Intracytoplasmic morphologically selected sperm injection or IMSI as it is more commonly known is used in the IVF where high-magnification digital imaging microscope (6000 times) is used to magnify a sperm to examine and select sperm for microinjection into the egg.
This is a more sophisticated technique that enables the fertility specialists to assess the structure of the sperm better so that sperm with abnormalities are excluded and most normal looking sperm is used for injection.
The IMSI is a step up or to Intracytoplasmic Sperm injection or ICSI which involves injecting a single sperm inside the mature egg mechanically by specialized equipment called micromanipulator starting off the process of fertilization. The ICSI uses a high magnification of 400 times as opposed to IMSI which uses magnification on 6000, 15times the ICSI – making IMSI a better and more sophisticated technique.
IMSI is typically recommended or used for men with high numbers of abnormal sperm and previous poor outcomes with ICSI, wherein the enhanced selection tool may improve the likelihood of fertilisation, diminishing the chances of abnormal sperms fertilising the eggs leading to normal embryo development.
The 6000 times magnification compared to 400 times makes it that much easier for the embryologist to examine the sperms and chose the best viable option. Using the digital high-magnification, a sperm that exhibits abnormalities are then excluded from being used to fertilise the egg. The sperms that are identified as being structurally normal are then used.
IMSI is advised and advocated to increase the fertilisation rates and normal embryo development in men with severe male factor subfertility (read our blog on Common Causes of Subfertility in Men), such as
- Men with a very high number of morphologically abnormal sperm
- Sperm retrieved from testes
- Poor outcomes with previous ICSI treatments.
Find out more about the procedure and clinics and choose carefully. Ask your specialists questions about the procedure.
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