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What is assisted fertilisation?

Assisted Fertilisation is used to describe techniques which help a sperm fertilise an egg by bypassing some of the steps that normally occur.

Normally, fertilisation involves a complex sequence of events. Of the various techniques tried, the one that has been universally adopted in Intra-cytoplasmic Sperm Injection (ICSI). This uses sophisticated equipment to inject a single sperm into the middle of each mature oocyte. The sperm does not have to do any work itself.

Men with Azoospermia (no sperm in the ejaculate)

Sperm are produced in the seminiferous tubules and pass into the testis and on into the epididymis. If a man has a blockage to the outflow tract - from infection, vasectomy or even congenital absence of the vas, this will give rise to “obstructive azoospermia”. Sperm production continues but the sperm are absorbed as they move down the epididymis. Other men have sperm production in the testis but the number produced is too few for them to appear in the ejaculate. This is called “non obstructive azoospermia”. Occasionally in these men, there may be a few sperm in the ejaculate one month but none the next. 

It is important to be able to differentiate between the two types of azoospermia since with obstructive azoospermia it is always possible to retrieve sperm from the testis for ICSI whereas with non-obstructive azoospermia, retrieval of sperm for ICSI is only possible in 50% of men. The differentiation can usually be made on physical examination and a blood test. Occasionally a testicular biopsy will be necessary to be sure. 

Therefore, in men with non-obstructive azoospermia, a biopsy is really only helpful to those people who want to be certain it is possible to retrieve sperm from the testis. Since a testicular biopsy is not without risk, whether or not to have a testicular biopsy before proceeding to IVF, needs careful discussion.