Role of the Gubernaculum in Testicular Descent and Treatment Options for Undescended Testes
The gubernaculum plays a critical role in testicular descent by anchoring the testis during abdominal growth and guiding its migration to the scrotum, and undescended testes should be surgically corrected via orchidopexy by 18 months of age to preserve fertility potential and reduce cancer risk. 1
Gubernaculum and Testicular Descent
Testicular descent occurs in two distinct phases:
Phase 1: Transabdominal Descent (8-15 weeks gestation)
- The gubernaculum forms initially as a conus inguinalis connecting the abdominal wall to the caudal part of the mesonephric fold 2
- The gubernaculum thickens and anchors the testis to the scrotum through the inguinal rings while the craniosuspensory ligament regresses 1
- This phase is primarily controlled by Insulin-like 3 (INSL3) from Leydig cells, which stimulates gubernacular growth 3, 4
- Testosterone causes regression of the cranial ligament, allowing the testis to remain anchored as the abdomen elongates 1, 5
Phase 2: Inguinoscrotal Descent (25-35 weeks gestation)
- The gubernaculum guides the testis from its retroperitoneal position through the inguinal canal 1
- The testis draws with it an extension of peritoneal lining (processus vaginalis) 1
- This phase is androgen-dependent and involves migration of the gubernaculum from groin to scrotum 3
- The genitofemoral nerve releases calcitonin gene-related peptide under androgen influence to guide gubernacular migration 3
Undescended Testes (Cryptorchidism)
Epidemiology
- Occurs in 1-3% of full-term male infants and 15-30% of premature infants 1
- Prevalence increases with decreasing birth weight - approaching 100% in infants <900g 1
- Right-sided cryptorchidism is more common (60%) as left processus vaginalis involution precedes the right 1
Diagnosis and Evaluation
- Gestational history should be obtained at initial evaluation 1
- Testes should be palpated for quality and position at each well-child visit 1
- Approximately 70% of undescended testes are palpable; the remainder may be intra-abdominal (55%), inguinal-scrotal (30%), or absent (15%) 1
- Spontaneous descent may occur in the first six months of life but is unlikely after this period 1
Treatment Options
Timing of Referral and Treatment
- Infants with cryptorchidism detected at birth who don't have spontaneous descent by six months (corrected for gestational age) should be referred to a surgical specialist 1
- Boys with newly diagnosed (acquired) cryptorchidism after six months should also be promptly referred 1
- Orchidopexy in the first 18 months of life is recommended to preserve fertility potential 1
Surgical Management
- Scrotal or inguinal orchidopexy is the standard treatment for palpable cryptorchid testes 1
- Early surgical correction (before 18 months) is associated with:
Hormonal Therapy
- Hormonal therapy (hCG or GnRH) should not be used to induce testicular descent 1
- Success rates for hormonal therapy range from 6-38% in well-controlled studies 1
- Current evidence does not support the use of hormone therapy due to low response rates and lack of evidence for long-term efficacy 1, 6
Follow-up
- Boys with retractile testes should have testicular position assessed at least annually to monitor for secondary ascent 1
- Acquired cryptorchidism occurs in 1-7% of boys, peaking around 8 years of age 1
Clinical Implications and Complications
- Untreated cryptorchidism is associated with:
The gubernaculum's role in testicular descent is crucial, and proper management of undescended testes through timely surgical intervention is essential for optimizing fertility potential and reducing cancer risk.