IMSI (Intracytoplasmic Morphologically Selected Sperm Injection)

IMSI treatment is a variation of ICSI that we use to aid the sperm selection for fertilisation. This technique uses an even higher power magnification to visualize inside the sperm, allowing our specialists to pick the sperm with the highest chance of achieving a successful fertilisation.

This technique is particularly important in cases of repeated IVF failure where we undertake sperm DNA fragmentation analysis. DNA fragmentation occurs when there is an alteration or a break in one of the DNA strands inside the sperm itself and can affect the possibility of a successful pregnancy. We have very good results with IMSI.

How does IMSI work?

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 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 fertilisation 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 me?

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.

Whilst this technique is not evidence based, the clinic will only offer it when your consultant deems it appropriate for the treatment.