Nahid Yari - Research and Clinical Center for Infertility, Shahid Sadoughi University of Medical Sciences, Yazd, Iran
Sahabeh Etebary - Research and Clinical Center for Infertility, Shahid Sadoughi University of Medical Sciences, Yazd, Iran
Mohammad Ali Khalili - Research and Clinical Center for Infertility, Shahid Sadoughi University of Medical Sciences, Yazd, Iran
Ali Reza Talebi - Research and Clinical Center for Infertility, Shahid Sadoughi University of Medical Sciences, Yazd, Iran

Background: The nuclear vacuoles in human spermatozoa revealed with the introduction of Nomarski differential interference contrast microscope. Cryopreservation is associated with alterations of sperm structure. The most important impairments of sperm morphology after cryopreservation, often described in the literature, are damage to sperm membranes, coiled tails and acrosomal defects. Therefore, less attention has been paid to detailed assessment of sperm head structures such as the vacuole.Methods: In 30 sperm samples from subjects, analysis of conventional sperm parameters (motility, vitality, and normal morphology) and a morphological analysis at high magnification for vacuoles examination was done before cooling and after warming. vitality was observed following cryopreservation (P ˂0.001). Also, normal morphology decreased significantly after cryopreservation (P < 0.05). Spermatozoa with a vacuole-free head had a significant reduction in cryopreservation group (P= 0 .013). The percentage of spermatozoa with small vacuole increased slightly, but not significantly after cryopreservation (P= 0 .296).Conclusion: MSOME is a powerful research tool for investigating spermatozoa abnormalities such as vacuole that exerts a negative effect on ART outcomes.

MSOME, Spermatozoa, Thawing, Vacuoles, Freezing