Reply: A single cut-off value of anti-Mullerian hormone should not be used for the diagnosis of PCOS in all reproductive-aged women

Sir, It has been suggested by Mahboobifard et al. (2022) that a short-coming of our paper exploring the substitution of serum anti-Müllerian hormone (AMH) levels for polycystic ovary morphology (PCOM) for making the diagnosis of PCOS (Bell et al., 2021) was that we did not use age-specific AMH cut-offs for the participants aged 18–39 years, but used a single value for all women in the study. The same could be said for serum testosterone and androstenedione, which exhibit mean declines of 25% and 31% between the ages of 18 and 39 years, respectively (Skiba et al., 2019), and yet age-specific cut-offs for the identification of hyper-androgenaemia are not used in the identification of women with PCOS. Furthermore, the antral follicle count also declines with age across the reproductive years, notably linearly with serum AMH (Loy et al., 2017). Yet, the recommended criteria for the identification of PCOM are not age-specific. Thus, since all of these variables change together with age, taking an age-specific approach for the assessment of AMH seems out-of-step as a diagnostic marker of PCOS. Furthermore, it should not be assumed that every woman’s biological age can be predicted by their chronological age. As we noted in our Discussion, it remains to be seen whether AMH or the morphological assessment of PCOM is eventually shown to be a more appropriate indicator of the metabolic disturbances that are a feature of PCOS.