Rick Teichgraeber plays with his granddaughter, Avery Ortega. The size… (Dayna Smith/TWP/ )
When James and Rebecca Ortega brought their newborn daughter, Avery, to the pediatrician for her first visit last December, the doctor plotted her height, weight and head circumference on a growth chart, a standardized graph that gives parents a picture of how well their child is growing.
The Ortegas, who live in Alexandria, were surprised to learn of their daughter’s seemingly disproportionate size: Her height was in the 75th percentile, her weight in the 50th, and her head relatively huge — in the 98th percentile.
“I immediately thought that she had elephantiasis,’’ a disease characterized by swollen body parts, Rebecca Ortega says. The pediatrician reassured the Ortegas that Avery’s head size and development generally were normal. Indeed, with age, Avery’s head has become more proportional to her body.
Still, Ortega wonders whether pediatric growth charts are less helpful than they are anxiety-producing — encouraging worry, guilt, even competitiveness in parents who may not understand them.
“They drive people to compare their babies to others when, in fact, all babies grow and develop at different rates. In our comparison-prone world, we certainly don’t need more fuel for the fire,” Ortega says.
Typically, pediatricians weigh and measure children approximately every few months until age 2 to 3 and then yearly after that. They look for steady and proportional growth in height, weight and head circumference, an indicator of brain development. As long as a child continues to gain weight and height proportionally over the years — even if he or she remains in a lower-than-average percentile — it is an indication of steady growth.
Deviations from a steady growth curve can indicate such problems as nutritional inadequacies, growth hormone deficiencies, metabolic disorders and obesity. Sometimes, a faltering growth pattern can be a sign of a more serious disease, such as cystic fibrosis.
Doctors and other health professionals in the United States began using growth charts in 1977. Over time, pediatricians began routinely sharing them with parents, a practice that probably grew from growing consumer activism, when many patients began insisting on getting more medical information and having a greater role in medical decision-making for themselves, and, in this case, their children.
“Parents like to see them,” says Francis M. Palumbo, a pediatrician and associate professor of pediatrics at Georgetown University School of Medicine. But the terminology can be confusing.
“Growth numbers are described in percentiles, and everyone thinks they should be close to 100 because that’s how we were graded in school,’’ says Van Hubbard, director of the National Institutes of Health’s Division of Nutrition Research Coordination. “But in growth, higher is not necessarily better. The most important thing is to look at growth patterns, wherever they fall on the chart.’’
A 2009 study of 1,000 American parents found that most of those who thought they understood growth charts actually had trouble interpreting them. The study, which appeared online in the journal Pediatrics, found that 79 percent of the parents surveyed said they were familiar with growth charts, yet when provided with questions and multiple-choice answers, only 64 percent could identify a child’s weight when shown a plotted point on a growth chart. Only 68 percent could identify the percentile of the plotted point, and only 56 percent could identify the definition of percentile. Up to 77 percent incorrectly interpreted charts containing height/weight measurements in tandem.
‘A terrific tool’
The pediatric growth chart is “a terrific tool for health-care practitioners to track children’s growth, which it was initially developed for, but the question is whether it should be used as an educational tool for parents, because it wasn’t designed for that,’’ says pediatrician Elana Pearl Ben-Joseph, one of the authors of the 2009 study. “I think you can create some kind of visual display of information that is easier for a parent to understand than an X axis and a Y axis and percentiles.’’
The growth charts are a series of curves that illustrate the distribution of body measurements by sex and age. If a 3-month-old girl, for example, is in the 40th percentile for weight and the 80th for height, it means that, compared to 100 representative girls the same age, she is heavier than 40 of them and taller than 80 of them. This seems fairly straightforward, but “many parents don’t grasp the concept of percentiles, no matter how it is explained to them,’’ Pearl Ben-Joseph says.