Given bilateral testicular volume of 10 mL, follicle‑stimulating hormone 9.9 IU/L (reference 1–12.4 IU/L), and two semen analyses showing sperm concentrations of 56 million/mL and 43 million/mL, is this decline normal variation or should I be concerned about a progressive decrease in sperm count?

Sperm Count Variation: Normal Fluctuation vs. Progressive Decline

Your sperm counts of 56 million/mL and 43 million/mL both fall well within the normal range, and this degree of variation is expected—you do not need to worry about progressive decline to azoospermia. 1

Understanding Your Results

Your semen parameters place you in a reassuring position:

• Both counts exceed the WHO lower reference limit of 16 million/mL by 2.7-3.5 times 1
• Your testicular volume of 10 mL per testis (20 mL total) is borderline-small but not severely atrophic 2, 3
• Your FSH of 9.9 IU/L is in the upper-normal range, indicating some testicular stress but not primary testicular failure 1, 4

Normal Biological Variation

Sperm concentration naturally fluctuates by 20-30% between samples due to:

• Abstinence interval differences (longer abstinence = higher concentration) 1
• Seasonal variation, illness, stress, and sleep quality 1
• Laboratory measurement variability 1

A drop from 56 to 43 million/mL represents only a 23% decrease, which falls within expected biological variation. 1 Single semen analyses can be misleading, and repeat testing in 3-6 months will establish whether your parameters are stable or declining. 1

Your FSH Level: What It Means

Your FSH of 9.9 IU/L indicates:

• You have reduced testicular reserve compared to men with FSH <4.5 IU/L 4
• Men with FSH >7.5 IU/L have a 5-13 fold higher risk of abnormal sperm concentration compared to men with FSH <2.8 IU/L 4
• However, FSH levels alone cannot predict fertility status—up to 50% of men with non-obstructive azoospermia and elevated FSH still have retrievable sperm 1

The combination of borderline-elevated FSH with normal sperm counts is the classic pattern of oligospermia with compensated testicular function, not progressive testicular failure. 1

Risk Assessment for Future Decline

Your risk of progression to azoospermia is low based on:

• Current sperm production far exceeds the threshold for natural conception 1
• Testicular volume of 10 mL per testis typically produces oligospermia (reduced counts), not azoospermia (zero sperm) 1, 3, 5
• Men with testicular volumes <10 mL are typically azoospermic, while volumes of 10-20 mL are associated with oligospermia 3

Critical Actions to Protect Your Fertility

Avoid These Fertility-Destroying Exposures:

1. Never use exogenous testosterone or anabolic steroids—these will completely suppress spermatogenesis through negative feedback, causing azoospermia that can take months to years to recover 1

2. Optimize modifiable factors:

   • Smoking cessation 1
   • Maintain healthy body weight (BMI <25) 1
   • Minimize heat exposure to testes (avoid hot tubs, saunas, laptop on lap) 1
   • Limit alcohol consumption 1

3. Check for reversible causes:

   • Measure LH and total testosterone to distinguish primary testicular dysfunction from secondary hypogonadism 1
   • Check thyroid function (TSH, free T4)—thyroid disorders commonly affect reproductive hormones 1
   • Evaluate for varicocele on physical examination—correction of palpable varicoceles can improve semen quality 1

Monitoring Strategy

Repeat semen analysis in 6 months to establish your baseline pattern. 1 If your concentration drops below 20 million/mL or continues declining on serial analyses, then consider:

• Genetic testing (karyotype and Y-chromosome microdeletion) if concentration falls below 5 million/mL 1
• Sperm cryopreservation (banking 2-3 ejaculates) if parameters show a declining trend 1
• Urology referral if concentration drops below 10 million/mL or rapid testicular atrophy occurs 1

Fertility Outlook

With a total motile sperm count well above 10 million per ejaculate, you have excellent natural conception potential. 1 The 13 million/mL difference between your two samples does not predict progressive decline—it reflects normal biological variation. Your borderline-elevated FSH indicates reduced testicular reserve, meaning you have less capacity to compensate if additional stressors occur, but your current sperm production is more than adequate for natural conception. 1, 4