Intra-cytoplasmic Morphologically Selected Sperm Injection (IMSI)

When there is significant male infertility, the embryologist injects a sperm into each egg using a technique called ICSI. IMSI is a variation of ICSI (Intracytoplasmic sperm injection) using higher magnification, that allows the embryologist to look at the sperm head in detail.
Benefits of IMSI:
  • Higher pregnancy rates have been reported in selected groups of patients.
  • The chance of miscarriage may be reduced by selecting better sperm.
Who can benefit from IMSI?
  • Men with poor sperm morphology because poor morphology makes sperm more susceptible to oxidation damage.
  • Men with a higher level of DNA fragmentation in their sperm (DNA fragmentation is a sign of oxidation damage).
  • People with few embryos developing to the blastocyst stage.
  • People who have not become pregnant despite the transfer of several reasonable quality embryos.
How IMSI works:
  • Washed sperm are viewed at a magnification 600 times their normal size.
  • This magnification shows irregular features in sperm heads that otherwise cannot be seen.
  • The embryologist then chooses sperm with the most normal looking heads.
Useful to know:
  • IMSI is not useful for sperm taken directly from the testis.
About ICSI (Intracytoplasmic Sperm Injection)
  • ICSI is a variation of IVF. Instead of the sperm and eggs being mixed in a test tube, a single sperm is injected into each mature egg. ICSI is used when sperm quality is too poor for conventional IVF to work. ICSI allows almost any man with sperm, either in his semen or in his testis, to try IVF.

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