Figure 1 (A) Crude and age-standardised prevalence of pre-existing maternal diabetes in pregnancy by year of delivery, Victoria 1999–2008; (B) Crude number of GDM cases by year of delivery and maternal age group, Victoria 1999–2008; (C) Crude GDM … For the entire 10-year period, the greatest absolute number of pregnancies in women with pre-existing diabetes occurred
in Australian-born non-Indigenous women, PD173955? and for the migrant groups, in those born in South-East Asia and Southern and Central Asia; pre-existing diabetes prevalence rates were however highest in pregnancies among women born in Southern and Central Asia and Sub-Saharan Africa (data not shown). Prevalence of GDM Of all pregnancies in Victoria from 1999 to 2008, 29 147 (4.6%) were complicated by GDM. Overall, the annual number of GDM pregnancies increased by 64% between 1999 and 2008. Increases in the absolute number of GDM pregnancies over time were apparent in all but the youngest group of women (figure 1B). GDM also increased as a proportion of total pregnancies, such that in 2008, the age-standardised GDM prevalence rate was 31% higher than in 1999 (table 2). Over the study period, crude GDM prevalence
rates tended to increase in pregnancies among women in most age groups (figure 1C). Analysis of data from women in their first pregnancy who did not have pre-existing diabetes revealed a significant positive linear trend in the prevalence of the crude (p<0.001) and age-standardised (p<0.001) rates
of GDM over the study period. Considerable differences in GDM prevalence rates existed by maternal region of birth (figure 2). Prevalence increased over time, both among Australian-born non-Indigenous women and overseas-born women considered collectively. However, the same pattern was not evident when considering Indigenous Australians and each migrant group individually. The extent of the changes in GDM prevalence rates over time varied by migrant origin status. In Australian-born non-Indigenous women, age-standardised GDM prevalence in 2007 and 2008 was 29% higher than in 1999 and 2000 (4% vs 3.1%), whereas among all overseas-born women collectively, prevalence increased by 12.3% between these two time periods (8.2% vs 7.3%; figure 2) with differences between the various groups. Figure 2 Age-standardised Carfilzomib GDM prevalence rates* by maternal region of birth and year of delivery, Victoria 1999–2008. *The denominator used to calculate prevalence of GDM is all pregnancies. Effect of denominator variation Including or excluding women with pre-existing diabetes had little effect on GDM prevalence rates overall (table 2). Estimates were generally similar, albeit lower, when considering only women in their first pregnancy (see online supplementary table S1). Including or excluding women with pre-existing diabetes also had very little effect on GDM prevalence rates by maternal region of birth (data not shown).