Effect of increased scrotal temperature on sperm production in normal men

Fertil Steril. 1997 Aug;68(2):334-9. doi: 10.1016/s0015-0282(97)81525-7.


Objective: To determine whether application of polyester-lined athletic supports to bring the testes closer to the abdomen increases scrotal temperature and decreases sperm production.

Design: Prospective clinical study.

Setting: University academic medical center.

Patient(s): Twenty-one healthy male volunteers.

Intervention(s): The study consisted of a pretreatment period of 6 weeks, a treatment phase of 52 weeks, and a recovery phase until return to normal sperm production. During the treatment phase, the men wore polyester-lined athletic supports (single layer, double layer, or double layer impregnated with aluminum) throughout the day.

Main outcome measure(s): Semen parameters and sperm function tests.

Result(s): In all three groups of subjects, scrotal temperature was consistently increased by 0.8 to 1 degree C while the subjects were wearing the athletic supports. Mean sperm concentration; sperm motility, morphology, and viability; sperm hyperactivation; and ability of spermatozoa to penetrate zone-free hamster oocytes were not affected by the increase in scrotal temperature.

Conclusion(s): The increase in scrotal temperature induced by polyester-lined athletic supports was insufficient to cause significant suppression of spermatogenesis or alteration of sperm function.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Adult
  • Animals
  • Body Temperature*
  • Cricetinae
  • Female
  • Hot Temperature
  • Humans
  • Male
  • Prospective Studies
  • Scrotum / physiology*
  • Semen / cytology
  • Semen / physiology
  • Sperm Motility
  • Sperm-Ovum Interactions
  • Spermatogenesis*
  • Spermatozoa / physiology