Growth and Puberty

Question 1

What are the four phases of normal human growth?

Answer 1

Fetal, the infantile phase, childhood phase and the pubertal growth spurt

Question 2

What is the size at birth determined by?

Answer 2

The size of the mother and by placental nutrient supply

Question 3

What is growth during the infantile phase determined by?

Answer 3

Adequate nutrition, good health and normal thyroid function

Question 4

What is failure to thrive?

Answer 4

Inadequate rate of weight gain during the infantile phase

Question 5

What is growth during the childhood phase largely determined by?

Answer 5

Pituitary growth hormone secretion acting to produce IGF-1 at the epiphyses is the main determinant of a child’s rate of growth, provided there is adequate nutrition and good health.

Question 6

What can negatively affect growth during the childhood phase?

Answer 6

Thyroid hormone, vitamin D and steroids. Profound chronic unhappiness can decrease GH secretion and accounts for psychosocial short stature

Question 7

What causes the pubertal growth spurt?

Answer 7

Sex hormones, mainly testosterone and oestradiol, cause the back to lengthen and boost GH secretion

Question 8

What stops growth?

Answer 8

Testosterone and oestradiol cause fusion of the epiphyseal growth places and a cessation of growth, so patients that suffer from early puberty may be short

Question 9

How can growth be measured?

Answer 9

Weight, height/length (difficult in young children) and head circumference

Question 10

What are the female features of puberty and when do they happen?

Answer 10

Breast development - 8.5-12.5 years
Pubic hair growth and growth spurt - immediately after breast development
Menarche - 2.5 years after the start of puberty

Question 11

What are the male features of puberty and when do they happen?

Answer 11

Testicular enlargement - first sign of puberty
Pubic hair growth - between 10 and 14 years of age
Growth spurt - 18 months after testicular enlargement

Question 12

What are features of puberty that are present in both sexes?

Answer 12

Acne, axillary hair, body odour and mood changes

Question 13

How can abnormally early or late puberty by assessed?

Answer 13

Bone age measurement from X-ray

Females: pelvic US to assess uterine size and endometrial thickness

Question 14

How is short stature defined

Answer 14

Height below the second centile or 0.4th centile

Question 15

How do you measure height velocity and what is abnormal?

Answer 15

Two accurate measurements at least 6 months but preferably a year apart. A height velocity persistently below the 25th centile is abnormal and that child will be short.

Question 16

How do you calculate a genetic target centile for growth?

Answer 16

The mean of the fathers and mothers height with 7cm added for the mid-parental target of a boy, and 7cm subtracted for a girl

Question 17

What is the link between IUGR/extreme prematurity and growth?

Answer 17

1/3 of children born with severe IUGR or who were born extremely premature remain short. Growth hormone treatment may be indicated

Question 18

What is constitutional delay of growth and puberty?

Answer 18

These children have delayed puberty, which is often familial, usually having occurred in the parent of the same sex

Question 19

Is constitutional delay of growth and puberty more common in males or females?

Answer 19

Males

Question 20

Which endocrine conditions can cause short stature?

Answer 20

Hypothyroidism, GH deficiency, IGF-1 deficiency and steroid excess are uncommon causes of short stature. They are associated with overweight children

Question 21

Can you treat short stature due to hypothyroidism?

Answer 21

Yes, catch up growth rapidly occurs but often with a rapid entry into puberty that can limit final height

Question 22

What is the main cause of hypothyroidism in children?

Answer 22

Autoimmune thyroiditis

Question 23

Can you treat short stature due to corticosteroid therapy?

Answer 23

Normalisation of body shape and height occurs on withdrawal of treatment of the underlying steroid excess. Cushing syndrome during puberty can result in permanent loss of height

Question 24

What may be short stature due to inadequate nutrition be due to?

Answer 24

Insufficient food, restricted diets or poor appetite associated with chronic illness, or from the increased nutritional requirement from a raised metabolic rate.

Question 25

Which chronic diseases may present with short stature?

Answer 25

Coeliac disease Crohn's disease Chronic renal failure

Question 26

What chromosomal disorders can cause short stature?

Answer 26

Down syndrome (usually already diagnosed), but Turner (most common out of undiagnosed), Noonan and Russell-Silver syndromes may present with short stature

Question 27

How would you treat short stature caused by growth hormone deficiency?

Answer 27

Subcutaneous injection of biosynthetic growth hormone

Question 28

What are the causes of tall stature?

Answer 28

Familial, obesity, hyperthyroidism, excess sex steroids (precocious puberty), congenital adrenal hyperplasia, gigantism, Marfan syndrome, Klinefelter syndrome.

Question 29

How does obesity affect growth?

