ICSI (Intra Cytoplasmic Sperm Injection) is the process of injecting sperm selected under a microscope into mature eggs using micropipettes. It is preferred for couples with extremely low fertilisation rates with conventional IVF method (fertilising by placing egg and sperm in the same environment and promoting survival of the fittest by leaving the sperm to inject the egg itself) in terms of sperm count and motility, this method is also known as microinjection. IMSI has been used routinely in many clinics since 1993 for two main reasons:
- It does not cause serious problems to children, compared to conventional IVF;
- It also leads to a significant fall in cancelled treatments due to fertilisation problems.
In the ICSI method, sperm used for fertilisation are selected under a microscope which magnifies cells by x400-600. The procedure uses a maximum number of sperm with normal morphology and motility.
What is IMSI?
IMSI (Intra-cytoplasmic Morphologically-selected Sperm Injection) is the microinjection of morphologically highest quality sperm into the oocyte cytoplasm. In other words, compared to the conventional microinjection procedures, IMSI involves morphologically selecting the sperm in much more detail using high optic magnification (x6000-8000) before performing the microinjection procedure. Written media refers to this sperm selection method as MSOME.
Who can benefit from IMSI?
Used correctly and for the actual purpose, a significant difference in treatment should not be expected in couples with good sperm value and quality in both techniques (ICSI and IMSI), having said that, IMSI can be preferred for sperm selection in couples that have poor sperm morphology and quality.
IMSI involves significant investment in time and workload for the laboratory performing the procedure. Once IMSI is chosen as the preferred option by couples with serious decrease in sperm cells based on sperm count, motility and morphology, it might be possible to achieve significant improvements in embryo quality and conception, compared to previous treatments, due to the use of good quality sperm.
Both ICSI and IMSI select sperm according to the appearance of sperm cells under microscope. That is why these methods are not capable of detecting genetic disorders or DNA damage that are present in the genetic structure of sperm cells which might be increasing/decreasing during treatment. Some recent studies report that sperm cells selected with IMSI have healthier genetics and carry less genetic damage.
Current medical information and results will determine whether your doctor will use IMSI for your treatment and whether this method would benefit your treatment personally.
As with many other new technologies, IMSI method will not yield the favourable results in some cases, which do not provide technical advantages if infertility is not due to, poor sperm quality. The reason why this technique is not always beneficial is because infertility is usually related to a problem other than sperm selection.