1. The authors should be congratulated for their scientific modesty, admitting there are many unknown and equivocal matters in this important issue. Similarly, the group, who has published the first delivery after transplantation of thawed-cryopreserved ovarian tissue, has recently [2] published their disappointing results in IVF after ovarian autotransplantation: ‘‘IVF in women with orthotopically grafted frozen-thawed ovarian tissue involves a higher risk of empty follicles, abnormal or immature oocytes, and low embryo transfer rates’’. They [2] have described an empty follicle rate per retrieval of 29%; 16 oocytes were recovered, of which six were abnormal or immature (38%); three MII oocytes failed to fertilize, two showed abnormal fertilization, and five normal MII oocytes successfully fertilized with subsequent normal embryo development, yielding an ET rate of only 24% per retrieval. No pregnancy occurred. Therefore, we should all admit that we are still far from having a ubiquitous solution for all the young women facing gonadotoxic treatments... 2. None of the suggested avenues for fertility preservation guarantees unequivocal success in future fertility preservation. Even IVF and cryopreservation of a few embryos cannot guarantee future pregnancy. Therefore, several modalities should be combined and considered. 3. Another recent, preprint electronic publication [3] has detected an overall ovarian metastases rate of 8.4– 55.8% in women younger than 40 years, and 13.3% in the lymphoma patients. These investigators [3] concluded that since there is no reliable method to detect minimal residual disease in the cryopreserved tissue, the safety of reimplantation cannot be guaranteed yet. 4. Although we agree with most of the authors comments [1], we humbly disagree with the following: Nietzsche et al. [1] claim that: ‘‘A clinical example for why gonadal suppression may not protect ovaries is the fact that prepubertal children receiving high-dose chemotherapy given before hematopoietic stem cell transplantation still suffer from ovarian failure’’. Recently, Remerand et al. [4] have described four spontaneous pregnancies and successful deliveries in a patient after prepubertal high dose busulphan and cyclophosphamide (Bu–Cy) conditioning and BMT, demonstrating that successful pregnancies are possible in patients undergoing prepubertal BMT. Similarly, we have recently described repeated spontaneous pregnancies and two successful deliveries after repeated autologous stem cell transplantations and GnRH-agonist treatment in a postpubertal lymphoma patient, suggesting that the prepubertal milieu induced by the GnRH-a cotreatment might have contributed to the preserved fertility despite repeated BMT [5]. 5. Only 0.6% of patients conceive after one autologous or allogeneic BMT, according to an extensive survey, Z. Blumenfeld (&) Department of Obstetrics and Gynecology, Technion Faculty of Medicine, Rambam Medical Center, 31096, Haifa, Israel e-mail: bzeev@techunix.technion.ac.il; z_blumenfeld@rambam.health.gov.il