended when more support is needed. ICSI involves injecting a single sperm directly into an egg and can be useful when sperm numbers are very low.

Donor sperm may also be considered when viable sperm cannot be retrieved. Your fertility specialist can explain all available options so you can make an informed decision

We assess both partners from the beginning because male and female factors can both contribute to infertility. Our fertility specialists, andrology services, surgical sperm retrieval procedures and advanced ICSI treatment are available as part of your fertility care.

• Male fertility evaluation as part of the couple’s initial consultation
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• Semen testing based on standardised protocols
• Advanced procedures including ICSI, PESA, TESA and micro-TESE
• Transparent and itemised pricing
• 50+ centres across India, with 120+ fertility specialists
• Private and comfortable consultations
• Block in the reproductive system
• Hormonal Imbalance
• Poor Sperm Production
• Abnormal Sperm Morphology
• Low Sperm Motility