Male Infertility: Common Causes and Diagnostic Screenings Available

The process of sperm development is a complex and lengthy biological cycle that requires a coordinated sequence of hormonal signals, anatomical structures, and cellular processes. Factors related to male reproductive health are significant contributors to a couple’s ability to conceive.

Because the reproductive system relies on such a precise chain of events, any disruption along this pathway can influence sperm production, quality, or delivery. A comprehensive fertility evaluation is designed to identify specific factors affecting reproductive potential, allowing for a clearer understanding of a couple’s path toward conception.

Factors Affecting Sperm Production

Varicocele

Enlarged veins within the scrotum create varicoceles (swollen veins similar to varicose veins). These elevate testicular temperature above the optimal range for sperm production. The elevated temperature disrupts the thermal environment required for sperm development. This affects sperm count, motility (ability to swim), and morphology (shape and structure).

Physical examination typically reveals a “bag of worms” sensation above the testicle. This is most commonly found on the left side due to the angle at which the left testicular vein drains into the renal vein. Varicoceles may be present without symptoms.

Hormonal Imbalances

The hypothalamic-pituitary-gonadal axis (the interconnected system linking the brain and reproductive organs) regulates testosterone and sperm production. It does this through follicle-stimulating hormone (FSH, which signals the testes to produce sperm) and luteinising hormone (LH, which signals the testes to produce testosterone). Disruptions at any level can impair this hormonal cascade. These include pituitary tumours or thyroid dysfunction.

Low testosterone affects sperm production directly within the testes. Elevated prolactin (a hormone that, when too high, can suppress reproductive function) levels suppress gonadotropin release. Exogenous testosterone (testosterone taken as medication or supplements) actually suppresses sperm production. It does this by signalling the pituitary to reduce the output of FSH and LH.

Genetic Factors

Chromosomal abnormalities (variations in the genetic material that contain instructions for body functions) affect the genetic blueprint for sperm development. Klinefelter syndrome (47, XXY) represents a frequently encountered genetic cause. It results in small testes and reduced sperm production. Y-chromosome microdeletions (missing sections of the Y chromosome) remove genes necessary for sperm development. Different deletion patterns correlate with varying degrees of impairment in sperm production.

Cystic fibrosis gene mutations can cause congenital bilateral absence of the vas deferens (CBAVD). In this condition, sperm are produced but have no pathway to reach the ejaculate because the tubes that typically carry sperm are missing. Men with this condition typically have normal testicular function but azoospermia (no sperm in the ejaculate).

Anatomical and Obstructive Causes

Ejaculatory Duct Obstruction

Blockages within the ejaculatory ducts (the passageways that carry sperm and fluid from the reproductive organs into the urethra) prevent sperm from entering the urethra during ejaculation. Causes include:

• Congenital cysts (fluid-filled sacs present from birth)
• Prior infections
• Surgical trauma

Men with ejaculatory duct obstruction typically have low ejaculate volume alongside azoospermia or severe oligospermia (very low sperm count).

Transrectal ultrasound (an imaging test using sound waves through the rectum) can visualise dilated seminal vesicles or midline prostatic cysts, which may suggest obstruction. Seminal fructose levels (a type of sugar typically present in semen) help differentiate ejaculatory duct obstruction from other causes of azoospermia. This is because the seminal vesicles produce fructose.

Prior Vasectomy

Vasectomy creates intentional vas deferens obstruction (surgical blockage of the tubes that carry sperm). Vasectomy reversal (vasovasostomy or vasoepididymostomy—surgical procedures to reconnect the tubes) can restore sperm to the ejaculate. Longer intervals since vasectomy correlate with increased likelihood of secondary epididymal obstruction and anti-sperm antibody development.

Infections and Inflammation

Epididymitis (inflammation of the coiled tube at the back of the testicle), orchitis (inflammation of the testicle), and prostatitis (inflammation of the prostate gland) can damage reproductive tract structures. They can also create obstructions through scarring. Mumps orchitis (testicular inflammation caused by the mumps virus) occurring after puberty poses a particular risk to testicular function. Sexually transmitted infections (such as chlamydia and gonorrhoea) may cause epididymal scarring without obvious acute symptoms.

Lifestyle and Environmental Factors

Thermal Exposure

Testicular temperature must remain several degrees below core body temperature for optimal sperm production. Several factors elevate scrotal temperature:

• Frequent hot tub use
• Saunas
• Laptop computers placed directly on the lap
• Prolonged sitting

Occupations requiring extended sitting or heat exposure correlate with altered semen parameters.

Fever can temporarily suppress sperm production. Effects are visible in semen analysis approximately two to three months later. Recovery typically occurs within one to two subsequent sperm cycles.

Substance Use

Tobacco smoke contains compounds that directly damage sperm DNA and reduce sperm motility. Cannabis affects the endocannabinoid system (a biological system involved in regulating various functions) present in testicular tissue. This potentially disrupts sperm development and function. Alcohol in moderate to heavy amounts suppresses testosterone production and may directly impair sperm development.

