In Vitro Maturation: Biphasic Protocols

In Vitro Maturation (IVM) is a groundbreaking fertility treatment offering an alternative to conventional IVF by maturing oocytes (eggs) outside the body with minimal or no ovarian stimulation. This article provides a comprehensive overview of In Vitro Maturation: Biphasic Protocols, specifically the Capacitation In Vitro Maturation (CAPA-IVM) system, detailing its development, methodology, advantages, and applications for students exploring advanced reproductive technologies. We'll examine how these innovative protocols address limitations of older IVM methods and offer a safer, more patient-friendly approach.

Understanding In Vitro Maturation (IVM) and Its Evolution

Since 1981, In Vitro Maturation (IVM) has aimed to obtain mature oocytes with no or minimal ovarian stimulation. This approach contrasts sharply with conventional IVF, which relies heavily on ovarian stimulation, often leading to potential complications and burdens for patients. IVM seeks to reduce medication costs, avoid Ovarian Hyperstimulation Syndrome (OHSS), and offer a generally safer, less costly, and more patient-friendly treatment.

Challenges with Traditional IVM Protocols

Early IVM protocols, such as hCG-IVM and Standard IVM, faced significant challenges:

• hCG-IVM: Involved 2-6 days of FSH priming, an hCG trigger before OPU, and one-step IVM culture.
• Standard IVM: Included 0-3 days of FSH priming, no hCG trigger, and one-step IVM culture.

These older methods often resulted in a low maturation rate, poor oocyte quality, and consequently, a low number and poor quality of embryos. A key problem was the early meiosis resumption triggered by hCG and/or OPU, leading to a discrepancy between genetic and cytoplasmic maturation.

The Innovation of Biphasic IVM Protocols

Biphasic IVM protocols, particularly the CAPA-IVM concept, emerged to overcome the limitations of earlier methods. This innovative approach aims to prevent premature meiotic resumption, allowing for prolonged oocyte-cumulus cell communication through TransZonal Projections (TZPs), which is crucial for cytoplasmic maturation. The concept leverages an initial