ObjectiveThe association between gestational diabetes mellitus (GDM) and common carotid artery (CCA)-intima media thickness (IMT) is still controversial. In the present study, we aimed to compare the CCA-IMT measured in GDM women to that obtained in healthy pregnant women in the third trimester of pregnancy. Secondly, we investigated the main independent predictors of persistent CCA-IMT increase (defined as CCA-IMT ≥ 0.6 mm) in postpartum period in GDM women. Study design30 consecutive GDM women and 30 healthy pregnant women matched for anagraphic age (34.1 ± 4.5 vs 32.8 ± 4.2 yrs, p = 0.25), ethnicity (caucasian 56.7 vs 63.3%, p = 0.59), gestational age (36.2 ± 1.7 vs 36.5 ± 1.6 weeks, p = 0.48) and cardiovascular risk factors were examined in this prospective case-control study. All women underwent obstetric visit, blood tests, conventional transthoracic echocardiography implemented with two-dimensional speckle tracking echocardiography analysis of left ventricular and left atrial myocardial strain parameters and carotid ultrasound examination at two time points: 36–38 weeks’ gestation and 6–10 weeks after delivery. ResultsAt 36.2 ± 1.7 weeks of gestation, CCA-IMT was significantly increased in GDM women than controls (0.81 ± 0.11 vs 0.55 ± 0.12, p < 0.001). Twelve GDM women (40% of the total) were found with persistent CCA-IMT increase (0.76 ± 0.14 mm) in postpartum period (8.2 ± 2.2 weeks), whereas the remaining 18 (60% of the total) showed a normalization in CCA-IMT (0.56 ± 0.1 mm). At multivariate logistic regression analysis, third trimester body mass index (BMI) (OR 1.78, 95%CI 1.24–2.54, p = 0.01), glycosylated hemoglobin (HbA1C) (OR 1.51, 95%CI 1.13–1.89, p = 0.03) and neutrophil-to-lymphocyte ratio (NLR) (OR 1.68, 95%CI 1.25–4.65, p = 0.02) resulted to be independently associated with persistent CCA-IMT increase in postpartum period in GDM women. A BMI ≥ 29.2 Kg/m2, an HbA1C ≥ 37.5 mmol/mol and a NLR ≥ 5.5 were the best cut-off values for identifying GDM women with persistent CCA-IMT increase in postpartum period. ConclusionsGDM is associated with increased CCA-IMT during pregnancy. This increase may be persistent in postpartum period in GDM women with obesity, uncontrolled diabetes and increased inflammatory markers.