fundamentals of growth and puberty Flashcards
what are the requirements for normal human growth?
Absence of chronic disease, emotional stability, secure family environment, adequate nutrition, hormones/growth factors, healthy growth plates
what is the ICP model and what dos it show?
ICP model – Infant Child Puberty Model
Human grows in 3 different ways depending on whether they are in infancy, childhood or puberty
Overall growth pattern is a sum of these 3 growths
during infancy, what is the most important factor of growth?
nutrition
what is the rate of growth at infancy?
25cm/year
what is the most important factor of growth during childhood?
GH-IGF axis – pituitary makes growth hormone which leads to the production of insulin like growth factor.
what is the rate of growth in childhood?
4-8cm/year
what is the most important factor of growth during puberty?
sex steroids: increase in growth hormone
what is the rate of growth during puberty?
12cm/year
why do we measure growth?
indicator of general health and well-being
why do we measure height and weight?
useful for identifying disorders affecting growth (such as Turner’s syndrome (lack an X chromosome) and growth hormone deficiency) - special growth charts for this.
More controversial; screening for tall stature – some diseases lead to tall stature and need to be screened for.
what are the elements of a well-functioning monitoring system?
- Calibrated equipment
- Correct measurement technique
- Systematically collected growth data
- Appropriate, up-to-date growth reference
- Screening rules for abnormal growth
- Referral criteria
- Adherence to guidelines
- Appropriate diagnostic work-up
how should babies be weighed?
without any clothes or nappy
how should children older than 2 years be weighed?
in vest and pants but no shoes or dolls/teddies in hand
how should children over 2’s length be measured?
use proper equipment; length board or mat. No nappy or footwear
when should length be measured?
after 2 years of age
how should you measure the length of a child under the age of 2?
board or mat – requires 2 measurers. 1 measurer holds head of child, and the other adjusts the sliding board to see where the legs end
what equipment do you use to measure height?
rigid ruler or stadiometer
how should height be measured?
o Ensure heels, bottom, back and head are touching the apparatus
o Measurer holds child over the mastoid processes to ensure contact is maintained with the stadiometer
o Don’t try to stretch up, measure on expiration
o No footwear
what are centiles?
describes the % of people below that line
why are there no centile lines between 0 and 2 weeks?
because some degree of weight loss is common after birth for healthy term infants. Birth weight gained back after 2nd week.
in what cases do children need further assessment of growth?
- Where weight or height or BMI is below the 0.4th centile, unless already fully investigated
- If the height centile is more than 3 centile spaces below the mid-parental centile.
- A drop-in height centile, position of more than 2 centile spaces (exclusion of measurement error).
how will advanced bone age present?
often tall stature and may have central precocious puberty (too soon).
how does delayed bone age present?
growth failure secondary to paediatric Cushing’s disease
define short stature
Defined as a length or height less than - 2SDS (mean height standard deviation score) = 2.3 centile for age and sex of appropriate reference population
how can you evaluate short stature?
- height vs centile weight - failure to thrive or grow
- when it starts
- body proportions - primary or secondary growth disorder
- presenting signs
what are the types of short stature?
proportionate
disproportionate
if it’s disproportionate short stature then what can it be?
skeletal dysplasia
severe case of rickets
if it’s proportionate short stature, then what tests do you carry out and what do these show?
psychosocial assessment - psychosocial growth retardation
syndromic features karyotype (girls) - Turner Syndrome
tests for systemic disorders - chronic renal insufficiency, GI disease, nutritional disease
tests for endocrine disorders - hypothyroidism, hypercortisolism
what is linear growth a combination of?
- Detaled auxological assessment
- Bone age assessment
- Estimate height velocity (cm/year)
- Signs and symptoms of underlying case
- Assess pubertal status
- Consider genetic growth potential from parental heights
what does the HPG axis initiate?
growth and maturation
when does puberty occur?
when GnRH secretion and HPG axis are re-activated (caused by pulsatile GnRH release from hypothalamus)
when are the first physical markers of the onset of puberty in boys and girls?
- In girls 8-13 years
* In boys 9.5-14 years.
which gender has a taller prepubertal height?
males
what is the difference in adult height between males and females?
13cm
What is Puberty Staging by Tanner?
method of assessing the pubertal staging of boys and girls
explain the puberty staging by tanner in girls
In girls we look at the axillary hair, pubic hair and breasts. (APB)
explain the puberty staging by tanner in boys
we look at axillary hair, pubic hair and testes (genitals) – APG
what is the prepubertal staging in boys and girls?
A1B1P1 for girls and A1P1G1 for boys. As soon as its 2, its onset of puberty.
what is the onset of puberty defined as in terms of Tanner staging?
- Tanner stage B2 for girls (budding of the breast)
* Tanner Stage G2 = Testis volume > 3mL in boys
when is the mean onset of puberty for boys and girls?
11yrs for girls
12 yrs for boys
what is the range of ages for when puberty can starts in boys and girls?
boys - 9 and 15
girls - 8 and 15
what is the difference in adult height between men and women and why is this?
- 2 additional years of prepubertal growth in boys
- Taller prepubertal height in males
- Greater amplitude of the spurt in males
why does earlier onset of puberty mean you grow less?
bc your body is exposed to higher amounts of oestrogen and progesterone which fuses growth plates
what conditions can early onset of puberty lead to?
breast cancer, endometrial cancer, type 2 diabetes, hypertension, obesity, adolescent risk behaviour, adult height and psychosexual development
what conditions can late onset of puberty lead to?
cognitive and learning disabilities, self esteem, adult height, osteoperosis, psychosexual development
