Child Growth and Development Flashcards
Why do we measure growth?
poor growth in infancy is associated with high childhood morbidity and mortality.
- Growth is best indicator of health
- Demonstration of normality of growth by age and stage of puberty
- Identify disorders of growth
- Assess obesity
What is a centile chart?
Centile charts are a way of expressing variation within the population. We measure:
- head circumference: the head can enlarge if there is excess fluid, or not grow if there is death
- weight
- height/length
- leg length
- BMI
- growth velocity
- specialist charts
Centiles are not a “normal range”
- you can be taller or shorter than the centile lines and still be completely normal and healthy. E.g is you have very tall parents, you would have genes for tall height.
Most children set out on a centile by about 2 years and grow on the same centile during childhood - see diagram of the centile graph
Pattern of growth is more important than position on the centiles.
- Most very tall or very short people are healthy and grow in a normal pattern.
A child who falls significantly in their centile position is not growing normally, whatever their height.
Describe the height in terms of a centile chart
It is cumulative slide 6
Lines plateau because you stop growing at the end of puberty
What do height centiles show?
They express how many people in the population are at a particular height at any age
See diagram
Describe height velocity
Expressed in cm/year
[Height velocity calculation:
height now - height last visit]/[age now - age last visit]
Interval approximately 6 months
See diagram - Massive growth in utero. Puberty causes massive growth acceleration (caused by GH) Then your sex steroid comes and your growth plates fuse
What is the endocrine control of growth?
- GH-IGF-1 axis regulator of human linear growth
- GH single chain polypeptide; meaning must be given i.v
- Somatotroph cells of anterior pituitary
- Pulsatile secretion
1) Influenced by nutrition, sleep, exercise, stress.
See slide 13 for a diagram. GH is stimulated to be released from the anterior pituitary by GHRH. Somatostatin inhibits the secretion of GH. GH then acts on GH receptors which stimulates the production of IGF-1.
Both GH and IGF-1 have their own actions. IGF-1 binds to IGF-1 receptors on growth plates causing you to grow.
Describe the antenatal phase of growth
Antenatal - the most rapid phase of growth.
Maternal health and the placenta are important factors.
Define infancy
- Rapid initial growth ~23-25 cm in first year
- Continuation of fetal growth
- Nutritionally dependant
- 9-12 months influence of GH starts to take over. You need GH from 9-12 months onwards to grow normally
Define childhood
- Post infancy to adolescence
- Growth rates in boys and girls similar
- GH/IGF-1 axis drives growth
- Nutrition less impact
Switch between infancy and childhood
What affects the speed of growth in height?
Look at height velocity chart for girls and boys. Girls get puberty before boys. Girls also get their growth spurt before boys while boys get their growth spurt towards the end of puberty.
- Puberty, sex steroids and GH stimulate the pubertal growth spurt. The sex steroids accelerate growth and cause the fusion of the growth plates.
Describe the growth of bone in children?
The bones mature and epiphyses fuse at the end of puberty.
The final part of growth occurs in the spine and the final epiphyses to fuse are in the pelvis.
What are the causes of short stature?
- Genetic
- Pubertal and growth delay
- IUGR(interuterine growth retardation - when you’re born tiny and never really grow and catch up to the normal)/SGA
- Dysmorphic syndromes (Downs)
- Endocrine disorders (hypothyroidism)
- Chronic paediatric disease (If you have lots of inflammatory cytokines this triggers a pathway that blocks the effect of GH)
- Psychosocial depravation (neglect = causes changes in GH pulsitility)
What is the cause of most short children?
Normal growth pattern
Most short children have a normal growth pattern and do not have any medical problem.
They are usually the children of short parents
Describe children with intrauterine growth restriction?
Not all children with intrauterine growth restriction catch up completely. Growth will be normal in childhood but they have “lost” some height in the antenatal period.
How do you examine a short child? What questions do you ask?
Birth history and weight
Parental heights
Medical history
Previous measurements
full blood count, CRP, serum iron - checking if they are anaemic.
Liver and kidney function - to see if they are ill
thyroid function
coeliac screen
IGF 1
bone age
MRI pituitary
Pituitary function testing