Is anti-Müllerian hormone (AMH) a marker of ovarian reserve?

Anti-Müllerian hormone (AMH) is established as a primary clinical biomarker for assessing the ovarian reserve, representing the quantity of remaining eggs in a woman's ovaries. As women approach their mid-40s, AMH levels naturally decline, often reaching low or undetectable levels as the follicle pool nears depletion.

Clinical and effectiveness evidence

AMH is widely recognized by reproductive societies, including the American Society for Reproductive Medicine (ASRM), as a superior marker for evaluating the functional ovarian reserve compared to traditional hormone tests like follicle-stimulating hormone (FSH).

• Correlation with Follicle Count: Research shows a strong positive correlation (Pearson's r ≈ 0.66) between serum AMH levels and the antral follicle count (AFC) observed via ultrasound.
• Predictive Value: In clinical settings, AMH is highly predictive of the ovarian response to gonadotropin stimulation during IVF. Low AMH levels consistently indicate diminished ovarian reserve (DOR) and a higher likelihood of a "poor response" or low oocyte yield during fertility treatments.
• Age-Related Decline: In women aged 44, AMH levels are typically at the lower end of the spectrum, reflecting the biological reduction in the primordial follicle pool that occurs with advanced reproductive age.

Mechanistic explanations

The utility of AMH as a marker is rooted in its specific site of production within the ovary.

• Granulosa Cell Secretion: AMH is secreted exclusively by the granulosa cells of preantral and small antral follicles (less than 8mm in diameter).
• Functional Proxy: Because these small follicles represent the cohort recruited from the "resting" primordial follicle pool, AMH levels serve as a reliable proxy for the total remaining egg supply.
• Independence from Menstrual Cycle: Unlike FSH, AMH levels remain relatively stable throughout the menstrual cycle because its production is not regulated by the traditional hypothalamic-pituitary-ovarian feedback loop, making it a convenient "any-cycle-day" test for clinicians.

Bottom line

AMH is a scientifically validated marker that accurately reflects the quantity of remaining follicles; for a woman aged 44, it is the most reliable blood test to assess the current status of the ovarian reserve and predict potential success in assisted reproduction.