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ObjectivesÂ
At the end of this session the student should be able to
- Define growth
- Describe the phases of growth and the influences for each
- List the parameters used to measure growth
- Describe the instruments used to measure growth
- Use appropriate growth charts to interpret growth data
- --------------------------Growth vs development
- Growth means an increase in size.
- Development means maturation of function.
- Although these are two distinct processes, they are also interrelated.
GROWTH
Growth (increase in size) is the result of two processes
1.Hyperplasia – increase in the number of cells
2.Hypertrophy – increase in the size of cells
These cells will undergo a process of differentiation to grow in to various structures you find in the body.
- ------------------------------
- A child's growth can be divided into four periods:
1Fetal (from conception to birth)
2Infantile (from birth to 1 year)
3Childhood (from 1 year till puberty)
4Pubertal (during puberty)
----------------------------------------
Fetal growth
- Period from conception to birth
- Fastest period of growth
- Accounts for 30% of eventual height
- Can be assessed by ultrasound scan
- Depend on size of the mother & placental nutrient supply
- Severe IUGR & extreme prematurity can lead to permanent short stature
- --------------------------------Infantile growth
- Growth during infancy
- Dependent on
- adequate nutrition
- good health
- normal thyroid function
- Rapid but decelerating growth rate
- Accounts for 15% of eventual height
- At the end child changed from their fetal length (largely determined by the uterine environment) to their genetically determined height
- Inadequate weight gain during this period is called "Failure to Thrive"
- ---------------------------------
Childhood growth
- A slow, steady, prolonged period of growth
- Contributes to 40% of final height
- Mainly depend on growth hormone (GH) secretion
- GH lead to secretion of IGF 1 at the epiphysis which is the main determinant of growth
- For optimum growth there should be adequate nutrition & good health
- Other factors which affect cartilage cell division & bone formation
- Thyroid hormone
- vitamin D
- steroids
- Profound chronic unhappiness can reduce GH secretion and lead to psycho-social short stature
- --------------------------------Pubertal growth spurt
- Depend on sex hormones, mainly testosterone and oestradiol.
- The increase in sex steroids boost GH secretion
- There is lengthening of the trunk
- Adds 15% to final height.
- The onset of puberty is related to the nutritional status of the individual, particularly the body fat stores.
- When the fat stores are adequate, it denotes that the body is able to carryout reproductive functions and nourish an offspring
- The signal for this is via Leptin
- These sex steroids also cause fusion of the epiphyseal growth plates and cessation of growth
- If puberty is early (more common in girls) the final height is reduced due to early epiphyseal fusion
- During this phase the the size, shape and the body composition is changed
–Muscle and fat mass
–Bone mineral density
–Total body water
–Haemoglobin concentration
- -----------------------------------------------------Growth curves of different tissues
- Different tissues of the body grow at different phases
- Brain and lymphoid tissues grow most rapidly in childhood
- Reproductive organs grow later
 --------------------------------------
- “Catch up” and “Catch down” growth
A change in the growth trajectory of a baby from its place at birth to a different point in the growth curve
- Usually happens during the 1st 1-2 months of life
Catch up growth
A child born with a low birth weight due to extrinsic factors (e.g. maternal PIH) will have accelerated growth to reach their full potential and then settle to their inherent growth line
Catch down growth
A child born with a weight over and above the growth potential will not be able to sustain this growth and will drop to a lower growth trajectory
Assessment of Growth
Intro
- Growth monitoring is an essential part of paediatric health surveillance
- Since growth is a continuous process, serial measurements are needed for assessment
- Assessment of growth is not only measuring growth parameters, but also interpreting and taking action
Steps in growth monitoring
1.Measurement of growth parameters
2.Recording
3.Interpretation
4.Taking necessary action
Measurement of growth parameters
- The 1st step in any growth and nutritional assessment programme
- Important to take accurate measurements
- Using standardised methods of measurements
- Using proper equipment which have to be calibrated regularly
- -----------------------Growth parameters
- Length or height
- Weight
- Occipito-frontal circumference
- Mid upper arm circumference
- Skin fold thickness
- Waist circumference
- ------------------------------Weight:
- Measurement done with minimum light clothing and without footwear
- Two types of weighing scales
–Beam balance
e.g. Triple beam balance
–Spring balance
e.g. Cradle balance, bathroom scale
----------------------------------------
Measurement of length/height
- Length is measured in children who cannot stand (< 2 years)
- Height is measured in those who can stand
(> 2years)
- Length is measured using an infantometer
- Height is measured using a stadiometer.
Sitting height / standing height
- Upper segment = sitting height
- Lower segment = standing height – sitting height
Body proportions
- Body proportions change from birth to adulthood
- At birth the head is large and the length of trunk is relatively long
- As the age increases this proportions change
- In an adult the limbs are longer than the trunk
-------------------------------------------
OFC
- Measured in children under 2 years of age.
- OFC at birth > chest circumference.
- OFC at 1 year = chest circumference.
- OFC increases rapidly and gains about 10-12cm by the end of infancy.
"Rule of thumb”
2cm/month — in 1st 3months
1cm/month — in 2nd 3 months
0.5cm/month — in 6-12 months
or
35cm – at birth
+4cm in first 4 months - 39cm by 3 months
+3cm in the next 4 months - 42cm by 6 months
+2cm in the next 3 months - 44cm by 9 months
+1cm in the last 3 months - 45cm by 12 months
-------------------------------------------------------
Growth charts
- Once anthropometric measurements are made they have to be interpreted to see whether they are within the normal range for age and sex
This is done by comparing with population based growth charts/standards
- There are two types of growth charts
1. Distance charts
shows the growth of that parameter since birth
2. Velocity charts
shows the growth of that parameter over a unit time
How are growth charts compiled?
