Growth and Puberty Flashcards
How often should height and weight be measured and plotted
each visit which coincides with well child care due dates until age 21
Growth can be worrisome along 2 variables:
- overall height (short stature)
- growth velocity (falling off the growth curve)
*Short stature and growth failure frequently but not always occur together.
what is considered short stature
as height over 2 SD below the mean for age and gender or over 2 SD below mid-parental height.
what is considered growth failure
abnormally slow growth velocity or crossing 2 percentile lines on the growth chart
growth failure may be the first and sometimes only sign of:
an underlying health problem like
- cardiac
- GI
- renal
- endocrine abnormalities
the consequences of a delayed or missed diagnosis of growth failure may mean:
permanent height deficits as these children may have an insufficient time, even if the underlying problem is fixed, to make up lost growth potential
parameters in identifying concerning growth
- accurate measurements (if in doubt, re-measure)
- calculate mid-parental height
- possible evaluation of skeletal maturation (by bone Xray) and body proportions to determine if pt needs further w/u
how do you accurately measure height
- measure supine until age 2
- standing, no shoes, no hair ties
- have head, shoulder blades, but, and heels touch wall
- standing measurements should not be compared to previous supine measurements
why should standing measurements NOT be compared to previous supine measurements
as during the transition at 2y/o, as standing will be a little shorter
How do you calculate growth potential for boys and girls
*I remember it as the average of the biological mother and father’s heights with 1 adjustment- because girls start puberty earlier than boys and do not grow as much during puberty as boys, they lose the extra growth (equivalent to 5 inches).
Girls- subtract 5 inches from dad’s height before averaging
Boys- add 5 inches to mom’s height before averaging.
- should be w/in +/- 3 inches
- it is possible that one of the parents had an undiagnosed growth problem so their final height in the calculation may skew the child’s calculation, leaving your falsely reassured. So, ask if the parent’s height is consistent with their other biological family members.
____ is directly correlated with skeletal maturation
The time of epiphyseal closure
*If skeletal maturation (bone age) is delayed, then the patient will have more time, than their chronological age would suggest, to catch up in their height
__ can be helpful in diagnosing constitutional growth delays (CGD), but are generally reassuring in patients who have short stature due to systemic disorders that are being corrected and you are hoping to give them a better height outcome.
bone age x-ray
what is a bone age x-ray
an A/P view of the left hand and wrist. The radiologist will use the Greulich-Pyle standards to report a bone age for the patient compared against their chronological age.
How do you use bone age x-rays to assess growth?
- place a dashed line moving their current height back into the growth chart to match their skeletal age. In this particular case, doing so indicates that this patient with delayed skeletal maturation is actually on target to meet their genetic potential (mid-parental height)
- This patient will have a delayed onset of puberty with corresponding delay in epiphyseal closure, giving them extra time to meet that genetic potential.
why are bone height predictions not completely accurate in any patient
because they cannot predict the tempo of puberty.
describe a dx of familial short stature
- reflects those who are tracking fine on the growth chart headed to a mid-parental height projection of their short parents.
- Because the intrauterine environment and nutrition in pregnancy are the determinants of birth weight and initial growth, these infants will be on a higher growth percentile until age 6-18m after which they re-establish a new trajectory consistent with their genetic potential. This can be concerning until they show a normal growth velocity just along a lower growth percentile.
Because the ___ and ___ in pregnancy are the determinants of birth weight and initial growth, these infants will be on a higher growth percentile until age ____- after which they re-establish a new trajectory consistent with their genetic potential.
intrauterine environment and nutrition
6-18 months
(short stature)
how do you screen for skeletal dysplasia
An arm span significantly shorter than height is concerning. Measure the arm span fingertip to fingertip.
- In prepubertal children, the arm span should only be about 1cm less than height.
- The ratio of upper body to lower body should be 1:1 by age 10.
- At age 4y, it is 1.4:1.
