Male factors affecting fertility

Azoospermia is the absence of sperm in the ejaculate occurs usually because of an obstruction in the testes, or because sperm are not being produced in the testes. Semen analysis demonstrates the absence of sperm, but hormonal blood tests and other investigations are needed to find the cause of the azoospermia.

Testicular failure occurs when the tubules (the sperm-producing cells) in the testes do not develop or are irreversibly damaged. This can be associated with the failure of the testes to descend into the scrotum during childhood, inflammation of the testes, or as a result of treatment with certain drugs (particularly chemotherapy agents). Often sperm can be found in the testes when a biopsy is performed.

Hormonal imbalances can impact on the production of sperm. Insufficient levels of follicle stimulating hormone (FSH) and luteinizing hormone (LH), hormones produced by the pituitary gland, can arrest testicular function and sperm production. Replacement of these hormones artificially may encourage sperm production, but treatment is required over several months, and needs to be repeated for subsequent pregnancy attempts. High levels of prolactin, another hormone produced by the pituitary, can also stop sperm development. Hyperprolactinaemia is treated by medication to reduce the output of prolactin by the pituitary. These medically treatable causes are rare.

Obstructions can occur at several sites in the male reproductive anatomy.

These can arise for several reasons:

• congenital disorders of development
• in association with chronic lung disease (ie. cystic fibrosis)
• scarring from inflammatory processes
• scarring from an operative procedure

Some patients can be treated by bypass surgery joining the tube in the epididymis to the vas deferens. The results depend on the level of the block, with blocks closer to the testes being less successful. A method of obtaining sperm from men with this type of infertility is the Testicular Biopsy. A small needle removes tissue from the testes which is then examined under the microscope and the sperm are isolated and collected for intra cytoplasmic sperm injection (ICSI)/IVF.

Abnormal Semen Analysis

Very few men have absolutely normal semen tests, and each test may vary in its results. This is why your doctor may have you undergo two or more semen analyses. The commonest abnormal finding is a lower number of sperm present than is usual - oligospermia.

Other abnormal common findings include: reduced motility -asthenospermia, and an increase in abnormal morphology (shape) - teratospermia. These changes in semen quality will vary from mild to severe. A couples' chances of pregnancy each month are reduced if the number of sperm is decreased, if the sperm swim poorly or they are unable to penetrate the egg to fertilise it.

At present very little is known about the mechanisms by which sperm production and function are reduced either in men with an obvious cause, such as previous undescended testes or inflammation of the testes, or in men who have no apparent cause.

Some factors that are known to be associated with abnormal results include:

• recent illness
• heavy alcohol or social drug consumption
• obesity
• use of anabolic steroids or some prescription drug treatments
• repeated raising of the temperature of the testicles (hot baths, spas)
• excessive cannabis usage

Removing these causes can lead to an improvement in the test results within months.

Other factors that are often suspected of having an untoward effect on sperm function or production, include:

• tobacco smoking
• moderate alcohol intake
• excessive exercise
• stress and anxiety
• tight underwear
• exposure to environmental toxins

Changing your lifestyle to reduce exposure to these factors may be important for good health in the long term, but there is often no consistent marked change in the semen test result.

Varicocele

A varicocele is a bundle of enlarged (varicose) veins in the scrotum, that can be found in about 20 - 40 % of infertile men, but also in a substantial number of normally fertile men. As blood pools in the vein, there is an increase in heat in the area which has a detrimental effect on sperm production. Physical examination of the scrotum by the doctor will generally detect this disorder and it can be surgically treated by removing the vein or by tying it off higher in the body. The mere presence of a varicocele does not mean that surgical treatment is necessary, but it may be recommended for an infertile man with abnormalities of semen quality if no other explanation is found. Treatment is not always followed by an improvement in semen quality or fertility.

Sperm antibodies

Antibodies are normally produced in response to the introduction of foreign material into the body and are a protective mechanism. As the male gametes generally do not come into contact with the body's immune system, when sperm do come into contact with the immune system they may be seen as foreign and antibodies to them formed. This often happens with vasectomy and so although sperm are present in the ejaculate after reversal, the sperm antibodies lead to continuing infertility. Why antibodies form is not always known, though some other causes include injury and infection. The sperm antibodies are often present in the blood, as well as in the semen and coating the sperm.

The antibodies affect fertility at several levels: such as interference with sperm production and reducing sperm numbers in the semen, causing clumping together of the sperm, reducing sperm motility, preventing sperm from swimming through cervical mucus, and interfering with the sperms' ability to penetrate the egg.

Men with significant levels of sperm antibodies (ie sperm that are unable to penetrate normal mid-cycle female mucus), have reduced fertility. Treatment with cortisone type drugs for several months will reduce the antibody levels, increase sperm motility and mucus penetration, and improve fertility. There may be serious side effects to this treatment which has a relatively low success rate. IVF with ICSI is the treatment of choice in such cases.

Disorders of Sexual Function

In a small number of couples disorders of sexual function are the main reason for infertility. These include impotence, premature ejaculation and retrograde ejaculation, and as the sperm is not ejaculated into the vagina in these cases, conception does not occur. With retrograde ejaculation, the tube between the bladder and penis does not close during ejaculation so semen passes into the bladder instead of out via the urethra. Occasionally these conditions respond to treatment, but if not then sperm may be obtained by masturbation, electro-ejaculation or testicular biopsy for use with artificial insemination or IVF. With some sexual disorders counselling may benefit the couple.