In a study comparing frozen sperm samples stored for many years, researchers found that the method used for preserving sperm since the late 1990s maintained high survival rates even after long-term storage. They looked at samples from cancer patients frozen between 2002 and 2011 and then thawed and tested them in 2014. Surprisingly, the survival rate of sperm after prolonged freezing was the same as those tested after just one day. This suggests that the technique used to clean and prepare the sperm before freezing helps keep it viable for later use in fertility treatments. Overall, the study shows that sperm can be successfully stored for many years without affecting their ability to survive the thawing process.