Understanding Growth Charts

Understanding Growth Charts


by Dr. Michelle Salassi

Percentiles explained: Making sense of your child’s growth chart

One of the most important components of a well-child visit is assessing a child’s growth – primarily by plotting his or her measurements on a standard growth chart. Although those curved lines and percentiles may seem daunting, growth charts are not difficult to understand.

What are growth charts?

Growth charts were created using decades of data collected about children’s growth. In children less than 2 years old, growth charts developed by the World Health Organization are used to plot length, weight and head circumference. Children 2 to 20 years old use the Centers for Disease Control and Prevention (CDC) growth charts on which height, weight and body mass index (BMI) are recorded. Boys and girls are plotted on different curves because their growth patterns are different. These charts serve as a reference for pediatricians – a tool that allows comparisons.

What do the percentiles mean?

Growth charts allow pediatricians to compare your child with other children of the same age and gender. The charts consist of smooth curved lines that represent different percentiles. The higher the percentile, the bigger the child is compared to other children. For example, if your 5-year-old son’s weight is at the 25th percentile, then 25 percent of 5-year-old boys weigh less than him and 75 percent weigh more.

Healthy children do not have an ideal or a goal percentile because growth is influenced by genetics, environment, nutrition, activity and illness. It’s helpful to look at a child’s growth at one moment in time, but it is more valuable to observe his or her growth over time by comparing the measurements from today’s check-up with previous ones. Your pediatrician looks at the overall growth trend to ensure that your child is growing normally.

When should I be concerned?

Remember that growth charts must be interpreted in the context of a child’s overall well being. However, certain growth patterns may prompt further investigation or intervention from your pediatrician:

  • A child’s growth that suddenly changes percentile curves. For example, a child who has consistently been on the 85th percentile curve for weight suddenly drops to the 25th percentile.
  • Children greater than the 95th percentile or less than the 5th. Family members’ growth helps determine if this is a problem.
  • Height and weight percentiles that are very different or changing at different rates. This may indicate a child is overweight or underweight.

Are all children represented by these growth charts?

Children provided with good nutrition, access to health care, good social and general living conditions have similar growth patterns, regardless of race or ethnicity. There are specialized growth charts for premature infants and children with certain health conditions, such as Down syndrome and Turner syndrome. These charts have some limitations, but they are useful additions to the standard growth charts.

Growth is a reflection of a child’s overall health and nutrition. It’s one of the most important aspects of a well-child visit. Your pediatrician would love to show and discuss your child’s growth chart at his or her next check-up. You can also download these charts yourself or read more about growth charts at the CDC website.

About Dr. Salassi

Michele Salassi, MD, FAAP received her medical degree from Louisiana State University School of Medicine in New Orleans, LA. She also completed her residency in Internal Medicine and Pediatrics at Louisiana State University Health Sciences Center in New Orleans, LA. Dr. Salassi is a member of the American Academy of Pediatrics, the American College of Physicians, and the Louisiana State Medical Society. She treats common disorders of the cardiovascular, respiratory, gastrointestinal and reproductive systems including diabetes, hypertension, hyperlipidemia, asthma, chronic obstructive pulmonary disease and chronic kidney disease. Dr. Salassi also performs routine childhood and adolescent health exams. Click here to make an appointment online with Dr. Salassi.