Intracytoplasmic morphologic sperm injection (IMSI) IMSI involves the use of a high-powered microscope to better identify good quality sperm (based on the absence of vacuoles in the sperm head). Synonyms: Intracytoplasmic morphologic sperm injection, IMSI Related Articles: Complete guide to sperm quality Evidence-based recommendations from ESHRE for 27 IVF add-ons Study reviews 34 common male fertility sperm supplement brands for safety, efficacy Italian fertility group issues 2025 guidance on 28 IVF add-ons What IVF add-ons work best for older patients? Results of a meta-analysis