Childhood growth

Question 1

How should weight be measured in paediatrics?

Answer 1

Class 3 electronic scales
Use metric measurements
Babies should be weighted naked
Children over 2yrs - vest and pants, no footwear, dolls or teddies

Question 2

How should height/length be measured in paediatrics?

Answer 2

Under 2yrs - length board or mat with foot wear and nappy removed
Over 2 yrs - rigid upright T piece or stadiometer - heels bottom and back should touch the apparatus, Frankfurt plan, measure on expiration

Question 3

How shoud head circumference be measured in babies?

Answer 3

Narrow plastic or disposable paper tape
Remove hats
Measure at widest point

Question 4

How should centile lines, spaces and numbers be interpreted on a growth chart?

Answer 4

50th = median
2nd and 98th equal 2SD above and below the median
Each centile space is 2/3 of a standard deviation
Each number of the line describes the percentage expected to be below that line.

Question 5

What percentage of weight loss is normal after birth?
Why?

Answer 5

Up to 10%
Due to fluid shifits in first few days
Should regain birth weight before 3w.

Question 6

What are the key points of plotting data on a growth chart?

Answer 6

Record measurements and date ligibly in black ink
Plot in pencil - use dots (NOT crosses), do not connect the dots
Correct for babies born 37w or prior until 2yrs -> allows for catch-up growth. (correct by drawing back by the number of weeks born prior to 37)

Question 7

How to calculate mid-parental height?
Why is this important?

Answer 7

Plot maternal and paternal height on chart - join up
Crosses percentile line = percentile expected for child
Check if current growth for child is on this percentile
Typically 90% are within two centile spaces of mid-parental centile

Question 8

How to calculate adult heigh predictor?
Why is this important?

Answer 8

Plot the most recent height centile on the reveltn centile line and read off predicted adult height
Can compared to mid-parental centile to ensure child is achieving their growth potential.

Question 9

What is a special circumstance when a different growth chart may be used for a child?

Answer 9

Down syndrome
Normal to have reduced growth - standard charts create unrealistic and unhelpful expectations.

Question 10

What are the trends in height growth velocity during childhood?

Answer 10

Greatest velocity in infancy
Velocity decreases rapidly into childhood till 3yrs
Then decreases slowly
Velocity of growths peaks again during puberty - typically to a lesser extent and earlier (age 12yrs) in girls and greater Ager 14yrs) in boys
Then velocity decreases to stable height

Question 11

What are the preferrred terms for failing to thrive?

Answer 11

Faltering Growth
Weight faltering

Question 12

What might cause a neonate to loose more than 10% of their birth weight?
How should this be managed?

Answer 12

Dehydration
Underlying illness

Consider - feeding support/observation
Further clinical investigation if concerned

Question 13

How does the child initial birth weight influence at what point we would be concerned about any weight loss?

Answer 13

All birth weight -> if below 2nd centile for age
Below 9th centile -> a fall across 1 or more centile spaces
9th to 91st centile -> fall across 2 or more centile spaces
above 91st centile -> fall across 3 or more centile spaces

Question 14

What are the overweight/obesity thresholds for children?

Answer 14

Severely obese = BMI >99.6th centile
Obese = BMI >95th centile
Overweight = BMI > 85th centile

Question 15

What are the trends to consider in children that are obese by BMI?

Answer 15

Typically are tall for their age - less of a concerns
If short and obese consider endocrine causes -> hypothyroidism.

Question 16

What system is used for the staging of puberty in children?

Answer 16

Tanners staging

Question 17

What is the main driver of puberty in males?

Answer 17

Testosterone

Question 18

What are the different tanner stages for males?
What are the key changes?

Answer 18

Stage 1 = prepubertal
Stage 5 = post pubertal
Typically lasts 3.2yrs

1. Increase in testicular volume >3ml starts puberty
2. Lenghtening of penile shaft with darkening of scrotum
3. Increase in pubic hair

Question 19

How does growth relate to puberty in boys?

Answer 19

Delay of ~2yrs from onset of inc testicular volume to maximum growth spurt
Growth spurt occurs at end of puberty ~14yrs

Question 20

What are the key drives of puberty in girls?

Answer 20

Breast development, growth spurt and uterine lining = oestrogen from ovaries
Pubic and axillary hair - androgens from adrenal gland

Question 21

What are the key stages of puberty development in girls?
What are the key changes?

Answer 21

1 = prepuberty
5 = post puberty

1 - first sign is breast development (thelarche at 9/10yrs)
2 - growth spurt towards start of puberty (10yrs)
3. Takes around 2.4yrs

Question 22

In boys when is puberty considered delayed?

