Anti-Müllerian hormone: ovarian reserve testing and its potential clinical implications

In women, anti-Müllerian hormone (AMH) is exclusively produced by granulosa cells of ovarian follicles during the early stages of follicle development. After an initial increase until early adulthood, AMH concentrations slowly decrease with increasing age until becoming undetectable ∼5 years before menopause when the stock of primordial follicles is exhausted. However, major individual variability exists in the pace of follicle pool depletion and the initial size of the follicle pool, reflected by a wide range of age at menopause. Individual AMH serum concentration does accurately reflect the size of the pool of antral follicles, representing the quantity of the remaining primordial follicles. Accordingly, AMH levels may vary significantly in women of the same chronological age, allowing AMH to predict the remaining length of a woman's reproductive lifespan. Following 10 years of intense clinical research in this area (with over 300 papers published in core clinical journals every year), the level of evidence justifying use of AMH in ovarian reserve testing is rapidly increasing. We have conducted a summarizing review regarding all evidence published. Many studies have convincingly demonstrated that AMH is the best currently available measure of ovarian reserve under a variety of clinical situations, such as infertility treatment (especially IVF), the forecasting of reproductive lifespan, ovarian dysfunction (especially polycystic ovary syndrome) and gonadotoxic cancer treatment or ovarian surgery. Moreover, AMH may help to individualize dosing for ovarian stimulation thereby improving the efficiency and safety of IVF. However, there are concerns about the performance of the AMH assay under different conditions regarding storage of samples and handling techniques. Therefore an international guideline for laboratories and a reference preparation are needed to make test results between laboratories truly comparable. AMH is the best current available measure of ovarian reserve for different clinical conditions. However, prospective well powered studies comparing different infertility treatment strategies based on initial AMH levels using appropriate end-points, such as live birth and cost-effectiveness, are urgently awaited. Such studies could represent a true step forward in rendering counseling and infertility care more patient tailored.