Objective: To compare the prevalence and clinical characteristics of early gestational diabetes (eGDM) and associated birth outcomes among women of different ethnic groups. Methods: This is a secondary analysis of an international, multicenter randomized controlled trial of treating eGDM among pregnant women with GDM risk factors enrolled at < 20 weeks’ gestation. GDM diagnosis was made using WHO-2013 criteria. Ethnicity was classified by self-identification. While Europids required at least one risk factor for recruitment, for others, ethnicity itself was a risk factor. Results: Among women of Europid (n = 1567), South Asian (SA: n = 971), East and South-East Asian (ESEA: n = 498), Middle Eastern (ME: n = 242), and Māori and Pasifika (MP: n = 174) ethnicities; MP (26.4%) had the highest eGDM crude prevalence compared with Europid (20.3%), SA (24.7%), ESEA (22.3%), and ME (21.1%) (P < .001). Compared with Europid, the highest eGDM adjusted odds ratio (aOR) was seen in SA (2.43 [95% CI 1.9-3.11]) and ESEA (aOR 2.28 [95% CI 1.68-3.08]); in late GDM, SA had the highest prevalence (20.4%: aOR 2.16 [95% CI 1.61-2.9]). Glucose patterns varied between ethnic groups and ESEA were predominantly diagnosed with eGDM through post-glucose load values, while all other ethnic groups were mainly diagnosed on fasting glucose values. There were no differences in the eGDM composite primary outcome or neonatal and pregnancy-related hypertension outcomes between the ethnic groups. Conclusion: In women with risk factors, eGDM was most prevalent in SA and ESEA women, particularly identified by the post-glucose load samples. These findings suggest an early oral glucose tolerance test should particularly be performed in women from these ethnic groups.

The global prevalence of hyperglycaemia in pregnancy (HIP) is rising alongside increases in the prevalence of obesity and diabetes. The IDF estimates that 19.7% of live births in 2024 were affected, with 79% of cases due to gestational diabetes mellitus (GDM) and 20% due to overt diabetes in pregnancy and pre-existing diabetes in pregnancy combined. HIP is linked to complications for both mother and child, including long-term health risks. Significant ethnic and geographical variations exist in the prevalence and outcomes of HIP, with women from South Asia being at the highest risk of GDM. Variations in prevalence of HIP exist both between regions (e.g. 13.8% in Africa compared with 31.8% in South-East Asia) and within individual countries. Social determinants of health, such as healthcare access and delivery, economic stability, discrimination, migration, lifestyle and other sociocultural factors, along with environmental, biological and genetic factors, contribute to these ethnic differences. Geography impacts risk through factors such as seasonality, pollution and rurality. Further variation occurs due to substantial diversity in national approaches to screening and diagnostic criteria. Ethnic disparities in GDM outcomes include variations in complications such as preeclampsia and preterm delivery. To address these disparities, a standardised and cost-effective approach to GDM screening and diagnosis that reflects the ethnic diversity in glucose profiles is recommended. Locally tailored, national prevention strategies for those with prior GDM should be introduced as a matter of urgency. Furthermore, each country should implement tailored HIP management policies and guidelines that include strategies to address the ethnic, geographical and social disparities in outcomes. Graphical Abstract

Background: To test the feasibility of benchmarking the care of women with pregnancies complicated by hyperglycaemia. Methods: A retrospective audit of volunteer diabetes services in Australia and New Zealand involving singleton pregnancies resulting in live births between 2014 and 2020. Ranges are shown and compared across services. Results: The audit included 10,144 pregnancies (gestational diabetes mellitus (GDM) = 8696; type 1 diabetes (T1D) = 435; type 2 diabetes (T2D) = 1013) from 11 diabetes services. Among women with GDM, diet alone was used in 39.4% (ranging among centres from 28.8–57.3%), metformin alone in 18.8% (0.4–43.7%), and metformin and insulin in 10.1% (1.5–23.4%); when compared between sites, all p < 0.001. Birth was by elective caesarean in 12.1% (3.6–23.7%) or emergency caesarean in 9.5% (3.5–21.2%) (all p < 0.001). Preterm births (<37 weeks) ranged from 3.7% to 9.4% (p < 0.05), large for gestational age 10.3–26.7% (p < 0.001), admission to special care nursery 16.7–25.0% (p < 0.001), and neonatal hypoglycaemia (<2.6 mmol/L) 6.0–27.0% (p < 0.001). Many women with T1D and T2D had limited pregnancy planning including first trimester hyperglycaemia (HbA1c > 6.5% (48 mmol/mol)), 78.4% and 54.6%, respectively (p < 0.001). Conclusion: Management of maternal hyperglycaemia and pregnancy outcomes varied significantly. The maintenance and extension of this benchmarking service provides opportunities to identify policy and clinical approaches to improve pregnancy outcomes among women with hyperglycaemia in pregnancy.

Introduction: Australia, but not New Zealand (NZ), has adopted the International Association of Diabetes and Pregnancy Study Groups (IADPSG) criteria to diagnose gestational diabetes (GDM). We compared pregnancy outcomes using these different diagnostic approaches. Method: Prospective data of women with GDM were collected from one NZ (NZ) and one Australian (Aus) hospital between 2007–2018. Aus screening criteria with 2-step risk-based 50 g Glucose Challenge Testing (GCT) followed by 75 g-oral glucose tolerance testing (OGTT): fasting ≥ 5.5, 2-h ≥ 8.0 mmol/L (ADIPS98) changed to a universal OGTT and fasting ≥5.1, 1-h ≥ 10, 2-h ≥ 8.5 mmol/L (IADPSG). NZ used GCT followed by OGTT with fasting ≥ 5.5, 2-h ≥ 9.0 mmol/L (NZSSD); in 2015 adopted a booking HbA1c (NZMOH). Primary outcome was a composite of macrosomia, perinatal death, preterm delivery, neonatal hypoglycaemia, and phototherapy. An Aus subset positive using NZSSD was also defined. RESULTS: The composite outcome odds ratio compared to IADPSG (1788 pregnancies) was higher for NZMOH (934 pregnancies) 2.227 (95%CI: 1.84–2.68), NZSSD (1344 pregnancies) 2.19 (1.83–2.61), and ADIPS98 (3452 pregnancies) 1.91 (1.66–2.20). Composite outcomes were similar between the Aus subset and NZ. Conclusions: The IADPSG diagnostic criteria were associated with the lowest rate of composite outcomes. Earlier NZ screening with HbA1c was not associated with a change in adverse pregnancy outcomes.