Sperm vacuoles are not modified by freezing--thawing procedures

Area of Science:

• Reproductive Biology
• Sperm Morphology
• Cryopreservation Science

Background:

• The motile sperm organellar morphology examination (MSOME) assesses sperm head vacuoles at high magnification.
• Cryopreservation is known to impact overall sperm quality, but its effect on sperm vacuoles is unstudied.

Purpose of the Study:

• To investigate the impact of cryopreservation (freezing-thawing) on human sperm vacuoles.
• To determine if MSOME normality criteria for vacuoles are consistent for fresh and frozen sperm.

Main Methods:

• Sperm samples from 27 fertile men were analyzed before and after freezing-thawing.
• Conventional sperm parameters (motility, vitality, normal forms) and high-magnification morphological analysis (MSOME) were performed.
• Image analysis software quantified vacuole characteristics.

Main Results:

• Sperm motility, vitality, and percentage of normal forms significantly decreased after cryopreservation.
• No significant differences were observed in any vacuolar criteria (e.g., relative vacuole area, total vacuole area, vacuole distribution) after freezing-thawing.
• Specific vacuole size thresholds (≤6.5% and >13%) showed no change post-cryopreservation.

Conclusions:

• Human sperm vacuoles are unaffected by standard freezing-thawing procedures.
• The morphological normality criteria for sperm vacuoles using MSOME can be applied to both fresh and cryopreserved spermatozoa.
• This supports the consistent application of MSOME for sperm selection in assisted reproductive technologies regardless of sperm storage status.