Growth and Puberty Lecture

Question 1

Growth from pregnancy until when?

Answer 1

• Peaks in 2nd trimester
• Continious until end of linear growth at aged 15-16 yrs

Question 2

3 phases of growth

Answer 2

• Infant growth
• Childhood
• Pubertal

Question 3

Infant growth

Answer 3

• Rapid but decelerating
• Dependent on nutrition
• Birth weight reflects IU environment
• SGA babies often short
• Catch up/catch down growth where child achieves own growth centile

Question 4

Symmetrical SGA vs assymetrical

Answer 4

• Symmetrical - head circumference and other measurements are proportional

Question 5

Causes of symmetrical SGA

Answer 5

• Constituitional - parents small
• Chromosone abnormality

Question 6

Childhood growth phase

Answer 6

• Velocity 5-7cm/yr
• Falls slowly to less than 5cm/yr pre-pubertal
• Mid childhood spurt 6-8yrs old
• GH is main determinant of growth in childhood
• Boys same as girls

ACTH and thyroid responsible too

Question 7

Pubertal growth

Answer 7

• Preceeded by release of pituitary hormones from mid childhood
• Girls enter puberty 2 yrs earlier
• Ht velocity increases up to 12cm/yr
• Boys average 12cm taller than
• Boys have greater GH peak

Question 8

Why does growth stop?

Answer 8

• Occurs when epiphyses fuse
• Sex steroids play vital role - oestrogen most important
• Stop growing from feet upwards

Question 9

First sign puberty in boys and girls

Answer 9

• Breast changes - girls
• Testicular growth - 4mls in boys

Question 10

Completion of puberty boys vs girls

Answer 10

• Menarche in girls
• 10mls size testes boys

Question 11

Growth assessment tools

Answer 11

• Height
• Head circumference
• Scales for weight
• Prader orchidometer
• Growth charts
• Bone age
• BMI - no set cut off, plot chart
• Mid parental height

Question 12

Length vs height

Answer 12

• Until unable to stand still to measure (before aged 2) do lying - without nappy and footwear
• After this do height

Question 13

What do centiles mean?

Answer 13

• That percent is below the line
• Eg 50th percentile = 50% of children on average sit below them on this line

Question 14

Mid parental height

Answer 14

• Mother and father height in cm divide by 2
• • 7 in boys
• • 7 in girls
• MPH +/- 10cm = target centile

Question 15

Definition short stature

Answer 15

• Outside target height - mid parental height +/- 10cm

Question 16

Constitutional delay - characteristics

Answer 16

• Short stature with normal velocity
• Small but along centiles
• Often associated with medical condition
• Later onset puberty
• Often familial
• Delayed bone age
• Eventually achieve genetic potential

Question 17

Differentials for short stature with slow velocity

Answer 17

• Chronic disease - coeliac
• GH deficiency
• Skeletal dysplasia
• Syndromes eg Turner, Downs
• Endocrine - hypothyroidism, hypopituitarism, cushings
• Psychosocial

Question 18

GH axis - what does it produce

Answer 18

• Insulin like growth factor 1

Question 19

GH deficiency characteristics

Answer 19

• Fine for first couple of years - determined by nutrition
• Then as get older, growth falters

Question 20

GH deficiency management

Answer 20

• GH injection each evening - SC
• 14-16 years treatment
• Then achieve predicted height

Question 21

Turners syndrome presenting symptoms

Answer 21

• Short
• Recurrent ear infections
• Learning issues
• CHD
• Lyphoedema of hands/feet in neonates
• Delayed puberty - primary amenorrhoea

Question 22

Turner phenotype

Answer 22

• Low set ears
• Webbed neck
• Low hairline
• FINISh

Question 23

Diagnosis of Turner syndrome

Answer 23

Karyotype

Question 24

Management of Turners syndrome

Answer 24

• Growth hormone - supraphysiological doses
• Educational help
• Hearing aid/grommets
• Pubertal hormones
• Fertility issue management
• Cardiac montioring
• Bone density

Question 25

GH for genetic causes for short stature eg downs?

Answer 25

Will not work

Question 26

Phenotypic features of down syndrome

Answer 26

* Short palpebral fissures * Flat midface * Short nose * Indistinct philtrum * Thin upper lip

Question 27

Prader willi syndrome - Chr15 deletion

Answer 27

* Hypotonia * Sleeping * Feeding difficulties/failure to thrive * Delayed milestone * Strabismus * Scoliosis * Hypothalamic disorder * Then gain weight easily, can't stop eating as get older

Question 28

Newborn heel prick testing UK - which ones tested

Answer 28

* Done via Guthrie card - 4 blood spots * Phenylketonuria * Congenital hypothyroidism (look for high TSH) * Medium chain Acyl-CoA-dehydrogenase deficiency (MCADD) * Sickle cell disease * Cystic fibrosis

Question 29

Consequence of untreated congenital hypothyroidism

Answer 29

* Severe mental disability * Short stature * Large mouth * Previously called cretinism

Question 30

Causes for tall child

Answer 30

* Familial * Early/precocious puberty - will then not achieve height though * Hyperthyroidism * GH secreting adenomas * Sotos * Marfans/Klinefelters

Question 31

Marfans characteristics

Answer 31

* Marfan thumb * Wide wing span

Question 32

Klinefelters syndrome

Answer 32

XXY Can cause tall stature

Question 33

Precocious puberty ages

Answer 33

Girl before 8 Boys before 9

Question 34

Delayed puberty ages

Answer 34

* Boys - no testicular development by 14 * Girls - no breast tissue development by 13 or no menstruation by 15

Question 35

Pubertal problems

Answer 35

* Premature adrenarche * Precocious puberty * Delayed puberty * Isolated menarche

Question 36

Cause of obesity and slowed growth

Answer 36

* Cushings syndrome