AJA: Tight Underwear Linked to Impaired Sperm Motility and Morphology
16:39 6 November, 2026Wearing tight underwear is associated with less favorable semen parameters, including sperm motility and DNA integrity. This was demonstrated by a study involving 26,836 men who sought fertility evaluations. The findings were published in the Asian Journal of Andrology.
Researchers from the University of Science and Technology of China compared data from 21,221 men who predominantly wore loose-fitting underwear and 5,615 men who preferred tight-fitting underwear. Participants reported which type they had worn most often over the previous three months. The median age was 30.
Smoking, alcohol consumption, varicocele and prostatitis were more common in the tight-underwear group. The researchers therefore accounted for these potential confounding factors in their statistical analysis.
After adjustments, tight underwear remained associated with lower ejaculate volume, impaired sperm motility and a lower proportion of normally shaped sperm. The adjusted odds of having an elevated DNA fragmentation index were approximately twice as high, while the odds of having a reduced proportion of normally shaped sperm were about 1.5 times higher.