Improved rescue of immature oocytes obtained from conventional gonadotropin stimulation cycles via human induced pluripotent stem cell-derived ovarian support cell co-culture

Assisted reproductive technologies (ART) have significantly impacted fertility treatment worldwide through innovations such as in vitro fertilization (IVF) and in vitro maturation (IVM). Currently, traditional controlled ovarian hyperstimulation combined with IVF or intracytoplasmic sperm injection (ICSI) is considered the most efficacious form of ART and, therefore, it is used far more frequently than abbreviated ovarian stimulation combined with IVM and subsequent IVF/ICSI as a treatment for infertility or genetic problems. During this process, oocyte maturation happens in the ovary, driven by a lengthy stimulation protocol of gonadotropin injections. Despite that, a significant number of the oocytes retrieved during typical IVF cycles can be immature and are therefore excluded from further treatments. In vitro maturation and fertilization appear as a solution to improve the outcome of mature oocytes for patients, however this is not yet routinely used in the clinic due to suboptimal maturation rates despite being highly utilized in animal models. We recently reported the development of human ovarian support cells (OSCs) generated from human induced pluripotent stem cells (hiPSCs) and demonstrated their ability to recapitulate dynamic ovarian function in vitro. Here we investigate the utilization of these OSCs in an in vitro co-culture system to mimic the ovarian environment and promote IVM to rescue denuded immature oocytes derived from conventional gonadotropin stimulated cycles. We find that OSC-IVM significantly improves oocyte maturation rates compared to spontaneous maturation in media matched controls. Additionally, oocytes matured in OSC-IVM are transcriptionally more similar to conventional IVF MII oocytes than those that spontaneously matured in media controls. Together, these findings demonstrate the efficacy of a novel approach to improve the outcome of matured MII oocytes in modern ART practice by leveraging an optimized IVM system that better mimics the ovarian environment in vitro. ### Competing Interest Statement The majority of this work was performed by employees and shareholders of the for-profit biotechnology company Gameto Inc. C.C.K., S.P., M.M., A.G., B.P., K.S.P., G.R., A.D.N., are listed on a patent covering the use of OSCs for in vitro maturation, Non-provisional Patent Application No. 63/492,210. Additionally, C.K. and K.W. are listed on two patents covering the use of OSCs for in vitro maturation: Non-provisional Patent Application No. 17/846,845 and U.S. Non-provisional Patent Application No. 17/846,725. C.C.K., M.P.S. and P.C. additionally are listed on a patent for the TF-direct production of granulosa-like cells from stem cells: U.S. Provisional Application No. 63/326,640.