Fertility And Male Age

When a man reaches middle-age and beyond gradual changes in his ability to function sexually will occur. Older men often notice reduced libido, a lessening in their ability to sustain an erection and a reduction in their ability to sustain a sexual encounter. Symptoms such as these are common but not necessarily universal. However, they can also impact on the fertility of a man. These symptoms can be preceded or accompanied by associated urinary problems.

Some men will not experience any reduction in urinary functions or sexual power and prowess. However, the vast majority of men will have to deal with at least some of the above issues as they get older.

Testosterone is the male hormone circulating through a man’s body that is responsible for the development and maintenance of the male organs and characteristics such as facial hair, muscle mass and body hair. It is also responsible for the growth at puberty of the prostate gland, penis and testicles. Post-puberty it is also responsible for the production of sperm by the testes. Testosterone is also important in a male for regulating moods and the libido. Hence, the level of testosterone in a man’s blood can affect his fertility. The level of testosterone in the blood is maintained by a feed-back mechanism starting in the brains hypothalamus.

An important part of this mechanism is as follows; the hypothalamus stimulates the pituitary gland (also in the brain) to produce and release the hormone LH (luteinizing hormone). LH stimulates the Leydig cells in the testicles to produce and release testosterone. Unfortunately the Leydig cells do not release the hormone testosterone uniformly throughout any one 24 hour period. Instead the release of testosterone is rather spasmodic.

Generally the levels of testosterone in a male’s blood will vary in line with other functions of his general circadian rhythm. eg Alertness, metabolism and the release of other hormones. Generally these are at their peak during the morning and decline as the day goes on. Considering the role of the hormone testosterone in the male, this may well explain why some men experience a level of sexual arousal in the morning greater than that in the evening. The circadian rhythm can also have an effect throughout the year. Contrary to popular belief, generally levels of testosterone in males are higher in the fall than in the spring when allegedly, "a young man’s fancy turns to thoughts of love".

Any time from the age of around 40 years the testosterone level in a man can start to diminish. The main causes of this are that the pituitary gland gradually secretes less of the hormone LH. This leads to a reduction in the level of stimulation to the Leydig cells and hence a drop in the production and, therefore, the release of the male hormone testosterone.

The result of this is that there is a slow but sure reduction in the male libido, arousal and the quality of his erection. By the age of 50 years 1 in 5 males (20%) can experience erections inadequate for sexual penetration. At age 60 years the figure rises to 30% (3 in 10) and by the age of 80 years it is 50% (1 in 2). This does, of course, also mean that approximately 80% of men at age 50 experience no such sexual problems.

However, as previously mentioned, the production of testosterone is essential to the production of sperm – the male gamete. Therefore, as the level of testosterone falls it will lead to a decline in the ability of a male to father children. Advancing years do not inevitably lead to male infertility, after all 1 in 2 octogenarians are still capable of fathering a child.