ESPE Abstracts

Background: Premature thelarche (PT) may evolve into precocious puberty (PP). The incidence of PP in girls has increased during the last two decades. The epidemiology of PT in the first years of life is less well described.

Objective and hypotheses: We aimed to identify 0–6 year old girls referred to paediatric evaluation for PT in order to examine if the number of girls with PT is increasing, and to describe clinical characteristics of the girls with PT who evolve into PP.

Method: Register-based retrospective follow-up study, including 0–6 year old girls referred with PT in the period 2006–2012 in the Central Denmark Region (population 1,277,538). PT was defined as isolated breast development Tanner stage ≧B2. Review of para-clinical data from patient files.

Results: 121 girls met the inclusion criteria. The incidence proportion of PT for girls born in 2006 was 0.24%. The number of girls with PT increased during the years 2006 (7.4% of the cohort) to 2012 (20.7% of the cohort). 50.4% of the girls with PT were 1–2 years old at referral. 11 girls (9.1%) developed PP. A GnRH test was performed in 45 girls at referral. The peak LH/FSH in response to the GnRH test was 0.38 (median) (range 0.09–2.67) in girls with PP and 0.19 (median) (range 0.06–1.25) in girls with PT. The girls with PP had a median bone age increase corresponding to 18.5 months (range – 2.5–40 months). 17 patients (14%) had a magnetic resonance imaging (MRI) of the brain. One PP patient had a tuber cinereum hamartoma.

Conclusion: The referral rate of patients with PT increased over the years 2006–2012 indicating an increasing incidence. PT patients evolving into PP were characterized by an increased median peak LH/FSH ratio compared to patients not evolving into PP, and bone age was significantly increased in most patients with PP.