ARE BOXER SHORTS REALLY BETTER? BR Gilbert, DG Schauer and RA Munkelwitz, Dept. Of Urology, Stony Brook University Medical School, Stony Brook, N.Y.

Objectives: To compare the effect of 'Boxer' type underwear to 'Brief' type underwear on scrotal temperature and semen parameters in men presenting with subfertility.

Design: A non-randomized, prospective study of 58 consecutive men presenting with subfertility. 29 wearing cotton 'briefs' and 29 wearing linen 'boxer' type underwear were evaluated.

Methods: Core body temperature was measured by a Thermoscan Pro-LT. Skin temperature on the upper extremity and midline scrotal temperature were measured with a dual probe differential Electro-Therm Digital Thermometer model# SH66A which has an accuracy of ±0.2% of the reading. Measurements were made in the supine position with and without underwear as well as in the standing position without underwear. Differential temperatures between the scrotum and extremity were simultaneously measured and calculated electronically to compensate for ambient temperature. In five patients a crossover study was done in which measurements were repeated after the patient changed from briefs to boxers for a period of two weeks.

Results: Mean scrotal temperature for briefs was 33.5±2.2 0C and 33.8±1.2 0C for boxers (mean±sd;NS). Mean differential temperature was 2.9±3.9 0C for briefs and 2.9±2.7 0C for boxers (mean±sd;NS). There was a significant difference (p0.001) of 0.79 0C when underwear was removed for patients wearing either briefs or boxers. Changing from briefs to boxers did not alter these results. There was no significant difference (NS) in semen parameters between patients wearing briefs or boxers. Total sperm count averaged 113.2±13.9 million, % motility was 44.8 ±2.6% (mean ±sem), Tapered forms 21.3±1.7 (mean±sd;NS). Most men had no significant change in differential scrotal temperature when standing without underwear. However, a group of men were identified with large varicoceles that had an increased number of tapered forms and a measured increase in differential scrotal temperature of 3.1±1.0 0C with standing.

Conclusions: Underwear type did not significantly affect measured scrotal temperature or semen quality in the group of men studied. Likewise, changing from boxers to briefs did not change measured scrotal temperature. Scrotal temperature averaged 0.79 0C less without underwear. In addition, large scrotal varicoceles resulted in an increased measured scrotal temperature when standing. This data suggests that 'boxer' type underwear does not have a measurable benefit over 'brief' type underwear. Rather, anatomic parameters such as varicoceles are more likely responsible for temperature related variations in semen quality.