HRC's California infertility clinics are leaders in infertility research and recently began offering egg freezing.  Egg freezing is particularly important for women who undergo therapies, such as cancer chemotherapy or radiation, that will destroy their ovaries.  Eggs can be retrieved and frozen prior to the therapy for use at a later date.

The membrane surrounding the egg, the zona pellucida, is more fragile than the embryonic membrane.  Because of this, embryos are less likely to rupture during the freezing process. Special techniques must be employed to protect the integrity of the egg while it is frozen.