Sperm Injection (ICSI)

ICSI has revolutionised the treatment of male infertility, offering assistance to couples who previously were unable to have a baby whose father was the genetic parent.

With ICSI, very few sperm are required and the ability of the sperm to penetrate the egg is no longer important as this penetration is bypassed by the injection technique. This has changed the course of the treatment of male infertility, helping up to 95% of couples to reach embryo transfer who previously had only donor sperm or adoption to choose from. It is important to remember that whilst ICSI is a technique used in the laboratory to help fertilisation occur, it does not guarantee it. From the couple's perspective this technique is the same as IVF treatment, the only difference being the laboratory process used to fertilise the egg.

Our Centre was one of the first NHS units in the UK to be licensed to offer this treatment and has since carried out several thousand ICSI cycles with consistently good fertilisation and pregnancy rates. For couples requiring ICSI the treatment pathway is identical to that of IVF, except for the method of insemination. For ICSI, the sperm is injected directly into the prepared egg, rather than simply mixed with the eggs in a dish.

Specialist equipment is used to enable our embryologists to manipulate the eggs and sperm under the control of high-powered microscopes, performing very precise surgical procedures on a microscopically small scale. Tiny glass instruments are used in the laboratory which hold the eggs in place (micropipettes) and enable sperm to be injected through the outer layers of the egg (micro-needles), past the shell of the egg (zona pellucida) and into the main body of the egg (cytoplasm).

The couples go through the same preparatory processes as IVF, namely ovulation induction and egg collection. The difference is how the embryologist deals with the eggs and sperm in the laboratory.

ICSI is used in the following circumstances:

  • Where there is a severe problem with sperm quality; such as very low numbers, a high percentage of abnormally shaped sperm or a low percentage of mobile sperm)
  • Where in previous IVF treatment(s) none or few of the eggs fertilised
  • Where sperm was obtained surgically, directly from the testicle (TESE) or epididymis (PESA)
  • Where sperm quality on the day of egg collection is insufficient for IVF, most likely due to natural variation in semen samples

Only eggs from large follicles that are sufficiently mature can be injected by ICSI. It must be noted that the process of injecting the sperm into the egg can result in damage to the egg which means that approximately 90% of the eggs injected survive. ICSI does not guarantee fertilisation but, on average, we expect that 60-70% of injected eggs will fertilise. ICSI is at least as successful as standard IVF.

ICSI cannot be performed if there are no sperm being produced by the testes which is, however, rare.

According to the HFEA regulations, if no fertilisation occurs following routine IVF insemination, those eggs cannot then undergo ICSI in the same cycle.

Because intra-cytoplasmic sperm injection (ICSI) is a fairly new treatment (it was introduced in 1992), it is not yet known whether there is any risk that injecting the sperm into the egg could damage it, with possible long-term consequences for the child.

According to HFEA the risks that have so far been associated with ICSI are:

  • Certain genetic and developmental defects in a very small number of children born using this treatment. However, problems that have been linked with ICSI may have been caused by the underlying infertility, rather than the technique itself
  • An increased risk of miscarriage because the technique uses sperm that would not otherwise have been able to fertilise an egg
  • A low sperm count caused by genetic problems could be passed on to a male child, so may want to undergo genetic tests before going ahead with ICSI. Infertile men with low sperm count or no sperm in their ejaculate may be tested for cystic fibrosis genes and chromosome abnormalities. You may want to discuss the full implications of taking these tests with your clinician before going ahead

There is a link with the gene mutation which causes cystic fibrosis and very severe male infertility. We recommend that all patients with an extremely low sperm count are tested to determine whether or not they carry this mutation.
 

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