My testicular volume is about 8 mL bilaterally, sperm concentration is 80 million per milliliter, and follicle‑stimulating hormone (FSH) is 9.9 IU/L (reference 1–12.4). How can I have a normal/high sperm count despite relatively small testicular size?

Normal Sperm Count with Small Testicular Volume: Understanding the Paradox

Your testicular volume of 8 mL bilaterally is definitively atrophic (normal ≥12 mL), yet your sperm concentration of 80 million/mL is well above the WHO reference limit of 16 million/mL—this apparent paradox occurs because testicular volume correlates with total spermatogenic capacity but does not determine efficiency of sperm production, and your borderline-elevated FSH of 9.9 IU/L indicates your pituitary is compensating by driving remaining functional testicular tissue harder to maintain normal output. 1, 2

Why Small Testes Can Still Produce Normal Sperm Counts

The Volume-Production Relationship

• Testicular volume <12 mL is classified as atrophic and typically correlates with reduced total sperm count and impaired spermatogenesis, but this relationship is statistical—not absolute. 1
• Mean testicular size strongly correlates with total sperm count and sperm concentration across populations, but individual men can maintain adequate sperm production despite reduced testicular volume if the remaining seminiferous tubules are functioning efficiently. 1
• Your FSH of 9.9 IU/L (upper-normal range) reflects compensatory pituitary stimulation—the elevated FSH is driving your smaller testes to produce sperm at near-maximal efficiency, maintaining your current output. 3, 2

The Compensated Testicular Dysfunction Pattern

• Men with borderline-elevated FSH (>7.6 IU/L) and normal sperm counts represent compensated primary testicular disease—normal fertility is maintained at the expense of chronically elevated FSH levels. 4
• FSH levels >4.5 IU/L are associated with five- to thirteen-fold higher risk of abnormal sperm concentration compared to FSH <2.8 IU/L, but this indicates reduced testicular reserve, not necessarily current dysfunction. 2
• Your situation demonstrates that FSH measurement may be a more sensitive index of underlying testicular disease than semen analysis alone, as you have subclinical testicular impairment despite normal sperm output. 4

Critical Implications: Reduced Testicular Reserve

What This Means for Your Fertility

• You have reduced testicular reserve—your testes are working at near-maximal capacity to maintain current sperm production, leaving little buffer if additional stressors occur. 3
• The combination of 8 mL testicular volume and FSH 9.9 IU/L indicates you have less capacity to compensate if fertility declines due to aging, illness, medications, or environmental factors. 3
• Testicular volumes <12 mL with elevated FSH typically present with oligospermia rather than normal counts, making your current parameters somewhat fragile and potentially unstable over time. 3, 5

Factors That Could Accelerate Decline

• Never use exogenous testosterone or anabolic steroids—these will completely suppress FSH and LH through negative feedback, causing azoospermia that can take months to years to recover. 3
• Chemotherapy, radiation therapy, or gonadotoxic medications could cause additional impairment, with rates of azoospermia highest within the first 12 months and nadir between 2-6 years following exposure. 1
• Chronic opioid use, metabolic syndrome, obesity (BMI >25), and certain medications can suppress the hypothalamic-pituitary-gonadal axis and accelerate testicular decline. 3

Essential Diagnostic Workup

Mandatory Next Steps

• Measure LH and total testosterone (morning samples, 08:00-10:00 h, on two separate occasions) to distinguish primary testicular failure from secondary hypogonadism—elevated LH suggests primary testicular dysfunction, while low/normal LH points toward pituitary causes. 3, 1
• Calculate free testosterone by measuring SHBG, as high SHBG can reduce bioavailable testosterone even when total testosterone appears normal, potentially contributing to impaired spermatogenesis. 3
• Obtain scrotal ultrasound with Doppler to confirm testicular volume using the Lambert formula (Length × Width × Height × 0.71), assess for varicocele, and rule out structural abnormalities or masses. 1

Genetic Testing Considerations

• Karyotype analysis and Y-chromosome microdeletion testing (AZFa, AZFb, AZFc regions) are not currently indicated with your sperm concentration of 80 million/mL, as genetic testing is recommended only when concentration drops below 5 million/mL. 3, 5
• However, if your sperm count declines on repeat testing to <5 million/mL, genetic testing becomes mandatory to assess sperm retrieval potential and guide counseling. 3