- The lower body is measured pubic symphysis to the floor and upper body is total height minus the lower body measurement.
nutritional causes of short stature/abnormal growth
- zinc, iron deficiency
- anorexia
- IBD, celiac, CF
endocrine causes of short stature/abnormal growth
- hypothyroid
- GH deficiency
- Cushing
- Precocious puberty
chromosomal defect causes of short stature/abnormal growth
- Turner Syndrome
- Noonan Syndrome
- Prader-Willi Syndrome
other causes of short stature/abnormal growth
- Skeletal dysplasia
- IUGR/SGA
- Metabolic
- Chronic diseases
- Pscyhosocial deprivation
- Drugs (glucocorticoids, stimulants)
describe CGD
- A fall off in growth typically occurs with the first 2-3 years of life and following this, CGD patients will have normal growth velocity following a percentile shorter than their genetic potential.
- diagnosis of exclusion, so these kids should get a work up for “failure to thrive”
that growth charts are designed for the general population, which expects that a male will have a growth spurt around age ___, and females at ___
13-14y
11-12y
*therefore a CGD kid will appear to fall further off the curve at that age.
A history clue to CGD is
parents were “late bloomers” with maternal delay of menarche and paternal growth beyond high school.
treatment of CGD
- usually reassurance.
- An endocrinologist may consider a short course of testosterone for boys or estrogen for girls at puberty.
describe what failure to thrive is
deceleration of weight gain to less than 3% (-2SD) or crossing 2 major percentile lines in the first 3 years of life.
-Nutritional growth retardation occurs when their poor nutritional status begins to affect their linear growth with evidence of falling off the height curve.
causes of failure to thrive
1. good diet history is essential, also consider diseases which may affect: 2. metabolism or 3. GI absorption, such a 4. cardiac, 5. renal disease, 6. celiac 7. IBD among others.
-Usually these children have poor nutrition and/or 8. psychosocial factors as the cause, but don’t skip consideration of chronic diseases
After age ___, children should not fall off the height curve due to CGD or familial short stature.
3y
what height and weight pattern should alert you to underlying endocrine disorder?
note the child’s height fell off the growth curve between 6-8y but her weight % stayed the same until 8-9y
Symptoms of hypothryoidism
- delayed bone growth
- youngness appearance
- puffy face
*you may not find typical adult hypothyroidism symptoms such as weight gain, loss of hair, cold intolerance, fatigue, etc
differentiate between primary and central hypothyroidism
- Primary: failure at the level of the thyroid gland (and pit. gland keeps signaling the thyroid gland
- low T4 and high TSH
- Central hypothyroidism: occurs at the level of the pituitary gland
- low T4 and an inappropriately low or normal TSH
- often occurs concurrently with GH deficiency and other pit. hormone deficiencies
- *Work up for brain tumor
Primary hypothyroidism will respond to
exogenous levothyroxine within 4-6 weeks and the patient’s growth will improve.
The function of growth hormone is to promote:
linear growth but also to increase lean muscle mass
Causes of acquired GH deficiency
- Trauma
- CNS infection
- Tumor
- cranial irradiation
Sx of GH deficiency
- short stature
2. lack of lean muscle mass actually gives them a chubby appearance
how should you test for GH deficiency
- A random serum GH level is not helpful as GHRH generates a pulsatile release of GH, especially at night during sleep.
- However, insulin growth factor (IGF)-1 is produced from the liver in response to GH and this can be measured in serum. Additionally, the production of the binding protein for transporting IGF-1, which is known as IGFBP-3, is also controlled by GH, and is the more accurate serum level to check in infants to screen for GH deficiency.
-IGF-1 or IGFBP-3 can be done as a random draw as a screening test but are not diagnostic of growth hormone deficiency.
- Diagnosis of GHD requires a GH stimulation test, using medications such as clonidine and arginine.
- This test should be reserved for the endocrinologist.
tx of GH deficiency
exogenous GH
Hallmarks of Prader-Willi Syndrome
- short stature due to GH deficiency
- delayed puberty
- cognitive/developmental delays
- chronic hunger leading to excessive eating and obesity
Hallmarks of Noonan Syndrome
- Short stature
- possibly develoopmental delays
Facies: - wide-spaced downward slanting eyes
- low set ears
- CHD– most commonly pulmonary stenosis
what is the most common cause of genetic short stature in females
Turner Syndrome
What causes short stature in Prader-Willi syndrome and Noonan Syndrome
PW- GH deficient
Noonan- GH post receptor signaling resistance?
what is Turner syndrome
- absent or structurally abnormal 2nd x chromosome.
