 Participation in this study will last until the patients ovarian tissue is all used, or the patient decides to drop out of the study, or for the rest of her life. Freezing of ovarian tissue can be done only for research. Thawing and future use of the tissue to start a pregnancy must be done as part of a research program. After the age of 18, the patient will decide how and at what institution she wishes to use her own tissue in the future, for the purposes of becoming pregnant. The number of visits will be decided by the surgical procedure performed. The Investigators will contact the patient by phone, email, or mail until she has turned 18 years old, used her tissue or dropped out of the study whichever comes first to follow the patients medical and fertility status over time and to ask questions about any future use of her frozen tissue and the possible results of the treatment. Depending on the patients age at the time of enrollment, follow-up might be up to 30 years. 