I am a man of 25 and I may need to have chemotherapy for my cancer. My doctors have said this could affect my fertility but I could have sperm banking. What does this mean?

Some types of chemotherapy carry quite a high risk of damage to the male sperm and can lead to infertility. Sperm banking is a way of storing some of your sperm so that at a later date they can be used to artificially inseminate your partner so that you can still father your children.

Because of the risk of damage to the sperm from treatment, sperm banking is best before you start chemotherapy although it may be possible for it still to be done up to 4 to 6 weeks after treatment has started.

You must not have sex (or ejaculate) for at least 2 days before the sperm is collected. The sperm samples will be produced by you masturbating. (This can be embarrassing but this will be organised to make sure that things are private and comfortable for you.) Usually between 1 to 3 samples are collected over 1 to 3 days.

After collection the sperm are analysed, this means looking at the sample under the microscope and counting the number of sperm and how well they are swimming (their mobility). This gives an idea of how 'healthy' and fertile your sample is.

After this your sample is mixed with a cryopreservative (which protects the sperm during the freezing process) and then it is very carefully labelled, to clearly identify it is as your own sperm and frozen at temperatures as low as -190oC.

Legally sperm can only be stored for a maximum of 10 years, or until you are 55, whichever is the sooner, although in very special circumstances it may be possible to get these limits extended.

Once the sperm is needed in order to try for a pregnancy then it can be thawed. You will then need medical advice on how best to achieve the pregnancy. Usually this can be done by a simple insemination timed to the ovulation (release of the egg) of your partner. If your sperm count is low or the sperm have been damaged in any way by the freezing process, reducing their fertility then there are other special methods which have been developed which can increase the chance of a pregnancy, these include in-vitro fertilisation (IVF) and intracytoplasmic sperm injection (ICSI).

Sperm banking is usually done in special units which will only be at a few selected hospitals so you may have to travel some distance for your sperm banking. If you are unwell, and travelling is difficult, then it may be possible to arrange sperm collection at your local hospital, or even at home, but it will be necessary to get the sperm to the sperm banking centre within 90 minutes to give the best chances of successful preservation.

If producing a sperm sample is difficult then it might be possible to arrange for something called percutaneous epididymal sperm aspiration (PESA). This involves having a needle inserted into the testis to withdraw some sperm and it can be done with local anaesthetic, as an out-patient.

The sperm banking centres do charge for collecting, preserving and storing sperm samples. Very often this cost will be met by your own hospital as part of your overall treatment but sometimes you may find you are asked to contribute towards the costs. Also when you do try for a pregnancy there are differences around the country on the levels of fertility services available on the NHS and you may find again that you might have to pay for some parts of the process.

The whole idea of sperm banking and the doubts about future fertility can be very stressful and confusing, especially as you are coping with your cancer and chemotherapy as well. Most of the sperm banking centres do have trained counsellors who can help you with advice and support, so do ask about this.