Triggering change in stimulation protocols: a matter of oocyte maturation and beyond.

Since the birth of Louise Brown, in vitro fertilization (IVF) stimulation protocols have evolved significantly. One particular area of focus has been the process of final oocyte maturation, during which the oocyte gains competence to support fertilization and early embryonic development up to implantation. The field of human assisted reproductive technology (ART) is witnessing increased utilization of GnRH agonists (GnRHa) as trigger agents, in addition to or instead of the traditionally used human chorionic gonadotropin (hCG). Future translational studies will reveal whether oocyte developmental competence, as reflected in live birth outcomes, are not only non-inferior, but also superior with the use of GnRHa as a trigger for both nuclear and cytoplasmic oocyte maturation.