In the past when the male partner had a very poor or even zero sperm count, donor insemination or adoption provided the only realistic means of having a family.

In standard IVF, each egg is incubated with up to 100,000 prepared sperm. In 5 to 10% of IVF cycles, there is a complete failure of the eggs to become fertilised.

The development of micro-assisted fertilisation by means of ICSI is the most major advance in achieving a successful pregnancy, as long as some live sperm (even in very, very low numbers) can be obtained. When ICSI is carried out, a single live sperm is injected through the wall of a prepared egg and released into the cytoplasm within the egg.

Very complex micromanipulation equipment is required to carry out ICSI. Our embryology laboratory was constructed with the ICSI option in mind. Our embryologists have undergone specialised training in the technique and have been granted licences as ICSI practitioners.

ICSI may be a suitable treatment for the following groups of patients:

• Failed fertilisation at IVF
• Very poor sperm preparations, which would be unsuitable for IVF
• When the sperm count is zero and donor insemination is not wanted

Even if the sperm count is zero, it may be possible to perform a surgical procedure to obtain at least a few sperm either from the epididymis at the beginning of the vas.

PESA or Percutaneous Epididymal Sperm Aspiration, or from the testicle itself (TESA or Testicular Sperm Aspiration and TESE or Testicular Sperm Extraction).

This is carried out under a suitable anaesthetic. However, the testicles must be normal as opposed to being poorly developed or seriously damaged.

Before being able to offer ICSI, the normal screening tests for IVF are performed. In addition all men (apart from those who have zero sperm counts due to vasectomy) have their chromosome make-up (Karyotype) checked, as it is known that chromosome abnormalities are commoner in male infertility.

If the sperm count has always been known to be zero, additional preliminary tests are necessary. A blood test is performed to measure hormone levels to check if the absence of sperm is due to testicular failure.

In some cases, of testicular failure, it may still be possible to obtain some sperm for ICSI. These cases are more difficult. Referral to a urological surgeon for testicular biopsy may be necessary to determine whether the cells in the testicle are manufacturing any sperm.

It would also be possible to carry out PESA or TESA as a "dummy run" to see if sperm can be retrieved. Such sperm could then be stored for your future use. However, freezing of low numbers of sperm is no guarantee of their survival or suitability for ICSI

When the sperm count is very low or zero, screening for cystic fibrosis is performed as well. One in 25 of us carry the gene for cystic fibrosis and this can be linked to poor sperm production or to a congenital absence of each vas leading to a zero sperm count. If the male partner were found to be a carrier of the cystic fibrosis gene, screening would then be carried out on the female partner to ensure that she is not a carrier too.

At our centre the surgical retrieval of sperm by PESA, TESA or TESE will be carried out first. Then egg retrieval is performed. This has the advantage that fresh sperm are used for ICSI as opposed to frozen stored sperm. As the sperm numbers retrieved may be very low, there is no doubt that fresh sperm are preferable for ICSI.

Another issue raised by PESA/TESA/TESE is that occasionally no sperm can be retrieved. The female partner is committed to proceeding with egg retrieval as the hCG injection has already been given.

During the planning of your treatment cycle considerable time is spent discussing the option of using donor sperm for IVF should this situation arise. The alternative is to discard the eggs, although in the near future it may be possible to think in terms of egg storage.

As both partners are involved in a surgical procedure involving anaesthesia or sedation on the same day, you will be advised on transport arrangements as neither of you will be able to drive for twenty-four hours.

Not all eggs are suitable for treatment by ICSI. It is essential that the eggs are mature. Whether or not an egg is mature can only be detected after the outer coating of cells has been stripped away. Immature eggs will simply not fertilise.

In addition up to 5% of eggs may be damaged during the ICSI process and others will not fertilise. Overall, about 65% of eggs treated by ICSI will become fertilised and develop into embryos. If fertilisation occurs, this can usually be confirmed within 16 to 20 hours after ICSI has been carried out.

You will appreciate that there is a considerable amount of counselling involved before you will embark upon our ICSI programme. You will be made very aware of the limitations and the risks of the procedure.