- By using cross sectional or longitudinal data of large number of normal children
- For a particular parameter all data are arranged in rank order and the middle figure which divides the data set into 2 equal halves identified – this is the median line or 50th centile line
- On either side of the median line further centile lines are drawn – 3rd, 10th, 90th 97th etc
- Each line indicates the percentage of children whose growth parameter value would fall below that particular line compare to the population.
- Some charts use SD scores and lines representing -3SD, -2SD, -1SD, median, +1SD, +2SD, +3SD
Which chart to use?
- Most of the reference charts available are those made in the developed countries.
- Ideal is to use national reference charts.
- However, in most of the developing countries such charts are not available.
- In that situation use of WHO growth references is acceptable.
•CDC / NCHS growth charts (US)
http://www.cdc.gov/growthcharts
- British growth charts
- WHO growth charts
The growth charts used in the current Sri Lankan CHDR are the WHO growth charts.
Interpretation of growth measurements
- A single reading is not adequate to comment on growth
- It is important to have a series of readings plotted on a chart before commenting on an anthropometric parameter
- Always compare different parameters before commenting e.g. weight, height, OFC
-------------------------------------Summary
- Growth is a continuous process
- Growth monitoring is an integral part of any child health service
- Use of correct equipment and standardised techniques are essential
- Serial measurements are more important than single measures
- Interpretation of growth patterns need other anthropometric data
- The pattern of growth over time is more important than the position in the growth chart
- ---------------------------
Assessment of Growth
Intro
- Growth monitoring is an essential part of paediatric health surveillance
- Since growth is a continuous process, serial measurements are needed for assessment
- Assessment of growth is not only measuring growth parameters, but also interpreting and taking action
Steps in growth monitoring
1.Measurement of growth parameters
2.Recording
3.Interpretation
4.Taking necessary action
Measurement of growth parameters
- The 1st step in any growth and nutritional assessment programme
- Important to take accurate measurements
- Using standardised methods of measurements
- Using proper equipment which have to be calibrated regularly
- -----------------------Growth parameters
- Length or height
- Weight
- Occipito-frontal circumference
- Mid upper arm circumference
- Skin fold thickness
- Waist circumference
- ------------------------------Weight:
- Measurement done with minimum light clothing and without footwear
- Two types of weighing scales
–Beam balance
e.g. Triple beam balance
–Spring balance
e.g. Cradle balance, bathroom scale
----------------------------------------
Measurement of length/height
- Length is measured in children who cannot stand (< 2 years)
- Height is measured in those who can stand
(> 2years)
- Length is measured using an infantometer
- Height is measured using a stadiometer.
Sitting height / standing height
- Upper segment = sitting height
- Lower segment = standing height – sitting height
Body proportions
- Body proportions change from birth to adulthood
- At birth the head is large and the length of trunk is relatively long
- As the age increases this proportions change
- In an adult the limbs are longer than the trunk
-------------------------------------------
OFC
- Measured in children under 2 years of age.
- OFC at birth > chest circumference.
- OFC at 1 year = chest circumference.
- OFC increases rapidly and gains about 10-12cm by the end of infancy.
"Rule of thumb”
2cm/month — in 1st 3months
1cm/month — in 2nd 3 months
0.5cm/month — in 6-12 months
or
35cm – at birth
+4cm in first 4 months - 39cm by 3 months
+3cm in the next 4 months - 42cm by 6 months
+2cm in the next 3 months - 44cm by 9 months
+1cm in the last 3 months - 45cm by 12 months
-------------------------------------------------------
Growth charts
- Once anthropometric measurements are made they have to be interpreted to see whether they are within the normal range for age and sex
This is done by comparing with population based growth charts/standards
- There are two types of growth charts
1. Distance charts
shows the growth of that parameter since birth
2. Velocity charts
shows the growth of that parameter over a unit time
How are growth charts compiled?
- By using cross sectional or longitudinal data of large number of normal children
- For a particular parameter all data are arranged in rank order and the middle figure which divides the data set into 2 equal halves identified – this is the median line or 50th centile line
- On either side of the median line further centile lines are drawn – 3rd, 10th, 90th 97th etc
- Each line indicates the percentage of children whose growth parameter value would fall below that particular line compare to the population.
- Some charts use SD scores and lines representing -3SD, -2SD, -1SD, median, +1SD, +2SD, +3SD
Which chart to use?
- Most of the reference charts available are those made in the developed countries.
- Ideal is to use national reference charts.
- However, in most of the developing countries such charts are not available.
- In that situation use of WHO growth references is acceptable.
•CDC / NCHS growth charts (US)
http://www.cdc.gov/growthcharts
- British growth charts
- WHO growth charts
The growth charts used in the current Sri Lankan CHDR are the WHO growth charts.
Interpretation of growth measurements
- A single reading is not adequate to comment on growth
- It is important to have a series of readings plotted on a chart before commenting on an anthropometric parameter
- Always compare different parameters before commenting e.g. weight, height, OFC
-------------------------------------Summary
- Growth is a continuous process
- Growth monitoring is an integral part of any child health service
- Use of correct equipment and standardised techniques are essential
- Serial measurements are more important than single measures
- Interpretation of growth patterns need other anthropometric data
- The pattern of growth over time is more important than the position in the growth chart
- ---------------------------
