Intracytoplasmatic Morphology Selected Sperm Injection (IMSI) was first described by Bartoov et al. in Israel in 2002 and later developed in France and Belgium. For many couples, it opens a new way to improve results of In Vitro Fertilisation with Intracitoplasmatic Sperm Injection (ICSI).

We are all fully aware of the fact that the male factor plays a significant role in the final results of assisted reproduction techniques. In the last few years, a remarkable progress has been made in analysing the genetic balance of the semen samples (DNA fragmentation test, in situ hybridization, …) These tests provide a more specific guidance to assess sperm quality but they do not help when it comes to selecting a particular spermatozoon to inseminate the oocyte.

More than a new technique, I would call it a new tool. With the help of a microscope, the size of the spermatozoon is amplified 10,000 times. By doing this, a better sperm selection can be carried out so that those that are used for the intracitoplasmatic injection are potentially better to generate good quality viable embryos.

Conventional magnification

ampliació convencional

Sperm in a conventional analysis (400 magnification)

IMSI/SUPERICSI magnification


Sperm image during IMSI (increased to 10,000 magnification)

Up to now, the embryologist selected spermatozoa for intracitoplasmatic injection only by observing their shape and mobility. IMSI (or SUPERICSI as some people call it) through its digitalized amplification capacity provides a much more detailed image of the shape of the spermatozoa and of their nucleus morphology which enables a much more accurate selection.

IMSI might not be indicated for all couples who undergo IVF cycles, but certainly for those who have already undergone one or two IVF-ICSI cycles unsuccessfully or in cases of severely altered semen samples when the selection of the best spermatozoa can be a determining factor.

It is a pioneering technique and it is performed regularly in very few centres world wide but in the future it might become indispensable in all assisted reproduction laboratories. A number of studies suggest that the pregnancy rate can increase by 20% and the miscarriage risk can be reduced if we select spermatozoa with IMSI.

Dr. Àngel Rocas