Ovarian reserve testing: assessing oocyte quantity and quality.

The oocyte provides the cellular architecture and molecular machinery for human development. Oocyte quality is closely tied to reproductive success; however, there is no consensus on how to measure it. As it stands, maternal age remains as the primary predictor of oocyte quality. Ovarian reserve, which conceptually reflects oocyte quantity and quality, is primarily assessed and expressed in terms of oocyte quantity. Ovarian reserve tests (ORT) serve as predictors of a patient's oocyte quantity and response to ovarian stimulation during in vitro fertilization (IVF). The question is not simply whether both oocyte quantity and quality decline with age-they do-but whether current ORTs, particularly anti-Müllerian hormone (AMH), can reliably predict both. An unresolved question is whether oocyte quality and quantity are inherently linked or are independent of one another. Oocyte quality has been described as a fertilized oocyte's ability to yield a live birth. With aging, oocyte aneuploidy rates increase and the likelihood of live birth declines. Yet, it remains unclear as to whether current markers of ovarian reserve can predict oocyte aneuploidy or IVF success. To gain deeper insight into the relationship between ORTs and reproductive potential requires a review of ovarian aging, contemporary ORT, and current evidence. Currently used ovarian reserve markers are reasonable predictors of relative oocyte quantity. AMH may also serve as a marker of egg quality. This review aims to provide a better understanding of the relationship between ovarian reserve tests, particularly AMH, and oocyte quantity and quality.