Answer 29

Obesity in childhood 'fuels' early growth and may result in tall stature, however, because puberty is often somewhat earlier than average, so it does not always increase final height

Question 30

When does the posterior and anterior fontanelle close?

Answer 30

Posterior - 8 weeks | Anterior - 12-18 months

Question 31

What are the causes of microcephaly (small head)?

Answer 31

Familial Autosomal recessive condition Congenital infection Acquired after an insult to the developing brain (hypoxia/meningitis/hypoglycaemia)

Question 32

What are the causes of macrocephaly (big head)?

Answer 32

``` Tall stature Familial Raised ICP (make sure to exclude this) Hydrocephalus Chronic subdural haematoma Cerebral tumour Neurofibromatosis ```

Question 33

What are the causes of an asymmetric head?

Answer 33

Imbalance of growth rate at the coronal, sagittal or lambdoid sutures, although the head circumference increases normally. Sometimes it's just because the baby sleeps on it's back and will improve on mobility

Question 34

Should you investigate precocious puberty different in boys and girls?

Answer 34

In girls it is usually due to the premature onset of normal puberty. In boys it more often has an organic cause (intracranial tumours)

Question 35

How do you manage precocious puberty?

Answer 35

Treat cause, address psychological/behavioural difficulties associated with early puberty, if necessary GnRH analogues

Question 36

What is premature breast development ?

Answer 36

Affects females between 6 months and 2 years old. Axillary and pubic hair and growth spurt is absent. It is non-progressive and self-limiting

Question 37

When does premature pubarche occur (pubic hair development)?

Answer 37

Before 8 years old in girls and before 9 years old in boys

Question 38

In what ethnicity is premature pubarche more common?

Answer 38

Asian and afro-Caribbean children

Question 39

Does premature pubarche need treating?

Answer 39

No, it is usually self-limiting, but if an aggressive form it may be caused by an adrenal tumour so rule that out

Question 40

What condition is at an increased risk after premature pubarche?

Answer 40

PCOS

Question 41

Is delayed puberty more common in boys or girls?

Answer 41

Boys, mostly due to constitutional delay in growth and puberty.

Question 42

What are the symptoms of delayed puberty?

Answer 42

Short during childhood, with a delay in sexual maturation and have delayed skeletal maturity on bone age. The legs will be long compared to the back. Target height will eventually be reached as they growth for longer

Question 43

What disorders would you investigate in delayed puberty in boys and girls?

Answer 43

Boys - chronic systemic disorders | Girls - karyotyping to identify Turner's syndrome, thyroid and sex steroid hormones.

Question 44

How would you treat delayed puberty?

Answer 44

Treat underlying pathology. Reassure that puberty will occur, then treatment is not often needed. If it is, steroids or sex hormones can be given

Question 45

What may be the cause of sexual differentiation (uncertainty about the infants sex)?

Answer 45

Excessive androgens producing virilisation in a female Inadequate androgen action, producing undervirilisation in a male Gonadotrophin insufficiency (Prader-Willi syndrome) Ovotesticular disorder of sex development (both XX and XY containing cells present)

Question 46

What can cause congenital adrenal hyperplasia?

Answer 46

A number of autosomal recessive disorders of adrenal steroid biosynthesis result in congenital adrenal hyperplasia, it is more common in consanguineous relationships

Question 47

How may congenital adrenal hyperplasia present at birth?

Answer 47

Virilisation of the external genitalia in female infants, with clitoral hypertrophy and variable fusion of the labia. In the infant male, the penis may be enlarged and the scrotum pigmented.

Question 48

How may congenital adrenal hyperplasia present in the first few weeks after birth?

Answer 48

A salt-losing adrenal crisis may occur at 1-3 weeks of age, presenting with vomiting and weight loss, floppiness and circulatory collapse

Question 49

What percentage of males are salt-losing in congenital adrenal hyperplasia

Answer 49

80% are salt-losing | 20% are non-salt-losing

Question 50

How may congenital adrenal hyperplasia present in later life?

Answer 50

Both male and female non-losers may present with tall stature, a muscular build, adult body odour, pubic hair and acne from excess androgen production, leading to precocious pubarche

Question 51

How is congenital adrenal hyperplasia diagnosed?

Answer 51

Markedly raised levels of the metabolic precursor 17 alpha-hydroxyprogesterone in the blood. In salt-losers: low plasma sodium, high plasma potassiu, metabolic acidosis, hypoglycaemia

Question 52

How is congenital adrenal hyperplasia managed?

Answer 52

Affected females will sometimes require corrective surgery to their external genitalia within the first year, definitely before sexual intercourse is attempted. Lifelong glucocorticoids to suppress ACTH levels. Monitoring of growth, skeletal maturity and plasma androgens

Question 53

How would you treat males in a salt-losing crisis?

Answer 53

Saline, dextrose and IV hydrocortisone