Transplantation of cryopreserved human ovarian tissue: restoration of reproductive function after two cycles of radio- and chemo-therapeutic treatments.

Background: Patient S. was born in 1983, developed a Ewing-Sarcoma and obtained low dose chemotherapy in 1996. In 2007, Patient S. received high-dose chemotherapy because lung-metastases were diagnosed. The aim of the study was to investigate the health of cryopreserved ovarian tissue and also to examine whether this ovarian tissue can restore the reproductive function of patient after two cycles of radio-and chemo-therapeutic treatments.

Methods: Twenty pieces of ovarian tissue (total of approximately 200 mm2) were conventionally frozen with 6% (v/v) dimethyl sulfoxide, 6% (v/v) ethylene glycol and 0.15 M sucrose and kept for five years before 8 pieces were thawed and transplanted back into the patient. Two small (1 x 2 x 1 mm) pieces of this thawed tissue were cultured in a chicken embryonic chorioallantoic membrane (CAM)-system for 5 days to assess the tissue viability.

Results: The ovarian tissue that was grafted re-established spontaneous menstrual bleeding within five months and serum 17-beta estradiol increased from 19 to 330 pg/mL. Ultrasound revealed a dominant follicle at the site of the transplanted tissue in the follicular phase after the menstrual bleed. Analysis of the CAM cultured tissue established that 88% of the primordial follicles had degenerated and there was limited growth of blood vessels.

Conclusions: In spite of the damage caused by the cryopreservation the surviving follicles could restore ovarian function after re-transplantation.