In an adult male with follicle‑stimulating hormone levels of 10–11 IU/L (reference 1–12.4 IU/L), testicular lengths decreasing from 4 cm to 3.1–3.4 cm on ultrasound, and semen concentrations of 56 and 43 million/mL, does this indicate testicular atrophy?

Assessment of Testicular Atrophy in Your Clinical Scenario

Your FSH levels of 10–11 IU/L combined with testicular size reduction from 4 cm to 3.1–3.4 cm and declining sperm concentrations (56 to 43 million/mL) indicate early testicular dysfunction with reduced testicular reserve, but this does NOT represent complete testicular atrophy or failure—you still have normal sperm production that exceeds WHO fertility thresholds. 1

Understanding Your Current Status

FSH Interpretation

• Your FSH levels (10–11 IU/L) fall in the borderline-elevated range, indicating compensated testicular dysfunction where your pituitary is working harder to maintain sperm production. 1
• FSH >7.6 IU/L is associated with a 5- to 13-fold higher risk of abnormal sperm parameters compared to FSH <2.8 IU/L, but this reflects impaired spermatogenesis, not absent spermatogenesis. 1, 2
• Critical distinction: FSH >7.6 IU/L with testicular atrophy typically indicates non-obstructive azoospermia (zero sperm), but your sperm concentration of 43–56 million/mL far exceeds the WHO lower reference limit of 16 million/mL. 1, 3
• Men can maintain normal sperm counts and fertility despite elevated FSH through compensated primary testicular disease—your case appears to fit this pattern. 3

Testicular Size Assessment

The reported size reduction requires urgent verification due to high likelihood of measurement error:

• A 4 cm testicular length corresponds to approximately 15–18 mL volume, which is normal and associated with adequate spermatogenesis. 4
• A 3.1–3.4 cm length would correspond to approximately 6–8 mL volume using proper ultrasound formulas (Length × Width × Height × 0.71), which would represent severe testicular atrophy. 4
• This dramatic 40–50% volume reduction over a short timeframe is biologically implausible in adults unless acute pathology occurred (torsion, severe trauma, acute orchitis)—none of which you've described. 4
• Most likely explanation: technical measurement error from improper caliper placement, use of incorrect formula (0.52 ellipsoid formula underestimates by 20–30%), or different measurement techniques between scans. 4

Sperm Production Analysis

Your sperm concentrations are reassuring:

• 56 million/mL and 43 million/mL both exceed the WHO lower reference limit of 16 million/mL by 2.5–3.5 times. 1
• With a typical ejaculate volume of 2–3 mL, your total sperm count would be 86–168 million per ejaculate, far exceeding the WHO threshold of 39 million. 1
• This level of sperm production is inconsistent with severe testicular atrophy (volume <12 mL), which typically produces oligospermia (<15 million/mL) or azoospermia. 1, 5

Essential Next Steps

1. Verify Testicular Measurements Immediately

Request repeat scrotal ultrasound with explicit instructions: 4

• Use high-frequency probes (>10 MHz) for maximum resolution
• Measure three perpendicular dimensions (length, width, height) on axial slices
• Calculate volume using Lambert formula: Length × Width × Height × 0.71
• Have the same sonographer remeasure the previous scan images to identify measurement discrepancies
• Compare size discrepancy between right and left testis (>2 mL or 20% difference warrants further evaluation)

2. Complete Hormonal Evaluation

Obtain morning fasting blood tests: 1

• LH and total testosterone to distinguish primary testicular failure (elevated LH, low-normal testosterone) from secondary hypogonadism (low-normal LH)
• SHBG to calculate free testosterone index, as high SHBG can reduce bioavailable testosterone despite normal total testosterone
• Prolactin to exclude hyperprolactinemia, which can disrupt gonadotropin secretion
• TSH and free T4 because thyroid dysfunction commonly affects reproductive hormones and can cause reversible FSH elevation

