Do most men with severe testicular atrophy still produce some sperm?

Sperm Production in Severely Atrophied Testes

Most men with severe testicular atrophy can still produce some sperm, with sperm retrieval possible in approximately 55-56% of cases, regardless of testicular volume. 1

Understanding Testicular Atrophy and Sperm Production

• Testicular atrophy is characterized by reduced testicular volume (≤2 ml in severe cases) and is often associated with elevated FSH levels and impaired spermatogenesis 1
• Men with atrophied testes typically present with non-obstructive azoospermia (NOA), defined as the absence of sperm in the ejaculate after centrifugation 2
• Clinically, men with NOA due to testicular atrophy usually have low testicular volume, normal sperm volume, and high FSH values (typically >7.6 IU/L) 2

Sperm Production Potential in Atrophied Testes

• Despite severe testicular atrophy, spermatogenesis often persists in small, isolated foci within the testes 2
• Studies show that testicular sperm extraction (TESE) can successfully retrieve sperm in approximately 55-56% of men with severe testicular atrophy (volume ≤2 ml) 1
• This success rate is comparable to men with larger testicular volumes, indicating that testicular size alone does not determine sperm production capability 1
• Even in men with azoospermia, markedly elevated FSH levels, and testicular atrophy, mature sperm can be identified in about 30% of cases through testicular biopsy 3

Factors Affecting Sperm Production in Atrophied Testes

• Age is a significant factor - younger men with atrophied testes have higher chances of successful sperm retrieval than older men 1
• Genetic factors play a role - men with Klinefelter syndrome (47,XXY) who have small testes can have successful sperm retrieval, particularly if they are younger than 30 years 1
• The pattern of spermatogenic failure impacts sperm production:
  • Hypospermatogenesis has better chances of sperm retrieval 4
  • Sertoli cell-only pattern and maturation arrest have lower chances of sperm retrieval 4
• Complete AZFa and AZFb Y-chromosome microdeletions result in almost zero likelihood of sperm retrieval 2

Clinical Implications

• Severe testicular atrophy should not be considered a contraindication to microdissection testicular sperm extraction (mTESE) 1
• The presence of hypospermatogenesis on testicular biopsy is associated with good accuracy in predicting positive sperm retrieval 2
• Medical management with hormonal therapy may benefit some men with non-obstructive azoospermia, particularly those with hypogonadotropic hypogonadism 5
• For men with intrinsic testicular impairment, medical therapy has limited benefit but may improve the quantity and quality of sperm retrieved for assisted reproductive techniques 5

Important Caveats

• Testicular volume alone should not be used to exclude men from sperm retrieval attempts 1
• There is no age cutoff beyond which sperm cannot be retrieved in men with small testes, though younger age is associated with better outcomes 1
• Hormonal levels (FSH, LH, inhibin B, AMH) have been variably correlated with sperm retrieval outcomes, but data are limited and from retrospective series 2
• The pattern of spermatogenic failure is more predictive of sperm retrieval success than testicular size 4