Precocious puberty

Chapter 31 PRECOCIOUS PUBERTY



Normal puberty begins in girls between 8 and 14 years of age with breast buds and skeletal growth, followed by the arrival of pubic hair, axillary hair, and menarche. The age at which pubertal milestones are attained varies. In addition, it is influenced by activity level and nutritional status. Girls with low body fat may have a significant delay in menarche (up to a year or more), whereas obese girls may have earlier onset of puberty.


Precocious puberty is defined as the development of secondary sexual characteristics before the age of 8 years in girls. It involves not only early physical changes of puberty but also linear growth acceleration and acceleration of bone maturation, which leads to early epiphyseal fusion and short adult height.


There are two types of precocious puberty. Central precocious puberty results, or gonadotropin-releasing hormone (GnRH)–dependent precocious puberty, results from the premature activation of the hypothalamic GnRH pulse generator–pituitary gonadotropin–gonadal axis. In GnRH-independent precocious puberty, sex steroid secretion is independent of the GnRH pulse generator. Pathologic causes of puberty are likely if sexual development occurs in very young children or if there is contrasexual development. Peripheral causes are always pathologic and tend to produce an atypical puberty with loss of synchronicity of pubertal milestones.


Central precocious puberty is more common by far in girls than in boys, and in girls it is idiopathic in 95% of cases. In girls, therefore, additional investigation can be based on the clinical impression. Central nervous system (CNS) disorders account for a higher percentage of cases in boys but must also be investigated in girls.


Pubertal variants cause isolated development of one of the secondary sexual characteristics without accelerated skeletal maturation, and on occasion, they can progress to precocious puberty:



Patients with precocious puberty and pubertal variants require an initial bone age as a baseline. In precocious puberty, the bone age is usually accelerated more than two standard deviations above the chronologic age. In pubertal variants, the bone age is within two standard deviations of the chronologic age. The bone age should be obtained at periodic intervals to determine whether pubertal variants have progressed to precocious puberty. The bone age is also used to monitor the effectiveness of therapy. Additional evaluation of precocious puberty is outlined below.


Jun 4, 2016 | Posted by in GYNECOLOGY | Comments Off on Precocious puberty

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