- Some girls may have mosaicism with the abnormal 2nd x chromosome present in only some of the cells of the body.
-The genotype and phenotype of Turner syndrome are not equivalent, with the physical manifestations varying girl to girl.
most common manifestation of all Turner syndrome patients is
short stature.
-They usually fall off the height growth curve fairly early, although girls with tall parents may fall off later
tx of Turner syndrome
GH treatment is helpful for these girls in improving their final height, although they are not truly GH deficient
Clinical presentation of Turner Syndrome
- short stature
- Increased carrying angle (due to lymphedema in utero
- Short webbed neck
- Micrognathia (small chin)
- Retrognathia (retracted chin)
- ovarian failure w/ delayed puberty (due to lack of 2 normal chromosomes)
Primary care work up evaluation of Growth and height
- plot height and growth at all visits
- recheck if doubt or concern
- Screening labs/ markers for nutritional growth retardation
- Bone age (left hand and wrist) for children under 3y/o
what screening labs do you order for worrisome growth
- metabolic panel- renal disorder
- CBC- underlying chronic conidtion
- Karyotype in girls- Turner
- TSH and T4 (IGF-1 or IGFBP-3)
- UA- renal disorder
Nutritional Growth retardation:
- ESR and history- IBD
- TTG and IgA- Celiac
Describe the HPG axis at the onset of puberty
- the hypothalamus begins to secrete GnRH in a pulsatile fashion, first at night.
- This stimulates the anterior pituitary to produce luteinizing hormone (LH) and follicle stimulating hormone (FSH) which stimulate the ovaries in girls to produce estrogen and the testes in boys to produce testosterone.
- Along with the specific changes to breast and sex organs, this also stimulates linear growth acceleration and advancement of bone age with eventual closure of growth plates.
The advancement of bone age is due to ___ in both sexes.
estrogen
*The ovaries produce estrogen for females, and males produce estrogen by converting testosterone to estrogen via aromatase
how roles does the adrenal gland play in puberty
- increased production of adrenal androgens (DHEA-S and androstenedione) which results in pubic and axillary hair, body odor and acne in both sexes.
- This is termed adrenarche and is independent of GnRH, FSH and LH.
Adrenarche is independent of:
GnRH, FSH, and LH
what is the term used to describe the activation of the HPG axis which initiates the sexual changes associated with puberty.
Gonadarche
describe Tanner stage I and II in females
Pre-pubertal appearance is Tanner I, and with respect to breast development,
Tanner 2 is the development of breast budding, followed by increasing growth of breast tissue.
What is the mean age and early age limit for breast development to begin in different ethnicities
White: EAL: 8y/o, Mean: 10.4y/o
Black: EAL: 6.6y/o, Mean: 9.5y/o
Hispanic: EAL: 6.8y, Mean: 9.8y
how to measure female puberty and development
- breast development
2. menarche
that pubic hair is controlled by the ___ component of puberty
Breast development and menarche are functions of __, and are evidence of estrogen secretion in girls
adrenal
gonadarche
Pubic hair occurs before breast development in about ___% of girls.
15
What is the mean age and early age limit for menarche in different ethnicities
White: EAL: 10.65y, Mean 12.55y
Black: EAL: 9.7y, Mean: 12.06y
Hispanic: EAL: 10.05y, Mean: 12.25y
The first change of puberty in males is ___, stimulated by: ___
testicular growth
FSH and LH
Androgens from the adrenal gland and testes result in:
pubic, facial and axillary hair, and penile enlargement.
how do you measure testicular size?
- Orchiometer– provides volume measurement (in ml)
2. tanner stage chart (in cm)
Describe the Tanner stage for males
I= 3cm (~2.5ml) 2= 4 cm (2.5-3.2 ml) 3= 10 cm (3.6ml) 4= 16 cm (4.1-4.5ml) 5= 25 cm (over 4.5ml)
Decribe the mean age for:
- testes 3ml (or 2.2 cm)
- pubic hair
- penile enlargement
- peak height velocity
- testes 3ml (or 2.2 cm) - 11.8y
- pubic hair- 12 y
- penile enlargement- 13 y
- peak height velocity- 14 y
Delayed puberty is defined by
no pubertal signs by 13 y in girls and 14y in boys or a lack of progression with no menarche 4 years after puberty onset in girls or incomplete genital growth in males 5 years after puberty onset.
