Intra-Cytoplasmic Morphologically-Selected Sperm Injection (IMSI) is very similar to ICSI.
What makes IMSI different from ICSI is that the sperm sample is carefully assessed under a microscope with a higher magnification and a digital imaging system. This microscope will not only detect abnormalities in the shape of the sperm. It will also show structures called vacuoles in the sperm’s head, which is related to a lower or abnormal embryo development. IMSI ensures that sperms of the best quality are injected into the egg for fertilisation.
IMSI is the procedure of choice for men above 40 years old and whose semen analysis showed a higher percentage of sperms with abnormal forms, unsuccessful treatment cycles which are not related to egg problems, and a history of miscarriages.