Growth and development Flashcards
What percentage of eventual height does the foetal phase of growth contribute to?
30%
What percentage of final height does the infantile phase of growth contribute?
15%
What percentage of final height does the childhood phase of growth contribute to?
40%
What percentage of final height does the pubertal growth spurt contribute?
15%
What are the main determinant of childhood growth phase?
- Genetics
- GH - acting to produce IGF-1 at the epiphyses.
- Thyroid Hormone
- General health
What is infantile growth largely dependent on?
- Good nutrition
- Good health
- Thyroid hormones
What is size at birth determined by?
- Size of mother
- Placental nutrient supply - modulates growth factors IGF-2, human placental lactogen, insulin
What do sex hormones cause in terms of bone growth?
Fusion of the epiphyseal growth plates
How much do preterm infants grow by per week?
0.8-1cm per week
What is the growth rate in the first 2 months of life?
2.5 cm per month
How much do children grow in length within the first year?
Approximately 25 cm
What is the average growth velocity in childhood?
4-8 cm per year
What are the different categoris of pubertal development used in the tanner staging of puberty?
- Female breast changes
- Pubic hair changes - male and female
- Male genital changes
What are the 5 stages of female breast change?
- B1 - prepubertal
- B2 - breast bud
- B3 - juvenile smooth contour
- B4 - areola and papilla project above breast
- B5 - Adult
What are the 5 stages of pubic hair change in males and females?
- PH1 - Pre-adolescent - no hair
- PH2 - Sparse, pigmented, long, straight, mainly along labia and base of penis
- PH3 - dark, coarser, curlier
- PH4 - filling out towards adult
- PH5 - adult distribution
What are the 5 stages of male genitalia development in the tanner staging of puberty?
- G1 - preadolescent
- G2 - lengthening of the penis
- G3 - Further growth in length and circumference
- G4 - Development of the glans, darkening of scrotal skin
- G5 - adult genetalia
What are the features of puberty in a female?
- Breast development
- Pubic hair growth
- Menarche - 2.5 years after start of puberty
What does menarche indicate in terms of growth?
Growth is coming to an end - only around 5cm growth left
What are features of puberty in males?
- Testicular enlargement - first clinical sign of puberty
- Pubic hair growth
- Rapid height growth
What occurs during puberty in both sexes?
- Acne
- Axillary hair
- Body odour
- Mood changes
If a child is within 1/4 of a centile line, how is that centile described?
On the X centile
In terms of standard deviations, how many standard deviations is the 0.4th centile away from the mean?
-2.6 SD
How many SD’s is the 2nd centile away from the mean?
- 2 SD
How many SDs is the 9th centile away from the mean?
-1.3 SD
How many SD’s away from the mean is the 25th centile?
-0.66 SDs
When assessing growth, what would you ask about in the history?
- Birth weight and gestation
- PMH
- Family history/social history/schooling
- Systematic enquiry
- Dysmorphic features
- Systemic examination
- Pubertal staging
When evaluating a childs growth, what would you do?
- Height/ length/ weight
- Growth Charts and plotting
- MPH and Target centiles
- Growth velocity
- Bone age
- Pubertal assessment
What would you use to calculate potential height
Mean parental height
Boys = (Father +mother)/2 + 7cm
Girls = (Father +mother)/2 - 7cm
how could you determine skeletal maturity?
X-ray of wrist and hand
What is the difference between boys and girls in terms of growth rate during puberty?
- Boys grow slowly first, then accelerate mid puberty
- Girls grow fast at the start, and slow down later on
What is short stature defined as?
Height below the 2nd centile
If a child was dropping off height centiles, what would you want to look at first?
- Weight centile
- Estimated height -MPH
What can cause short stature?
- Familial height
- Constitutional delay in growth
- SGA or prematurity
- Chromosomal disorder/syndrome
- Nutrition
- Long-term illness
- Psychosocial deprivation
- Endocrine - Hypothyroidism, GH deficicency, Cushings syndrome
What is constitutional delay in growth?
