Baby weight charts ignore ethnicity, say researchers

Healthy Asian babies may have been classified as underweight due a lack of regard for ethnicity in traditional baby weight charts, according to a University of British Columbia study.

Chinese and South Asian babies often wrongly classified

A study finds that babies of some ethnicities tend to weigh less 2:01

Healthy Asian babies may have been classified as underweight due a lack of regard for ethnicity in traditional baby weight charts, according to a study by the University of British Columbia.

UBC researchers looked at more than 100,000 babies born between 2006 and 2008 and found that those born to Chinese and South Asian parents were often wrongly classified as 'underweight.'

Lead author Dr. Gillian Hanley, a post-doctoral fellow at the UBC School of Population and Public Health, said her study found that healthy birth weights wary among different ethnicities, but common baby weight charts are based on infants born to white parents only.

"It means when we were using the population-based distributions, which included a lot of white babies, which we know [are] bigger than Chinese and South Asian babies, what we were doing was misclassifying some small but healthy Chinese and South Asian babies as small for gestational age," she said.

The fix, she said, is to create different charts for different ethnic groups.

"When a Chinese baby is born in the hospital, rather than being compared to the general population chart, they would be compared to a Chinese chart," she explained.

Hanley said that when people assume a one-size-fits-all weight chart defines a newborn's health, perfectly healthy babies can get medical intervention they dont really need.

Comparing the weights of babies against those in their own ethnic groups could end up reducing health care costs, allowing resources to be targeted at newborns who truly need increased medical attention, she said.

"We can do a better job of guiding healthcare resources to the babies that need them most," Hanley said.

It could also reduce parental anxiety and unnecessary testing on healthy newborns.

Dietician Vanessa Lam says she meets many parents who are concerned that their baby is underweight.

"Parents always want to do a good job. The important thing to remember is weight is only one part, health is another good indicator," she said.

With files from the CBC's Petti Fong and Rafferty Baker