Clinical and Behavioural Heterogeneity Among Women at Increased Risk for Gestational Diabetes: A Four-Country Analysis

Gestational diabetes mellitus (GDM) is a growing global health concern due to its impact on maternal and infant health. GDM risk factors vary across populations, but international comparisons using standardised assessment tools are lacking. This study aimed to examine variations in risk factors, demographics and health behaviours among pregnant women at increased risk of GDM across four international sites and to investigate factors associated with maternal body mass index (BMI), a modifiable risk factor for GDM. This cross-sectional study included data from 804 pregnant women in Dublin (<i>n</i> = 213), Bristol (<i>n</i> = 205), Granada (<i>n</i> = 211) and Melbourne (<i>n</i> = 175) identified as having an increased risk of GDM, using the Monash GDM screening tool. Between-site differences were analysed using analysis of variance, Kruskal-Wallis and chi-square tests and factors associated with BMI at each site were examined using multiple linear regression. Despite standardised risk screening, significant heterogeneity was observed between sites in key GDM risk factors, including age (mean range 33.8-36.7 years), BMI (Melbourne 28.9 vs. Granada 26.9 kg/m²), physical activity (34.86-41.77 METs/week) and dietary intake (mean energy 1881-2136 kcal/day). Multiple factors were independently associated with BMI, including education level, ethnicity, health literacy and energy intake, with patterns varying by site. This study challenges the concept of a homogeneous "high-risk" GDM population by revealing substantial variations in risk factors and characteristics across different patient cohorts, highlighting the importance of developing context-sensitive approaches to GDM prevention.