3. Repeat Semen Analysis

• Perform at least one additional semen analysis after 2–3 months to establish whether parameters are stable or declining. 1
• Single analyses can be misleading due to natural variability (illness, stress, heat exposure, abstinence duration). 1

4. Physical Examination by Reproductive Specialist

Essential examination findings to assess: 1, 6

• Testicular consistency (firm vs. soft suggests different pathology)
• Presence of varicocele on standing examination (palpable varicoceles can cause progressive testicular damage and are treatable)
• Vas deferens and epididymal abnormalities
• Signs of prior cryptorchidism or testicular trauma

Risk Stratification and Monitoring

You Are NOT in Immediate Danger of Azoospermia

• Your current sperm production (43–56 million/mL) places you well within the fertile range. 1
• However, the combination of borderline-elevated FSH and potentially reduced testicular volume indicates reduced testicular reserve, meaning less capacity to compensate if additional stressors occur. 1

Factors That Could Accelerate Decline

Absolutely avoid: 1

• Exogenous testosterone or anabolic steroids—these will completely suppress spermatogenesis through negative feedback, causing azoospermia that takes months to years to recover
• Gonadotoxic medications, chemotherapy, or radiation therapy
• Prolonged heat exposure to testes (hot tubs, saunas, tight underwear, laptop on lap)

Optimize modifiable factors: 1

• Smoking cessation
• Maintain healthy body weight (BMI <25)
• Optimize glycemic control if diabetic
• Correct thyroid dysfunction if present
• Treat clinical varicocele if present

Consider Fertility Preservation

If repeat ultrasound confirms testicular volume <12 mL: 1, 6

• Strongly consider sperm cryopreservation (banking 2–3 separate ejaculates with 2–3 days abstinence between collections)
• This provides insurance against progressive spermatogenic failure
• Once azoospermia develops, even microsurgical testicular sperm extraction (micro-TESE) only achieves 40–50% sperm retrieval rates

Genetic Testing Indications

Genetic testing is NOT currently indicated because your sperm concentration exceeds 5 million/mL. 1

However, obtain genetic testing if: 1

• Sperm concentration drops below 5 million/mL on repeat analysis
• Karyotype analysis to exclude Klinefelter syndrome (47,XXY)
• Y-chromosome microdeletion testing (AZFa, AZFb, AZFc regions) if concentration drops below 1 million/mL

Fertility Outlook

Current Fertility Status

• Your sperm parameters support excellent natural conception potential with total motile sperm count likely >36 million per ejaculate (assuming 50% motility). 1
• Couples with male total motile sperm count >10 million have good natural conception rates. 1
• Female partner age is the most critical factor determining conception success—if she is under 30, you have >90% chance of achieving pregnancy within 2–3 years of trying. 1

When to Seek Fertility Assistance

• If no conception after 12 months of timed intercourse (or 6 months if female partner >35 years). 1
• If repeat semen analysis shows declining trend approaching 20 million/mL or below. 1
• IVF/ICSI offers superior pregnancy rates compared to empiric hormonal therapy if parameters worsen. 1

Critical Pitfalls to Avoid

• Do not accept the ultrasound measurements at face value—the reported size reduction is biologically implausible given your normal sperm production and requires verification. 4
• Never start testosterone therapy if current or future fertility is desired—it will cause azoospermia. 1
• Do not delay fertility preservation if repeat ultrasound confirms volume <12 mL and you desire future children. 1, 6
• FSH levels alone cannot predict fertility status—your actual sperm production is far more important than the FSH number. 1

Summary Assessment

Most likely scenario: You have compensated primary testicular dysfunction with borderline-elevated FSH (10–11 IU/L) maintaining normal sperm production (43–56 million/mL) through increased pituitary drive, combined with probable ultrasound measurement error creating the appearance of dramatic testicular atrophy. 1, 3 True testicular volume <12 mL with this level of sperm production would be highly unusual. 5 Verify measurements, complete hormonal workup, and establish monitoring protocol to detect early decline.