Intra-cytoplasmic Morphologically selected Sperm Injection (IMSI)

IMSI is a new technique used to select those sperm that are morphologically normal and that should therefore be most likely to result in a successful pregnancy following intra-cytoplasmic sperm injection (ICSI).

The sperm are visualised using a high magnification microscope, which is almost 6000x more powerful than a normal ICSI microscope, to choose the sperm that appear to be the healthiest. The rationale is that the sperm that meet the criteria should have a superior genetic quality. Specifically, the sperm that are selected are those with the correct shape and size and with minimal vacuolisation (spaces) in the head. Vacuolisation in the sperm head relates to an increased incidence of poor DNA arrangement.

Once the sperm is selected they are injected into the egg using the ICSI procedure.

The IMSI selection should not:

  • harm the sperm;
  • negatively impact on the outcome of the ICSI procedure.

The IMSI selection will not increase the fertilization rate by ICSI or the outcome, but is intended to decrease the subsequent miscarriage rate.

IMSI is may be recommended in patients:

  • Who have had more than two failed ICSI cycles not related to egg quality
  • Who have a history of miscarriage
  • Who have a high number of abnormal forms
  • Who produce poor quality embryos not related to egg quality

IMSI is an adjunct treatment and is not recommended for all patients. Please speak to your consultant about whether it might be beneficial for you.

Further Reading

Please refer to the regulator’s web page regarding treatment “add-ons” for further information: HFEA

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