Puberty Flashcards
HPO Axis
During Childhood, HPO axis suppressed; GnRH, FSH and LH levels are low; From 8-9yrs, GnRH
pulsatile secretions initially sleep related, extending to throughout the day
• Secretion of FSH and LH from Pituitary glands – Follicular growth and Ovarian
Steroidogenesis;
• Well-defined sequence of stages; Tanner staging B (Breasts), PH (Pubic hair) in Females
Stages of Sexual Maturation
Adrenarche (around 7 years): Development of Zona Reticularis and production of adrenal androgens (DHEA and DHEA-S)
Thelarche: First physical signs of puberty, 2/3 years before Menarche
Gonadarche: Earliest development of genitals
Pubarche: First appearance of pubic hair, linked to androgen production
Menarche: Mean age 12
Causes of Premature Adrenarche
Normal variation
True Central Precocious Puberty
CAH
Androgen-Producing Tumours
Causes of Absent Adrenarche
Addison’s
Hypopituitarism
Precocious Puberty
<8 girls <9 in boys
Either gonadotrophin dependent (Central/True Stages) or Independent due to excess sex steroids outside pituitary gland
Management of Precocious Puberty
• Detection and treatment of underlying pathology – Intracranial MRI, particularly in males
• Reducing the rate of skeletal maturation and Addressing psychological and behavioural issues
• GnRH analogues can delay onset of Menarche in Gonadotrophin-dependent PP
• Sources of Excess Sex Steroids identified; Inhibition of Androgen or Oestrogen production or
action can be used (e.g. Cyproterone, Testolactone, Ketoconazole)
Delayed Puberty
Absence of pubertal development by 14 years in females, 15 years in males
More common in males due to relatively GnRH insensitive testes
Most commonly due to constitutional delay or dieting or excessive physical training
Bone Age would show moderate delay
Hypogonadotropic Hypogonadism
Anorexia, excessive exercise, chronic illness, diabetes, renal failure
Hypergonadotropic Hypogonadism
Gonad does not function despite high FSH – Klinefelter, Turner, Steroid Hormone enzyme deficiencies, Acquired damage (Postoperative, Chemoradiotherapy, Trauma, Autoimmune disease)