higher magnification (x 6000), compared to x600 or less for the standard ICSI procedure. The higher magnification allows much more detailed visualization of subcellular structures like the acrosome, the head, the midpiece, the cytoplasmic droplet or the tail of the spermatozoon. Therefore, with IMSI a much more precise selection of spermatozoa is achieved. Following the selection of particular spermatozoa, the IMSI procedure is identical to ICSI.
IMSI is recommended for couples with severe male factor infertility, especially for patients with very few sperm of normal morphology or those who have already been through several unsuccessful ICSI cycles.