Testicular Length Assessment
Your testicular lengths of 3.1cm and 3.4cm are below the normal adult range and warrant clinical evaluation, particularly if you are under 40 years old, have a history of undescended testicles, or have fertility concerns. 1, 2
Understanding Normal Testicular Dimensions
- Normal adult testicular length ranges from 3.5-5cm, corresponding to volumes typically greater than 12-14mL 2
- Your measurements of 3.1cm and 3.4cm fall below this threshold and suggest testicular volumes likely in the 8-10mL range, which is considered atrophic 1, 2
- Testicular volumes below 12mL are definitively pathological and associated with impaired sperm production and increased risk of testicular abnormalities 1, 2
Clinical Significance of Your Measurements
Fertility Implications:
- Testicular length below 3.5cm strongly correlates with reduced total sperm count and sperm concentration 2, 3
- Men with testicular length below 3.5cm typically have oligozoospermia (low sperm count) 3
- The mean testicular length for predicting infertility is 3.8cm, and your measurements fall significantly below this 4
Cancer Risk Considerations:
- If you are under 30-40 years old with testicular volume below 12mL, there is a greater than 34% risk of intratubular germ cell neoplasia (precancerous cells) in the presence of testicular cancer 1, 2
- This risk is substantially higher if you have a history of undescended testicles (cryptorchidism) 5, 2
What You Should Do Next
Immediate Actions:
- Obtain a semen analysis to assess sperm concentration, motility, and morphology, as testicular size strongly correlates with sperm production 1, 3
- Get hormonal blood tests including FSH, LH, and testosterone to distinguish primary testicular failure from other causes 1
- Provide your physician with detailed history focusing on: history of undescended testicles, fertility concerns, family history of testicular cancer, and any prior testicular problems 1
Consider Scrotal Ultrasound If:
- There is a size discrepancy between your testes greater than 2mL or 20% (your 3.1cm vs 3.4cm may warrant this) 1, 2
- You have palpable masses, epididymal enlargement, or other physical abnormalities 2
- You need accurate volume calculation using the Lambert formula (Length × Width × Height × 0.71) 1
High-Risk Scenarios Requiring Urology Referral:
- Age under 30 years with testicular length below 3.5cm 1
- History of cryptorchidism combined with small testicular size 5, 1
- Presence of testicular mass or rapid testicular atrophy 1
- Severe oligospermia (sperm count less than 5 million/mL) on semen analysis 1
Important Caveats
- Learn and perform monthly testicular self-examination given the increased cancer risk associated with smaller testicular volumes 1
- If you are planning to have children, discuss fertility preservation options such as sperm banking before any potential treatments 1
- Avoid unnecessary ultrasound screening for subclinical varicoceles, as only palpable varicoceles benefit from treatment 2, 6
- Karyotype testing is strongly recommended if semen analysis shows severe oligospermia or azoospermia, as chromosomal abnormalities occur in 10% of these patients 1