Dr. Tauhid Iqbali

MBBS (JIPMER)

MD Pead Jr. II (PMCH Patna)

Learning Objectives To define what is physical growth and to know normal pattern of growth

To understand what is percentiles z-scores and percentage of mean

To know techniques of growth measurement

To define growth monitoring

To know recommendations for interval and parameters for growth monitoring

To know about growth charts

To know what are common growth reference charts

To know how to calculate z-scores and correlation between percentiles and z-scores

Interpretation of growth charts

To know applications of growth charts with examples

GROWTH DEFINITION:

Growth denotes a net increase in the size or mass of tissue

Occurring because of two factors:-

- Multiplication of cells

- Increase of intra cellular substance

NORMAL PATTERN OF GROWTH FROM CONCEPTION TO ADOLESCENCE

FETAL GROWTH(TILL BIRTH ) It is broadly divided into 4 phases: • Up to 16 weeks – slow rate , less than 10 gram/week (100g)

• 16-28 weeks - Accelerated rate , approximately 85 g/week (1005g)

• 28-37 weeks - Maximum rate , nearly 200 g/week (2859g)

• 37-42 weeks - Decelerated rate , approximately 70 g/week (3685g)

BIRTH TO SCHOOL-AGED GROWTH (BIRTH TO 12 YEARS) WEIGHT: Infant looses 7-10% of birth weight in 1st week of life

Birth weight is again achieved by end of 2nd week

Subsequent rate of weight gain is as follows:

AGE WEIGHT GAIN

10days-3months 30g/day

3-6 months 20g/day

6-9 months 15g/day

9-12 months 12g/day

1-3 years 3g/day

4-12 years 2g/day

LENGTH/HEIGHT: Length of term newborn at birth is approximately 50 cm

AGE RATE OF LENGTH/Ht INCREASE

Birth-3 months 3.5 cm/month

3-6 months 2 cm/month

6-9 months 1.5 cm/month

9-12 months 1.3 cm/month

2-5 years 6-8 cm/year

5-12 years 5 cm/year

HEAD CIRCUMFERENCE: Head circumference at birth is 33-35 cm

AGE RATE OF HC INCREASE

0-3 months 2 cm/month

3-6 months 1 cm/month

7-12 months 0.5 cm/month

1-3 years 1 cm/6months

3-5 years 1 cm/year

ADOSESCENT GROWTH(12 YEARS TO 19 YEARS) Peak growth velocity( nearly double the prepubertal GV ) characterized

the commencement of adolescent growth

In girls peak GV start during early puberty ( Tanner stage II-III) with mean

GV of 9cm/yr (range7-11cm/yr)

In boys peak GV begins 2-3 years later than in girls at Tanner stage III-IV

with mean GV of 10.3 cm/yr (range7-13 cm/yr)

The average total growth during pubertal spurt is 27-30 cm

Boys have longer growth spurt period than girls

AGE DEPENDENT Weight Height HC Chest Circumference

AGE INDEPENDENT MUAC BMI Rao’s Index Kanawati’s Index

GROWTH PARAMETERS

TECHNIQUES OF GROWTH MEASUREMENT

Measure to the nearest 10g for infant and 100g for children Allow tared weighing Weighting time should be about half an hour before or after a feed Preferably measure at same time of the day

WEIGHT MEASUREMENT:

LENGTH/HEIGHT MEASUREMENT

Length measurement: For child <2 years of age (or < 87 cm if the age is not available)

Recumbent length is measured by infantometer

Head support Frankfurt plane

Knee straight Sole flat on foot piece Toe pointing upward

If a child is <2 year old but can not lie down then: Length(cm)= Height+ 0.7

Height measurement:

For child >2 years of age(or >=87 cm if the age is not available) and is able to stand

Height is measured by Stadiometer

Measure the height to the last completed 0.1 cm

Heels

Calf muscle

Buttocks

Shoulder blades

Back of head

Frankfurt plane

Head piece firmly on head

Hand on chin

Shoulder level

Hands by side

Left hand on knee: Knee together and leg straight

Right hand on shins: Neels against back And base of board

If a child is >=2 years of age but can not stand then: Height(cm)= Length – 0.7

HEAD CIRCUMFERENCE MEASUREMENT:

