title: [Normal physiological variations of pubertal development: starting age of puberty, menarcheal age and size].
abstract: OBJECTIVE
  To evaluate the impact of early, mid-onset, and late maturation, assessed by the age at menarche, height at the beginning of puberty, time of menarche, at one and two years after menarche in a group of healthy girls. The time lapse between the start of puberty and the advent of menarche was observed in that group of girls. To investigate whether their weight status (body mass index) is causally implicated in early start of puberty in these girls.
  
  
  METHODS
  A prospective observational study was performed on 266 healthy Caucasian girls, who were followed up with visits at the beginning of puberty, at menarche and then every six months. Physical examinations included height, weight and pubertal stages, and were assessed by clinical examination according to methods of Tanner. The statistical analysis was performed using the SPSS 12.0 package.
  
  
  RESULTS
  We found that mean age of breast development 2 (B2) was 10.72 years and mean menarcheal age was 12.43 years. The correlation coefficient (r) between the onset of puberty and its duration was r = -0.406 (p < 0.01), and that of age of pubertal onset versus age of menarche was r = 0.34 (p < 0.01). According to 25th and 80th percentiles, early matures were shorter at onset of puberty, at menarche and two years later. Post-menarcheal increase in stature was greatest in early maturers. There is also a correlation between the "z" score of body mass index and the age at onset of puberty (r = -0.398).
  
  
  CONCLUSIONS
  The puberty began at 10.72 years, the menarche appears at 12.43 as average. Girls who matured early were shorter at onset, at menarche and two years after, despite having greater peak height velocity and post-menarcheal increase in height. The age of menarche correlated with the "z" score of body mass index.
authors.affiliation: Servicio de Pediatría. Hospital Central de la Defensa Gómez Ulla. Madrid. España. mmarhe1@oc.mde.es
authors.forename: M
authors.initials: M
authors.lastname: Marco Hernández
authors.forename: R
authors.initials: R
authors.lastname: Benítez
authors.forename: I
authors.initials: I
authors.lastname: Medranda
authors.forename: C
authors.initials: C
authors.lastname: Pizarro
authors.forename: M J
authors.initials: MJ
authors.lastname: Méndez