6. Growth Flashcards
How is normal growth controlled?
Controlled by complex interaction of
Factors
- Nutrition
- Environment
- Internal Signaling Systems – hormones and growth factors
What are the 4 stages of growth?
- Foetal
- Infant (rapid)
- Childhood
- Pubertal (rapid)
What are the requirements for Normal Childhood Growth?
- Absence of Chronic Disease
- Emotional Stability, Secure family environment
- Adequate Nutrition (most over nourished but obesity is not an indicator)
- Normal Hormone Actions
- Absence of defects impairing cellular/bone growth
Why is growth monitoring important?
Monitoring growth extremely important as it is often how chronic illness is detected.
Health Surveillance, Should be carried out at all hospital visits. Done a lot in paediatrics, because of drug/dosing requirements.
How does chronic illness impact on childhood growth?
- Potent cause of growth failure
- Primary effect of disease on dividing cells
- Secondary effects on nutrition
- This is why growth monitoring is such an important part of child health surveillance
Dramatic growth failure caused by emotional deprivation? MOA? Tx?
Emotional Dwarfism.
No problem with growth hormone levels but it is not able to perform its function. In orphanges, there can be practical care, but little emotional care and this is bad.
Growth normalises when child removed from initial environment
What is the contribution of growth to Total Energy Expenditure?
Energy requirements for normal growth are modest
Growth makes the smallest contribution to Total Energy Expenditure ( 5-10%)
At what stage is the rate of foetal growth the highest? Rate? Pattern?
Growth velocity maximal in 2nd timester
Equivalent to 62cm /year
Linear Pattern of Growth (different to weight gain).
Discuss the pattern of weight gain in foetal growth?
40 Weeks
4-12wks = 0.1kg/yr 12-14wks = 2.7kg/yr 24-40 = 8.7kg/yr
Note: Childhood = 2-2.5kg/yr
What factors determine the rate of foetal growth?
Foetal growth constrained by..
- Maternal factors
- Placental function
It is coordinated by growth factors
So the size of the baby at birth is dependent on the intrauterine environment and not the genetics.
Discuss the role of the placenta in foetal growth?
Plays a rate limiting role
You can have a healthy mum, but an unhealthy placenta and vis versa.
Over/under eating during pregnancy does not have much of an effect.
What are the demands of Pregnancy on Total Energy Expenditure?
Overeating/undereating during pregenancy not much effect Calorific demands of pregnancy about 1/2 banana a day. So you are NOT eating for two
How does foetal growth affect health in later life?
- Related to health in later life
- Hypertension
- Cardiovascular Disease
- Cerebrovascular Disease
- Insulin Resistance
- NIDDM
What growth pattern is seen in infants?
An infant loses 5-10% of its birth weight but should regain it by 2 weeks
An infant doubles its birth weight by 4-6 months
Year 1 infants grow rapidly but at a sharply declining rate
Similar pattern has been observed for their weight.
What is the principle regulator of growth in the infant stage?
NUTRITION is the principal regulator of
growth over this period.
GH/IGF axis have a certain limited role
If nutrition is not good at this stage it will be difficult to catch up
What is the main determinant of size at the end of all growth?
The actual size of you is genetic, almost entirely, aside from any significant pathological interuption of growth
What does early obesity in infancy suggest?
More likely to lead to tall stature developing later in childhood
What relationship between birth weight+length and mid parental size?
At birth poor correlation between length, weight and mid parental size
When does the correlation between length and mid parental height emerge? How?
By 2 years good correlation between length and mid parental height.
Achieved in the 1st 2 years by:
- Catch up (accelerated growth) 6-18months
Or - Catch Down (Decelerated growth) 3-6 months and 9-10 months.
*From small/large birth weight which is intrauterine determined.
What is the growth velocity by around 4 years?
7cm/yr
What happens to the growth velocity after 4 years?
Thereafter declines steadily until adolescence
The prepubertal nadir (lowest VG) = 5cm
However:
• Definite mid-childhood growth spurt
• Seasonal variation in growth
What determines childhood growth?
GH and Thyroid hormone are the major determinants of growth in childhood.
Normal growth depends on inherent genetic mechanisms and external influences.
Therefore childhood is when a majordysfunction in the GH axis may be recognised.
What pattern is observed in childhood growth?
- Believed to be a non-linear process
- Weight changes show a reciprocal relationship with height changes
- Over childhood little difference in growth patterns between boys and girls
What is Puberty?
Puberty defined as the transition from the pre-pubertal state through the development of secondary sexual characteristics to the achievement of adult stature.
What patterns are observed in pubertal growth?
Marked sexual dimorphism in timing of puberty.
Wide inter-individual variation within sexes
Discuss sexual dimorphism in timing of puberty?
Boys – puberty on average 2 years later
Therefore boys get 2 years of extra prepubertal
growth equivalent to 8-10cm
Growth amplitude in puberty 3-5 cm higher in boys
So over all 12.5 cm difference in adult heights between the sexes
What is Constitutional Delay of Growth and Puberty?
The most common cause of short stature and delayed puberty.
A temporary delay in the SKELETAL growth and thus height of a child with no other physical abnormalities causing the delay.
Short stature may be the result of a growth pattern inherited from a parent (familial) or occur for no apparent reason (idiopathic).
Typically at some point during childhood, growth slows down, eventually resuming at a normal rate.
What is precocious puberty?
Precocious puberty refers to the appearance of physical and hormonal signs of pubertal development at an earlier age than is considered normal.