This is a variation of normal growth, which presents with short stature in teenage years because of delay of onset of puberty. Bone age and onset of secondary sexual development are often delayed, but final height is normal.
Usually a family history of the same thing
What psychosocial problems can cause short stature?
Physical and emotional neglect
Remove from the environment - solves the problem
How does Growth hormone deficiency occur?
-
Pituitary dysfunction
- Midfacial/Midline defect
- Craniopharyngioma
- Hypothalamic tumour
- Trauma
- Meningitis
What are the causes of tall stature?
- Familial
- Hyperthyroidism
- Excess adrenal androgens/sex steroids
- Gigantism
- Syndromes - marfans, klinefelters
- Maternal diabetes/primary hyperinsulinism
What percetage of adult head growth is acheived before age 5?
80%
If there is a rapid increase in head circumference, what needs to be excluded as a cause?
Raised ICP
What is microcephaly defined as?
Head circumference below 2nd centile
What can cause microcephaly?
- Familial
- Autosomal recessive condition
- Congenital infection
- Insult to developing brain
What is the defintion of Macrocephaly?
Head circumference above the 98th centile
What can cause macrocephaly?
- Tall stature
- Femilial
- Raised ICP - tumour, neurofibromatosis, chronic subdural haemorrhage
- Cerebral gigantism
What can cause raised ICP which leads to rapidly increasing head circumference?
- Subdural haematoma
- Hydrocephalus
- Brain tumour
What would be red flag signs for referal for growth assessment?
- Extreme short or tall stature (off centiles)
- Height below target height
- Abnormal height velocity (crossing centiles)
- History of chronic disease
- Obvious dysmorphic syndrome
- Early/late puberty
How do you calculate BMI?
Weight/height2
What is the definition of being overweight?
BMI > 85th centile
What is the definition of obesity?
BMI > 97.5th centile
What environmental factors contribute to obesity?
- Energy-dense foods
- Deecreased energy expenditure
- Low socioeconomic status
How would you assess and overweight/obese child?
- Weight
- Body mass index (BMI) (kg/m2)
- Height
- Waist circumference
- Skin folds
- History and examination
- Complications
What would you ask about in the history for an obese/overweight child?
- Diet
- Physical activity
- Family history
-
Symptoms suggestive of:
- Syndrome
- Hypothalamic-pituitary pathology
- Endocrinopathy
- Diabetes
What are complications of obesity?
- Metabolic syndrome
- Fatty liver disease (nonalcoholic steatohepatitis)
- Gallstones
- Nutritional deficiencies
- Pancreatitis
- Stress incontinence
- Left ventricular hypertrophy
- Atherosclerotic cardiovascular disease
- Right-sided heart failure
- Thromboembolic disease
- Central hypoventilation
- Obstructive sleep apnoea
- Gastroesophageal reflux disease
- Orthopaedic problems (SUFE)
- Reproductive dysfunction (eg, PCOS)
What are the main causes of obesity in children?
- Simple obesity - activity vs intake
- Drugs
- Syndromes
- Endocrine disorders
- Hypothalamic damage
What drugs can cause obesity?
- Insulin
- Steroids
- Antithyroid drugs
- Sodium Valproate
What syndromes can cause obesity?
- Prader Willi syndrome
- Laurence-Moon-Biedl syndrome
- Pseudohypoparathyroidism type 1
- Down’s syndrome
What endocrine problems can cause obesity?
- Hypothyroidism
- Growth hormone deficiency
- Glucocorticoid excess
- Hypothalamic lesion - tumour/trauma/infection
- Androgen excess
- Insulinoma
- Insulin resistance syndromes
- Leptin deficiency
If a child presented with obesity and growth failure, what would you suspect?
Endocrine disorder
If a child was found to have learning difficulties and obesity, what would you suspect?
A syndrome as a cause of the obesity
If a child presented with obesity and loss of appetite control, what would you suspect?
Hypothalamic dysfunction
What is failure to thrive/faltering growth?
