Male fertility problems have a variety of causes.
The most common cause is that the man’s semen has too few normal sperm to fertilise the egg. The first step in identifying the male factor fertility problem is a semen analysis.
A semen analysis should be carried out for any couple seeking treatment for fertility problems regardless of whether there is an identified female problem or a suspected male factor problem. It is a simple procedure which may reveal important information. Even if the male partner has previously fathered children, a semen analysis is necessary since problems may have developed in the intervening time.
A semen analysis includes the following tests:
- Semen volume and appearance
- Sperm concentration
- Number of sperm that are swimming
- Number of sperm that are normally shaped
Sperm concentration is usually considered to be the most critical factor and is expressed in terms of the number of million sperm per millilitre of semen. Sperm motility, or the number of sperm that are active, is usually expressed as a percentage of the total number of sperm.
Progressive motility is a more accurate value as it measures the percentage of sperm moving in one direction only (instead of round in circles) as these are the most likely sperm to fertilise the egg. Progressive motility is the most useful test from a semen analysis to predict fertility treatment success.
The number of sperm that are normally shaped, i.e. with normal morphology, is expressed as a percentage of the total number of sperm in the ejaculate.
As part of a semen analysis, a test may also be carried out to look for antisperm antibodies. If, as a result of trauma or surgery, sperm come into contact with the body’s immune system, antibodies may be produced. These antisperm antibodies cause the sperm to club together and thus affect their ability to fertilise an egg.
The following terms have been developed to describe conditions in which one or more of these factors are abnormal:
- Aspermia – The patient produces no semen
- Azoospermia – The patient produces semen containing no sperm
- Oligozoospermia or oligospermia – sperm concentration is low, less than 15 million per ml
- Asthenozoospermia or asthenospermia – less than 40% of the sperm are moving, and less than 32% are swimming progressively
- Teratozoospermia – less than 4% of the sperm are normally shaped
- Oligoasthenoteratozoospermia (sometimes referred to as OATS) – less than 15 million sperm per ml with less than 40% being motile and less than 4% are normally shaped
- Necrospermia – all sperm are dead
- Poor viability – less than 58% are alive
- Pyospermia or leucospermia – presence of large number of white blood cells (more than one million/mL) in the semen, often associated with an infection
If semen analysis has identified an abnormality, a further semen analysis will be necessary to establish the cause.
Causes of male fertility problems
The causes of male fertility problems may be genetic or physical.
The most common genetic abnormality leading to infertility in the male is Klinefelter Syndrome where the man has an extra X chromosome. Usually, a female has two X chromosomes (XX) and a male has one X and one Y (XY). Men who have Klinefelter Syndrome are born with an extra copy of the X chromosome (XXY). The vast majority of these patients produce no sperm at all. This condition is untreatable and generally patients can only be offered donor sperm.
Some cases of oligozoospermia may be associated with genetic abnormalities as may some cases of azoospermia. If sperm are present, such cases can be treated using in-vitro fertilisation (IVF) or intracytoplasmic sperm injection (ICSI). However, it is important to take into account the possibility that these genetic defects may be passed on, and any male children may also have fertility problems.
In some men, sperm fail to reach the ejaculate because of obstruction in a tube called the vas deferens which carries the sperm from the testis to the ejaculate. This tube may be obstructed on one side or on both sides. In the majority of these cases this condition is the result of genetic mutation which may also give rise to Cystic Fibrosis. These men may have sperm retrieved surgically and may achieve pregnancies using ICSI. However, it is very important that these couples receive genetic counselling and genetic screening as their offspring may be at risk from Cystic Fibrosis.
Apart from congenital obstructions of the reproductive tract, obstructions may also result from infection or from surgery or injury. If a man apparently has no sperm in his semen it is important to establish whether this is the result of an obstruction or whether his testes are not making sperm. A simple hormone test will usually give this information. If the obstruction occurs on one side only, then the sperm concentration may be reduced. If the obstruction is on both sides resulting in azoospermia, sperm can be retrieved surgically directly from the testis, in a tiny biopsy. This is performed as an out-patient procedure under local anaesthetic. However, because the numbers of sperm retrieved are usually low and these sperm may be immature, successful treatment is only likely with ICSI.
There are other sperm problems that cannot be identified by semen analysis. This means that a normal semen analysis does not guarantee fertility.
Sperm DNA damage
Some clinics now offer sperm DNA tests in addition to the traditional semen analysis. These tests are usually provided at dedicated labs, outside the fertility clinic. If the sperm DNA damage is high, the clinic will consider this information along with that of test results from the woman. It may be decided ICSI is a better choice than IVF as ICSI may give the egg a better chance of repairing sperm DNA damage.
Sperm DNA tests are also useful for couples with unexplained infertility as these tests can often pick up anomalies. Testing sperm DNA may also be useful after a failed cycle of IVF or if the man has previously been ill, on medication or has changed his lifestyle for the better. A sperm DNA test can guide the clinic and couple as to whether IVF or ICSI would be better for their next cycle of treatment.
There are very few cases of male infertility or sub fertility that can actually be cured. Generally when we refer to treatment we mean techniques that enable us to circumvent the problem.
Assisted conception treatment such as IVF may enable a man to achieve a pregnancy with his own sperm, however he will still be infertile and will need assistance if he wishes to have more children.
IVF is successful with low numbers of normal motile sperm because the sperm and egg are placed together in a petri dish in the lab. This makes it must easier for the sperm to fertilise the egg. Success rates with IVF vary with the severity of the sperm problems.
If the sperm are of low quality, an advance form of IVF called intracytoplasmic sperm injection (ICSI) can be used instead. This is a process whereby a single sperm is injected directly into the egg and can be carried out even when there are very few sperm present in the semen. ICSI can be used very successfully with sperm that have been surgically retrieved from the testis or from the epididymis. This technique has superseded all other micromanipulation techniques and has become the treatment of choice where fertilisation fails with conventional IVF. Since this technique has allowed men to father children who previously would have been unable to do so, concerns have been raised about the inheritance of male infertility, as well as the possibility of other genetic defects. To date, research suggests that there is a slightly raised incidence of sex chromosome abnormalities in children born as a result of ICSI. This is not a result of the technique, but rather a result of the presence of genetic defects in the fathers. However, the incidence is still very low, at around 3%. Couples who need treatment by ICSI should make sure they understand the genetic implications by asking their fertility doctor all the questions they have.
Our understanding of male infertility and of sperm function has increased tremendously over the last decade. The development of ICSI means that there are now very few men for whom there is no possibility of fathering their own genetic children. However, in terms of treatment leading to a cure, very little progress has been made. There are virtually no reliable drug treatments and very little that can be done to increase sperm concentrations.
Many patients ask whether there is anything they can do to improve their sperm count. The answer is generally no other than to live a normal healthy lifestyle. Future research is directed at improving results with the existing treatments, and also to find ways to improve fertility so that such invasive techniques such as ICSI or even IVF are not necessary.