What is Anti-Müllerian Hormone (Capillary Dried Blood Spot)?
Anti-Müllerian hormone is a dimeric glycoprotein of the transforming growth factor-beta family, secreted in the adult ovary almost exclusively by the granulosa cells of preantral and small antral follicles. Because this pool of growing follicles is proportional to the resting primordial follicle population, circulating AMH serves as an indirect index of the remaining ovarian follicle reserve. Secretion falls away once follicles are selected for dominance and become FSH-responsive, so AMH reflects the recruitable cohort rather than the dominant follicle. Levels are comparatively stable across the menstrual cycle relative to FSH, oestradiol, or inhibin B, which is why a single timed draw is generally not required. Concentrations rise through adolescence, peak in the early-to-mid twenties, and then decline progressively with age toward the menopausal transition.