Search

Objectives: Gestational diabetes mellitus (GDM) affects about 15% of pregnancies in Australia, with approximately 30% of those diagnosed with GDM requiring insulin therapy. There are several established risk factors for developing GDM, however limited studies show how these can be used to predict need for insulin treatment. The aim of this study is to identify predictors of insulin therapy in women diagnosed with GDM once an oral glucose tolerance test (OGTT) is performed during pregnancy.Study Design: This is a retrospective cohort study of women with singleton pregnancies complicated by GDM between 2016 and 2017 at a single, large health network in Melbourne, Australia. Data were obtained from hospital record and pathology result systems. Univariable and multivariable logistic regression models were fit to the data to obtain crude and adjusted odds ratios.Results: Of 2,048 women diagnosed with GDM, 647 (31.6%) required insulin therapy. Positive predictors included in the final multivariable model after backwards, stepwise elimination were an elevated fasting result on an OGTT (adjusted odds ratio (AOR) 2.93 [95% CI 2.34-3.66]), previous birth weight greater than 90th% (AOR 2.04 [95% CI 1.412.94]), previous diagnosis of GDM (AOR 1.68 [95% CI 1.28-2.21]), being born in the South Asian region (AOR 1.58 [95% CI 1.27-1.98]), the 2hr OGTT result (AOR 1.14 [95% CI 1.05-1.24]), body mass index (BMI; AOR 1.13 [95% CI 1.04-1.23]) and age (AOR 1.03 [95% CI 1.00-1.05]) The final predictive model had an area under the receiver-operating characteristics (ROC) curve of 0.744 (95% CI 0.720-0.767).Conclusions: This study highlights the possible predictors of insulin use, informing counselling for women who are newly diagnosed with gestational diabetes. [ABSTRACT FROM AUTHOR]

Background: The adoption of the International Association of Diabetes Study Groups (IADPSG) criteria for gestational diabetes mellitus (GDM) in Australia has been controversial. Obesity in pregnancy is also a growing concern. Aims: To assess the impact of IADPSG criteria on the incidence of GDM and pregnancy outcomes, and to compare this to the effect of obesity, particularly among women who would not have GDM by the Australasian Diabetes in Pregnancy Society 1998 criteria (ADIPS1998). Material and Methods: A retrospective observational cohort study linking results of 75 g glucose tolerance tests with demographic and pregnancy data was conducted. Results: In our cohort of 6175 pregnancies, GDM was present in 926 (15%) women by the ADIPS1998 criteria; it increased to 1098 (17.8%) women by the IADPSG criteria. Among the 5248 pregnancies which did not meet the ADIPS1998 criteria and were not treated for GDM, women with IADPSG GDM had increased risk of gestational hypertension, pre‐eclampsia, induction of labour (IOL), primary caesarean section (PCS) and large for gestational age (LGA) compared to women without GDM (all P < 0.05), whereas obese women had increased risk of gestational hypertension, pre‐eclampsia, IOL, PCS, small for gestational age (SGA) and shoulder dystocia compared to women of normal weight (all P < 0.05). On multivariate analysis, IADPSG GDM was an independent risk factor only for IOL (P = 0.04) and LGA (<0.001). Obesity was an independent risk factor for gestational hypertension, pre‐eclampsia, IOL, PCS, shoulder dystocia and SGA (all P < 0.001). Conclusions: Within our population, of women who are not currently treated for GDM, obesity is associated with greater pregnancy risk than GDM diagnosed by IADPSG criteria. [ABSTRACT FROM AUTHOR]