Identification and selection of completely immotile but viable spermatozoa for assisted reproductive technology

Intracytoplasmic sperm injection (ICSI) remains the most effective method for severe male infertility patients to obtain their genetic offspring. A viable spermatozoon is the prerequisite for initiating fertilization in ICSI. Motility is the primary sign of sperm viability. However, how to select immotile but viable spermatozoa for ICSI on the day of ovum pick-up is critical for ICSI. This review focuses on the techniques for the identification and selection of immotile but viable spermatozoa for assisted reproductive technology.