Objective: To report the 20-year experience in ovarian tissue cryopreservation
(OTC) and ovarian tissue transplantation (OTT) of the Bologna clinical center
(Bologna, Italy).
Design: Retrospective cohort study.
Patients: 1026 pediatrics and women aged between 2 and 38 years who
underwent OTC and OTT between January 2002 to January 2022.
Results: Of the 1026 patients, 238 (22.8%) were pediatrics (≤ 17 years, Group 1)
and 788 (77.2%) were adult women (range 18-38 years, Group 2). In Group 1,
184 (77.3%) patients had malignant diseases and 54 (22.7%) had non-malignant
diseases. In Group 2, 746 (94.7%) patients had malignant diseases and 42 (5.3%)
had non-malignant diseases. No real complications were observed during
surgery. In all the samples analyzed most of the follicles were in the resting
stage, while only a few follicles were growing. In both fresh and thawed
samples, follicular density was higher in Group 1 than in Group 2 (p < 0.01).
Regardless of age, good preservation of follicles and stroma was observed in
fresh and thawed ovarian tissue by histological and immunohistochemical
analyses (estrogen and progesterone receptors; Ki67 and Bcl2 markers;
TUNEL). To date, out of 1026 total women, 812 (79.1%) had their tissue
stored. Sixty-eight (6.6%) patients died from their primary disease. Twentyfour
(2.3%) women performed 33 OTTs between December 2011 and January
2022. Restoration of menstruation was observed in 15 out of 17 menopausal
women. Six pregnancies were achieved, two hesitated in abortion and four in
the birth of healthy babies.
Conclusion: OTC is the only fertility preservation technique applicable in prepubertal/
pediatrics and in adult patients when stimulation for oocytes/embryos
cryopreservation is not possible. The reported data can help future patients and
physicians in their discussions and decisions about the need and possibilities of
preserving ovarian function