Delayed puberty can be broken down into
- hypogonadotropic hypogonadism, AKA central hypogonadism- when the HPG axis is not working due to low GnRH or LH/FSH,
- hypergonadotropic hypogonadism, AKA primary hypogonadism- where the defect is in the target organs (ovary or testes).
causes/examples of central hypogonadism or hypogonadotropic hypogonadism
- CGD- although temporary
- Prader-Willi syndrome
- Kallman syndrome
- Acquired: pit or hypothalamic tumor, cranial irradiation or infection
- functional central hypogonadism
what is Kallman Syndrome
a isolated gonadotropin deficiency and also have symptoms of anosmia or hyposmia.
Some examples of functional central hypogonadism include
- anorexia or malnutrition,
- excessive exercise,
- hyperprolactinemia and
- hypothyroidism
The central hypogonadism is reversible when:
the underlying condition is treated.
The HPG axis is active for the __ of life in males, and the __ in females.
-Therefore, patients suspected of central hypogonadism or hypergonadotropic hypogonadism, such as those with suspected Prader-Willi (micropenis) or Turner syndrome (features or aortic coarctation) can be tested for: __ levels during that time period to get a peek at what hormone production they might have at puberty.
first 6 m
first 2 y
FSH and LH
*after that time HPG axis becomes quiescent until puberty
___ is primary ovarian or testicular failure, so they do not enter gonadarche, although they will have sign of adrenarche, as will patients with __
Hypergonadotropic hypogonadism
central hypogonadism.
Due to the lack of negative feedback from the gonads in hypergonadotropic hypogonadism, these patients will have an ___as their ___ are working fine.
elevated FSH and LH
GnRH generator and anterior pituitary
examples/causes of Hypergonadotropic hypogonadism
usually sex chromosome abnormalities
- Turner Syndrome (XO)
- Klinefelter (XXY)
Causes of primary ovarian failure include:
- xx gonadal dysgenesis
- galactosemia
- radiation and chemotherapy, and
- autoimmune destruction
- Hypergonadotropic hypogonadism- Turner and Klinefelter
Primary testicular failure can be seen in:
- Klinefelter’s and
- Noonan syndrome,
- cryptorchidism and
- secondary to radiation.
what causes testicular failure in Klinefelter sydnrome
seminiferous tubules fibrose
An individual affected w/ Klinefelter will have
- XXY
- microphallus,
- small testes,
- infertility,
- arrested puberty,
- gynecomastia and
- learning disabilities.
Describe the workup of delayed puberty
- Hx
- height and growth rate
- bone age (typically will be delayed)
- Labs: gonadotropins, testosterone, estradiol (may consider TSH, T4, prolactin, CBC, ESR, BMP)
- Karyotype if elevated gonadotropins or elevated FSH and LH)
*contact an endocrinologist for a bit of guidance to make sure you get the correct labs.
what labs should you order for delayed puberty
- FSH and LH (if the GnRH generator is functioning, the FSH and LH will be elevated, but will be low if the defect is at the level of the generator)
- gonadotropins,
- testosterone,
- estradiol
- (may consider TSH, T4, prolactin, CBC, ESR, BMP)
what history questions should you ask when evaluating delayed puberty?
- sense of smell
- cranial irradiation
- chemothearpy/ other radiation
- fhx of genetic disorders
- exercise/nutrition/eating disorders
- previous concerns about growth
Hypogonadism can be treated with ___ once the patient is under the care of an endocrinologist.
exogenous testosterone or estrogen/progesterone
Symptoms of central precocious puberty
- early onset and progression of sexual development including
- accelerated linear growth with
- advanced bone age,
-in boys: less than 9y and
-girls:
less than 7y (hispanic/AA)
less than 8 y(caucasian).
causes of CPP
- previous cranial irradiation
- /infection/
- trauma or
- brain tumor,
- although the most likely cause is idiopathic.
