Another intriguing aspect of the question is that the chronological age does not necessarily overlap with the reproductive age which, besides complicating the decisional process in the clinical practise, may also play as a confounding factor in the evaluation of the results from clinical trials. Several studies have validated the role of the so-called follicle antral count (AFC) and the anti-Mullerian hormone (AMH) circulating levels as having a predictive role in the evaluation of the actual reproductive age. In particular the latter, the AMH, appears to be easier to standardise and to be used as the best reference in multicentre clinical studies focussed on the reproductive age.