Intracytoplasmic sperm injection (ICSI) is an advanced technique that involves injecting a single sperm into an egg. It may be used as part of the IVF process to increase the chances of successful fertilisation.
During the IVF process, we normally use standard insemination — the egg, which sits in a laboratory dish, is exposed to thousands of sperm. The fittest sperm will fertilise the egg and in this sense, the process is ‘natural’.
However, for a sperm to successfully fertilise an egg during IVF, it must penetrate the egg’s outer covering. This process may prove difficult for the sperm for a number of reasons, including:
A semen analysis, the primary fertility test for males, will be performed as part of our initial fertility assessment to assess these parameters. Our semen analysis facility, based at our Box Hill clinic in Melbourne, meets the World Health Organisation’s 6th edition standards, reflecting the latest recommended criteria for semen testing. We are also one of only a few laboratories in Victoria able to offer DNA fragmentation testing of sperm.
Based on the results of your semen analysis, your fertility specialist will then inform you if ICSI is recommended to help increase the chances of a successful IVF treatment cycle. Additionally, we may recommend ICSI treatment if you have previously undergone one or more cycles of IVF, but these were unsuccessful due to poor fertilisation using the standard approach of natural insemination.
In intracytoplasmic sperm injection, a single sperm is injected directly into the centre of a mature egg. By injecting the sperm into the egg, the sperm no longer has to successfully penetrate the outer covering of the egg, making it easier for fertilisation to occur. However, it still does not guarantee successful fertilisation. This procedure requires expert technique and precision and thus is only performed by suitably experienced embryologists.
Intracytoplasmic sperm injection is performed as part of the IVF treatment process. Following egg retrieval and sperm collection (via self-collection or testicular biopsy), the sperm are microscopically assessed for motility, size and shape. Based on this assessment, one sperm is selected for intracytoplasmic sperm injection.
The selected sperm is gently injected into the centre of a mature egg (we will assess the egg first to ensure it is mature). If fertilisation is successful, the resultant embryo is then grown and transferred into your uterus (this procedure is referred to as ‘embryo transfer’).
For ICSI procedures, we use an incredibly powerful microscope that uses polarised light. This leading technology allows us to assess whether an egg is in optimal condition for fertilisation and to identify the best position to inject the sperm into the egg. Additionally, it provides feedback if fertilisation with ICSI treatment is unsuccessful; our scientists can assess whether the egg or the sperm was responsible by assessing a structure called the ‘spindle’. This knowledge assists us in planning our approach to subsequent IVF treatment cycles.
IMSI may be used if the semen analysis suggests abnormal sperm morphology (i.e. abnormal shape). This technique uses a high-powered microscope that magnifies structures over 6000 times, allowing us to visualise the sperm’s head, midpiece and tail. This enables our scientists to better identify abnormally shaped sperm and consequently choose the best sperm for the ICSI procedure.
High levels of sperm DNA fragmentation can prevent the sperm from fertilising the egg. However, we also know that sperm that can bind to a substance called hyaluronic acid have low levels of DNA fragmentation. Consequently, if semen analysis identifies that a man’s sperm has high levels of DNA fragmentation, we can use HA ICSI to help select the best sperm for the ICSI procedure.
*Fees correct as of 1 January 2023. Fees quoted represent out-of-pocket costs once Medicare rebate applied.
Fertility issues related to the male partner usually involves a low sperm concentration and count, poor sperm motility (movement) and/or abnormally-shaped sperm. Because of intracytoplasmic sperm injection, it is now possible to overcome these types of sperm-related issues. For some couples, the use of ICSI has resulted in pregnancy rates of up to 45%.1 However, it’s important to note that due to other factors, such as age and egg quality, success rates this high are not always possible.
More information about how ICSI treatment may improve your chances of a successful IVF treatment cycle can be found here.
Intracytoplasmic sperm injection (ICSI) is an insemination technique that may be incorporated into an IVF cycle. It involves injecting a single sperm directly into the centre of a mature egg. Fertility specialists may recommend ICSI to increase the chances of a successful IVF treatment cycle, particularly in instances of male infertility. They may also recommend ICSI if previous IVF cycles were unsuccessful.
Following egg collection and sperm retrieval, our embryologists seek to identify the highest-quality egg and sperm for use in the ICSI procedure.
First, they remove the support cells from around the eggs – these are the cells that nourish the egg throughout its growth and development. By doing this, they can identify the eggs that are mature and therefore, suitable for ICSI treatment. At this stage, our embryologists will also microscopically assess the motility, size and shape of the available sperm, so they can select the fittest sperm to inject into the mature egg.
Prior to injection, our embryologists will also examine the profile of the mature egg using a powerful microscope with polarised light. Specifically, they will look to identify the egg’s spindle – where the DNA is located. Research shows that mature eggs with visible spindles result in significantly higher rates of fertilisation, embryo formation and pregnancy, and thus represent better eggs to inject. Locating the spindle also enables the embryologist to determine the best position to inject the sperm into the egg. The embryologist will avoid injecting directly into the area of the spindle during the ICSI procedure to prevent damage to this vital structure.
Once a mature egg and sperm have been selected, the sperm is directly injected into the egg with extreme precision. This process facilitates fertilisation, as the sperm must no longer penetrate the egg’s outer cover. However, it still does not guarantee successful fertilisation.
Egg retrieval is a necessary step in both IVF and egg freezing. Learn more about what to expect and how to prepare for this procedure.
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