Victoria and NT lead the country in increasing rates of gestational diabetes

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Registered cases of gestational diabetes have increased by almost 70 per cent in Australia from 2016 to 2021, according to a nationwide analysis of over 1.8 million Australian pregnant women.

The condition, which impacts the health of the mother and baby, can result in lifelong medical conditions, including type 2 diabetes and high blood pressure.

In the five years to 2021, Victoria has doubled its incidence while the Northern Territory has almost tripled its incidence of the condition.

Of particular concern is the huge increase in gestational diabetes in women born outside of Australia. Specifically, Southeast Asian born women in Australia who had a doubling in gestational diabetes incidence from 12.2 per cent to 22.5 per cent in the six-year study period. The risk of gestational diabetes was also most marked in women from socioeconomically disadvantaged groups.

The Monash University study, led by PhD Candidate Wubet Takele and senior author Associate Professor Jacqueline Boyle, was recently published in the Australian and New Zealand Journal of Public Health, using data from the National Diabetes Services Scheme (NDSS) and Australian Bureau of Statistics (ABS).

Gestational diabetes is a type of diabetes that first appears during pregnancy and it increases the risk of adverse pregnancy and birth outcomes such as preeclampsia, caesarean birth, birth asphyxia, and preterm birth. It also leads to women being more likely to develop long-term Type 2 diabetes and high blood pressure.

Of the 1,845,182 women who gave birth in Australia from 2016 to 2021, the age-standardised incidence of gestational diabetes in each state/territory rose from:

  • NSW: 10.0% to 14.0%
  • Victoria: 7.2% to 14.4%
  • Qld: 9.0% to 14.5%
  • SA: 9.2% to 14.5%
  • WA: 6.8% to 11.8%
  • ACT: 11.2% to 22.4%
  • NT: 5.3% to 16.8%
  • Tasmania: 8.2% to 14.8%
  • Nationally: 8.2% to 12.2%

When looked at by the nationality of mothers, the study found the greatest increase was in those from Southeast Asia and South and Central Asia. In women from Southeast Asia, the incidence of gestational diabetes rose from 12.2 per cent in 2016 to 22.5 per cent in 2021. Whereas, in Australian-born mothers, increases in gestational diabetes were less pronounced, rising from 7.2 per cent in 2016 to 9.0 per cent in 2021.

“Being born in all these regions of Asia is a risk factor for GDM due to genetic susceptibility,” the study found. There may also be sociocultural factors contributing to this, as South Asian women may “experience higher expectations to focus primarily on housework and family-related responsibilities, limiting the opportunity to engage in health promotion activities, such as physical activity”. Further, unfamiliarity with health services led to “less opportunity to engage with preventive health practices”, resulting in missed opportunities among migrant women to engage in early prevention.

According to the authors, Professor Jacqueline Boyle, Dr Siew Lim and Wubet Takele from Monash’s Eastern Clinical School and Dr Lachlan Dalli from the School of Clinical Sciences, the overall increasing trends could be ascribed to “multiple risk factors, including the increasing prevalence of overweight or obesity among pregnant women, increasing age during pregnancy, and changing migration patterns with a higher proportion of people from ethnic groups at increased risk”.

The significant rise in the incidence of gestational diabetes may also be due to the change in screening practices, greater screening efforts and differences in the population composition across states and territories, Professor Boyle said. “Significant efforts have been in place to increase awareness, screening, identification, and improved models of care to manage diabetes during pregnancy,” she said.