IMSI (intracytoplasmic morphologically selected sperm injection) is a modified ICSI technique. It allows the embryologist to look at sperm under an extremely high-magnification microscope in order to look much more critically at the morphology. IMSI can take an additional two or three more hours to examine sperm to find the best looking (and more genetically promising) to be injected into the available eggs.
Research comparing the two methods ICSI and IMSI no significant difference in fertilization rates but couples who had IMSI had higher pregnancy rates and lower miscarriage rates than couples who had ICSI.
In our clinic we offer IMSI to couples with male factor infertility with excellent results.