12 Years of Pediatric Ovarian Tissue Freezing: Tracking Progress in Fertility Preservation

Table of Contents

• Introduction: Why Fertility Preservation Matters for Young Patients
• How the Research Was Conducted
• Patient Characteristics and Diagnoses
• Treatment Timing and Coordination of Care
• Research Participation and Tissue Donation
• Program Development and Milestones
• What This Means for Patients and Families
• Study Limitations
• Future Directions in Fertility Preservation
• Source Information

Introduction: Why Fertility Preservation Matters for Young Patients

Fertility preservation has become a critical component of comprehensive care for pediatric patients facing treatments that risk damaging their reproductive system. With survival rates for childhood cancers now exceeding 80%, most patients will live into adulthood, making quality of life issues like future fertility increasingly important.

Approximately 60% of childhood cancer survivors experience serious long-term complications, with infertility being a significant concern. Specific cancer treatments—particularly alkylating chemotherapies and radiation that targets the pelvic area or brain—can significantly increase the risk of premature ovarian insufficiency (early menopause) and infertility.

Major medical organizations including the American Society of Clinical Oncology, National Comprehensive Cancer Network, American Academy of Pediatrics, and American Society for Reproductive Medicine all recommend that patients and families receive comprehensive fertility preservation counseling before starting treatments that might affect future fertility.

Ovarian tissue cryopreservation (OTC)—freezing ovarian tissue for future use—has emerged as the only fertility preservation option for patients who haven't gone through puberty yet. It's also valuable for patients who need to start treatment immediately and cannot delay for the weeks required for egg stimulation and retrieval.

How the Research Was Conducted

This study reviewed 12 years of data from the Fertility & Hormone Preservation & Restoration Program at Ann & Robert H. Lurie Children's Hospital of Chicago. Researchers conducted a retrospective analysis of all patients who underwent ovarian tissue cryopreservation between March 2011 and February 2023.

The program followed strict ethical guidelines with institutional review board approval and obtained informed consent from all patients and families. Patients aged 18 and older provided their own consent, while younger patients provided assent along with parental consent.

The medical team performed unilateral oophorectomy (removal of one ovary) for tissue cryopreservation, typically using laparoscopic techniques. Whenever possible, this procedure was coordinated with other necessary medical procedures—such as port placement or bone marrow biopsy—to minimize anesthesia exposure.

The ovarian tissue processing followed standardized protocols: the ovary was thinned to 1.5-2.0 mm thickness and cut into strips 3-5 mm wide before being cryopreserved using specialized freezing media and controlled-rate freezing equipment. The frozen tissue was then transferred to long-term storage facilities.

Researchers collected extensive data on patient demographics, diagnosis, treatment history, pubertal status, and research participation. Statistical analysis was performed using specialized software to identify trends and patterns over the 12-year period.

Patient Characteristics and Diagnoses

The program performed ovarian tissue cryopreservation on 184 patients over the 12-year study period. The median age at the time of procedure was 8.99 years, with patients ranging from newborns to 27 years old. This reflects the program's focus on pediatric and young adult patients.

The patient population showed interesting demographic characteristics:

• 73.2% identified as White
• 8.2% identified as Black
• 5.4% identified as Asian
• 13.2% identified as other racial backgrounds
• 75.5% were non-Hispanic
• 15.8% identified as Hispanic or Latino
• 8.7% did not disclose ethnicity information

Regarding pubertal status, 115 patients (62.5%) were prepubertal at the time of their procedure, while 69 patients (37.5%) were postpubertal. The research revealed a significant trend toward younger patients undergoing OTC over time, with the median age decreasing from 16.4 to 6.6 years during the study period.

Cancer diagnoses varied between age groups: Prepubertal patients most commonly had:

1. Other solid tumors (typically Wilms' tumor or neuroblastoma)
2. Sarcoma
3. Brain or spine tumors

Postpubertal patients most commonly had:

1. Sarcoma
2. Leukemia or lymphoma
3. Benign hematologic conditions

The program also served patients from across the country, with 48 patients (26.0%) traveling from outside institutions for the procedure—some coming from as far as Seattle, Washington.

Treatment Timing and Coordination of Care

An important finding was that 128 patients (69.6%) had already received part of their planned cancer treatment before undergoing ovarian tissue cryopreservation. This occurred equally in both prepubertal and postpubertal patients, with 69.6% in each group receiving some treatment first.

This timing issue typically occurred for two reasons: the urgent need to start life-saving cancer treatment immediately, or families needing additional time to consider fertility preservation options before making a decision. All patients who received treatment before OTC were diagnosed with malignancies requiring prompt intervention.

The medical team excelled at coordinating care to minimize patient burden. In 61.4% of cases, the OTC procedure was performed during the same anesthesia as other necessary procedures—63.5% of prepubertal and 58.0% of postpubertal patients benefited from this coordinated approach.

Common procedures performed concurrently included:

• Central venous port placement
• Bone marrow biopsy
• Lumbar puncture
• Gastrostomy tube placement

Research Participation and Tissue Donation

Beginning in 2018, the program began systematically offering patients the opportunity to donate biological specimens for research. The participation rates were remarkably high, demonstrating strong patient and family support for advancing the science of fertility preservation.

