Growth, Growth Hormone, and Short Stature
Growth assessment
Growth integrates nutrition, thyroid hormone, growth hormone (GH)/IGF-1, sex steroids, and skeletal health. Plot length or height, weight, and head circumference on the correct chart for age and sex. Calculate height velocity over at least 6 months and express it as cm/year. A child crossing centiles downward is more concerning than a child growing steadily at the 3rd centile. Bone age of the left hand and wrist helps distinguish constitutional delay, with delayed bone age and predicted adult height near target, from familial short stature, with normal bone age and short target. Midparental height is (father + mother + 13 cm)/2 for boys and (father + mother − 13 cm)/2 for girls; the target range is ±8.5 cm.
GH deficiency is suggested by severe short stature, low velocity, delayed bone age, neonatal hypoglycemia, jaundice, micropenis, and midline defects. Confirm with provocative testing and IGF-1/IGFBP-3; a random GH is useless. GH resistance shows high GH, low IGF-1, and low IGFBP-3. Traps include measuring without a stadiometer, using adult BMI or uncorrected premature charts, and blaming GH before excluding hypothyroidism, celiac disease, inflammatory bowel disease, chronic kidney disease, Turner syndrome in girls, and psychosocial deprivation. During GH treatment monitor growth velocity, IGF-1, glucose, and symptoms of slipped capital femoral epiphysis or benign intracranial hypertension.
Worked rule
A boy whose father is 170 cm and mother 158 cm has midparental height (170 + 158 + 13)/2 = 170.5 cm, target 162–179 cm. If he is 145 cm at 12 years with bone age 10 years, constitutional delay is likely. If bone age is 12 years, investigate.