Monitoring a child’s growth is a part of pediatric healthcare. Plotting weight, height, and body mass index over time provides a snapshot of their overall health and nutritional status. These measurements are compared to reference data on a growth chart, which helps providers identify when a child’s growth pattern deviates from their peers. For most children, standard growth charts from organizations like the World Health Organization (WHO) are used. However, for children with certain health conditions, these general charts may not provide an accurate picture of their growth journey.
The Need for Specialized Growth Charts
For children with cerebral palsy (CP), standard growth charts are of limited use. The growth patterns of children with CP can differ substantially from the general pediatric population. Cerebral palsy affects muscle tone, movement, and posture, which influences body composition. Many children with CP have lower muscle mass and higher fat mass compared to their peers, a difference standard charts cannot account for.
These physiological differences mean a child with CP might be healthy but still fall below the 5th percentile on a standard chart. This can lead to misinterpretation or mask actual nutritional problems. Factors like spasticity can increase a child’s energy expenditure, while co-occurring issues like dysphagia (feeding and swallowing difficulties) can make it challenging to consume enough calories for growth.
Development and Types of CP Growth Charts
To address the limitations of standard charts, researchers developed growth charts specifically for children with cerebral palsy. These charts are descriptive reference tools created from data collected from thousands of children with CP. This approach ensures a child’s growth is compared to others who share a similar health condition, providing a more meaningful context.
A feature of these specialized charts is their stratification based on the Gross Motor Function Classification System (GMFCS). The GMFCS is a five-level system that categorizes a child’s gross motor function, particularly their ability to walk. Researchers found a strong correlation between a child’s GMFCS level and their growth pattern. Consequently, they created separate sets of growth charts for each GMFCS level, allowing for a more precise comparison of a child’s growth against their direct peers.
Measuring and Plotting Growth
Gathering measurements for children with CP requires specific techniques, as standard methods are often impractical. Obtaining a standing height can be difficult for a child who cannot stand straight due to muscle contractures, scoliosis, or challenges with motor control. To overcome this, healthcare providers use alternative, or segmental, measurements to estimate a child’s stature.
Common segmental measurements include knee height and upper arm length. These lengths are then used in validated formulas to calculate an estimated overall height. It is important that these measurements are taken consistently at each visit to ensure the data is reliable for tracking growth. Once weight and the estimated stature are obtained, they are plotted on the growth chart that corresponds to the child’s sex and GMFCS level.
Interpreting Growth Patterns
Once data is plotted on the correct GMFCS-specific chart, it offers a tool for interpretation. These charts allow parents and providers to see how a child is growing compared to others with the same functional ability level. A child consistently tracking along a certain percentile, for instance, the 40th, suggests a steady growth pattern relative to their peers. This provides a more reassuring picture than seeing the same child fall at the 3rd percentile on a standard WHO chart.
The primary use of these charts is for monitoring and screening, not for diagnosing a condition. A significant change in growth, such as a sharp drop across percentile lines, can signal an issue like increasing feeding difficulties. A rapid increase in weight percentiles might indicate a risk of obesity. This information is valuable for starting conversations about nutritional interventions, which could range from dietary adjustments to feeding support. By using these charts, the healthcare team can better address the unique nutritional needs of children with CP.