ICSI is an assisted reproductive technology (ART) technique that was initially developed in the 1980’s by a team at the Brussels Free University Centre for Reproductive Medicine, led by Prof. A Van Steirteghen.
It involves achieving fertilisation of an egg cell by injecting a single sperm cell into each egg rather than relying on the efforts of the sperm alone. The first child to be born as a result of this technique was in 1985 and whilst the total world wide number of children born by ICSI is unknown,it is certainly in the many hundreds of thousands.
This might seem like a more invasive method than allowing natural fertilisation (as in IVF) to occur. The value of this technique is demonstrated by the pregnancy rates that can be achieved where it is used appropriately. For example, in 2006, Fertility North’s clinical pregnancy rate for women under 38 treated using ICSI was 68%.
ICSI is used to treat infertility related to poor sperm quality and / or quantity.
In modern ART practice its use has been extended into other situations for example:
Unnecessary ICSI produces no benefit over routine IVF, 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.
All patients receive hormonal stimulation as for conventional IVF treatment, the differences between IVF and ICSI occur in the laboratory alone.
After its collection the egg is examined to ensure it is suitable for ICSI, and a single sperm is injected into the egg. The eggs are then placed in culture and examined the following day to see whether they have fertilised normally.
A semen sample will need to be provided on the morning of the egg collection by the partner. However, if the sperm is to be collected surgically, this will have been performed earlier and frozen, or collected on the days prior to, or on the day, of oocyte collection.
ICSI treatment cycles are conducted in exactly the same way as conventional IVF cycles and the side effects are identical.
The procedural risks of ICSI are the same as for conventional IVF.
Whilst extensive trials have been completed into the safety of ICSI and the embryologists undertaking the procedure are experienced, there may be as yet unforeseen complications.
Not all eggs collected may be of suitable quality or mature enough to undergo the injection procedure. If very few eggs are collected, none may be suitable for ICSI. As ICSI is a very delicate procedure, some eggs may be damaged, and therefore will not be available for transfer.
The weight of evidence from published studies regarding the incidence of abnormalities in foetuses and children resulting from ICSI procedures suggests that the risk is no greater than in those undergoing standard IVF. A small but measurable increase in the incidence of abnormalities above that is seen in the general population is recognised in relation to both IVF and ICSI. Whether this is greater than would be expected, given that patients under going IVF/ICSI are in general older and the reason for infertility in some, would be expected to produce high rates of abnormality, is a matter for on-going study.
One genetic abnormality that is known to be associated with male infertility is where there are Y- chromosome defects. The Y chromosome is the chromosome that provides the genes that are responsible for “maleness”. If these genes are defective or parts of them are missing (deletions), sperm production will be reduced or non-existent. If ICSI is used to overcome the very low sperm counts and a male child is born he will inherit this problem.
This inheritable cause for male infertility can be screened for and currently, at Fertility North, we 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). The test involves a simple blood sample that is sent for analysis at Monash IVF in Melbourne.
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.
Increased miscarriage rates are also seen in pregnancies resulting from ISCI using surgically collected sperm when it is used to overcome low sperm numbers.