in women without diabetes, little is known about the consequences of hyperglycaemia during pregnancy for the offspring cardiovascular structure and function.To investigate the association of maternal glycaemia during pregnancy with cardiovascular risk markers in their children in GUSTO, a Singaporean birth cohort study.Around 26 weeks' gestation, a 75g oral glucose tolerance test was performed and fasting (FPG) and 2-hr postprandial plasma glucose (2-hr PPPG) concentrations were measured. Gestational diabetes mellitus (GDM) was defined using WHO 1999 diagnostic criteria. At age 6 years, we measured the child's carotid intima-media thickness (cIMT), carotid-femoral pulse wave velocity (cfPWV), aortic augmentation index (AIx) and blood pressure (BP). Association of maternal glycaemia during pregnancy with cardiovascular risk markers in their children were analysed using multiple linear and logistic regressions.Analysis were performed on 479 mother-child dyads. Higher maternal FPG was associated with higher cIMT and in male, higher cfPWV in the offspring (adjusted β [CI 95%], cIMT: 0.08 per 10mm increase [0.02; 0.15], cfPWV: 0.36 m/s [0.01; 0.70]). Higher 2-hr PPPG was associated with higher cfPWV and AIx. GDM was associated with higher AIx. No association was found between maternal glycaemia and their offspring blood pressure.among mothers without pre-existing diabetes, higher glycaemia during pregnancy was associated with mild structural and functional vascular changes in their children at age 6 years across a continuum. These results support the necessity to monitor maternal glycaemia during pregnancy even in absence of pre-existing diabetes or diagnosed gestational diabetes.