Early puberty is defined as the onset of pubertal changes before the age of 8 in girls and 9 in boys. Early puberty can lead to a reduction in adult height due to premature fusion of the epiphyseal plates (growth plates). It also has a psychosocial impact (e.g., associated with early menstruation in girls).
Causes
The causes of early puberty are split into two groups:
- Gonadotropin-dependent precocious puberty (or central precocious puberty)
- Gonadotropin-independent precocious puberty (or peripheral precocious puberty)
Gonadotropin-dependent precocious puberty involves early activation of the hypothalamic-pituitary-gonadal axis. The hypothalamus starts producing gonadotropin-releasing hormone (GnRH) early. GnRH stimulates the anterior pituitary to produce luteinising hormone (LH) and follicle-stimulating hormone (FSH), which stimulates the ovaries or testes to start producing sex hormones, oestrogen or testosterone.
Causes of gonadotropin-dependent precocious puberty include:
- Idiopathic (common)
- Central nervous system pathology (e.g., tumours or radiotherapy)
- Genetic mutations (e.g., KISS1 and MKRN3 mutations)
Gonadotropin-independent precocious puberty occurs when there is an excess of sex hormones in the body that are not controlled by the HPG axis. Causes include:
- Exogenous sex steroids (e.g., using oestrogen cream prescribed for their mother)
- Ovarian or testicular tumours
- Congenital adrenal hyperplasia (CAH)
- McCune–Albright syndrome
Assessment
Assessment will involve a detailed history and examination, including height, weight, and Tanner stage. Neurological symptoms, such as headaches and visual changes, can indicate central nervous system pathology.
Investigations include:
- Oestradiol (girls) or testosterone (boys)
- FSH and LH
- 17-Hydroxyprogesterone (raised in CAH)
- X-ray of the wrist to assess bone age
- Pelvic ultrasound in girls to assess the ovaries
- Testicular ultrasound in boys
- MRI brain
Management
Management depends on the underlying cause.
Gonadotropin-dependent precocious puberty may be treated with GnRH agonists (e.g., leuprorelin). The pituitary normally responds to pulsatile stimulation from GnRH. Continuous stimulation by GnRH agonists has the reverse effect, shutting down the production of LH and FSH. These can delay the progression of puberty and help achieve a normal adult height.
Last updated November 2025
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