Intractoplasmic Sperm Injection
What is ICSI?
Intractoplasmic Sperm Injection ICSI) is a technique
that has been developed to assist fertilisation when sperm quality/quantity
is particularly poor. The technique involves injecting a single sperm into
the centre of each oocyte. The treated oocytes are checked the day after
the ICSI procedure to see if fertilisation has occurred.
The ICSI procedure was developed several years ago by a team at the Brussels Free University Centre for Reproductive Medicine led by Prof. A Van Steirteghen.
Who considers ICSI?
ICSI is used when there are problems with the sperm that would make it impossible to achieve fertilisation with conventional IVF. ICSI may be appropriate in the following cases:
Patients with very low sperm numbers (oligospermia);
Patients with very low motility (asthenozoospermia);
Patients with very high numbers of abnormal sperm (teratozoospermia);
When the sperm have been taken directly from the epididymis (MESA) or testicles (TESE);
When there is a high level of antibodies in the semen;
When there has been previous failure to achieve fertilisation with conventional IVF, or when very few oocytes have fertilised following IVF;
The Canberra Fertility Centre does not wish for couples to attempt ICSI unless it is absolutely necessary. Therefore ICSI will not be carried out unless one of the above criteria is met. Your specialist will advise you if ICSI is recommended for your cycle.
Benefits of ICSI
ICSI is only suitable for attempting to achieve fertilisation
where the sperm of the male partner are unable to achieve acceptable fertilisation
rates using routine IVF. ICSI has been shown to achieve fertilisation rates
of about 60% in the unit where it was developed. (“Normal” sperm
will fertilise about 70% of mature oocytes in normal IVF).
ICSI has resulted in pregnancy rates which are similar to IVF success rates at the Centre where it was developed. These rates depend to a large extent on:
1) Age of the woman;
2) The woman’s infertility status and cause;
3) Number of embryos replaced;
At Canberra Fertility Centre, IVF success rates vary between 21%–35%.
Disadvantages of ICSI
ICSI is a new technique and while extensive trials have been completed and the embryologists are experienced, there may yet be unforeseen complications.
Not all oocytes collected may be of suitable quality or mature enough to undergo the injection procedure. If very few oocytes are collected, none may be suitable for ICSI. As ICSI is a very delicate procedure, some oocytes may be damaged, and therefore will not be available for transfer.
Whilst there is evidence from the Brussels group that the incidence of abnormalities in foetuses and children resulting from ICSI procedures is no greater than in the normal population, there may indeed be an increased risk of abnormalities using ICSI. We cannot be sure that these risks will be at the same rate as in the “normal” population.
ICSI and genetic abnormalities
(Y-chromosome defects)
Research has shown that there is an association
between the defects on the Y chromosome, the chromosome that is responsible
for “maleness” and male infertility or sub-fertility. Genes and
groups of genes have been identified on the Y-chromosome, that are involved
in the production of sperm. If these genes are defective or parts of them
are missing (deletions), sperm production will be reduced or non-existent.
With the development of ICSI, we are now able to treat men with extremely
low sperm counts. Using this technique, in conjunction with surgical methods
of retrieving sperm directly from the testis, we are able to treat men who
have only small areas of sperm production within the testis. It is therefore
important that we understand the way in which genetic changes can affect
male fertility. It is now possible to detect deletions in the Y-chromosome.
While the Y-chromosome is essential for normal male development and for fertility,
it is unlikely that deletions on the Y-chromosome will have any other effect.
Thus, a man who has a defect on the Y-chromosome which affects sperm production,
may have male offspring who have the same defect and will also suffer from
infertility or sub-fertility, but will otherwise be normal.
Currently, at the Canberra Fertility Centre, we do offer screening for Y-chromosome deletions to male partners of couples who are about to undergo ICSI for low sperm counts (at the discretion of your specialist). A blood sample is taken and sent to Monash IVF where the test is performed. At present we do not know the frequency of these defects among ICSI patients but there is a considerable amount of research being done worldwide. It is important to understand that these genetic defects are only a concern for male offspring and, at worst these children will be expected to experience the same fertility problems as their fathers. However, we believe that it is important to make you aware if you have such a genetic defect so that you can take this into account when making decisions about your future treatment.
Patients who conceive following ICSI should carefully consider whether to have antenatal screening tests such as amniocentesis. Further advice will be given by your specialist gynaecologist. All children born from the ICSI technique may be required to be examined by a consultant paediatrician and a follow-up study of all children born may be undertaken. Patients having ICSI using surgically retrieved sperm for non obstructive azoospermia have a significantly increased risk of miscarriage. These miscarriages are the result of an increase in the level of the chromosomal disorder called mosaicism.
ICSI/IVF Treatment CycleThe oocyte is examined to ensure it is suitable for ICSI, and a single sperm is injected into the oocyte. The oocytes are placed in culture and examined the following day to see whether they have fertilised normally. The balance of the procedure is similar to IVF.
Should you require any further information please make an appointment to see your gynaecologist or Dr Chris Copeland (Reproductive Biologist).