Answer 22

Absence of testicular development <4ml by age 14yrs

Question 23

When is puberty considered delayed in girls?

Answer 23

Absence of breast development by age 13 yrs
Primary amenorrhea with normal breast development by age 15yrs.

Question 24

What are the most common causes of delayed puberty?

Answer 24

Typically is a constitutional delay - more common in boys, runs in families, not a medical conditions, later catch up.
Central - problem with the HPA axis
Peripheral - problem with specific sex orientated.

Question 25

What treatment may be used for delayed puberty?

Answer 25

Development with exogenous oestrogen or testosterone but often not required.

Question 26

Define precocious puberty

Answer 26

Early puberty - before age of average in peers - progression through tanner stages before 95% of peers Before 8yrs in females Before 9yrs in males

Question 27

What is the hormonal axis for puberty?

Answer 27

Hypothalamus - GnRH Pituitary - anterior - gonadotrophes - LH and FSH Stimulates the gonads to produce specific steroids/sex hormones.

Question 28

How do the testes respond to LH and FSH?

Answer 28

LH - acts on leydig cells - convert cholesterol to testosterone FSH - acts on sertoli cells -> inc sperm production

Question 29

How does the ovary respond to FSH and LH?

Answer 29

Oestrogen and progesteron LH - causes theca cells -> androgen FSH cause granulosa cells to convert this to oestrogen and progesterone Promotes menses, oocyte maturation

Question 30

What are the primary sex characteritics?

Answer 30

Gentials and gonads - directly involved in reproduction

Question 31

What are the secondary sex characteristics?

Answer 31

Features related by puberty and sexual development (distinguish males from females) but are not directly needed for reproduction E.g pubic hair and breast development

Question 32

What is gonadotropin-dependent precocious puberty?

Answer 32

Central precocious puberty - due to dysfunction of hypothalamus or pituitary gland Early maturation of the HPG axis Early FSH and LH release leading to increase sex hormones

Question 33

What are the typical causes of central precious puberty?

Answer 33

Idiopathic (influenced by weight and parental puberty age) Tumour in H/P secreting - GnRH or hCG (similar to LH) Infection/cyst Radiation damage to brain - impair negative feedback mechanism

Question 34

What is gonatroprin-independent precocious puberty?

Answer 34

Peripheral cause Typically ovaries or testes overporudcing sex hormones May be due to cyst, tumour, genetic conditions, dysfunction of thyroid/adrenal glands, exogenous from creams/meds

Question 35

What are the key features of precocious puberty?

Answer 35

Early sexual maturation Rapid growth Advanced bone age Acne Behavioural changes Emotional distress and bullying

Question 36

How is precocious puberty diagnosed?

Answer 36

Tanner scale - for stage of sexual development Bloods - FSH, LH Imaging - structural abnormalities in brain and gonads

Question 37

What is the treatment for central precocious puberty?

Answer 37

GnRH analogues - bind to GNRH receptor on pituitary gland - negative feedback to reduce FSH and LH

Question 38

What is the treatment for peripheral precocious puberty?

Answer 38

Dependent on the cause Typically, surgery to remove tumour/cyst from gonads.

Question 39

What hormones features is central to delayed puberty?

Answer 39

Hypogonadism

Question 40

What are the presentation of hypogonadism?

Answer 40

Delayed puberty Failure to develop functional primary and secondary sexual characteristics Permanent infertility.

Question 41

What is primary hypogonadism?

Answer 41

Failure of the gonads to produce sex hormones Either failure in synthetic process or failure to respond to FSH and LH This can be acquired - radio/chemo or trauma Or congential - Turner syndrome or Klinefelter

Question 42

What are the blood results/changes in the HPG axis for primary hypogonadism?

Answer 42

Hypergonadotropic hypogonadism High FSH and high LH Low oestrogen /testosterone/ progesterone

Question 43

What is secondary hypogonadism?

Answer 43

Hypogonadotropic hypogonadism -> low LH and low FSH Can't produce GnRH or LH/FSH May be suppressed by prolactin or thyroid hromone

Question 44

What are some potential causes of hypogonadotropic hypogonadism?

Answer 44

Acquired - radio/chemo, trauma Congenital - Kallman syndrome, panhypopituitarism General - chronic illness, excessive exercise, malnutrition, obesity and stress

Question 45

What is constitutional delay as a cause of delayed puberty?

Answer 45

Temporary delay in puberty - low GnRH No pathological - does not cause infertility Catch up later -> puberty progresses normally at a later age Tends to have a genetic components and run in families.

Question 46

What treatments may be considered in delayed puberty?

Answer 46

Watch and wait - constitutional Hormonal therapy - to trigger puberty Infertility treatments