The effect of temperature on sperm motility and viability

Area of Science:

• Reproductive biology
• Andrology
• Sperm cryopreservation

Background:

• Semen analysis is vital for fertility assessment.
• Optimal conditions for preserving semen quality post-collection are not universally established.
• Temperature significantly impacts sperm parameters over time.

Purpose of the Study:

• To evaluate the effect of different storage temperatures (4°C, 20°C, 37°C) on semen quality over 18 hours.
• To determine the ideal storage temperature to maintain sperm viability and motility for delayed analysis.
• To identify potential factors contributing to sperm degradation at various temperatures.

Main Methods:

• Semen specimens from fertile prevasectomy patients were collected.
• Samples were stored at 4°C, 20°C, and 37°C.
• Sperm viability (eosin-nigrosin stain) and motility were assessed at 3, 6, 12, and 18 hours.
• Bacterial counts and pH were also monitored.

Main Results:

• Sperm viability and motility decreased significantly over time at 20°C and 37°C, with a more rapid decline at 37°C.
• At 37°C, motility was halved by 12 hours; bacterial growth increased, and pH decreased.
• At 4°C, motility was nearly absent by 6 hours, but viability was maintained for 18 hours.
• Viability decline paralleled motility decline, except at 4°C.

Conclusions:

• Semen samples for analysis should be stored at room temperature (20°C) if immediate analysis is not possible.
• Storage at 37°C leads to rapid loss of sperm motility and viability, likely due to bacterial proliferation and pH changes.
• Refrigeration at 4°C preserves viability but severely impairs motility, making room temperature the preferred option for short-term storage.