Pubertal development Flashcards
When should puberty begin in girls
Between 8 and 13 years old
What are the stages of pubertal development in girls
- Breast development (palpable breast bud felt first)
- Pubic hair growth
- Accelerated height growth/spurt (may occur immediately after breast development)
- Menarche (11-15yo)
- Acne, axillary hair, body odour, mood changes
Describe the changes in height during puberty in girls
There is an accelerated height/growth spurt that reaches its maximum early in puberty (~12yo) before menarche commences
The onset of menarche signals that growth is coming to an end ~5cm left (~4% increase)
What are Tanner’s 5 breast development stages
Stage 1 = flat
Stage 2 = buds appear, breast and nipple raised, fat forms, areola enlarges
Stage 3 = breasts grow larger (conical → rounder shape)
Stage 4 = nipple and areola raise above mound; menstruation within 2 years of this stage
Stage 5 = mature adult breast is rounded, and only nipple is raised
How does the uterus change in morphology during puberty
Tubular shape → pear shape
When should puberty begin in boys
Between 9 and 14 years old
What are the stages of pubertal development in boys
- Testicular growth (10-15yo)
- Testicular volume >4ml indicates puberty
- Measure using a orchidometer - Pubic hair growth
- Enlargement of the scrotum
- Increase in length, then breadth of the penis
- Accelerated height growth/spurt
- Acne, axillary hair, body odour, mood changes
When does the accelerated height/growth spurt occur in boys
When the testicular volume is 12-15ml
Typically 18 months after the onset puberty
Maximum height spurt at 14 yo
Later and of greater magnitude than in girls
What are the differences between female and male pubertal development
In girls the height spurt can occur immediately after onset of puberty (breast development) but in boys the height spurt is delayed and can occur 18 months after onset (testicular enlargement
What are some pubertal changes that may occur that seem abnormal but are normal
gynaecomastia may develop in boys
asymmetrical breast growth may occur in girls
diffuse enlargement of the thyroid gland may be seen
What is the most common non-iatrogenic cause of insufficient corticosteroid and mineralocorticoid secretion
Congenital adrenal hyperplasia
What causes congenital adrenal hyperplasia and what can it lead to
Autosomal recessive disorders of adrenal steroid biosynthesis
90% due to 21-hydroxylase deficiency (Required for adrenal steroid synthesis (progesterone and 17-Hydroxyprogesterone → aldosterone and cortisol
Can also occur due to 17a-hydroxylase or 11b-hydroxylase deficiency
Insufficient aldosterone → salt-loss (High K, low Na)
ACTH overproduction → adrenal androgen overproduction
What can 17a-hydroxylase deficiency cause
increased 11-deoxycorticosterone (mineralocorticoid) and decreased androgens, this can lead to Na retention and K+ excretion, thus causing hypertension
What are the clinical features of congenital adrenal hyperplasia
Females: Virilisation of the external genitalia(clitoral hypertrophy, variable fusion of the labia)
Males: Enlarged penis and pigmented scrotum (much harder to see)
At 1-3 weeks: salt-losing adrenal crisis: vomiting, weight loss, hypotonia, circulatory collapse
Older children: Acne, hirsutism, accelerated growth and increased skeletal maturation (due to XS androgens)
Precocious puberty (small testes)
What investigations should be done for congenital adrenal hyperplasia
Bloods
- 17a-hydroxyprogesterone (greatly elevated if 21a-H or 11b-H)
- Testosterone
- ACTH: raised
- LH/FSH: raised
- U&Es (low Na, K high)
- Glucose: hypoglycaemia
- Karyotyping
Note: massive 17a-hydroxyprogesterone is seen in all newborns
What is the management for congenital adrenal hyperplasia
DSD are a medical and social emergency - pending urgent tests they should NOT name or register the birth until all tests are done (do not guess)
MDT: endocrinologist, urologist, geneticists and psychologists
Affected females (uterus and ovaries present) → corrective surgery for external genitalia within first year → definitive correction delayed until puberty
Life-long glucocorticoids (hydrocortisone) (suppresses ACTH levels → suppress testosterone → normal growth and maturation)
Mineralocorticoids (fludrocortisone) + NaCl supplementation PRN if there is a salt loss
± growth hormone
Monitor growth, skeletal maturity, plasma androgens and 17a-hydroxyprogesterone levels
What is the management for a salt losing crisis due to congenital adrenal hyperplasia
IV 0.9% NaCl- 20mL/kg over the first hour then repeated as necessary
IV dextrose
IV Hydrocortisone
What are the complications of congenital adrenal hyperplasia
Reduced female fertility
Short stature (premature epiphyseal closure secondary to steroid therapy
Steroid side effects
Death can occur from adrenal crisis at the time of illness or injury
Some females experience psychosexual problems which may relate to high androgen levels experienced IU prior to diagnosis
Obesity, insulin resistance and hypertension are more common
What is the prognosis for congenital adrenal hyperplasia
Good if diagnosed early
Undiagnosed infants die from salt-losing crisis
Describe 5a-reductase deficiency
XY genotype but cannot convert testosterone → dihydrotestosterone
→ feminisation → ambiguous genitalia with INTERNAL male organs
If left untreated, phenotypically female until puberty → increased testosterone → virilisation (‘penis at twelve’)
Can be assigned to male gender (dihydrotestosterone admin) or female (oestrogen and prophylactic orchidectomy)
Describe androgen insensitivity syndrome
X-linked recessive
Resistance to testosterone → genotypically male (46XY) with female phenotype
S/S: primary amenorrhoea, groin swelling, breast development (testosterone → oestradiol)
Ix: buccal smear or chromosomal analysis
What is the management for androgen insensitivity syndrome
Counselling- raise child as female?
Bilateral orchidectomy (increased risk of testicular cancer due to undescended testes)
Oestrogen therapy
Describe complete androgen resistance
The external genitalia is feminised but neither the female-type nor the male-type internal tracts develop
In the absence of the androgen receptor, the Wolffian ducts will degenerate.
There is also degeneration of the Mullerian ducts due to the normal effect of testicular Mullerian regression factor
