Österbrand M, et al. - In this first prospective population-based study of premature thelarche (PT), researchers examined the prevalence of PT in 18-month-old girls and the incidence of clinically assessed PT for girls aged 18–36 months. The study sample consisted of 3,140 girls born at Northern Älvsborg county hospital (NÄL) in Trollhättan, Sweden who were followed for two years. The data presented in this work showed a prevalence of PT at age 18 months of 1.6/1,000. Findings revealed that clinically assessed incidence of PT was 1.1/1,000. The outcome is consistent with other research reporting medical records prevalence of PT (0.4–40/1,000). As in the other studies, the outcomes in this study show that the vast majority of girls only show benign symptoms.