Men facing chemotherapy for cancer treatment will experience varying effects, but one to expect for sure is an inevitable impact to their sperm.

The extent to which chemotherapy affects sperm quality and quantity differs among patients. While chemotherapy always damages sperm production, some patients experience a permanent alteration, while others may endure a temporary impact.

"Either way, any chemotherapy, whether you're getting it for colon cancer or whether you're getting it for testicular cancer, can affect other spermatogenesis," said Jennifer Linehan, M.D., a urologist and associate professor of urologic oncology at Saint John's Cancer Institute at Providence Saint John's Health Center in Santa Monica, California.

If chemotherapy is in your future—and you are keen to keep your reproductive options open—here's what you need to know.

Bank sperm early—even if you're not sure about kids