Growth in childhood Flashcards
Factors which can adversely affect growth in height
nutrition, hormone problems, genetic diseases.
How long is the average term baby and how much do they weigh
50cm long and 3.3kg weight
What are centile charts commonly used for
height, weight, head circumference and BMI are the commonest
What must be done to ensure accurate height and weight are measured
The equipment should be accurate and maintained properly
Position the child properly to get an accurate height (read the instructions on the growth chart)
Make sure you get rid of things which interfere with measuring- shoes off, hair out of the way, clothes off to weigh.
Calculate the age and plot correctly on the chart.
Differentiate height velocity vs. what is shown on centile
The centile charts we use are for cumulative height – how tall the child is now, (the total of all the growth they have done up to now, from conception).
Height velocity is how fast a child is growing in cm per year, usually this is calculated over a whole year. Most short children are growing at a completely normal speed.
As well as centiles and height velocity, what else is useful information in assessing child growth
the height of family members- parents and siblings.
How do each of the following affect growth from conception into childhood
- Events before birth
- Think about
- Genetic factors
- Think about
- Events before birth- poor fetal growth, low birth weight, prematurity
- Medical issues in childhood- malnutrition, chronic disease, endocrine problems including growth hormone deficiency
- Genetic factors- the height of the family and any inherited disorders of growth.
- Randomness. Not every child of the same parents will be the same adult height, and tall parents can occasionally have a short child. There are multiple genes which determine adult height, and these are randomly distributed at conception.
What is the fastest phase of growth after birth (incl. puberty etc)
the first 2 years of life
When is there most fluctuation around a centile position for height during childhood, and when is does this normally fix
First 2 years of life. Children can move up and down through the centiles at this phase of growth.
Most children will move to a centile position by 2 to 3 years of age and then continue on this centile position through childhood.
T/f it is common for children to move around centiles throughout childhood. If you suspect a growth problem, how long would you need to monitor the child for
F Normal children grow fast enough to keep on the same centile and movement up or down is unusual.
Monitor for at least a year
When is there fast growth in childhood and what does this depend on
There is a phase of fast growth at puberty- the pubertal growth spurt. The timing of this depends on the age at which the child enters puberty.
When and why does growth stop
The skeleton matures as the child grows, the epiphyses fuse at the end of puberty, and growth stops.
T/f if a child is on the bottom of the centile chart they probably have a problem
F…. If a child is growing fast enough to continue to grow on the same centile they are not likely to have a problem even if they are at the bottom of the centile chart.
What can cause a child to fall behind in height during puberty
Timing of puberty can impact on height- children who are late in developing can fall behind in height.
Outline the key hormonal regulator of growth in children
i. where is it released from
ii. control of its release
iii. which factors mediate its release
Growth hormone (GH) is the most important hormonal factor in growth.
GH secretion is controlled by the hypothalamus, which secretes growth hormone releasing hormone (GHRH) which stimulates secretion and somatostatin which suppresses secretion.
Outline the pattern of GH release
H is released by the pituitary as pulses most of which occur overnight.
How does GH have its growth effects
GH has some growth effect itself and also stimulates the release of IGF1 (insulin like growth factor !).
How does IGF1 travel in the body
IGF 1 circulates bound to a number of binding proteins and stimulates growth in all the tissues of the body
Outline the negative feedback control of growth hormone release
IFG1 negatively feeds back to reduce GH release
And to increase somatostatin release from hypothalamus
Which factors influence the pulsatile secretion of the GH
Nutrition, health, age, puberty, psychological factors, exercise, sleep
Causes of abnormal growth
Poor nutrition, chronic disease, endocrine, genetic factors, psychoigcal distress and neglect
Examples of genetic and endocrine causes of short stautre
Endocrine causes- GH deficiency, thyroid hormone deficiency
Genetic disorders affecting bone growth (eg achondroplasia, Turner syndrome, Down syndrome, PWS).