Childhood cancer management requires multidisciplinary care to mitigate long-term health consequences while maximizing chances of a complete cure. The Mayo Clinic Pediatric Fertility Preservation Program, a part of the Mayo Clinic Children's Center, is one of two programs in the upper Midwest offering both ovarian and testicular tissue cryopreservation to children under Institutional Review Board-approved research protocols.

Asma J. Chattha, M.B.B.S., with Pediatric Gynecology at Mayo Clinic in Rochester, Minnesota, a co-founder of the Pediatric Fertility Preservation Program, notes: "As childhood cancer survival rates have improved, reaching upwards of 80% for the first time in decades, concern pertaining to long-term survivorship is growing. Research shows that fertility preservation counseling, particularly in pre-pubertal children, is not occurring frequently enough, despite being a key quality-of-life indicator for survivors."

While post-pubertal males can undergo sperm cryopreservation and post-menarchal females, if time allows, can proceed with egg (oocyte) cryopreservation, options for pre-pubertal children are not clinically available.

The Mayo Clinic Pediatric Fertility Preservation Program was established in 2016 as a multidisciplinary effort: It brings together the expertise of Pediatric Fertility Preservation Program to discuss next steps," explains Carola A S. Arndt, M.D., with Pediatric Hematology/Oncology at Mayo Clinic in Rochester, Minnesota.

Siobhan T. Pittock, M.B., B.Ch., with Pediatric Endocrinology at Mayo Clinic in Rochester, Minnesota, expands, "Depending on the age, gender and pubertal status of the child, fertility preservation protocols are discussed."

"One of the unique aspects of the Pediatric Fertility Preservation Program is its inclusion of indications other than oncologic conditions that could impair fertility, such as Turner or Klinefelter syndrome; nephrologic and rheumatologic conditions requiring gonadotoxic therapy; and transgender youth," expands Candace F. Granberg, M.D., with Urology at Mayo Clinic in Rochester, Minnesota. Dr. Granberg is a co-founder of the Pediatric Fertility Preservation Program.

Both ovarian and testicular tissue cryopreservation protocols remain experimental. However, over 130 live births have been reported from ovarian tissue reimplantation following conclusion of treatment.

"It is estimated that hormone function returns as a result of ovarian tissue reimplantation in over 90% of cases. It is difficult to determine the actual percentage of success of fertility potential returning after ovarian tissue reimplantation, but estimates run between 30% and 52%," clarifies Zaraq Khan, M.B.B.S., with Reproductive Endocrinology & Infertility at Mayo Clinic in Rochester, Minnesota. Dr. Khan is also a co-founder of the Pediatric Fertility Preservation Program.

Testicular tissue cryopreservation has not yielded live births in humans, but success has been achieved in rodents and primates with recent production of functional sperm and birth of healthy offspring after autologous grafting of cryopreserved pre-pubertal testes in rhesus macaques.

"In vitro maturation of immature oocytes is currently being explored under research protocols at Mayo Clinic, hopefully expanding fertility preservation options from ovarian tissue in the future," announces Yulian Zhao, M.D., Ph.D., with Reproductive Endocrinology & Infertility and director of the Fertility Testing Laboratory at Mayo Clinic in Rochester, Minnesota.