At what age should boys with undescended testes be referred to a specialist?

Referral Timing for Undescended Testes

Boys with undescended testes should be referred to a pediatric urologist or qualified surgical specialist at 6 months of age (corrected for gestational age) if spontaneous descent has not occurred. 1

Diagnostic Approach and Referral Criteria

Initial Assessment

• Physical examination should include palpation of testes for quality and position at each well-child visit 1
• Approximately 70% of undescended testes are palpable 1
• Gestational history is critical as premature infants have higher rates of cryptorchidism (15-30% vs 1-3% in full-term) 1

Key Referral Timepoints

• 6 months of age (corrected for gestational age) if testes remain undescended 1, 2
• Immediately for any phenotypic male newborn with bilateral, nonpalpable testes to evaluate for possible disorder of sex development 1
• Immediately if testicular torsion is suspected 2
• At any age after 6 months if undescended testis is newly diagnosed 2

Rationale for Early Referral

1. Spontaneous Descent Timeline:

   • Most undescended testes descend spontaneously within the first 6 months of life 1
   • Testes that remain undescended after 6 months are unlikely to descend spontaneously 1, 2

2. Prevention of Complications:

   • Delayed referral beyond 6 months can lead to irreversible testicular damage 1
   • Early intervention (before 18 months) preserves fertility potential 1
   • After 15-18 months, some cryptorchid boys begin to lack germ cells in the testes 1
   • By 8-11 years, about 40% of bilateral cryptorchid boys lack germ cells 1
   • Patients with undescended testes have threefold increased risk of testicular cancer 2

Common Pitfalls to Avoid

• Unnecessary Imaging: Ultrasound has poor sensitivity (45%) and specificity (78%) for non-palpable testes and is not recommended prior to specialist referral 1, 3

  • In one study, ultrasound incorrectly indicated UDT in 48% of cases 3

• Delayed Referral: Despite guidelines, referrals often occur late:

  • Median age of referral was 43.3 months in one study 3
  • Another study showed median time of orchiopexy for congenital UDT was 30 months 4
  • Only 16% of boys with congenital UDT had orchiopexy performed by 18 months of age 4

• Misdiagnosis: Distinguishing retractile testes from true undescended testes:

  • Only about half of referred patients actually have UDT 3
  • Most diagnostic errors occur in boys 1-10 years of age 3
  • Helpful diagnostic clues: history of UDT at birth, prematurity, and scrotal asymmetry strongly increase the risk of UDT 3

• Hormonal Therapy: Not recommended as primary treatment due to:

  • Low efficacy (15-20% descent rate with high re-ascent) 5
  • Potential harm to future spermatogenesis through increased germ cell apoptosis 5
  • Lack of evidence for long-term efficacy 1

Special Considerations

• Retractile Testes: Require annual monitoring due to 2-45% risk of secondary ascent 1
• Secondary Ascent: Previously descended testes that move out of the scrotum, most commonly with retractile testes 1
• Bilateral Non-palpable Testes: Require immediate specialist evaluation and additional testing including serum electrolytes, karyotype analysis, and hormonal testing 6

By adhering to the 6-month referral guideline, primary care providers can help ensure timely intervention, which is critical for preserving fertility and reducing cancer risk in boys with undescended testes.