Effect of thawing temperature on the motility recovery of cryopreserved human spermatozoa.

Objective: To investigate the effects of thawing temperature on sperm function after cryopreservation. The technical aspects of sperm cryopreservation have significantly improved over the last few decades. However, a standard protocol designed to optimize sperm motility recovery after thawing has not yet been established.

Design: Prospective study.

Setting: Private infertility institute and university-based research laboratory.

Patient(s): Eighty consenting normozoospermic patients consulting for infertility.

Intervention(s): Spermatozoa from donor semen samples were thawed at different temperatures.

Main Outcome Measure(s): Sperm motility, viability, adenosine-5'-triphosphate (ATP) content, acrosomal status, and DNA integrity were evaluated as a function of thawing temperature in cryopreserved human sperm samples.

Result(s): Thawing at 40 degrees C resulted in a statistically significant increase in sperm motility recovery compared with thawing at temperatures between 20 degrees C and 37 degrees C. There were no statistically significant differences in sperm viability, acrosomal status, ATP content, and DNA integrity after thawing at 40 degrees C compared with thawing at temperatures between 20 degrees C and 37 degrees C.

Conclusion(s): Sperm thawing at 40 degrees C could be safely used to improve motility recovery after sperm cryopreservation.