Gestational diabetes in Victoria in 1996: incidence, risk factors and outcomes

OBJECTIVES: To describe the epidemiology of gestational diabetes mellitus (GDM) in Victoria. STUDY DESIGN: Population study of all women having singleton births in Victoria in 1996. METHODS: Probabilistic record linkage of routinely collected data and capture-recapture techniques to provide an estimate of the incidence of GDM. MAIN OUTCOME MEASURES: Risk factors for and the adverse outcomes associated with GDM compared with the non-diabetic population by univariate and multivariate analysis. RESULTS: The estimated incidence of GDM was 3.6% (95% confidence interval [CI], 3.60%-3.64%). GDM is associated with women who are older, Aboriginal, non-Australian born, or who give birth in a larger hospital. The adverse outcomes associated with GDM pregnancies were hypertension/pre-eclampsia (adjusted odds ratio [OR], 1.6; 95% CI, 1.4-1.9), hyaline membrane disease (1.6; 1.2-2.2), neonatal jaundice (1.4; 1.2-1.7) and macrosomia (2.0; 1.8-2.3). Interventions during childbirth were also associated with GDM - for example, induction of labour (3.0; 2.7-3.4) and caesarean section (1.7; 1.6-1.9). CONCLUSION: Women with GDM had increased rates of hypertension, pre-eclampsia, induced labour, and interventional delivery. Their offspring had a higher risk of macrosomia, neonatal jaundice and hyaline membrane disease.