Anabolic steroids (synthetic versions of testosterone) create a particularly challenging situation. While users may have elevated circulating androgens, the exogenous hormones suppress the pituitary signals needed for testicular sperm production. Recovery after cessation can take months to over a year. Some men may not fully recover baseline fertility.

Medications

Several medication classes affect male fertility:

• 5-alpha reductase inhibitors (finasteride, dutasteride) for hair loss or prostate conditions reduce the conversion of testosterone to dihydrotestosterone (a more potent form of testosterone), sometimes affecting semen parameters
• Selective serotonin reuptake inhibitors (SSRIs—medications commonly used for depression and anxiety) may impact sperm DNA integrity
• Calcium channel blockers (medications used for high blood pressure and heart conditions) can affect the acrosome reaction (a process where sperm release enzymes to penetrate the egg) necessary for fertilisation
• Sulfasalazine for inflammatory bowel disease directly impairs sperm production (reversible upon discontinuation)
• Chemotherapy agents (cancer treatment medications) vary widely in gonadotoxicity (potential to damage reproductive organs), with alkylating agents posing considerable risk to long-term fertility.

? Did You Know?
The epididymis, a coiled tube behind each testicle, is quite long when uncoiled. Sperm spend many days travelling through this structure. During this time, they acquire the ability to swim progressively and undergo membrane changes necessary for fertilisation.

Semen Analysis

Semen analysis is commonly performed as a screening test that examines multiple parameters against World Health Organisation reference values established from fertile men.

Collection Requirements

Proper collection technique significantly affects results. Abstinence for several days standardises the assessment. Shorter intervals may show lower volume and count. More extended abstinence can reduce motility. The sample should reach the laboratory within an hour of collection, maintained at body temperature.

Samples collected via masturbation into a sterile container provide appropriate results. Special non-spermicidal collection condoms exist for men who cannot collect via masturbation. You should avoid lubricants unless approved explicitly for semen collection. Many lubricants contain spermicidal compounds.

Parameters Assessed

Volume: The lab expects a minimum threshold. Low volume suggests incomplete collection, ejaculatory duct obstruction, retrograde ejaculation (when semen goes backward into the bladder instead of out through the urethra), or hypogonadism (reduced hormone production by the testes).

Concentration: The lab expects a minimum number of sperm per millilitre. Below this threshold indicates oligospermia (low sperm count). Complete absence indicates azoospermia (no sperm in the sample).

Total motility: A substantial proportion of sperm should show movement. Progressive motility (forward movement in a relatively straight line) should be present.

Morphology: The lab expects a certain percentage of normal forms using strict criteria (specific standards for evaluating sperm shape). This parameter shows variability between laboratories.

pH and liquefaction: Normal semen liquefies (changes from gel-like to liquid) within an hour and maintains appropriate pH (a measure of acidity or alkalinity). Failure to liquefy or abnormal pH may indicate prostatic or seminal vesicle dysfunction.

Interpreting Results

A single abnormal semen analysis requires confirmation with repeat testing after several weeks. This is due to natural variation in sperm parameters. Even men with proven fertility show fluctuation across analyses. When both analyses demonstrate abnormalities, further investigation is warranted.

Azoospermia requires differentiation between obstructive causes (normal production but blocked delivery) and non-obstructive causes (impaired production). Your doctor will determine which type you have based on additional tests and examination findings.

Advanced Diagnostic Testing

Hormone Evaluation

Blood tests measure several hormones:

• FSH (which signals sperm production)
• LH (which signals testosterone production)
• Testosterone (the primary male hormone that supports sperm development)
• Prolactin (a hormone that can suppress reproductive function when elevated)

These tests help identify the level of reproductive axis dysfunction:

• Elevated FSH with low sperm count suggests primary testicular failure. The pituitary is signalling for more sperm production, but the testes cannot respond.
• Low FSH and LH with low testosterone indicate secondary hypogonadism. The pituitary isn’t providing adequate stimulation.
• Elevated prolactin suppresses gonadotropin (FSH and LH) release and warrants pituitary imaging.
• Thyroid function indirectly affects the reproductive axis. Your doctor will assess this when indicated.

Morning testosterone measurement provides an accurate assessment. Levels follow circadian rhythm (natural daily fluctuation) with peak values in the early morning.

Genetic Testing

Karyotype analysis (a test that examines the chromosomes under a microscope) identifies chromosomal abnormalities in men with severe oligospermia or azoospermia. Y-chromosome microdeletion testing assesses specific regions (AZFa, AZFb, AZFc) associated with sperm production failure. Results influence prognosis and have implications for male offspring who would inherit the same deletion.

Cystic fibrosis transmembrane conductance regulator (CFTR) gene testing may be recommended for men with congenital absence of the vas deferens or very low ejaculate volume. Partners should also undergo CFTR screening, given the inheritance pattern.

Imaging Studies

Scrotal ultrasound (an imaging test using sound waves to create pictures of the testicles and surrounding structures) evaluates testicular size, identifies varicoceles, and detects masses or structural abnormalities. Reduced testicular volume correlates with impaired sperm development.