In girls, the chance of brain tumor is 5%, in boys 50%
In girls under 5y/o who have CPP, they will typically not have signs of ___ but in girls over 5y/o with CPP, they will.
adrenarche,
Peripheral precocious puberty is puberty occurring __ of gonadotropin secretion
independent
Cause of peripheral precocious puberty in girls
- ovarian cysts, and
- exogenous estrogens including:
- lavender products and
- tea tree oil.
- McCune-Albright Syndrome*
- Severe primary hypothyroidism*
*also a cause of PPP in males
Cause of peripheral precocious puberty in boys
- adrenal,
- testicular, and
- hCG secreting tumors
- McCune-Albright Syndrome*
- Severe primary hypothyroidism*
*also a cause for PPP in females
McCune-Albright syndrome causes a triad of:
- precocious puberty,
- café-au-lait spots (often on butt and gential area),
- fibrous dysplasia of multiple bones
mechanism for PPP in primary hypothyroidism
hormonal overlap as TSH, which is secreted in abundance when the thyroid does not produce sufficient thyroid hormone, is structurally similar to FSH
presentation of PPP in primary hypothryroidism
- Girls will present with breast development and
- boys with testicular enlargement
- TSH over 500 leads to
- poor linear growth and delayed bone age (exact opposite of CPP)
* This is the tip-off to primary hypothyroidism as the cause of their precocious puberty.
describe the evaluation of precocious puberty
- Hx
- Growth pattern– nl or accelerated?
- PE: Tanner stage, size, symmetry and size of testes (w/ orchiometer), cafe-au-lait spots, neurologic findings for focal deficits
- Bone age, estradiol
- Random LH and FSH
- Possibly estradiol and pelvic ultz in girls, testosterone, androstenedione, DHEA-S, 17-hydroxyprogesterone, hCG, adrenal/testicular ultz
*touch base w/ endocrine when you start ordering labs
what history questions should you ask when evaluating precocious puberty?
- onset andprogression of pubertal changes,
- look for history clues in exogenous hormones:
(3. estrogen creams, - testosterone gel),
- cranial irradiation/infection
- trauma
how does looking at the growth chart help in precocious puberty
poor linear growth (hypothyroidism),
normal growth (benign forms early puberty such as benign thelarche and benign adrenarche which we will discuss momentarily) or
accelerated growth(central or peripheral precocious puberty).
If a random LH is elevated using supersensitive pediatric assays, this would indicate ___ and the next step is __
If LH is low, ___ is not ruled out, as the patient’s LH may have just hit a nadir. The patients may go on to need ___ and this should be initiated by the endocrinologist.
central precocious puberty
a brain MRI.
central preocious puberty
GnRH stimulation tests, etc.
The focus of treatment of precocious puberty is
- first to r/o treatable conditions such as hypothyroidism, brain tumors, testicular tumors, adrenal tumors, etc., and
- then to delay further pubertal development in an attempt to reclaim final height potential.
what is premature thelarche
- refers to the onset of breast development without other pubertal changes (adrenal changes of body hair, changes of gonadarche, etc.) and is not associated with growth acceleration or bone age advancement.
- It is a form of incomplete precocious puberty.
describe the breast development w/ premature thelarche and its causes
- Usually the breast development progresses very slowly or waxes and wanes in size. When it occurs less 2y, it is usually due to the greater ovarian hormone production during the first 2 years of life that I mentioned in the slide on delayed puberty.
- Beyond age 2y, it may represent periodic fluctuations in the HPG axis with temporary FSH secretion.
management of premature thelarche
- It is okay to watch for progression or changes in growth velocity about every 4 months.
- It is acceptable to get a bone age (if older than 3y) and/or estradiol level.
what is premature adrenarche
Premature adrenarche occurs when adrenal androgen secretion is activated, and results in pubic and/or axillary hair, with no evidence of gonardarche, in boys less than 9y and girls less than 8y (7y in AA girls).
*Linear growth and bone age should remain normal, and advancement suggests the need for further evaluation.
DDX for premature adrenarche
- benign premature adrenarche,
- adrenal or
- testicular tumors, and
- congenital adrenal hyperplasia
What labs could you order for premature adrenarche evaluation?
- serum testosterone,
- DHEA-S,
- androstenedione, and
- 17-hydroxyprogesterone.
