The Study
Right testicular volume is a dominant predictor of testicular function determined by sperm parameters and total testosterone
This study looked at guys who went to the doctor because they were having trouble having babies, and found that guys with bigger right testicles tended to have better sperm and more hormones. But it doesn't prove that a bigger testicle makes those things better — it just shows they often go together.
Analysis score
Maximum 44 for a cross-sectional study.
Where the score came from
Doctors measured both testicles in men trying to have babies and found that the right one’s size was a better clue about sperm and hormone levels, even though both testicles were usually the same size.
Where does this study sit?
Reviews of RCTs (Meta-analyses)
Max 100Randomized Trials
Max 90Reviews of Cohort Studies
Max 85Cohort Studies
Max 72Reviews of Case-Control Studies
Max 63Case-Control Studies
Max 58Cross-Sectional & Case Series
Max 50Expert Opinion
Max 544 / 100
Quality score
Snapshots of a population at a single point in time, or descriptions of small groups. Can identify correlations and prevalence, but cannot determine cause and effect.
Key takeaways
Summary
Based on the study abstract and findings.
- 1Yes — a small right testicle could help doctors spot fertility problems without invasive tests, though it’s not perfect.
- 2If the right testicle is smaller than 15 mL, there’s a 2.79x higher chance of low sperm count or low testosterone.
- 3It correctly flagged poor function in 67% of cases.
Score breakdown, methodology, conflicts of interest, evidence analysis & raw study data
Publication
Journal
Andrologia
Year
2018
Authors
Yan-Ping Huang, Wei Liu, Yidong Liu, Hong-xiang Wang, K. Hu, Bin Chen, M. Lu
Related Content
Claims (6)
In men with low sperm count or low testosterone, the size of the right testicle is more closely related to the number of sperm than to how well the sperm move or the level of testosterone in the blood.
Low testosterone levels result in a reduction in testicle size.
In men evaluated for fertility, a right testicle volume under 15 mL is linked to lower sperm count, reduced sperm movement, and lower testosterone levels, and correctly identifies reduced testicular function in about two-thirds of cases.
In men being evaluated for fertility, the size of the right testicle is more closely linked to sperm count and testosterone levels than the size of the left testicle, even though both testicles are typically the same average size.
Men with a right testicle smaller than 15 mL are more likely to have reduced sperm production and hormone levels during fertility testing, as measured by specific diagnostic thresholds.
In men being evaluated for fertility, the size of the right testicle is a better indicator of overall testicular function than the size of the left testicle, even when both testicles are the same size.
Not medical advice. For informational purposes only. Always consult a qualified healthcare professional before making health decisions.