Disorders of growth
1. Summarize normal growth velocity for children until the pubertal growth spurt.
Second 6 months: approximately 8 cm
Third year: approximately 8 cm
Later childhood until puberty (5 to 10 years): growth averages 5 to 6 cm/year
2. Summarize growth velocity during the pubertal growth spurt.
Maximum growth rate is 11 to 13 cm/year.
In girls, growth spurt occurs early in puberty (breast Tanner stage II).
Growth spurt is later in boys (pubic hair Tanner stage III-IV, testicular volume 12-15 mL).
Some children may experience a transient period of slow growth just before the onset of puberty.
3. How is height measured accurately?
The most essential tool for the detection of growth abnormalities is the ability to obtain accurate and reproducible measurements. This requires the availability of appropriate equipment as well as proper positioning of the patient.
Children should be shoeless, and hair decorations or braids may need to be removed.
4. What technique is used for infants up to 2 years of age?
Supine length should be measured in infants. Accurate measurement requires a supine stadiometer, a boxlike structure with a headboard and movable footplate. Two people are needed, with one holding the infant’s head against the headboard while the other straightens the legs and places the ankles at 90 degrees against the movable footplate. The length is read from the attached measuring device, or marks are made for measurement by tape measure.
5. Describe the technique for children 2 years of age and older.
1. Standing height is measured. Accurate measurement requires a stadiometer with a rigid headboard, footplate, and backboard.
2. The child stands against the backboard, with heels, buttocks, thoracic spine, and head touching.
3. The measurer exerts upward pressure on the patient at the angle of the jaw to bring the spine into full stretch, and the headboard is lowered until it touches the top of the head. A counter reads the measurement.
4. If a stadiometer is not available, the child should stand against a wall in the same position as used for a stadiometer. A rigid right angle is moved downward to touch the top of the head, and a mark is made and measured.
5. Weight and head circumference (when appropriate) should be recorded.
The second critical tool for evaluation of growth is the standardized growth curve, and all measurements should be plotted rather than just recorded in the chart. A carefully constructed and up-to-date growth curve is critical to the recognition of growth abnormalities. Furthermore, the more points that are plotted on the curve, the greater the understanding of the child’s growth. Thus efforts should be made to obtain growth measurements at all patient contacts, including illness visits, because well-child visits are infrequent during the middle childhood years when growth abnormalities are most common.
7. List the common errors in plotting growth charts.
Errors in plotting of growth points are a frequent cause of apparent growth abnormalities. Common errors include:
8. What is meant by “appropriate growth chart”?
A number of growth charts are available, and careful consideration should be given to the appropriate chart for a particular patient at a particular time. Commonly available growth charts include:
Charts for plotting supine length (the 0- to 36-month charts in common use)
Charts for plotting stature (i.e., standing height) (2- to 18-year charts)
Other specific growth charts are available and should be used when appropriate. These include:
9. How do age and position affect growth measurements?
10. What historic information is necessary for interpreting a growth chart?
Birth history and birth weight
Attainment of developmental milestones
Height of biological parents and family history of significant short stature
Timing of parental puberty and family history of significant pubertal delay
11. What physical examination findings help interpret a growth chart?
KEY POINTS 1: GENERAL GROWTH
1. Proper evaluation of growth depends on accurate measurement of height and correct plotting of measurements on the appropriate growth curve.
2. Common errors in plotting include plotting the wrong height, not plotting the patient’s height at the exact chronologic age, and use of an inappropriate growth chart.
3. An abnormal growth velocity for age generally distinguishes growth abnormalities from normal growth variants.
4. Apparent abnormalities in growth are most frequently due to normal growth variants. Poor growth secondary to chronic medical illness is the next most frequent cause. Hormonal causes are less frequent.
12. How does radiologic imaging help interpret a growth chart?
A bone-age film can provide important information about skeletal maturity. The degree of skeletal maturity is an important determinant of remaining growth potential and can help estimate expected height in children developing more slowly or more rapidly than their peers.
13. Explain the significance of parental target height or “midparental height.”
Parental height helps determine expected adult height on the basis of genetic potential. Add the parents’ heights in centimeters; add 13 cm if the child is male, and subtract 13 cm if the child is female; then divide by two. The resulting midparental height ±5 cm gives the 10th to 90th percentile for offspring of those parents.
14. What is the most important factor in identifying an abnormal growth curve?
An abnormal growth velocity for age generally distinguishes growth abnormalities from normal growth variants. Although there are many causes of short stature, including genetic, short normal children grow normally, whereas children with a problem almost always have an abnormal growth velocity. For example, a child with stature in the fifth percentile who is growing with a normal growth velocity is less worrisome than the child whose stature has fallen from the 90th to the 75th percentile, even though the latter is taller than the former. Growth velocity abnormalities may, however, be subtle.
15. What causes abnormal growth in children?
Abnormalities in growth are most frequently due to either normal growth variants (familial short stature or constitutional delay of growth and puberty) or underlying chronic medical illness, either recognized or unrecognized. Hormonal causes are less frequent.
16. Which syndromes are associated with abnormal growth?
17. List nonendocrine diseases and treatments that may be associated with poor growth.
Pulmonary disease (cystic fibrosis, asthma)
Gastrointestinal disease (Crohn’s disease, inflammatory bowel disease)
18. Using the tools of growth curve, bone age, and height, how does one distinguish between familial (genetic) short stature and other causes?
