The results of in vitro maturation (IVM) investigations suggest the potential for wider clinical application. This document discusses the efficacy of IVM as reported in the published literature to date.
In vitro fertilization (IVF) typically involves ovarian stimulation with the use of exogenous gonadotropins to induce the maturation of gonadotropin-sensitive follicles and inhibit the atresia of nondominant folicles (1, 2). The classic use of the term in vitro maturation (IVM) refers to the maturation of immature cumulus-oocyte complexes (COCs) in culture from prophase I (i.e., from the germinal vesicle [GV] stage) through meiosis I to reach metaphase II (MII) after their recovery from follicles that have not been exposed to the preovulatory trigger (3). This was defined largely in nonhuman animal studies. In clinical human IVF, however, the term IVM is often used to refer to in vitro maturation of oocytes retrieved at the GV or metaphase I (MI) stage from follicles after exposure to exogenous FSH and/or hCG (‘‘follicle priming’’) to increase the likelihood of obtaining some mature oocytes (4, 5). Interpretation of studies reported in the literature could be clarified if specific terminology was used to delineate between IVM with and without short gonadotropin stimulation, and with and without hCG exposure before retrieval (6, 7).
In vitro fertilization (IVF) typically involves ovarian stimulation with the use of exogenous gonadotropins to induce the maturation of gonadotropin-sensitive follicles and inhibit the atresia of nondominant folicles (1, 2). The classic use of the term in vitro maturation (IVM) refers to the maturation of immature cumulus-oocyte complexes (COCs) in culture from prophase I (i.e., from the germinal vesicle [GV] stage) through meiosis I to reach metaphase II (MII) after their recovery from follicles that have not been exposed to the preovulatory trigger (3). This was defined largely in nonhuman animal studies. In clinical human IVF, however, the term IVM is often used to refer to in vitro maturation of oocytes retrieved at the GV or metaphase I (MI) stage from follicles after exposure to exogenous FSH and/or hCG (‘‘follicle priming’’) to increase the likelihood of obtaining some mature oocytes (4, 5). Interpretation of studies reported in the literature could be clarified if specific terminology was used to delineate between IVM with and without short gonadotropin stimulation, and with and without hCG exposure before retrieval (6, 7).
