Can sexually transmitted diseases (STDs) cause non-obstructive azoospermia?

STDs and Non-Obstructive Azoospermia

STDs are not directly identified as a primary cause of non-obstructive azoospermia in current clinical guidelines, though they may contribute to inflammatory processes that affect spermatogenesis in some cases. 1

Understanding Non-Obstructive Azoospermia

Non-obstructive azoospermia (NOA) is defined as the absence of sperm in the ejaculate due to failure of spermatogenesis within the testes, rather than due to blockage in the reproductive tract. 1

Diagnostic Characteristics:

• Testicular atrophy on physical examination 1
• Elevated FSH levels (typically >7.6 IU/L) 1
• Normal semen volume and pH (unlike obstructive azoospermia) 1

Known Causes of Non-Obstructive Azoospermia

The 2024 AUA/ASRM and 2025 EAU guidelines identify several established causes of NOA:

Genetic Factors:

• Karyotype abnormalities (most common genetic cause) 1
  • Klinefelter syndrome (47,XXY) 1
  • Structural chromosomal anomalies (deletions, duplications, inversions) 1
• Y-chromosome microdeletions (AZFa, AZFb, AZFc regions) 1, 2
  • Complete deletion of AZFa region associated with Sertoli cell-only syndrome 1
  • Complete deletion of AZFb region associated with spermatogenic arrest 1

Hormonal Factors:

• Hypogonadotropic hypogonadism 3
• Exogenous testosterone use (suppresses spermatogenesis) 1

Environmental/Lifestyle Factors:

• Exposure to certain toxins (lead, cadmium) 1
• Occupational exposures (oil and natural gas extraction) 1

Potential Role of STDs in Non-Obstructive Azoospermia

While current guidelines do not explicitly list STDs as a direct cause of non-obstructive azoospermia, there are several potential mechanisms by which STDs might contribute:

• Inflammatory processes from untreated infections could potentially damage testicular tissue 4
• Severe orchitis (testicular inflammation) from certain infections might lead to permanent damage to seminiferous tubules 5
• Systemic effects of chronic infections could potentially impact the hypothalamic-pituitary-testicular axis 5

Evaluation of Non-Obstructive Azoospermia

For patients with azoospermia, guidelines recommend:

• Hormonal evaluation (FSH, testosterone, LH) 1
• Genetic testing:
  • Karyotype analysis for men with azoospermia or sperm concentration <5 million/mL 1
  • Y-chromosome microdeletion testing for men with azoospermia or severe oligospermia 1
• Testicular biopsy (for definitive diagnosis and potential sperm retrieval) 4

Management Options

• For men with NOA, microsurgical testicular sperm extraction (micro-TESE) offers the best chance of retrieving sperm for use with assisted reproductive technology 1
• Success rates for sperm retrieval in NOA range from 30-70% depending on the underlying cause 4
• Pregnancy rates of 20-50% may be achieved with retrieved sperm using intracytoplasmic sperm injection (ICSI) 4

Conclusion

While STDs are not specifically identified in current guidelines as a primary cause of non-obstructive azoospermia, they may potentially contribute to testicular damage through inflammatory processes. The primary established causes include genetic abnormalities, hormonal disorders, and certain environmental exposures. Comprehensive evaluation including hormonal and genetic testing is essential for proper diagnosis and management.