ICR-Pediatric Growth Disorders Flashcards
Greatest determinate of size during intrauterine life. What are the big growth factors during this time?
Maternal-placental-fetal unit. IGF1 & IFG2 are the major growth factors.
Causes of intrauterine growth restriction
Abnormal placenta, crowding, infection, toxins and chromosomal abnormality
When do you know that intrauterine growth restriction will affect a baby’s adult height?
If you don’t see catch up growth in the first year of life.
Average growth rate during intrauterine life
26 inches per year
Average growth rate during infancy
6-12 inches per year
How common is rechanneling?
Maternal factors lessen over 12-18 months and channeling can be normal during this time. This is not normal after 3 years of age.
Average growth rate during childhood? Major growth factors during this period?
2-3 inches per year. GH and thyroid hormone are critical during this period.
How does obesity contribute to length growth?
You get linear growth. However, obese kids are not taller because they tend to advance their growth plates as well.
How does hypercortisolism contribute to growth?
You see rapid weight gain with tapering of height
Average onset age for puberty in girls
8-13. Breast development is first evident. Peak heigh velocity at Tanner 2-3.
Average onset age for puberty in boys
9-14. Testicular volume increase is first evident. Peak height velocity at Tanner 4-5.
Tanner staging
*
Major growth factor in puberty
Sex steroids
What bones begin growing 1st in puberty?
Distal (feet and hands) get big 1st.
Weight 2 standard deviations below the mean for age
Failure to thrive. You can also consider genetic potential and crossing lines.
Height 2 standard deviations below the mean for age
Short stature. You can also consider genetic potential and crossing lines.
Mid-parental height prediction
This is about 75% accurate. The further apart the parents are in height, the less accurate the test is.
Medications that affect childhood growth
Glucocorticoids (autoimmune or asthma) or stimulants (ADHD suppresses appetite).
How might mid-line defects affect stature?
Pituitary is also midline and TSH or GH deficiency may cause short stature.
Screening labs you might use for growth disorders
CBC, ESR, serum electrolytes, LFT’s, urinalysis, thyroid function (TSH, fT4) and bone age (compare growth plates to give picture of skeletal maturity)
Secondary labs to do for assessing growth disorders
Karyotype (45X), IGF-1 (GH surrogate measurement), other pituitary hormones (GnRH, Estradiol, testosterone, cortisol), celiac panel, Cl- sweat test and MRI of brain and sella.
What will the bone age be in kids with constitutional delay of puberty (late bloomers)?
Bone age is delayed. They hit puberty later so they have more room in their growth plates when everyone else is growing and growth plates are reducing.
Important factors in determining constitutional delay of puberty?
Late maternal menarche or paternal height growth after high school. Also confirm that there is absence of chronic disease.
What will the bone age be in kids with genetic short stature?
Bone age = chronological age. There is no delay in puberty and they have a normal growth rate and velocity, they may have just started at a lower percentile due to genetics.
What is causing this growth failure?
Loss of height w/gain in weight = endocrine.
What is causing this growth failure?
He’s already small, but crosses weight and height lines at puberty = nutrition or GI
What is the most sensitive predictor of health in kids?
Growth
