Interacytoplasmic Morphologically Selected Sperm Injection: A Tool for Selecting the Best Sperm in Real Time

Abstract

Routine sperm parameters are used to evaluate fertility potential of the male partner. Since the introduction of intracytoplasmic sperm injection (ICSI), it seems that the importance of routine parameters of sperm morphology has decreased in the field of assisted reproduction. ICSI has facilitated to achieve fertilization, embryo development, and pregnancies, from the treatment of males with poor-quality spermatozoa. Morphology is the only criteria for sperm aspiration during ICSI. Routine criteria are based on the raw ejaculatestained sperm cells. Thus, it is important to score and aspirate a good-quality motile spermatozoon, which will contribute to the quality of the developing embryo after ICSI, in real time of the procedure. In ICSI, assessment of sperm morphology is limited due to the low magnification (200 × 400×) and concomitant low resolution. By using intracytoplasmic morphologically selected sperm injection (IMSI), it was demonstrated that a spermatozoon with normal morphology, and more precisely normal nucleus, might affect the incidence of pregnancy. Although the usage of IMSI is currently wider, it is necessary to standardize which sperm to aspirate, due to criteria based on accumulating data. Correlation to DNA integrity, embryo development in vitro, female age, male age, or the routine use of IMSI for all cases are raised in order to maximize the efficiency of IMSI technology.