Prevalence, socio-demographic, and socio-economic factors associated with gestational diabetes in Australia: A population study.

AIMS: To examine the prevalence of gestational diabetes mellitus and associated socio-demographic and socio-economic factors in Victoria, Australia. METHODS: A retrospective cohort study was conducted using data from the Victorian Perinatal Data Collection, a population-based dataset. The analysis included all women who gave birth in Victoria in 2020, excluding those with pre-existing diabetes. Associations between socio-demographic, obstetric, and area-level factors and gestational diabetes mellitus were assessed using mixed-effects Poisson regression to estimate relative risks with 95% confidence intervals. RESULTS: Overall, 18% of women who gave birth in Victoria in 2020 reported being diagnosed with gestational diabetes mellitus. Higher prevalence was reported in the most disadvantaged areas compared with the most advantaged areas. About of 19% of gestational diabetes mellitus cases were diagnosed before 20 weeks of gestation. Women in the least disadvantaged areas had a significantly lower risk compared to those in the most disadvantaged areas (adjusted prevalence ratio (aPR) 0.62, 95% CI 0.57-0.67). Compared with women >35 years, younger women had lower gestational diabetes mellitus prevalence ratio: ≤20 (aPR 0.32, 95% CI 0.26-0.4), 21-25 (0.48, 0.45-0.52), 26-30 (0.61, 0.58-0.64), and 31-35 (0.77, 0.74-0.8). Grand multigravida women had a higher prevalence ratio than primigravida women (aPR 1.14, 95% CI 1.07-1.22). Spatial analysis identified gestational diabetes mellitus hotspots in south-eastern Melbourne and western Victoria. CONCLUSIONS: Gestational diabetes mellitus prevalence in Victoria shows geographic and area level disparities, highlighting the need for targeted public health interventions.