Girls <9 years
What is the rule of thumb with regard to late/early puberty?
Short stature, late puberty
Tall stature, early puberty.
What changes in body composition occur in puberty?
Puberty associated with changes in body composition
- Boys gain 30Kg (more muscle)
- Girls 18.5 Kg (more fat)
What is the central principle in clinical recognition of normal growth?
The ability to quantify growth over time against well constructed reference standards is the cornerstone of auxological assessment.
Because of variations in growth observation needs to be over as long a period as possible - ideally a year
Once off measurement not helpful, you really need 6 month interval measurements
UK growth foundation, growth charts used
What are the tools required for Growth Assessment?
- Growth Charts
- Standards for pubertal timing
- Bone Age
- Orchidometer (testicular volume beads)
How is bone age given and what does it correlate strongly to?
Ossification centers in wrists and hand used to give bone age, which correlates more closely to pubertal development.
What else is a useful indicator of pubertal development?
Testicular volume also a useful indicator.
Onset puberty between bead 3-4
How is growth velocity (practically) measured?
2 years – standing height – STADIOMETER
Parental heights
Purpose is to assess growth velocity
Note: Hourly variation in spinal height, reset at night.
When should weight be used as an indicator of growth?
Weight can be a surrogate marker for growth. Eg neonates. i.e. Don’t guilt parents if somewhat obese
Should not be used as an indicator of growth in the older child i.e. Do guilt parents if somewhat obese.
Centile charts are a way to broach the issue of excessive weight with parents. Your responsibility to tell them.
Use BMI SDS
Take into account comorbidities
What clinical assessments of growth are made?
- Accurate measurements – child and family
- Family history e.g. Pubertal delay
- Growth velocity
- Staging of puberty
What is the aetiology of child hood obesity?
Complex aetiology. Socioeconomic Diet (inc weening 2 soon) Activity Genetic Obesogenic Environment
What is the prevalence of childhood obesity in Ireland?
(25%)
What are common causes of short stature?
- Familial
- Chromosomal
- Low Birth Weight
- Chronic Disease
- Central
- Psychosocial
- Endocrine – Hypothyroidism
What are the clinical signs of Growth Hormone Insufficiency?
- Short stature – age 2-3 years
- Chubby
- Immature facies
Usually other hormonal co morbidities
What are the common causes of GH insufficiency?
- Congenital
- Gene mutation
- Idiopathic
- Developmental
- Acquired
- Perinatal trauma, Tumour
- Secondary - irradiation, infection, trauma
Why should you be conservative in the investigations and treatments you use in children?
INVESTIGATING NORMAL CHILDREN CONSTITUTES AN ASSAULT
What is the formula for calculating the mid-parental height of a Boy?
[(Mother’s Height +13cm) + (Father’s Height)] / 2
What is the formula for calculating the mid-parental height of a Girl?
: [(Father’s Height-13) + Mother’s Height ]/ 2
What is the acceptable range for MPH?
± 10cm
How do you measure the head circumference?
What you are measuring is Occipital Head Circumference.
Flexible tape measure ideally paper as no stretch
Widest possible circumference
Measure 3 times
Take the largest
What are average OCP measurements?
OFC is 34cm +/-2cm term baby
Increases by 2cm/month 1st 3month
Then 1cm/month 2nd 3months
By 0.5cm/month last 6months of infancy
Total growth 12cm
What Staging System is used in Pubertal Growth?
Tanner Staging Sytem.
Boys:
Penis, pubic hair, testicular maturation (stages 1-5 for each)
Assess testicular volume (adult 20-25ml)
Acne, shaving, voice useful but not formal
Girls:
Breast, pubic hair, onset of menstrual cycle (stage 1-5 for each, except MC onset which is single event)
What are should be assessed during physical examination of child?
Dysmorphic syndromes associated with height
Skin creases
Carrying angle of arms
Neck +face with particular attention to palate or midline deformities
Resp + CVS
Visual fields
On a velocity centile chart what is considered to be abnormal growth?
Even crude estimates can be used for calculating height velocity expressed in cm per year
Shape of a velocity curve should mimic shape of growth curve.
Abnormal growth rate =Below 25th centile/Above 75th/Less than 4cm at any time = assume abnormal.
Height velocity charts allow the detection of changes in growth pattern quicker than in absolute height charts preventing missed diagnosis.
Drop in weight, if occurring soon after breast feeding?
May suggest coeliac disease (distended tummy, loose stools, flatulence, Screen Transglutaminase antibodies and IgA. Gold standard of dx is crypt blunting and villous atrophy on gluten.
What are growth red flags in a child?
- Short Stature (with obesity)
- Intellectual disability
- Dysmorphic Feature
- Snoring (sleep apnea )
- Goitre
- Low Mood
What are the signs and symptoms of turners syndrome?
Short Stature Low Hairline Widely Spaced Nipples Shortened Metacarpal IV Small Finger Nails Nevi (Brown Spots) Characteristic Facial Features Webbed Fold of Skin Constriction of the Aorta Poor Breast Development Elbow Deformity Rudimentary Ovaries No menstruation
What are the signs of non-accidental injury?
Delayed Presentation
Non-mobile child w/suspected fracture
Multiple Historic Injuries
What are the next steps if you suspect non-accidental injury?
Admission Bloods Skeletal survey Ophthalmology Social work referral
DO THE MEDICAL WORK UP
KEEP THE BABY SAFE (Admission)
