ICSI / IMSI

Intracytoplasmic sperm injection (ICSI)

ICSI is a procedure that can be used as part of an IVF (in vitro fertilisation) treatment. It was introduced in 1992 and since then has become the most successful technique in male infertility treatment. In ICSI only one sperm is needed per egg retrieved, which is injected directly into the egg. ICSI is now used in nearly half of all IVF treatments.

Who might benefit?

ICSI can offer real hope to couples where the male has a very low sperm count, has few swimming sperm, produces few good-quality sperm, has a problem with anti-sperm antibodies or where sperm DNA fragmentation levels are elevated.

With ICSI, sperm do not have to travel to the egg or penetrate the outer layers of the egg. It can also be used to help couples where the male has had an irreversible vasectomy, or has no sperm in his semen due to missing tubes or blockages in his reproductive organs.

Couples who have tried IVF can move on to ICSI if the eggs retrieved for IVF were unsuccessfully fertilised in vitro.

How it's done

As with standard IVF treatment, the female will be given fertility drugs to stimulate her ovaries to develop several mature eggs for fertilisation (women normally release only one egg a month).

A sperm sample is produced. In patients where there is no sperm in his semen, the CRMW team can retrieve sperm from the male sugically. In most cases the sperm is extracted with a needle from the epididymis or a testicle under anaesthetic. If this doesn't remove enough sperm, the doctor will take a biopsy of testicular tissue, which sometimes has sperm inside. Surgical sperm retrieval is sometimes performed before the treatment cycle begins, and the retrieved sperm are frozen.

After giving the woman a local anaesthetic, eggs are removed using a fine, hollow needle (an ultrasound helps locate the eggs.) The embryologist then isolates individual sperm and injects them into individual eggs. Next day the majoity of eggs will be fertilised.

The procedure then follows the same steps as in IVF. One, two or occasionally three embryos are transferred into the woman's uterus through her cervix using a thin catheter. Extra embryos, if there are any, may be frozen for future use.

What are the advantages?

This technique opens doors to parenthood that were previously closed to some couples with a male factor fertility problem. ICSI gives men with a very low sperm count or other fertility problems a chance of conceiving their genetic child.

It is possible to use immature sperm that have been retrieved from the man's testicles so ICSI can be used, for example, to help men who have had a vasectomy that cannot be reversed.

ICSI can also be used to help couples with unexplained infertility, but experts have not found that it makes pregnancy more likely than standard IVF.

What are the disadvantages?

During normal conception, only the hardiest sperm manage to travel great distances and break through the membrane of an egg to fertilise it. Weaker sperm never make it. Because ICSI bypasses this process, critics worry about higher rates of miscarriage, and long-term health and development problems for children conceived using whatever sperm are available.

Research to date has been reassuring about most potential risks. No impact seen so far, for example, on the cognitive and motor skills of children conceived using ICSI. If you are at all concerned, talk to your consultant.

Intracytoplasmic Morpholigically-Selected Sperm Injection (IMSI)

IMSI is similar to ICSI with the exception of being able to see sperm at 6000x magnification rather than the conventional 600x with ICSI. Digital magnification enables us to see sperm at extremely high magnification. This enables embryologists to be able to identify sperm defects that may not be visible with conventional ICSI.

Who might benefit?

Published data suggests that 3 groups of patients may benefit from the increased selection of sperm that IMSI offers. These groups are:

  • Men with elevated sperm DNA fragmentation levels
  • Men with very poor sperm morphology (very high levels of abnormal sperm)
  • Couples who have had a previous failed ICSI cycle