Michelle Emblenton, a biochemist at inviTRA, tells us about the situations in which IMSI is used:
When we look at male factor infertility, which can account for up to 30% of cases where couples seek fertility treatments, it can often be due to problems with the sperm themselves. If a man has a low sperm count or perhaps has sperm with poor motility (they don't move forward progressively properly) or the sperm are of poor morphology (they don't have the correct shape and structure that a healthy sperm cell has), the IMSI technique can be very beneficial.
This is especially true in cases of teratozoospermia, which is sperm with a poor morphology. If the sperm sample presents with a great deal of abnormally shaped sperm, IMSI will allow the specialist to actually choose the best morphologically shaped sperm in order to go ahead and use for fertilization. I'd like to point out that IMSI is not a standard procedure in IVF protocols and, indeed, requires your IVF center to have the necessary microscope and expertise to perform the treatment, but it is a useful technique to be used, for example, when we've had previous failures with ICSI techniques.
Or for example we are seeing a lot of sperm DNA fragmentation. Perhaps there is implantation failure or repeated previous miscarriages. If it is a case that fertilization occurs but then the embryos stop growing for whatever reason, it may be useful to try the IMSI technique. It is also sometimes used for couples who have had long-term unexplained infertility, where the actual reasons for the infertility may not be known but this technique has been shown to help increase success rates for these people.
