As the assumption next of independence that underlies tests for linear trend was not fulfilled, such analyses were not performed, and age-standardised prevalence rates were considered significantly different if 95% CIs did not overlap. For sensitivity analysis, annual prevalence rates of pre-existing diabetes, GDM and all diabetes were calculated after restricting to women giving birth for the first time, and tests for linear trend were

performed for this subgroup. Data were analysed using Stata V.11.0. Permission to access and analyse data was granted by the Consultative Council on Obstetric and Paediatric Mortality and Morbidity, Victorian Department of Health. The Flinders University Social and Behavioural Research ethics committee exempted this study from requiring ethics approval, as it involved analysis of existing de-identified data. Results During the 10-year

study period, there were 634 932 pregnancies resulting in a birth registration with the VPDC (table 1). In 2008 there were 15.7% more pregnancies than in 1999. Mean maternal age increased from 29.7 years in 1999 to 30.8 years in 2008. The number of births to women aged 40 years and over was 91.3% higher in 2008 than in 1999. Table 1 Maternal demographic characteristics for pregnancies yielding births notified to the Victorian Perinatal Data Collection by year of delivery, Victoria 1999–2008* Maternal region of birth was known for 99.7% (n=632 805) of pregnancies, of which 74.6% occurred in Australian-born women of non-Indigenous descent (table 1). There was an overall trend of an increasing number of pregnancies in women born in all regions, with the exception of North-West Europe and Southern and Eastern Europe where there was a decline.

The trend of increasing pregnancies was particularly strong in women from Southern and Central Asia (table 1). The number of women becoming pregnant for the first time increased during the study period with 5486 (22.1%) more first pregnancies recorded in 2008 compared with 1999 (table 1). Cilengitide Diabetes in pregnancy In 2008, 6.1% of all pregnancies were complicated by some form of diabetes, compared with 4.3% in 1999 (table 2). Each year, pregnancies occurring in older women (those aged 35–39 years and 40 years or older) had higher prevalence of any form of diabetes than pregnancies in younger women (data not shown). Table 2 Crude and age-standardised prevalence of GDM by year of delivery and denominator, Victoria 1999–2008 Prevalence of pre-existing maternal diabetes in pregnancy Between 1999 and 2008, 2954 pregnancies (0.5%) occurred in women with known pre-existing diabetes. The prevalence rate of pre-existing diabetes increased from 0.4% to 0.6%, representing an increase of 50% over the study period and there was little difference between the crude and age-standardised estimates (figure 1A).