Transrectal ultrasound (an imaging test using sound waves through the rectum) visualises the seminal vesicles, ejaculatory ducts, and prostate when obstruction is suspected. Dilated seminal vesicles or midline cysts suggest ejaculatory duct obstruction.

MRI of the pituitary (a detailed imaging scan of the gland at the base of the brain that controls hormone production) may be recommended when hormone testing suggests pituitary dysfunction or when prolactin is elevated.

Sperm Function Tests

Beyond standard semen analysis, specialised tests assess sperm capability:

• DNA fragmentation testing measures sperm chromatin integrity (the quality and structure of genetic material within sperm). Elevated fragmentation correlates with reduced fertilisation rates and increased miscarriage risk, even when standard parameters appear normal.
• Anti-sperm antibody testing identifies immune factors (proteins produced by the immune system) that may impair sperm motility or fertilisation capacity.
• Reactive oxygen species measurement assesses oxidative stress levels (harmful molecules that can damage cells) in semen.

⚠️ Important Note
Men with azoospermia should not assume they cannot father biological children. Testicular sperm extraction procedures (surgical procedures where a doctor removes a small tissue sample directly from the testicle to retrieve sperm) can retrieve sperm directly from testicular tissue for use with intracytoplasmic sperm injection (ICSI, a procedure where a single sperm is injected directly into an egg), even when no sperm appear in the ejaculate.

What Dr. Azhari Says

Clinical evaluation begins with thorough history-taking. Understanding prior fertility, childhood illnesses, surgeries, medications, and occupational exposures often provides diagnostic direction before any testing. Physical examination can identify varicoceles, assess testicular size, and detect abnormalities of the vas deferens that directly inform the workup.

Preparing for Your Fertility Evaluation

Before your appointment: Document your complete medical history. Include childhood illnesses, surgeries, medications, and any known family history of infertility or genetic conditions.

Medication review: Bring a list of all current medications, supplements, and any substances used in the past year. Include over-the-counter products and herbal supplements.

Abstinence timing: For semen analysis, maintain several days of ejaculatory abstinence before collection. Your clinic will provide specific instructions.

Lifestyle inventory: Be prepared to discuss alcohol consumption, tobacco use, recreational drug use, exercise habits, and occupational exposures.

Partner coordination: Male fertility evaluation often occurs alongside female partner assessment. Coordinating appointments and information-sharing streamlines the process.

When to Seek Professional Help

• Inability to conceive after a year of regular unprotected intercourse (or a shorter period if the female partner is over 35)
• Known risk factors such as undescended testes, prior genital surgery, or chemotherapy exposure
• Sexual dysfunction, including erectile difficulties or ejaculatory problems
• Pain, swelling, or lumps in the testicular area
• History of sexually transmitted infections
• Partner with recurrent pregnancy loss
• Planning future fertility and wanting a baseline assessment

Commonly Asked Questions

How long should we try before seeking a fertility evaluation?

Standard guidance suggests evaluation after a year of regular unprotected intercourse. This is reduced to a shorter period when the female partner is over 35. However, men with known risk factors may benefit from earlier assessment, regardless of attempts to conceive. These risk factors include undescended testes, prior chemotherapy, testicular surgery, or known genetic conditions.

Can lifestyle changes improve sperm parameters?

Modifiable factors can positively influence semen parameters. These include smoking cessation, reducing alcohol intake, maintaining a healthy weight, and avoiding excessive heat exposure. Given the extended sperm production cycle, improvements typically appear in testing after approximately three months of sustained changes.

Is one semen analysis sufficient for diagnosis?

No. Natural variation in sperm parameters means a single abnormal result requires confirmation with repeat analysis after several weeks. Consistent abnormalities across multiple samples provide more reliable diagnostic information.

What does azoospermia mean for fertility options?

Azoospermia (no sperm in the ejaculate) doesn’t necessarily preclude biological fatherhood. Obstructive azoospermia may be surgically correctable. Both obstructive and non-obstructive causes may allow sperm retrieval directly from the testes for use with assisted reproductive techniques (medical procedures that help with conception, such as IVF).

Should I stop testosterone therapy if trying to conceive?

Exogenous testosterone (testosterone taken as medication or supplements) suppresses the hormonal signals needed for sperm production. Men using testosterone therapy who wish to conceive should discuss alternatives with a healthcare professional. Medications like clomiphene citrate or human chorionic gonadotropin can maintain testosterone levels while preserving or restoring sperm development.

Next Steps

Accurate diagnosis identifies treatable factors, including varicocele, hormonal imbalances, or anatomical obstructions. Even azoospermia may allow sperm retrieval for assisted reproduction. Male fertility testing provides the foundation for targeted intervention.

If you’re experiencing difficulty conceiving, low sperm count, or have risk factors such as prior testicular surgery or varicocele, consult Dr Azhari for comprehensive evaluation and treatment planning in male reproductive health.