Of the 113 patients who underwent OTC between 2018-2022:

• 104 patients (92.0%) donated tissue to research
• 99 patients (87.6%) donated blood samples
• 102 patients (90.2%) donated processing media that would normally be discarded

Notably, 52 of the tissue donors (50.0%) had received previous cancer treatment, providing valuable research material for studying how treatments affect ovarian tissue. The program specifically requested tissue donations from patients who had undergone gonadotoxic therapy before OTC to better understand treatment effects on the pediatric ovary.

When ovarian tissue was limited (less than 80% would remain for patient use after research donation), the program prioritized patient tissue for cryopreservation over research needs, ensuring the primary goal of fertility preservation wasn't compromised.

Program Development and Milestones

The program underwent significant evolution during the 12-year study period. It began in 2011 when Lurie Children's Hospital joined Northwestern University's Oncofertility Consortium to offer ovarian tissue cryopreservation as a fertility preservation option.

Key milestones included:

1. 2011: First OTC case performed at the hospital
2. 2012: ASRM removed experimental label from egg cryopreservation
3. 2016: Program formalized as the Fertility & Hormone Preservation & Restoration Program with dedicated research support
4. 2018: Expanded to include patients with differences in sex development; exceeded 30 cases annually
5. 2019: ASRM removed experimental label from ovarian tissue cryopreservation
6. 2020: Opened dedicated Gonadal Tissue Processing Suite within the hospital

The increasing case volume—reaching over 30 procedures annually—prompted the development of a specialized processing laboratory within the children's hospital itself. This Gonadal Tissue Processing Suite opened in December 2020, during the COVID-19 pandemic, and received necessary FDA and Illinois Department of Public Health registrations.

What This Means for Patients and Families

This 12-year review demonstrates significant progress in making fertility preservation accessible to pediatric patients. The increasing number of procedures, decreasing patient age, and high research participation rates all indicate growing acceptance and implementation of fertility preservation standards.

For families facing childhood cancer diagnoses, this research confirms that:

• Fertility preservation discussion should be part of comprehensive cancer care
• Ovarian tissue cryopreservation is a viable option even for very young patients
• Procedures can often be coordinated with other necessary treatments to minimize burden
• Research participation helps advance the field for future patients

The removal of the "experimental" label from ovarian tissue cryopreservation by the American Society for Reproductive Medicine in 2019 represents a major milestone. This recognition likely contributed to increased insurance coverage and accessibility, similar to what occurred with egg cryopreservation after its experimental label was removed in 2012.

Patients and families should know that while ovarian tissue cryopreservation doesn't guarantee future biological children, it provides additional options for fertility and hormone restoration. The procedure preserves the possibility of future ovarian tissue transplantation, which has resulted in over 140 live births worldwide as of 2020.

Study Limitations

While this study provides valuable insights into a growing pediatric fertility preservation program, it has several limitations. As a retrospective review from a single institution, the findings may not be generalizable to all healthcare settings.

The study focused on process metrics and program development rather than long-term outcomes for patients. Future research will need to track whether patients actually use their cryopreserved tissue and what success rates they experience with ovarian tissue transplantation.

Demographic data showed limited diversity in the patient population, with predominantly White, non-Hispanic patients utilizing these services. This suggests potential disparities in access to fertility preservation that need to be addressed.

The study also couldn't capture the complex decision-making processes that families undergo when considering fertility preservation options during already stressful cancer diagnoses.

Future Directions in Fertility Preservation

This research program continues to evolve with several important initiatives underway. The team is working to optimize fertility and hormone restoration techniques through ovarian tissue transplantation research. They're also developing protocols for patients with differences in sex development who may benefit from gonadal tissue cryopreservation.

An important future direction involves expanding access through collaborative models with other institutions. The program is exploring partnerships that would allow patients to have the initial ovary removal procedure at local hospitals, with the tissue then shipped to Lurie Children's for specialized processing and cryopreservation.

This model—already successful in countries like Denmark, Germany, and the United Kingdom—could dramatically increase access to fertility preservation for patients who cannot travel to specialized centers. It would particularly benefit patients from diverse geographic and socioeconomic backgrounds.

Continued research using donated tissue samples will help improve freezing techniques, better understand how cancer treatments affect ovarian tissue, and develop new methods for restoring fertility and hormone function in survivors.

Source Information

Original Article Title: A dozen years of ovarian tissue cryopreservation at a pediatric hospital: tracking program and patient metrics while adapting to increasing needs

Authors: Kathryn L. McElhinney, MD; Tara Kennedy, BS; Erin E. Rowell, MD; Monica M. Laronda, PhD

Publication: F S Reports (Volume 5, Issue 2, June 2024, Pages 197-204)

Note: This patient-friendly article is based on peer-reviewed research originally published in a scientific medical journal. It maintains all key findings, statistics, and conclusions from the original study while making the information accessible to patients and families.