Childhood growth Flashcards
How should weight be measured in paediatrics?
Class 3 electronic scales
Use metric measurements
Babies should be weighted naked
Children over 2yrs - vest and pants, no footwear, dolls or teddies
How should height/length be measured in paediatrics?
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
How shoud head circumference be measured in babies?
Narrow plastic or disposable paper tape
Remove hats
Measure at widest point
How should centile lines, spaces and numbers be interpreted on a growth chart?
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.
What percentage of weight loss is normal after birth?
Why?
Up to 10%
Due to fluid shifits in first few days
Should regain birth weight before 3w.
What are the key points of plotting data on a growth chart?
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)
How to calculate mid-parental height?
Why is this important?
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
How to calculate adult heigh predictor?
Why is this important?
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.
What is a special circumstance when a different growth chart may be used for a child?
Down syndrome
Normal to have reduced growth - standard charts create unrealistic and unhelpful expectations.
What are the trends in height growth velocity during childhood?
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
What are the preferrred terms for failing to thrive?
Faltering Growth
Weight faltering
What might cause a neonate to loose more than 10% of their birth weight?
How should this be managed?
Dehydration
Underlying illness
Consider - feeding support/observation
Further clinical investigation if concerned
How does the child initial birth weight influence at what point we would be concerned about any weight loss?
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
What are the overweight/obesity thresholds for children?
Severely obese = BMI >99.6th centile
Obese = BMI >95th centile
Overweight = BMI > 85th centile
What are the trends to consider in children that are obese by BMI?
Typically are tall for their age - less of a concerns
If short and obese consider endocrine causes -> hypothyroidism.
What system is used for the staging of puberty in children?
Tanners staging
What is the main driver of puberty in males?
Testosterone
What are the different tanner stages for males?
What are the key changes?
Stage 1 = prepubertal
Stage 5 = post pubertal
Typically lasts 3.2yrs
- Increase in testicular volume >3ml starts puberty
- Lenghtening of penile shaft with darkening of scrotum
- Increase in pubic hair
How does growth relate to puberty in boys?
Delay of ~2yrs from onset of inc testicular volume to maximum growth spurt
Growth spurt occurs at end of puberty ~14yrs
What are the key drives of puberty in girls?
Breast development, growth spurt and uterine lining = oestrogen from ovaries
Pubic and axillary hair - androgens from adrenal gland
What are the key stages of puberty development in girls?
What are the key changes?
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
In boys when is puberty considered delayed?
Absence of testicular development <4ml by age 14yrs
When is puberty considered delayed in girls?
Absence of breast development by age 13 yrs
Primary amenorrhea with normal breast development by age 15yrs.
What are the most common causes of delayed puberty?
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.
What treatment may be used for delayed puberty?
Development with exogenous oestrogen or testosterone but often not required.
Define precocious puberty
Early puberty - before age of average in peers - progression through tanner stages before 95% of peers
Before 8yrs in females
Before 9yrs in males
What is the hormonal axis for puberty?
Hypothalamus - GnRH
Pituitary - anterior - gonadotrophes - LH and FSH
Stimulates the gonads to produce specific steroids/sex hormones.
How do the testes respond to LH and FSH?
LH - acts on leydig cells - convert cholesterol to testosterone
FSH - acts on sertoli cells -> inc sperm production
How does the ovary respond to FSH and LH?
Oestrogen and progesteron
LH - causes theca cells -> androgen
FSH cause granulosa cells to convert this to oestrogen and progesterone
Promotes menses, oocyte maturation
What are the primary sex characteritics?
Gentials and gonads - directly involved in reproduction
What are the secondary sex characteristics?
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
What is gonadotropin-dependent precocious puberty?
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
What are the typical causes of central precious puberty?
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
What is gonatroprin-independent precocious puberty?
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
What are the key features of precocious puberty?
Early sexual maturation
Rapid growth
Advanced bone age
Acne
Behavioural changes
Emotional distress and bullying
How is precocious puberty diagnosed?
Tanner scale - for stage of sexual development
Bloods - FSH, LH
Imaging - structural abnormalities in brain and gonads
What is the treatment for central precocious puberty?
GnRH analogues - bind to GNRH receptor on pituitary gland - negative feedback to reduce FSH and LH
What is the treatment for peripheral precocious puberty?
Dependent on the cause
Typically, surgery to remove tumour/cyst from gonads.
What hormones features is central to delayed puberty?
Hypogonadism
What are the presentation of hypogonadism?
Delayed puberty
Failure to develop functional primary and secondary sexual characteristics
Permanent infertility.
What is primary hypogonadism?
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
What are the blood results/changes in the HPG axis for primary hypogonadism?
Hypergonadotropic hypogonadism
High FSH and high LH
Low oestrogen /testosterone/ progesterone
What is secondary hypogonadism?
Hypogonadotropic hypogonadism -> low LH and low FSH
Can’t produce GnRH or LH/FSH
May be suppressed by prolactin or thyroid hromone
What are some potential causes of hypogonadotropic hypogonadism?
Acquired - radio/chemo, trauma
Congenital - Kallman syndrome, panhypopituitarism
General - chronic illness, excessive exercise, malnutrition, obesity and stress
What is constitutional delay as a cause of delayed puberty?
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.
What treatments may be considered in delayed puberty?
Watch and wait - constitutional
Hormonal therapy - to trigger puberty
Infertility treatments
