Assuring Pediatric Nutrition in the Community

FREQUENTLY USED GUIDELINES:
Assessing Nutritional Status - Growth Charts

What are growth charts?
Plotting at regular intervals
Change in percentiles
Changing from infant to child/adolescent charts

What are growth charts?
Growth charts were constructed from data collected from large numbers of healthy children. The most commonly used charts in North America were prepared by an expert committee for the Centers for Disease Control and Prevention (CDC) and consist of percentile curves describing rates of growth. These charts were released in 2000 and replace the 1977 National Center for Health Statistics (NCHS) charts. At present, the following charts are available:

Birth to 36 months: weight for age, length for age, weight for length, head circumference for age for boys and for girls. Children used for these charts were weighed nude; recumbent length measurements were made.

2 to 20 years: weight for age, height for age, weight for height (for children less than 120 cm), body mass index (BMI) for age for boys and for girls. Children used for these charts were weighed in light clothing and stocking feet; standing height measurements were made.

More information about the new charts, including guidelines for use can be found on the CDC website.

Specialty growth charts that include data from populations of children with special health care needs (e.g., children with cerebral palsy and Down syndrome) have been compiled.

Should growth be plotted at regular intervals?
Plot growth at regular intervals to provide information for a comprehensive assessment. Patterns of growth are far more useful than static data.

Example: When any one point in time is examined, this child appears to be at significant nutritional risk. When previous growth data are included, however, it becomes evident that this child's growth rate has remained constant. (In fact, she has cerebral palsy, a medical condition sometimes associated with a decreased growth rate.) She remains at nutritional risk, but the data are less alarming when compared to previous measurements.

Do most children continue to grow in the same percentile?
Growth charts depict the mean rate of growth for a large population of children. The growth of an individual child may not follow the curve exactly. Because all children do not grow at the same rate, it is likely that a child’s stature and/or weight may cross channels. When data is viewed longitudinally, patterns that indicate appropriate growth can be observed.

Example: Although the growth of this child crossed channels, the changes were consistent. This child's rate of growth followed the general shape of the growth curve and was appropriate.

What does a change in percentile channels mean?
It is not uncommon for growth to cross channels in an upward direction during growth spurts. Likewise, periods of illness may be marked by a decrease in growth channels. Thus, professional judgement should be used when interpreting growth data. When a child’s growth crosses channels it is prudent to obtain a recent health and diet history of factors that can affect growth rates.

When do I change from infant (0 to 36 months) to children (2 to 20 years) growth charts?
When to switch charts varies from institution to institution—it is fine to switch anytime between 2 to 3 years of age. Determining an exact time at which charts should be changed is not as important as understanding the differences between the two sets of charts. (Recumbent length was used for the 0-36 month old charts, while standing height was used for the 2-20 year old charts.) An individual’s standing height is typically less than his or her recumbent length. Thus, if the method of measurement used for an individual is not the same as the method used with the study population, assessments can be skewed, and a child’s rate of growth may appear delayed or accelerated.

Example: This child's growth appears stunted when height is measured and plotted on birth to 36 months growth charts. When height is plotted on the correct chart (2 to 20 years), however, growth is appropriate.