Male Infertility

Types of Male Factor Infertility
What causes abnormalities in a semen analysis?
Physiological Issues

Types of Male Factor Infertility

The results of a semen analysis are evaluated by the doctor along with the couples’ history and the results of investigations of the female, and these are all taken into consideration when making diagnoses and recommendations for treatment.

A general outline of the main types of male factor infertility that may be identified in a semen analysis is outlined below. It is not uncommon for more than one of these characteristics to be seen in the same semen analysis.

Oligozoospermia - Low sperm count

When the number of sperm in the ejaculate is low, the chances of a sperm reaching and fertilising the egg following intercourse may be reduced. In cases of mild oligozoospermia, IUI might be the appropriate treatment, as the sperm can be concentrated before placing in the uterus. More commonly, however, IVF or in severe cases ICSI, may be recommended as fewer sperm are required and fertilisation can be achieved in the laboratory.

Asthenozoospermia - Reduced motility and/or impaired progression.

When the number of actively swimming sperm in the ejaculate is very low, or if the way the sperm are swimming is impaired, the chances of a sperm reaching and fertilising the egg following intercourse may be reduced. When it is just the number of motile sperm that is low, IUI or IVF may be recommended as the motile sperm can be extracted from the ejaculate and concentrated in the laboratory. However, if the ability of the sperm to swim is severely impaired, the chances of fertilisation through IVF may also be low, so ICSI may be recommended.

Teratozoospermia - Raised levels of abnormal sperm

Abnormal sperm have a reduced capacity to fertilise eggs or form viable embryos. When the number of normal sperm in the ejaculate is below normal, the chance that a normal sperm will reach and fertilise the egg may also be reduced. In cases of mild teratozoospermia, IVF may be the appropriate treatment, because a preparation of the most normal sperm can be prepared in the laboratory and used to achieve fertilisation in vitro. When the number of normal sperm is very low however, ICSI may be recommended because the embryologist can examine individual sperm and identify the most normal sperm for injection into the egg to achieve fertilisation.

Azoospermia - No sperm present in the ejaculate.

There are various reasons for complete absence of sperm in the ejaculate. In some cases, the cause of azoospermia may be ‘obstructive’ which means that it is caused by a blockage in the route between the site of sperm production (the testes) and ejaculation. In other cases the cause of azoospermia may be ‘non obstructive’, which means that it is caused by a partial or complete failure in sperm production in the testes.

Obstructive azoospermia may be caused by a blockage in the epididymis, the area where the sperm are held after production or perhaps in the vas deferens, the tubes through which sperm leave the testicles. In some cases the tubes may be completely absent, a condition called congenital absence of the vas deferens (CBAVD). In other cases, the blockage may be caused by a previous vasectomy or failed vasectomy reversal.

In cases of obstructive azoospermia it is usually possible for a urologist to surgically extract sperm from the epididymis or the testes by MESA or TESE and for the embryologist to use such sperm to achieve fertilisation in the laboratory through ICSI.

In cases of non-obstructive azoospermia, an exploratory TESE can be carried out confirm whether sperm is being produced or not. Occasionally, although the ejaculate is azoospermic, there may be small pockets of sperm production within the testis and if these can be extracted, the sperm can be used to achieve fertilisation through ICSI.

If sperm cannot be identified through testicular exploration, the option of using donor sperm [LINK – donor sperm] in combination with IUI or IVF can be explored.

Immunological infertility - Significant anti-sperm antibodies bound to the sperm.

Anti-sperm antibodies are large protein molecules that are detected bound to sperm in the ejaculates of some men. These antibodies have very varied effects on fertility and in some men they have no effect at all. They can be caused by testicular trauma, genital infections and previous vasectomy, although in most cases their cause is unknown. In some cases the antibodies cause the sperm to stick to one another and so effectively reduce the number of free swimming sperm available to fertilise the egg.

In some cases, the antibodies seem to slow the sperms’ swimming and in other cases they appear to directly interfere with their ability to bind to and fertilise the egg. Depending on the level of antibodies detected on a semen analysis and their effects on the sperm, IUI, IVF, or ICSI may be recommended.

What causes abnormalities in a semen analysis?

Abnormalities in the semen are primarily due to a defect in sperm production by the testes. The cause of this is usually unknown. Occasionally abnormalities may be associated with previous infections, surgery or excessive drinking. In addition, certain drugs, radiation and radiotherapy may have a detrimental effect on the production of sperm. The presence of a varicoele (a condition where there is an increase in the blood flow around the testicles due to dilated veins) may lead to a rise in the temperature around the testicles, which may adversely affect sperm production and motility.
 

Complete absence of sperm in the ejaculate as a result of testicular failure, may be the result of a chromosomal disorder, or previous infections such as the mumps. It may also be associated with the history of maldescent of the testes into the scrotum

Physiological Issues


Absence of sperm in the ejaculate (azoospermia) may be due to an obstruction at the level of the vas deferens, epididymis, or even at the level of the testes. It may also be due to bilateral congenital absence of the vas. Some men may have testicular failure which is failure of production of the spermatozoa. This may be the result of a chromosomal disorder or previous infections such as mumps. It may also be associated with the history of failure of descent of the testes into the scrotum.
 

On rare occasions there may be anti–sperm antibodies in the semen which impair their motility. This may occur following a reversal of a vasectomy or other surgery on the male genitals and may also be related to previous infections or injury. Your semen sample will be tested for sperm antibodies during the analysis.