Intracytoplasmic Morphologically selected Sperm Injection. A detailed analysis of sperm using a high powered microscope to improve sperm selection for use in ICSI.

Intracytoplasmic morphologically selected sperm injection, otherwise known as IMSI, is a procedure which may be suggested to you during fertility treatment by your specialist. This is an additional option to the intracytoplasmic sperm injection (ICSI) procedure, and may be introduced as a topic when you start discussing laboratory methods. 

IMSI is used to select particular sperm for use in ICSI IVF treatments and is carried out using a high-powered light microscope. The magnification on the microscopes used during the process are increased by about 800-6000 times in order to allow an embryologist to see the detailed structure of each sperm cell. 

From this, the specialist should be able to pinpoint the sperm which offer good morphology (a good shape, which is not considered abnormal at any part) and those which have abnormally shaped heads or vacuoles (cavities) present. Although IMSI is a relatively new procedure, it is widely believed that these abnormal sperm cells are less likely to carry healthy genetic material that will go on to help create a healthy embryo. As such, it is an important step in the process to be able to identify these and ensure these sperm cells are not selected.

Sperm cells with a good morphology will then be selected for use in the procedure instead. Once they have been introduced to the egg cell, it is hoped that they will fertilise it to create an embryo.

Scientific studies haven’t shown that the IMSI procedure adds any extra risks to ICSI IVF. However, it should also be noted that having it carried out has also not been proven to increase a patient’s or couple’s chances of having a baby, either. 

What has been found at GENNET City Fertility is that it can help an embryology team to select the highest quality sperm available for the injection process instead. Some studies have also shown increased rates of successful pregnancy and pregnancy outcome in the following instances:

  • High sperm DNA fragmentation
  • Poor embryo quality
  • Repeated failed ICSI cycles
  • Repetitive miscarriages post-ICSI treatment

IMSI is outlined as an additional treatment option by the Human Fertilisation and Embryology Authority (HFEA). Currently, it has also been deemed red in the HFEA traffic light system for additional treatment options. This is because there is no conclusive proof or evidence from randomised controlled trials to show that it is effective in improving the chances of having a baby for most fertility patients.