IMSI - Intracytoplasmic Morphologically Selected Sperm Injection Treatment
Intracytoplasmic morphologically selected sperm injection (IMSI) is a technique used in IVF treatment to examine and select sperm using a high-magnification digital imaging microscope for microinjection into the egg.
For men with high numbers of abnormal sperm and previous poor outcomes in IVF with ICSI, an enhanced selection tool may improve the likelihood of fertilization and normal embryo development.
Using digital high-magnification of sperm our scientists can examine the individual sperm at 6,000 times magnification to identify the sperm that exhibit abnormalities and exclude them from being used to fertilize the egg. The sperm that are identified as being structurally normal is then used in the fertilization procedure using the ICSI method.
In comparison, traditional methods of selecting sperm involve our scientists assessing sperm for any visible abnormalities at 400 times magnification and selecting the most normal looking sperm to microinject into the egg.
Your fertility specialist Doctor Prathiba Govindaiah may recommend IMSI if:
- You have very low numbers of sperm, and
- A high proportion of abnormally shaped sperm, or
- Evidence of poor outcomes with previous ICSI treatments
IMSI uses a high power light microscope, enhanced by digital imaging, to magnify a sperm sample more than 6,000 times its normal size. This enables the embryologist to detect problems and subtle structural alterations that a normal microscope cannot see. The embryologist then selects the sperm with the most normally-shaped nuclei and the highest level of motility.
The procedure is otherwise very similar to ICSI. Fertility drugs are given to the female to stimulate egg production in the ovaries. Once the leading follicle in an ovary grows to 17-22mm, the eggs are ready to be collected. The female is given a hormone injection of human chorionic gonadotrophin (hCG) around 36 hours before the egg collection procedure takes place. The hCG injection stimulates the eggs to mature.
Under light sedation, the eggs are collected using an ultrasound-guided vaginal probe to locate the follicles and aspirate its contents. The eggs are then placed in culture in our state of the art laboratory. In the laboratory, the embryologists will inject the one carefully selected sperm into each egg.
How long do IMSI embryos take to develop?
The embryologist will look for signs of fertilization the day after the sperm is injected into each egg. Embryos can be transferred at any stage from the second day to the sixth day after the initial procedure. The embryos should reach the blastocyst stage by day five or six.
Is IMSI for you?
IMSI may be recommended to those who have failed IVF cycles in the past, or for couples who have a component of male infertility. IMSI can be more expensive than traditional IVF treatment.