A prospective cohort study published in Open Heart assessed cardiovascular changes in pregnant women with type 1 diabetes compared with healthy controls. The study enrolled 63 women (24 with type 1 diabetes and 39 controls) matched for age and BMI. Participants underwent three consecutive cardiac magnetic resonance imaging (CMR) scans at gestational weeks 15–20, 26–30, and 34–37, along with blood pressure and vascular measurements.

Women with type 1 diabetes showed impaired left ventricular (LV) remodeling. They had lower LV end-diastolic volume index (64.2±11.1 vs 77.6±13.9 mL/m², p<0.001), lower end-systolic volume index (26.0±7.3 vs 33.5±7.7 mL/m², p=0.003), reduced stroke volume index (38.2±7.2 vs 44.1±8.4 mL/m², p=0.008), lower cardiac index (3.37±0.55 vs 3.62±0.51 L/min/m², p=0.046), and impaired global longitudinal strain (−13.5±2.3% vs −15.2±2.1%, p=0.04). Concentricity was higher (0.84±0.13 vs 0.68±0.10 g/mL, p<0.001), and myocardial T1 values were elevated (998±28 vs 983±25 ms, p=0.03).

They also showed vascular maladaptation, with higher systolic blood pressure (128.1±7.8 vs 117.4±11.1 mmHg, p=0.007), higher mean arterial pressure (94.8±6.7 vs 88.1±9.7 mmHg, p=0.03), increased total peripheral resistance (28.9±5.3 vs 24.7±4.0 mmHg·min·m²/L, p=0.001), and lower arterial compliance (0.79±0.19 vs 1.02±0.21 mL/m²/mmHg, p<0.001).

The results show that pregnancy in women with type 1 diabetes leads to impaired LV remodeling and diminished vascular adaptation compared with controls.