In Vitro Maturation of Oocytes Retrieved from Ovarian Tissue: Outcomes from Current Approaches and Future Perspectives

Abstract

In vitro maturation (IVM) of transvaginally aspirated immature oocytes is an effective and safe assisted reproductive treatment for predicted or high responder patients. Currently, immature oocytes are also being collected from the contralateral ovary during laparoscopy/laparotomy and even ex vivo from the excised ovary or the spent media during ovarian tissue preparation prior to ovarian cortex cryopreservation. The first live births from in vitro-matured ovarian tissue oocytes (OTO-IVM) were reported after monophasic OTO-IVM, showing the ability to achieve mature OTO-IVM oocytes. However, fertilisations rates and further embryological developmental capacity appeared impaired. The introduction of a biphasic IVM, also called capacitation (CAPA)-IVM, has been a significant improvement of the oocytes maturation protocol. However, evidence on OTO-IVM is still scarce and validation of the first results is of utmost importance to confirm reproducibility, including the follow-up of OTO-IVM children. Differences between IVM and OTO-IVM should be well understood to provide realistic expectations to patients.

Twenty-first century oocyte cryopreservation—in vitro maturation of immature oocytes from ovarian tissue cryopreservation in cancer patients: A systematic review

“…Therefore, based on the successful outcome in OC following IVM, the idea of combining IVM following OTO (ovarian tissue oocyte–in vitro maturation) 16 has received considerable attention to improve the outcome of FP. 2 , 8 , 17 In this procedure, the immature oocytes collected during the OTC can mature via IVM and subsequently cryopreserved together with ovarian tissue.…”

Fertility preservation in the pediatric population—experience from a German Cryobank for ovarian tissue

“…In vitro maturation of immature oocytes from prepubertal females harvested during the OTC procedure showed a lower maturation potential compared with oocytes from adult females ( 17 ). Recently, the first deliveries were reported after in vitro maturation of oocytes collected at the time of OTC and subsequent vitrification ( 18 ). The transplantation techniques for male childhood cancer survivors are still more experimental ( 19 – 21 ).…”

Effect of endometrial cell-conditioned medium and platelet-rich plasma on the developmental competence of mouse preantral follicles: An in vitro study

“…Moreover, each group was complemented with either 10% FBS (control), 10% PRP, 10% CM, and 10% PRP+10% CM, then incubated for 8 days at 37°C. The medium was substituted once every 2 days [6,11,34].…”

“…Mature oocytes were identified based on the identification of polar bodies via stereomicroscopy. Next, the mature follicles were assessed regarding the presence of the meiotic spindle (through fluorescence microscopy), relevant gene expression, and in vitro fertilization (IVF) [6].…”

“…Furthermore, substantial concerns exist regarding cancer recurrence after ovarian tissue cryopreservation and autotransplantation due to the possibility of malignant cell contamination [2][3][4]. In this context, in vitro follicle culture may be superior to the mentioned methods because it does not increase the risk of can-cer recurrence and does not delay the treatment of cancer patients [2,[5][6][7].…”