Improved maturation competence of ovarian tissue oocytes using a biphasic in vitro maturation system for patients with gynecological malignancy: a study on sibling oocytes.

Purpose: To investigate the developmental competence of ovarian tissue oocytes from patients with gynecological tumors using a biphasic in vitro maturation system with capacitation (CAPA-IVM) in comparison with standard IVM.

Methods: This sibling pilot study included 210 oocytes in 10 patients with gynecological malignancies. After ovariectomies, ovaries were cut into even halves and immature cumulus-oocyte complexes (COCs) were retrieved from the ovarian tissue. COCs were separately cultured in either a biphasic CAPA-IVM system for 53 h or in standard IVM for 48 h. After IVM, all COCs were denuded and mature oocytes were either vitrified (N=5) or used for ICSI (N=5). Embryos were cultured for 5-6 days and obtained blastocysts were vitrified.

Results: Use of the CAPA-IVM system led to a higher meiotic maturation rate in ovarian tissue oocytes (OTO) compared to standard IVM (56 vs 35%, p=0.0045) and had a tendency to result in lower degeneration after IVM. Only the CAPA-IVM method supported blastocyst formation.

Conclusions: The biphasic in vitro maturation system improved the competence of OTO in comparison to the standard IVM method. The study suggests that fertility preservation programs could become more efficient using IVM after capacitation culture.