For a growing number of young people faced with a cancer diagnosis , one agonizing choice needs to be made quickly: Save your fertility, or hold on to those thousands of dollars — if you even have them — for treatment or whatever else life may bring. Fertility loss is often a guaranteed side effect of chemotherapy, radiation, some surgeries, and even some targeted therapies. But egg-freezing, sperm-freezing, and IVF are generally considered "elective" procedures that you can choose to do, but