Evaluate for Underlying Causes

• History of cryptorchidism (undescended testes) is the single most important risk factor to identify, as it substantially increases risk of testicular atrophy, impaired spermatogenesis, and testicular cancer (3.6-7.4 times higher risk). 1, 5
• Check for clinical varicocele on standing examination—palpable varicoceles can cause progressive testicular damage, and repair may improve testosterone levels, reduce FSH, and stabilize testicular volume. 3
• Screen for systemic conditions including thyroid dysfunction, diabetes, chronic liver or kidney disease, HIV infection, and prior chemotherapy/radiation, as these can cause progressive testicular damage. 5

Fertility Preservation Strategy

Immediate Protective Actions

• Bank sperm immediately—collect 2-3 separate ejaculates with 2-3 days abstinence between collections to provide insurance against technical failures, poor post-thaw recovery, or need for multiple treatment attempts. 3
• Sperm cryopreservation is strongly recommended for men with reduced testicular reserve before any intervention or while parameters remain normal, as once azoospermia develops, even microsurgical testicular sperm extraction (micro-TESE) only achieves 40-50% sperm retrieval rates. 3
• Banking multiple specimens is critical because sperm concentration and progressive motility decrease significantly after cryopreservation, though DNA integrity is preserved. 3

Monitoring Protocol

• Repeat semen analysis every 6-12 months to detect early decline in sperm parameters, as single analyses can be misleading due to natural variability. 3, 1
• If sperm concentration drops below 20 million/mL or approaches 5 million/mL, remeasure FSH, LH, and testosterone, and strongly consider additional sperm banking. 3
• Perform testicular self-examination monthly given the 3.6-7.4 times higher risk of germ cell tumors associated with testicular atrophy, especially if you have a history of cryptorchidism. 1, 5

Cancer Risk Considerations

When to Worry About Testicular Cancer

• Testicular volume <12 mL is a risk factor for testicular cancer, and men younger than 30-40 years with volume <12 mL have a ≥34% risk of intratubular germ cell neoplasia (TIN) in the contralateral testis if testicular cancer develops. 1
• If untreated, invasive testicular tumor develops in 70% of TIN-positive testes within 7 years. 1
• Testicular biopsy is indicated if you are under 30-40 years with history of cryptorchidism, testicular microcalcifications on ultrasound, or development of a palpable testicular mass. 1, 5

Red-Flag Symptoms Requiring Urgent Evaluation

• Development of a palpable testicular mass or rapid testicular atrophy warrants immediate urology referral. 3
• Size discrepancy between testes >2 mL or 20% warrants ultrasound evaluation to exclude pathology, regardless of absolute volume. 1

Optimizing Modifiable Factors

Lifestyle Modifications to Protect Fertility

• Maintain healthy body weight (BMI <25)—obesity and metabolic syndrome impair male fertility through disruption of the hypothalamic-pituitary-gonadal axis. 3
• Smoking cessation is essential, as smoking negatively affects spermatogenesis and accelerates testicular decline. 3
• Minimize heat exposure to the testes—avoid hot tubs, saunas, prolonged sitting, and laptop use on the lap. 3
• Avoid gonadotoxic exposures including lead, cadmium, pesticides, and occupational hazards like oil and natural gas extraction. 3

Medications to Avoid

• Never start testosterone replacement therapy if current or future fertility is desired—exogenous testosterone will completely suppress remaining spermatogenesis and can cause azoospermia. 3, 5
• Avoid chronic opioid use, high-dose corticosteroids, and anabolic steroids, as these suppress the hypothalamic-pituitary-gonadal axis and cause testicular atrophy. 5

Common Pitfalls to Avoid

• Do not assume your fertility is secure based on current sperm count alone—your reduced testicular reserve means you have limited buffer against future decline. 3
• Do not delay sperm banking if you desire future fertility—waiting until parameters decline may result in insufficient sperm for cryopreservation. 3
• Do not treat subclinical varicoceles found only on ultrasound—only palpable varicoceles improve fertility outcomes after repair. 5
• Do not start empiric hormonal therapy (SERMs, aromatase inhibitors, FSH analogues) without first banking sperm and confirming stable parameters, as benefits are limited and assisted reproductive technology (IVF/ICSI) offers superior pregnancy rates. 3