Gestational diabetes is on the rise and a Canadian study may have found out why

Gestational diabetes is on the rise worldwide, but a new Canadian study said the reason for it may be linked to a change in screening methods.

Gestational diabetes is on the rise worldwide, and a new Canadian study said the reason for it may not be linked to previous speculation such as obesity, maternal age or lack of exercise.

The increase could be that screening methods for gestational diabetes — a type of diabetes that occurs during the second or third trimester of pregnancy — have improved.

The study out of British Columbia and published Monday in the Canadian Medical Association Journal (CMAJ) said in Canada, the rate of gestational diabetes rose to seven per cent in 2014 from four per cent in 2004 across all racial and ethnic groups.

“We were interested in understanding why rates of gestational diabetes were increasing in British Columbia. What we found was that rates of gestational diabetes … there was a change in the way that we screen for diabetes, which has really been taken up in British Columbia,” explained Elizabeth Nethery, lead author of the study and PhD in the School of Population and Public Health at the University of British Columbia.

“We’ve been using a much more sensitive method to screen, and we found that that change in screening practice has really led to the almost doubling of gestational diabetes cases in British Columbia.”

The jump in diabetes in pregnancy has previously been linked to maternal age (the risk of diabetes when pregnant goes up with age), less exercise and poor diet, but the authors argued this is likely not the case.

The researchers looked at data from more than 550,000 pregnancies in B.C. from 2005 to 2019 as well as screening methods. During the study period, diagnoses of gestational diabetes doubled, to 14.7 per cent from 7.2 per cent in the province, and so did the amount and type of screenings.

In order for someone to be diagnosed with gestational diabetes, a glucose screening test needs to be completed.