Growth and Puberty Flashcards
What is the birth weight and height influenced by?
Intrauterine conditions
Babies small for gestational age (SGA) are below which centile. A concerned mom asks you how it will affect their growth in the future. Will it remain on the same centile line?
<10th centile
That is okay as there is usually catchup growth where it is normal for them to go up a centile
A concerned mom asks you how breastfeeding will affect their growth in the future. Will it remain on the same centile line?
Breastfed babies initially may drop a centile compared to formula-fed infants = catch down growth. This is only for the first 3 months of life!!
What is the normal growth/year between the ages 0-2.5 years. What is this growth mostly influenced by?
0-2.5 years: 25cm/year influenced mostly by nutrition
between the ages 2.5 -3 years. What is this growth mostly influenced by?
Nutrition + growth hormone
When is target height measured? How is it calculated?
What age do you measure the target height?
Target height is measured between 2.5-3 years
it is the Mid-parental height +/- 10cm
Mid-parental height is calculated by adding the parents heights +12.5 if boy and -12.5 if girl, all divided by 2.
What is the normal growth/year between the ages 2.5 years until puberty . What is this growth mostly influenced by?
4-8cm/year
Growth hormone
What is growth during and after puberty mostly influenced by?
Sex steroids and growth hormone
When is it best to measure height?
In the morning
Height is composed of spine + legs
What is the normal ratio at birth. When does it stabilize by? What is the ratio then?
At birth: 1.7:1
10yo: 1:1
You come to measure a patient’s height and notice that their leg length is shorter than their spine length. What do you suspect?
SHOX gene deficiency
Achondroplasia/hypochondroplasia
How would you calculate the approximate length of the femur? What is it called?
Subischeal length = standing height - sitting height
You suspect someone has scoliosis, how would you quickly confirm your suspicion?
Short sitting height indicates scoliosis.
How does puberty start?
Hypothalamic pituitary axis: Hypothalamus produces GnRH hormone (gonadotropin releasing hormone) stimulates the release of gonadotropins (LH and FSH) from anterior pituitary which act on the gonads (ovary and testes) to produce sex steroids (estrogen and testosterone) (Gonadarche)
Average age of onset = 11
Premature in girls if <8 and in boys if <9
What is the average age of onset of puberty
What is considered premature onset of puberty in each gender.
Average age of onset = 11
Premature in girls if <8 and in boys if <9
What is meant by true puberty?
True puberty = Gonadarche = production of sex hormones in the presence of primary sexual characteristics such as breast budding and testicular volume increase
What is used to measure the stages of puberty?
What is Gonadarche? What does that mean for each gender?
What Tanner stage indicates that puberty has begun?
Tanner Staging
Gonadarche is the activation of the gonads in producing sex steroids and this is referred to as true puberty. In girls that will show as Breast Budding and in boys it is testicular volume 4ml or more. Both of these represent Tanner stage 2 => start of puberty
How do you measure testicular growth?
Orchidometer
What is Pubarche or Adrenarche
Adrenarche is the fake puberty which is the production of androgens by the adrenal glands giving rise to secondary sexual characteristics such as pubic hair, body odour, acne, and greasy hair
During what stage is the peak height velocity. Does it occur earlier in boys or girls?
During puberty. And like everything related to this, girls have it first