Human oocyte capacitation culture: Essential step toward hormone-free assisted reproductive technology

Abstract

Background: In vitro oocyte maturation (IVM) is not a novel concept; however, its wide-scale practice has been limited because of the lower clinical outcomes compared to conventional assisted reproductive technologies. Methods: This comprehensive review addresses the significant advances made in oocyte in vitro maturation with the biphasic capacitation (CAPA)-IVM strategy applied to small ovarian antral follicles in humans over the last 10 years. CAPA-IVM consists of a prematuration phase wherein immature oocytes are temporarily meiotically arrested to gain competence before undergoing meiotic resumption. Main findings: The integration of knowledge from basic research in animal models into clinical practice has led to a reevaluation of IVM for policystic ovary syndrome (PCOS) and onco-fertility patients. The introduction of meticulously conceived growth factors, hormonal supplements, and culture conditions led to an integrated biphasic CAPA-IVM system that promotes oocyte competence. A series of prospective randomized controlled studies validated the reproducible improvements in clinical outcomes and the safety of CAPA-IVM. So far, nearly 1000 babies have been born using this approach. Conclusion: The use of CAPA-IVM in clinical studies has set the tone for major progress in the field and is achieving a safer, less expensive, and less emotionally loaded IVF experience, currently validated for PCOS patients.