The most common reasons for deviant measurements are technical (i.e., faulty equipment and human errors). Repeating a deviant measurement is the first step. Separate growth charts are available and should be used for very low birth weight infants (weight <1500 g) and for those with Turner syndrome, Down syndrome, achondroplasia, and various other dysmorphology syndromes.
Variability in body proportions occurs from fetal to adultlife. Newborns’ heads are significantly larger in proportion tothe rest of their body. This difference gradually disappears.Certain growth disturbances result in characteristic changesin the proportional sizes of the trunk, extremities, and head.Patterns requiring further assessment are summarized inTable 6-1.
Evaluating a child over time, coupled with a careful history and physical examination, helps determine whether the growth pattern is normal or abnormal. Parental heights may be useful when deciding whether to proceed with a further evaluation. Children, in general, follow their parents’ growth pattern, although there are many exceptions.
For a girl, midparental height is calculated as follows: −2.5 2
For a boy, midparental height is calculated as follows: +2.5 2
Actual growth depends on too many variables to makean accurate prediction from midparental height determination for every child. The growth pattern of a child with lowweight, length, and head circumference is commonly associated with familial short stature (see Chapter 173). Thesechildren are genetically normal but are smaller than most
Discrepant percentiles (e.g., weight 5th, length 5th, head circumference 50th, or other discrepancies)
Caloric insufficiency Midparental heights Thyroid hormone Growth factors, growth hormone testing Evaluation of pubertal children. A child who, by age, is preadolescent or adolescentand who starts puberty later than others may have the normal variant called constitutional short stature (see Chapter173); careful examination for abnormalities of pubertaldevelopment should be done, although most are normal. Anevaluation for primary amenorrhea should be consideredfor any female adolescent who has not reached menarche by15 years or has not done so within 3 years of thelarche. Lackof breast development by age 13 years also should be evaluated (see Chapter 174).
Starting out in high growth percentiles, many children assumea lower percentile between 6 and 18 months until they matchtheir genetic programming, then grow along new, lower percentiles. They usually do not decrease more than two major percentiles and have normal developmental, behavioral, and physicalexaminations. These children with catch-down growth should be followed closely, but no further evaluation is warranted.
Infants born small for gestational age, or prematurely, ingestmore breast milk or formula and, unless there are complicationsthat require extra calories, usually exhibit catch-up growth in the first 6 months. These infants should be fed on demand and provided as much as they want unless they are vomiting (notjust spitting up [see Chapter 128]). Some may benefit from ahigher caloric content formula. Many psychosocial risk factorsthat may have led to being born small or early may contributeto nonorganic failure to thrive (see Chapter 21). Converselyinfants who recover from being low birth weight or prematurehave an increased risk of developing childhood obesity.
Growth of the nervous system is most rapid in the first 2 years, correlating with increasing physical, emotional, behavioral, and cognitive development. There is again rapid change during adolescence. Osseous maturation (bone age) is determined from radiographs on the basis of the number and size of calcified epiphyseal centers; the size, shape, density, and sharpness of outline of the ends of bones; and the distance separating the epiphyseal center from the zone of provisional calcification.
Parallel to the changes in the developing brain (i.e., cognition, language, behavior) are changes in the physical development of the body.