Hjollund Niels Henrik I, Storgaard Lone, Ernst Erik, Bonde Jens Peter E, Christensen Kaare, Olsen Jørn
Department of Occupational Medicine, Aarhus University Hospital, Noerrebrogade 44, DK-8000 Aarhus C, Denmark.
Hum Reprod. 2002 Jul;17(7):1837-8. doi: 10.1093/humrep/17.7.1837.
Scrotal temperature and semen quality have been found to be inversely correlated in several studies, and variation in scrotal temperature may contribute to the well known variation in semen quality. The reason for the variation in scrotal temperature is not well understood although determinants could be of a genetic nature.
We monitored scrotal skin temperature for 24 h in a group of monozygotic and dizygotic twins and single-born brothers (n = 48 males). A thermistor was attached to the underwear and the temperature of the scrotal skin was recorded every 5 min using a small portable data logger.
A correlation in median scrotal temperature was found among monozygotic twins (r = 0.64, P = 0.01), but not in dizygotic twins and single-born brothers (r = 0.17, NS). Similar results were found for other percentiles of temperature.
The results suggest a genetic component to the variation in scrotal temperature. An hereditary element in male fecundity may be expressed through scrotal temperature, which constitutes a mechanism independent of those responsible for the development of the sperm producing epithelium.
