Gestational diabetes mellitus in Australia, 2005-06 is the first national report on the incidence of gestational diabetes mellitus (GDM) among Australian women. The report contains the most recent national data on the incidence of GDM among Australian women of child-bearing age who give birth in hospital, described in this report as confinements. Additional analyses are presented for women from high-risk groups-those aged over 30 years, women who identify as Aboriginal or Torres Strait Islander and women born overseas.

Some of the main findings about the incidence of GDM among Australian women are given below.

The incidence of gestational diabetes is increasing.

  • In 2005-06, GDM was diagnosed in 4.6% of confinements among women aged 15-49 years.
  • The incidence of confinements with GDM among women aged 15-49 years increased by over 20% between 2000-01 and 2005-06.

The risk of GDM increases with age.

  • In 2005-06, the risk of GDM increased with age: from 1% among 15-19 year old women to 13% among women aged 44-49 years.
  • Women aged 30-34 years accounted for more than one-third of GDM cases in 2005-06.

Aboriginal and Torres Strait Islander women are at high risk.

  • In 2005-06, the age-adjusted incidence rate of GDM among Indigenous Australian women was 1.5 times that of Other Australian women.
  • The risk of GDM was higher among Indigenous compared to Other Australian women across all age groups.
  • Indigenous Australian women aged 15-29 years accounted for 51% of GDM cases in 2005-06, compared to 30% among Other Australian women in this age group.

Women born overseas are at greater risk.

  • In 2005-06, women born overseas had twice the incidence rate of GDM compared with women born in Australia.
  • The incidence of GDM was greatest among women born in Southern Asia, at 3.4 times the rate of women born in Australia.