What is damaged sperm and how can it impact the chances for successful fertilization?

When I say that the sperm may not be safe in the setting of a patient having received their therapy, what we’re really getting at is that we don’t know what effect the cancer treatment will have on an individual’s sperm. So it is possible that chemotherapy or radiation therapy may damage an individual’s sperm without us being able to really assess the sperm and find out what the degree of damage has been. The bottom line with sperm is that there’s not an adequate way to look at it to assess the DNA damage without destroying the sperm, and so that somewhat limits our ability to sort through a sample of semen and determine which sperm are good and which are bad. But again there are a number of other markers that we can use, such as the motility of the sperm, the overall appearance, the shape of the sperm, that may provide at least some degree of insight into the overall health of an individual’s sperm.