Does head size matter?
The most common charts used by paediatricians to measure head growth in toddlers may be inaccurate.
Head-circumference growth curves are used by paediatricians millions of times annually to identify children who may need extra follow-up or testing
because of a large head, also called macrocephaly, or a rapidly growing head.
"The study was done because primary care doctors were concerned that the curves weren't working well for our patients," said study leader Carrie Daymont, a paediatric researcher formerly at The Children's Hospital of Philadelphia.
The researchers used the electronic health records of more than 75,000 infants in the Children's Hospital primary care network. They compared the most widely used charts with actual measurements and found that the most commonly used chart would lead to a diagnosis of macrocephaly, defined as a head circumference above the 95th percentile for age, in 2.5 times more one-year-olds
When using the CDC curves, the percentage of children diagnosed with macrocephaly changes with age. One-fifth of the expected number of one-month olds and 2.5 times the expected number of one-year-olds were classified as having macrocephaly. Many of these older infants may have received unnecessary follow-up tests and speciality referrals, and their parents may have been unnecessarily worried, the researchers said.
Using the CDC curves may cause a delay in diagnosis in babies under two months old with diseases causing large heads, and may cause children 6 months to 3 years to be labeled as having large or rapidly growing heads, when in fact they are healthy and have a typical head size, Daymont said. Use of the WHO curves would cause an excess of children to be labelled as having large heads at all ages. The researchers at Children's Hospital used the data from this study to develop a new growth curve.
"More research is also needed to determine how doctors can use head circumference growth curves to identify children with problems without causing unnecessary worry to parents of healthy children," said David Rubin, M.D. "We are currently working on research related to this question."
The team at Children's Hospital is currently evaluating other sources of data to see if the new head-circumference growth curves work in other populations.Was your child misdiagnosed with any sort of "problem" as a baby? Share with us below.