OG23.1 | Normal and Abnormal Puberty — Summary & Reflection

KEY TAKEAWAYS

Puberty in girls is a coordinated neuroendocrine process initiated by KNDy-neuron-driven GnRH pulsatility, driving LH and FSH release from the anterior pituitary, which stimulates ovarian oestradiol production and the appearance of secondary sex characteristics. The normal sequence is: thelarche (B2, mean 10.5–11 yr) → pubarche (PH2) → peak height velocity (B3) → menarche (B4, mean 12.5–13 yr in India), with 2–2.5 years from B2 to menarche. The Tanner staging system (B1–B5 for breast; PH1–PH5 for pubic hair) provides the standardised clinical tool. Precocious puberty (<8 yr) is central (GnRH-dependent, HPO axis activated — usually idiopathic; brain MRI required) or peripheral (GnRH-independent — McCune-Albright, ovarian tumour, CAH). Delayed puberty: no B2 by age 13, or no menarche by age 15. Classified as hypogonadotropic (CDGP, Kallmann — low FSH/LH), hypergonadotropic (Turner syndrome — high FSH/LH), or eugonadism with outflow obstruction (imperforate hymen, MRKH — normal FSH/LH). Management is cause-specific: GnRH analogues for central precocious puberty; watchful waiting for CDGP; oestrogen replacement for Turner; surgical correction for outflow obstruction.

REFLECT

Think about a clinical scenario where a parent presents with a 7-year-old girl showing signs of early puberty. What would you say to the parent in the first five minutes of the consultation? What examination and investigations would you perform, and how would you decide between reassurance and active treatment? Reflect on how your understanding of the HPO axis and Tanner staging shapes the framework of that consultation.