Egg freezing /Embryo freezing Egg freezing- is a method used to preserve a woman's reproductive potential. Eggs are harvested from your ovaries, frozen unfertilized and stored for later use. A frozen egg can be thawed, combined with sperm in a laboratory and implanted in your uterus (in vitro fertilization). You might consider egg freezing if you are about to undergo cancer treatment such as radiation or chemotherapy, which can harm your fertility. Egg freezing before treatment might allow you to have biological children at a later date. Egg freezing might be appealing if you're concerned about age-related infertility, but the method isn't recommended for this purpose due to the risks, costs and limited success rates. Embryo Freezing - In this procedure, eggs are harvested from your ovaries, fertilized through in vitro fertilization (IVF), frozen and stored.