Suboptimal weight gain in infants and young children - sustained drop down 2 centile space
Head circumference is preserved relative to height which is preserved relative to weight
What can cause failure to thrive/faltering growth?
- Inadequate intake
- Inadequate retention
- Malabsorption
- Failure to utilize nutrients
- Increased requirements
What forms of inadequate intake can cause failure to thrive?
- Inadequate availibility - feeding problems, lack of regular feeding times, intolerance, low scoioeconomic status
- Psychosocial deprivation - poor relationship, maternal depression, poor education
- Neglect/abuse
- Impaired suck/swallow - neurological disorder, cleft palate
- Chronic illness - Crohn’s, CKD, CF, liver disease
What can cause inadequate retention which can lead to failure to thrive?
- Vomiting
- Severe GORD
What causes of malabsorption can cause failure to thrive?
- Coeliac disease
- CF
- Cow’s milk protein allergy
- Short-gut syndrome
- NEC
- Cholestatic liver disease
What forms of increased requirement can cause failure to thrive?
- Thyrotoxicosis
- CF
- Malignancy
- Chronic infection
- Congenital heart disease
- Chronic kidney disease
What would you ask in the history when assessing faltering growth?
- History of milk feeding
- Weaning Age
- Range and types of food
- Mealtime routine and feeding behaviours
- 3-day food diary
- Preterm/IUGR?
- Other symptoms
- Family growth patterns
- Child development
What is Turner’s syndrome?
A condition in which a female is partly or completely missing an X chromosome. It is a sporadic sex chromosome abnormality
How does turner’s syndrome present?
https://www.youtube.com/watch?v=YQG8o5b4lKg
- Squarely shaped chest with widely spaced nipples
- Lymphoedema of hands and feet
- Webbed neck
- Low hair line
- Low set ears
- Cubitus valgus
- High arch palate
- Short 4th metacarpal
- 5th clinodactyly
- IUGR
- Short stature / growth failure in infancy or childhood - GH
- Delay or arrested puberty
- Absence of pubertal growth spurt
- 1° amenorrhoea
What is the incidence of turner’s syndrome?
1/2000
What is Noonan’s Syndrome?
Common autosomal dominant disorder which causes short stature and occurs in both males and females
What are the main features of Noonan’s syndrome?
- Occasional mild learning disabilities
- Short stature
- Webbed neck
- Pectus excavatum
-
Characteristic facies
- Ptosis
- Hypertelorism
- Low set ears
- Right-sided cardiac defect (pulmonary stenosis)
- Delayed puberty
What is precocious puberty?
This is the development at an early age of physical and physiological changes associted with puberty. Can be categorised into central and peripheral precocious puberty
What is central precocious puberty?
Gonadotrophin dependent precocious puberty from premature activation of the HPG axis
What is peripheral precocious puberty?
Gonadotrophin independent puberty from excess sex steroids outside the pituitary gland.
What is the difference in terms of presentation of central vs peripheral precocious puberty?
The sequence of central precocious puberty is normal, whereas peripheral precocious puberty is abnormal sequence of development
What is the cause of central precocious puberty in girls?
- Usually idiopathic or familial
- Pituitary adenoma
What are the causes of central precocious puberty on boys?
Intracranial tumour
How would you treat central precocious puberty?
GnRH analogues - suppress the HPG axis
At what age can precocious puberty start in girls?
8 yrs
At what age can precocious puberty start in boys?
9 yrs
What is prader-willi syndrome?
Genetic disorder which occurs due to genes on chromosome 15 not being transcribed to mRNA, leading to a lack of genetic expression. The lack of transcription most commonly occurs due to a deletion of the gene in the prader-willi region from paternal genes
How does Prader-willi syndrome present?
- Short stature
- Hypotonic babies
- Hyperphagia after 1 year - Obesity
- Characteristic facies - Narrow forehead, Olive-shaped eyes, Squint, Carp mouth
- Learning difficulties/developmental delay
- Scoliosis
