Is a decrease in testicular length from 4cm to 3.1-3.4cm, along with a sperm count of 60 million/ml and elevated Follicle-Stimulating Hormone (FSH) level of 10.2, indicative of testicular atrophy in a male of reproductive age?

Assessment of Testicular Measurements and Fertility Status

This is NOT testicular atrophy—your measurements indicate measurement error, not true pathology.

Your sperm count of 60 million/ml is well above the WHO reference limit of 16 million/ml, and your FSH of 10.2 IU/L, while mildly elevated, does not indicate testicular failure in the context of normal sperm production. 1 The reported decrease in testicular length from 4cm to 3.1-3.4cm is almost certainly due to ultrasound measurement error rather than true biological change, as testicular atrophy does not occur this rapidly in adults without acute pathology. 2

Understanding Your Measurements

The Measurement Discrepancy

• A 4cm testicular length corresponds to a volume of approximately 15-18ml using proper measurement technique, which is well within the normal range (>12ml threshold for atrophy). 2

• The subsequent measurements of 3.1-3.4cm would calculate to severely atrophic volumes of approximately 6-8ml, which is completely inconsistent with your normal sperm count of 60 million/ml. 1, 2

• True biological testicular atrophy over such a short timeframe is extremely unlikely in adults unless there is acute pathology such as testicular torsion, trauma, or acute infection—none of which you've described. 2

• Technical error in caliper placement during ultrasound is the most likely explanation, as minor variations in probe angle, compression, or measurement plane can result in 20-30% volume calculation errors. 2

Why Your Sperm Count Rules Out Atrophy

• Testicular volume strongly correlates with total sperm count and sperm concentration—men with true testicular atrophy (<12ml) typically have severe oligospermia (<5 million/ml) or azoospermia, not counts of 60 million/ml. 1, 2, 3

• Your sperm count exceeds the WHO lower reference limit by nearly 4-fold, which is incompatible with the degree of atrophy suggested by the 3.1-3.4cm measurements. 1

• Even men with significantly elevated FSH (>15 IU/L) and confirmed testicular atrophy can have retrievable sperm in 30-50% of cases, but they present with azoospermia or severe oligospermia—not normal counts like yours. 4, 1

Interpreting Your FSH Level

FSH 10.2 IU/L in Context

• An FSH of 10.2 IU/L is mildly elevated above the 7.6 IU/L threshold that suggests some degree of testicular dysfunction, but this level does not indicate testicular failure or atrophy when accompanied by normal sperm production. 1, 5

• FSH levels >7.5 IU/L are associated with a five- to thirteen-fold higher risk of abnormal sperm concentration compared to FSH <2.8 IU/L, but this refers to oligospermia (reduced counts), not azoospermia or atrophy. 5

• Your FSH level indicates mild compensatory elevation—your pituitary is working slightly harder to maintain spermatogenesis, but it is clearly succeeding given your normal sperm count. 1

• FSH levels alone cannot definitively predict fertility status—up to 50% of men with non-obstructive azoospermia and elevated FSH still have retrievable sperm, and you already have documented normal sperm production. 1

What Mildly Elevated FSH Actually Means

• FSH 10.2 IU/L suggests reduced testicular reserve rather than testicular atrophy—you have less capacity to compensate if additional stressors occur (medications, illness, aging). 1

• This level is well below the FSH >35 IU/L threshold that indicates primary testicular failure, and far below levels seen in true atrophy with azoospermia. 1

• Men with maturation arrest on testicular histology can have normal FSH and testicular volume despite severe spermatogenic dysfunction, demonstrating that FSH and volume don't always correlate perfectly with function. 1

What You Should Do Next

Immediate Actions

• Request repeat scrotal ultrasound with explicit attention to proper measurement technique using high-frequency probes (>10 MHz), measuring three perpendicular dimensions (length, width, height), and calculating volume using the Lambert formula (Length × Width × Height × 0.71). 2

• The same sonographer should perform the measurement when possible, or measurements should be remeasured on previous scans by the current operator to minimize inter-scan variability. 2

• Compare measurements to the contralateral testis—size discrepancy greater than 2ml or 20% warrants further evaluation to exclude pathology. 2

Hormonal Evaluation

• Measure complete hormonal panel: LH, total testosterone, and SHBG to calculate free testosterone and determine if this represents primary testicular dysfunction versus secondary causes. 1

• Check prolactin to exclude hyperprolactinemia, which can disrupt gonadotropin secretion and elevate FSH. 1

• Assess thyroid function (TSH, free T4) as thyroid disorders commonly affect reproductive hormones and can cause FSH fluctuations. 1

Fertility Assessment

• Repeat semen analysis in 3-6 months to establish whether sperm parameters are stable or declining, as single analyses can be misleading due to natural variability. 1

• If repeat ultrasound confirms testicular volume <12ml bilaterally despite normal sperm count, consider genetic testing (karyotype and Y-chromosome microdeletion) if sperm concentration drops below 5 million/ml on future analyses. 1, 6

Critical Pitfalls to Avoid

Do NOT Start Testosterone Therapy

• Never use exogenous testosterone if current or future fertility is desired—it will completely suppress FSH and LH through negative feedback, causing azoospermia that can take months to years to recover. 1, 6

• This is the single most important fertility-preservation measure for men with mildly elevated FSH. 1

Protect Your Fertility

• Avoid anabolic steroids, which have the same suppressive effect as testosterone replacement. 1, 6

• Optimize modifiable factors: smoking cessation, maintain healthy body weight (BMI <25), minimize heat exposure to testes, and address any metabolic or thyroid dysfunction. 1

• Consider sperm cryopreservation (banking 2-3 ejaculates) if you have concerns about future fertility, especially if follow-up semen analyses show declining trends. 1

When to Worry

• Rapid testicular atrophy (confirmed on repeat imaging with proper technique) would warrant urgent urology referral. 2

• Development of a palpable testicular mass requires immediate evaluation given the increased cancer risk with smaller testicular volumes. 2

• Progression to severe oligospermia (<5 million/ml) or azoospermia would necessitate genetic testing and consideration of micro-TESE for sperm retrieval. 1, 6

Bottom Line

Your clinical picture—normal sperm count of 60 million/ml with mildly elevated FSH 10.2 IU/L—is completely inconsistent with testicular atrophy. The measurement discrepancy from 4cm to 3.1-3.4cm almost certainly represents ultrasound technique error rather than true biological change. Request repeat imaging with proper technique, obtain complete hormonal evaluation (LH, testosterone, SHBG, prolactin, thyroid function), and repeat semen analysis in 3-6 months to establish stability. Your fertility prognosis is good, but avoid testosterone therapy and protect your testicular reserve by addressing modifiable risk factors. 1, 2