The prevalence of type 2 diabetes in Australian women with a history of gestational diabetes is much lower than internationally reported rates, an Australian study shows.

The study that included about 1,300 women from NSW who were referred with a diagnosis of gestational diabetes according to the Australasian Diabetes in Pregnancy Society criteria between 1991 and 2010 found an overall type 2 diabetes prevalence rate of 10.3 percent.

However, the study authors led by Professor Robert Moses, director of diabetes services for the Illawarra Shoalhaven Local Health District, pointed out that although the rate was low it was still about twice the rate for the overall Australian population.

Speaking to the limbic Professor Moses said the women were referred from both private practitioners and the public hospital antenatal clinics.

“In a population going back 25 years in which we could contact just over half the women, the prevalence of diabetes following gestational diabetes was surprisingly low,” he said.

Known risk factors – a higher pre-pregnancy BMI and a family history of diabetes -were predictive of progression to diabetes.

The study found the rate of undiagnosed diabetes in women during the follow-up was a low 0.9%.

“Progression as a whole is surprisingly low and the rate of undiagnosed diabetes is also very encouragingly low,” Professor  Moses said.

He said the area of referral had an ethnic distribution representative of the Australian population nationwide.

The majority Caucasian demographic (86%), adequate care and low rates of undiagnosed diabetes were the most likely factors explaining the lower rate of progression than in overseas studies which are as high as 50%-70%.

“We need this perspective from a nationally representative population so we don’t go around talking up the problem,” Professor Moses said.

He said while the progression rate might be lower in this cohort, the advice during pregnancy and for post-partum surveillance remained the same.

The study was published in the Australian and New Zealand Journal of Obstetrics and Gynaecology.