Fertility in aging men.
A wide variety of disorders, medications, physical factors, and trauma can alter testicular function and reproductive function in men as they age. There are no precise age limits for 'aging men', but most studies consider 50-80-yr-old subjects. Assuming we have healthy individuals, there are still changes that occur with aging. There is progressive testicular failure as evidenced by gradually increasing levels of both gonadotropins with aging. Although basal levels of male hormone remain reasonably normal in healthy older men, the ability of the Leydig cells to respond to acute stimulation with LH is reduced. There are changes in the penis, prostate, and seminal vesicle which occur with aging. Potency tends to be reduced with age. Sperm production per testis falls off with aging. The amount of capsular tissue increases in the testis with advancing years. There is very limited data about men in extreme old age (80 yr and older). Of older men who produce spermatozoa in their ejaculates, sperm motility, a manifestation of viability and fertilizing capacity, tends to be reduced. The ability of men to impregnate their wives gradually reduces from age 25 onward. Using the zona pellucida-free hamster egg, penetration by spermatozoa from aged healthy men appears to be as good as that from younger fathers. This test cannot guarantee equal fertility, but it is the best test available and correlated reasonably well with fertility. Thus, if an older man can get an erection, can ejaculate, and can produce an ejaculate with a reasonable number of motile sperm, the likelihood is that he is fertile.
D000328:Adult; D000368:Aged; D000375:Aging; D005298:Fertility; D006801:Humans; D007985:Leydig Cells / Q000502:physiology; D008297:Male; D008875:Middle Aged; D010413:Penis / Q000502:physiology; D011467:Prostate / Q000502:physiology; D012661:Semen / Q000502:physiology; D012669:Seminal Vesicles / Q000502:physiology; D012671:Seminiferous Tubules / Q000502:physiology