Background: The Australasian Diabetes in Pregnancy Society (ADIPS) has recently endorsed the World Health Organization (WHO) terminology and classification of hyperglycaemia in pregnancy. The prevalence is likely to increase, but no prospective data are available for a representative Australian population. Aims: To determine the prevalence of hyperglycaemia in pregnancy (HIP) using results from both the public and private sectors in a population that has a similar ethnicity to the overall Australian population. Material and Methods: The results of all pregnancy oral glucose tolerance tests (POGTT) in the public sector and by a dominant private pathology provider in a major city have been prospectively collected for a three-year period and analysed using the ADIPS (WHO) criteria. Results: The prevalence of hyperglycaemia in pregnancy (HIP) was 13.1% with diabetes mellitus in pregnancy (DIP) being 0.4% and gestational diabetes mellitus (GDM) being 12.7%. Conclusion: The new criteria will diagnose about one-third more women with GDM than the previous ADIPS criteria. This will have resource and health implications. Focussed local health economic data will be important.