Measured upto age of 5 years

Should not be measured before 36 hours of age

Measured to the nearest 0.1cm

Use flexible nonstretchable tape for the measurement

Occipital prominence

Supraorbital ridges

MID-UPPER ARM CIRCUMFERENCE(MUAC): Measured in children between 6 months to 5 years of age

It is an age independent parameter

Measured in left arm

Measured mid-way between tip of left shoulder(acromion process) and tip of elbow

(olecranon process)

Locate tip of shoulder

Locate tip of elbow

Flex elbow

Place tape at tip of shoulder Pull tape past tip Of bent elbow

Mark the midpoint

Arm hanging by side While measuring

If using 3-colour tape: A measurement in-

Green zone - properly nourished

Yellow zone – Moderate acute malnutrition

Red zone – Severe acute malnutrition

GROWTH MONITORING

Definition: Following the growth rate of a child in comparison to a standard by frequent periodic anthropometric measurements in order to assess growth adequacy

The purpose is to determine whether

a child is growing “normally” or growing “ abnormally” i.e. Has a growth problem

Purpose of growth monitoring:

Growth Monitoring involves five steps

Step 1: Determining correct age of the child

Step 2: Accurate weighing of the child

Step 3: Plotting the weight accurately on a growth chart of appropriate gender

Step 4: Interpreting the direction of the growth curve and recognising if the child

is growing properly

Step 5: Discussing the child’s growth and follow-up action needed with the mother

STEPS IN GROWTH MONITORING

RECOMMENDATIONS FOR INTERVAL AND PARAMETERS FOR GROWTH MONITORING

Age group Parameters Intervals

Birth -18 months Weight, Length Head circumference

Birth, 6wks,10wks,14wks, 9 Mo,15 Mo and 18Mo

18 months -5 yrs Weight, Height 6 monthly

>5 years Weight, Height , BMI Annually

GROWTH CHARTS

The most powerful tool for growth monitoring

Growth charts are visible display of child’s physical growth and development

It was first designed by David Morley and was later modified by WHO

Blue charts for boys and pink charts for girls

COMMON GROWTH REFERENCE CHARTS

• NCHS 1977(National Center for Health Statistics) • WHO 2006 • CDC 2000(Center for Disease Control and Prevention) • Indian reference charts Agarwal DK et al Khadilkar VV et al Marwaha RK et al

WHO CHARTS Available for age group of birth to 19 years Standards for age 0-60 months were developed from data collected in WHO- MGRS

(Multicenter Growth Reference Study) which represent the best physiological growth standards from birth to 5 years of age in breastfed infants Standards for age 5 years to 19 years were developed from original NCHS 1977 data Disadvantage of WHO growth charts Few children aged 0-60 months are diagnosed underweight even if they are not

CDC 2000 CHARTS Available for age group of birth – 20 years These are revised version of original NCHS 1977 data Sample population were formula/mixed fed children Disadvantage of CDC growth charts Do not truly reflect ideal growth of breastfed children

WHICH GROWTH CHART TO USE?

RECOMMENDATIONS:

Under 5 children - WHO 2006 STANDARDS

Above 5 children - Nationally representative references

Recommendation for indian children:

INTERPRETATION OF GROWTH CHARTS AND GROWTH PARAMETERS

PERCENTILES

Percentiles are obtained by dividing an ordered set of data into 100 equal sized group If a 3-month-old child is in the 40th percentile for weight that means 40 percent of 3-month-old boys weigh the same as or less than this baby and 60 percent weigh more

50th percentile means 50 per cent above or under

Z-scores or SD scores

It is used to describe mathematically how far a measurement is from the median (average)

50% 50%

97%

Correlation between percentiles and z-scores

Z-score Exact percentile

Rounded percentile

0 50 50

-1 15.9 15

-2 2.3 3

-3 0.1 1

1 84.1 85

2 97.7 97

3 99.9 99

How to calculate Z scores (Standard Deviation Score)

