B. Lemcke et al., FREQUENTLY SUBNORMAL SEMEN PROFILES OF NORMAL VOLUNTEERS RECRUITED OVER 17 YEARS, International journal of andrology, 20(3), 1997, pp. 144-152
In order to establish semen profiles for men in the general population
, we analysed the semen parameters of 187 men attending the Institute
of Reproductive Medicine between 1977 and 1993 as volunteers for clini
cal studies. If several ejaculates were obtained from the volunteer, o
nly the first ejaculate was used for analysis. More than half of the e
jaculates of these healthy men showed at least one abnormal parameter,
so that only 46% of the volunteers could be classified as being 'norm
ozoospermic' according to WHO guidelines. Aside from a decrease in the
proportion of motile spermatozoa, no change in semen parameters could
be detected with advancing age of the volunteers. No negative influen
ce of the presence of a varicocele, the grade of varicocele or a histo
ry of maldescended testis on semen parameters was detected. The serum
levels of FSH, LH and testosterone showed no significant age-related c
hange over the period of investigation. Follow-up analysis of the fert
ility of the volunteers revealed a proportion of unwanted barrenness s
imilar to or even lower than that in the general population. The analy
sis demonstrates that the limits of normality for semen parameters may
require redefinition.