Puberty

Question 1

Puberty - background

Answer 1

1. Puberty is the time at which a child becomes an adult physically, sexually and psychologically, under the influence of sex hormones
2. Girls = onset usually varies between 9 and 14y
3. Initiation of puberty associated with an increase in gonadotrophin-releasing hormone (GnRH) in the hypothalamus, stimulating the hypothalamic-pituitary axis
4. GnRH stimulates the anterior pituitary to secrete FSH and LH
5. FSH causes the ovaries to release estradiol -> stimulates breast growth. The ovaries and adrenal glands secrete androgens that instigate the development of sexual hair growth (LH stimulates testosterone production). Maturation of the hypothalamus -> growth hormone -> growth spurt

Question 2

Stages of puberty

Answer 2

5 stages:

1. Growth spurt
2. Thelarche (breast development)
3. Adrenarche (pubic hair development)
4. Menarche (the onset of menstruation)
5. Urogenital changes

Question 3

Delayed puberty - definition

Answer 3

Absence of secondary sexual characteristics by age 13, and absence of menstruation by age 15 in the presence of secondary sexual characteristics

Question 4

Delayed puberty - causes

Answer 4

1. Constitutional delay
2. Chronic systemic disease, weight loss/excessive exercise, anorexia nervosa
3. Hypothalamo-pituitary disorders (hypogonadotrophic hypogonadism,
   pituitary tumours including prolactinomas, CAH, primary hypothyroidism [why?], Cushing’s disease [why?])
4. Ovarian failure (Turner syndrome, Swyer syndrome, iatrogenic)
5. Mullerian agenesis, vaginal septum, imperforate hymen

Question 5

Delayed puberty - hx

Answer 5

1. Chronic illnesses
2. Anorexia
3. Excessive exercise
4. Family history of similar problems
5. Symptoms of underlying causes (e.g. Cushing’s syndrome, pituitary tumours…)

Question 6

Delayed puberty - ex

Answer 6

1. Height and weight
2. Pubertal (Tanner) stage
3. Visual fields
4. Hirsutism (why?)
5. Any stigmata of chronic disease, signs of Turner syndrome, hypothyroidism, galactorrhoea, gonadal dysgenesis

Question 7

Delayed puberty - ix

Answer 7

1. FH/FSH, testosterone, TFTs, and prolactin
2. Karyotype
3. Pelvic ultrasound or MRI if Müllerian anomaly suspected
4. Cranial MRI if prolactin >1500mU/L
5. X-ray for bone age

Rarely: examination under anaesthesia or diagnostic laparoscopy

Question 8

Delayed puberty - mx

Answer 8

1. Referral to appropriate specialist. Input may be required from endocrinologists, psychologists and neurosurgeons. Tx dependent on dx
2. Physiological delay = reassurance that the anticipated development will occur
3. Removal or correction of a primary etiology when detected - e.g. tx hypothyroidism, hormone therapy in hypogonadism (+ long-term tx with estrogen replacement to prevent osteoporosis)
4. Tx to induce puberty in girls who have not developed secondary sexual characteristics = initiate with very small doses of ethinylestradiol 1mcg daily for 6mo, increasing to 2, 5, 10 and 20mcg over 6-monthly intervals. Need referral to specialist. Can use low-dose 17 beta-estradiol patch can be used as an alternative. Progestogen should be added to the unopposed estrogen regime after 2y or when vaginal bleeding occurs
5. OCP (combination of estrogen and progestogen) has traditionally been the drug of choice for long-term tx. HRT preparations - greater choice now available. Girls on long-term estrogen supplementation should have their bone density checked at regular intervals

Question 9

Precocious puberty - definition

Answer 9

When pubertal changes occur before 6y and/or menarche before 8y -> requires investigation as to causation

Question 10

Precocious puberty - causes (2)

Answer 10

1. Central precocious puberty (gonadotrophin-dependentl) (3)
   - Idiopathic (75%)
   - CNS causes
   - Other (e.g. cerebral palsy)
2. Peripheral precocious puberty (gonadotrophin-independent) (5)
   - Primary hypothyroidism
   - Hormone-secreting ovarian cysts
   - McCune-Albright syndrome (polyostotic fibrous dysplasia) - mutation in G protein coupled receptor causing unchecked autonomous sex steroid activity in tissues
   - Late onset CAH (premature pubic hair)
   - Ectopic hormone production

Question 11

Precocious puberty - hx and ex

Answer 11

Enquire about:

1. Cerebral palsy
2. Previous dx of intracranial SOL
3. Exposure to sex steroids

Examination

4. Document Tanner stage
5. …?

Question 12

Precocious puberty - ix

Answer 12

1. Bone age (X-ray wrist).
2. Cranial MRI.
3. Pelvic USS.
4. FSH/LH/oestradiol/17-hydroxyprogesterone, TFTs
5. Gonadotrophin-releasing hormone (GnRH) stimulation test.

Question 13

Precocious puberty - mx

Answer 13

1. Identify etiology and tx reversible causes (e.g. surgery for cranial tumours)
2. Attempt to maximise final height (bc high levels of estrogen will close the epiphyses in long bones and cause short stature). Generally achieved with GnRH agonist therapy, and exogenous growth hormone may be indicated
3. GnRH analogues can also cause breast, uterine and ovarian regression (so that the child resembles their peers). No long-term effect on bone mineral density in this age group; safe to use for 4-5y
4. Girls with precocious puberty more likely to suffer from psychological trauma and sexual abuse -> may need support and counselling
5. May need early contraceptive advice