title: The response to gonadotropin releasing hormone (GnRH) stimulation test does not predict the progression to true precocious puberty in girls with onset of premature thelarche in the first three years of life.
abstract: BACKGROUND
  Premature thelarche in early childhood may evolve into true precocious puberty. The individuation of cases progressing to precocious puberty is challenging.
  
  
  OBJECTIVE
  We analyzed the parameters predictive for progression in girls younger than 3 years.
  
  
  METHODS
  We conducted a retrospective longitudinal study.
  
  
  METHODS
  A total of 450 girls referred for premature thelarche were initially evaluated, 353 were clinically monitored at 3-month intervals, and 97 underwent endocrine and imaging assessment. Central precocious puberty (CPP) was diagnosed in girls showing LH peak response to GnRH testing >5 mU/mL with tuber cinereum hamartoma at magnetic resonance imaging, or with normal magnetic resonance imaging but progression of puberty during follow-up.
  
  
  METHODS
  We measured the progression to precocious puberty.
  
  
  RESULTS
  Idiopathic premature thelarche (IPT) was diagnosed in 85 of the 97 girls who underwent extensive evaluation, CPP in nine girls, and peripheral precocious puberty in three girls. The uterus was >34 mm in six (7%) IPT girls and six (66.6%) CPP girls. Basal LH was >0.2 mU/mL in one (1.17%) IPT girl and eight (88.8%) CPP girls. LH peak was >5 mU/mL in 31 (36.4%) IPT girls and nine (100%) CPP girls. LH peak/FSH peak ratio was >1 in six (66.6%) CPP girls.
  
  
  CONCLUSIONS
  None of the available tests alone allows identification of girls who will progress to precocious puberty. Elevated LH responses to GnRH are common but are not related to progression toward puberty. The combined measurement of basal LH and longitudinal diameter of the uterus represents a reliable screening approach to identify subjects who should undergo GnRH testing.
authors.affiliation: Endocrinology and Diabetes Unit (C.B., M.C.), "Bambino Gesù" Children's Hospital, 00165 Rome, Italy; Dipartimento Pediatrico Universitario Ospedaliero (G.L.S., G.B., G.M., S.C.), "Bambino Gesù" Children's Hospital-Tor Vergata University, 00165 Rome, Italy; Department of Chemistry (G.G.), "Bambino Gesù" Children's Hospital, 00165 Rome, Italy; and Department of Women's and Children's Health (S.C.), Karolinska Institute, SE 17177 Stockholm, Sweden.
authors.forename: Carla
authors.initials: C
authors.lastname: Bizzarri
authors.forename: Gian Luigi
authors.initials: GL
authors.lastname: Spadoni
authors.forename: Giorgia
authors.initials: G
authors.lastname: Bottaro
authors.forename: Giulia
authors.initials: G
authors.lastname: Montanari
authors.forename: Germana
authors.initials: G
authors.lastname: Giannone
authors.forename: Marco
authors.initials: M
authors.lastname: Cappa
authors.forename: Stefano
authors.initials: S
authors.lastname: Cianfarani
mesh_terms: D002675:Child, Preschool; D003940:Diagnostic Techniques, Endocrine; D018450:Disease Progression; D005260:Female; D005640:Follicle Stimulating Hormone / Q000097:blood*; D007987:Gonadotropin-Releasing Hormone; D006801:Humans; D007223:Infant; D008137:Longitudinal Studies; D007986:Luteinizing Hormone / Q000097:blood*; D011629:Puberty, Precocious / Q000097:blood / Q000175:diagnosis*; D012189:Retrospective Studies
chemical_list: D007987:Gonadotropin-Releasing Hormone; D007986:Luteinizing Hormone; D005640:Follicle Stimulating Hormone