Anti-Mullerian Hormone: Above and Beyond Conventional Ovarian Reserve Markers

Abstract

Management of ovarian dysfunctions requires accurate estimation of ovarian reserve (OR). Therefore, reproductive hormones and antral follicle count (AFC) are assessed to indicate OR. Serum anti-Mullerian hormone (AMH) is a unique biomarker that has a critical role in folliculogenesis as well as steroidogenesis within ovaries. Secretion from preantral and early antral follicles renders AMH as the earliest marker to show OR decline. In this review we discuss the dynamics of circulating AMH that remarkably vary with sex and age. As it emerges as a marker of gonadal development and reproductive disorders, here we summarize the role of AMH in female reproductive physiology and provide evidence of higher accuracy in predicting ovarian response to stimulation. Further, we attempt to compile potential clinical applications in children and adults. We propose that AMH evaluation has a potential role in effectively monitoring chemotherapy and pelvic radiation induced ovarian toxicity. Furthermore, AMH guided ovarian stimulation can lead to individualization of therapeutic strategies for infertility treatment. However future research on AMH levels within follicular fluid may pave the way to establish it as a marker of "quality" besides "quantity" of the growing follicles.

Figure 1

Schematic representation of hormonal surges across the follicular phase of ovarian cycle. 1: initial recruitment; 2: cyclic recruitment; 3: selection; 4: dominance; 5: ovulation. (−) non/poorly visualized; (+) well visualized. AMH is secreted by all growing follicles but its serum levels reflect only the secretion from follicles lying close to the vascular bed. It has an inhibitory effect on steps 1 and 2, thus maintaining the ovarian pool. The emphasis is on AMH production in early stages of follicle development as opposed to all other hormones that are released at later stages. Follicular fluid AMH levels show a better correlation with oocyte competence and hence can prove to be a reliable marker of embryo transfer outcomes.