Women with GDM are at increased risk of developing Type 2 diabetes and their babies are more likely to have a high birth weight and suffer birth trauma.

The report, Gestational Diabetes Mellitus, 2005-06, showed that in 2005-06, 4.6 per cent women aged 15-49 years, who gave birth in hospital, were diagnosed with GDM. "This amounts to more than 12,400 women and their babies affected," said Mardi Templeton of the Australian Institute of Health and Welfare's (AIHW) Cardiovascular, Diabetes and Kidney Unit.

The report found the incidence of gestational diabetes among all Australian women in the 15-49 year age bracket increased by over 20 per cent between 2000-01 and 2005-06, according to an AIHW release.

The risk of being diagnosed with gestational diabetes increases with age - from one per cent among the women aged 15-19 years to 13 per cent among women 44-49 years of age.

"Women born overseas are at greatest risk of being diagnosed with gestational diabetes, with twice the incidence rate of women born in Australia," she said.