Oocyte or embryo preservation after ovarian stimu­lation, ovarian tissue cryopreservation, invitro mat­uration (IVM) of cumulo-oocyte complexes, and downregulation of ovaries with gonadotropin­releasing hormone analogue during chemotherapy are methods that have been attempted to preserve fertility in the female oncological patient. Though some of these options are controversial or experi­mental, others are more established for fertility preservation. The American Society of Clinical Oncology and the American Society for Reproductive Medicine state that ovarian stimula­tion for embryo or mature oocyte cryopreservation is the most established strategy to result in a future pregnancy [87, 88]. In those with estrogen-sensitive tumors or those who cannot delay cancer therapy, transvaginal retrieval of immature oocytes within IVM of oocytes may be considered. In this method, immature oocytes are retrieved from unstimulated postpubertal ovaries and subsequently matured in the laboratory for mature oocyte or embryo cryo­preservation [88]. In a study by Sonigo etal., the researcher found that 20 antral follicles and 3.7ng/ ml AMH were the thresholds for cryopreservation of at least 10 meiosis II oocytes after IVM, while having ≤19 follicles or ≤3.0ng/ml AMH was asso- ciated with a risk of cryopreservation of ≤2 mature oocytes [89]. However, due to limited studies on the safety and efcacy of this approach in the oncologi­cal patient, this technique is still considered investi­gational [88]. More studies need to be done to assess the efcacy and safety of this method and the poten­tial of these oocytes after cryopreservation in patients with malignancies.