Functional studies of subcutaneous ovarian transplants in non-human primates: steroidogenesis, endometrial development, ovulation, menstrual patterns and gamete morphology*

BACKGROUND: The study objective was to determine if ovarian function would be restored following fresh and cryopreserved extrapelvic autologous ovarian transplantation and if vascular endothelial growth factor (VEGF) administration would augment the success rate. METHODS: Sixteen regularly cycling female cynomolgus monkeys underwent bilateral oophorectomy and were randomly assigned to one of three treatment groups: (i) sham transplant group (n = 5) underwent transplantation of pieces of adipose tissue; (ii) fresh autologous ovarian transplantation without VEGF administration (n = 6) and (iii) fresh autologous ovarian transplantation with 1 μg of VEGF (n = 5) administered at the transplantation site daily for 14 days after transplantation. The ovarian tissue from the sham transplanted group was cryopreserved. This material was later thawed and transplanted in four out of five of the sham operated group. RESULTS: Five out of six (83%) of the primates in our transplantation group without VEGF had functioning ovarian transplants while two of five (40%) primates in our transplantation group with VEGF administration had functioning ovarian transplants. The cryopreserved group had two of four primates (50%) with functioning transplants. Ovarian stimulation yielded multiple follicles and one metaphase II oocyte from the fresh and one metaphase II oocyte from the cryopreserved group. CONCLUSIONS: The success of ovarian transplantation in these non-human primates with menstrual cycles bodes well for the development of ovarian transplantation protocols for women at risk of ovarian failure.