Eckert-Lind C, Busch AS, Petersen JH, et al. - Experts conducted a systematic review and meta-analysis to evaluate published data on pubertal timing based on age at thelarche and assess the change in pubertal onset in healthy girls around the world. Before June 20, 2019, they performed a systematic literature search in PubMed and Embase of all original peer-reviewed articles published in English. Using a random-effects model, a weighted regression analysis was conducted. The literature search resulted in a sum of 3,602 studies, of which 30 studies met the eligibility criteria. Between 1977 and 2013, the age at thelarche has declined a mean of almost 3 months per decade. The current diagnostic decision-making can be changed by a younger age at pubertal onset. Because the traditional definition may be outdated, the medical community requires current and relevant data to redefine “precocious puberty,” at least in some regions of the world.