Older men are also producing less sperm, and of a poorer quality. The worrying trend, observed mainly in younger men and those attending infertility clinics, is affecting those aged between 35 and 69, researchers have found.
The trial, carried out in Finland, checked the sperm levels and quality of 528 men in 1981 and again in 1991 to see if there had been any deterioration. Researchers from the University of Helsinki found there had been a significant reduction in the levels of normal sperm being produced in that time.
Researchers were unable to pinpoint any particular cause for the decrease (BMJ, 1997; 314: 13-8).
For more information, see the WDDTY Guide to Men's Health, and WDDTY vol 1, no 8.