Example: Actual length 96.1 cm Median 90.4 cm Standard deviation 3.3 Z score = ( 96.1-90.4)/3.3 = 5.7/3.3 = +1.73

97%

PERCENTAGE OF MEDIAN

This is merely the weight/height of the individual child relative to the average weight/height of the comparable children in the reference population, expressed as a percentage For example: A 80 cm tall girl weigh 8.0 kg and the average weight for 80 cm tall girls is 10.2 kg Therefore, the percent of median for this 8.0 kg girl is 78.4 %

For height <90% - Short stature

For weight <80% - Underweight

Under weight

Growth chart types

Percentile graphs have a narrower range, because the 97th centile corresponds approximately to a Z score +2 Hence a Z-score of +3 or -3 is more likely to be definitely abnormal (above 97 centile or below 3 centile)

Percentile chart Z-score chart

INTERPRETATION OF GROWTH CURVE

This is determining whether the child is growing appropriately or not.

Normal growth curve: a healthy child’s growth curve is parallel to the printed curves on the chart.

• The direction of the growth curve is more important than the position of the curve on the chart

Important consideration on premature infants where growth failure can be over diagnosed, this can be avoided by subtracting the weeks of prematurity from postnatal age when plotting the growth measurements

A horizontal growth curve (static) :

• This indicates danger, this means the child is not growing.

• A sign of disease, especially malnutrition.

• This makes them prone to recurrent infection as they can not resist disease

Downward growth curve:

• Indicates a very dangerous situation where the child is losing the weight.

• This requires extra care immediately

An upward curve in the growth chart is ideal

A flat and downward curves are not desirable

INTERPERATION OF GROWTH PARAMETERS

May be abnormal

Use BMI

EXAMPLES AND APPLICATIONS

CALCULATING AND PLOTTING MPH

MPH is plotted on growth chart at 18 years of age Normal range is 2SD above or below the MPH (Which approximately corresponds to +/- 8cm

For example: Father Ht - 164cm

Mother Ht - 151cm

Assessment

MPH-151(143-159cm)

CALCULATING AND PLOTTING GROWTH VELOCITY

For example: 12 year old girl Ht – 135 cm

After 6 months Ht – 138.5 cm

A = 3.5

B = 6

GV=3.5 X 12/6 =7 cm Per year

Point -12.25 years

Assessment GV – 50 Percentile

GV = A x 12/B Per year A- Interval growth B- Months b/t measurements

12 year old girl

Ht - 135cm,Wt - 28kg

Father Ht - 164cm

Mother Ht - 151cm

Assessment: MPH-151(143-159cm)

Ht age-9.5years Wt age-8.5 years

Familial short stature

Follow-up 6 months

Ht – 138.5 cm

GV=3.5 X 12/6 =7 cm Per year

Assessment GV – 50 Percentile

13 year old boy

Ht – 135cm,Wt – 30kg

Father Ht-169 Mother Ht-156

Bone age – 10.5 years

Assessment MPH - 169 cm

Height age -9.5 years Weight age -9.5 years

Constitutional short stature

10 year old girl

Ht-120cm Wt-15kg

Father Ht-163cm

Mother Ht-150cm

Interpretation Height age-7years

Weight age-4 years

Nutritional short stature

8 year old boy

Ht-100cm Wt-18kg

Father Ht-169cm

Mother Ht-156cm

Bone age-3 years

Interpretation Ht age - 3.5cm Wt age - 5 cm

Endocrine-GHD/Hypothyroidism

12 year old boy, obese

Ht-160cm Wt-70kg

Father Ht-169cm

Mother Ht-156cm

Interpretation Ht age-13.5years Wt age-19 years

Constitutional obesity

12 year boy, Obese

Ht-132cm Wt-59kg

Father Ht-169cm

Mother Ht-156cm

Interpretation Ht age – 9years

Wt age - 15.5years

Pathological obesity

SHORT STATURE

Wt age << Ht age < Age – Nutritional

Ht age << Wt age < Age - Endocrine

OBESITY

Age < Ht age < Wt age – Nutritional

Ht age < Age < Wt age - Endocrine