Defining echocardiographic norms in pregnancy: a large longitudinal study of cardiometabolic complications

Cardiometabolic disorders in pregnancy (HDP, GDM) alter cardiac function, yet echocardiographic reference values in both physiology and pathology are lacking. The aim of this study was to define normative reference echocardiographic parameters during pregnancy.

219 Pregnant women were prospectively followed with maternal echocardiography at 11+4 to 15+6 weeks of gestation and at 25+0 to 27+6 weeks of gestation at the HDP clinic of two centers.

Compared to physiological pregnancies, both HDP and GDM showed distinct and progressive alterations in cardiac structure and function over gestation.

HDP (Table 1): Significant increases were observed in LV mass (114.7 ± 22.4 g vs. 93.9 ± 16.8 g, p=0.012) and indexed LV mass (64.3 ± 10.6 g/m² vs. 55.1 ± 8.4 g/m², p=0.017), particularly in the late second/third trimester, indicating progressive structural remodeling. Indexed left atrial volume was higher in HDP (26.7 ± 7.0 ml/m² vs. 23.5 ± 7.2 ml/m², p=0.009), significantly increasing in the late second/third trimester. Diastolic dysfunction was evident with higher E/e' lateral (11.03 ± 6.65 vs. 6.71 ± 4.61, p=0.004) and septal (7.89 ± 2.10 vs. 6.94 ± 1.43, p=0.041), worsening over time. Lateral systolic velocity (s lat: 7.98 ± 2.99 vs. 10.79 ± 3.10, p=0.011) was lower in the first trimester and further decreased by the late second/third trimester, reflecting increasing cardiac workload.

GDM (Table 2): Structural changes included significantly increased indexed LV mass (89.56 ± 34.7 g/m² vs. 72.35 ± 21.1 g/m², p<0.001), which was more pronounced in the late second/third trimester, consistent with metabolic-induced cardiac remodeling. Functional impairments were observed with reduced GLS (-20.20 ± 1.42 vs. -21.37 ± 1.97, p=0.004), with the difference becoming significant only in the late second/third trimester. Altered diastolic filling patterns (E/A ratio: 1.84 ± 0.61 vs. 1.61 ± 0.38, p=0.007) were already present in the first trimester and persisted. Additionally, ventricular dilation was evident, with larger EDV (98.06 ± 28.28 vs. 85.92 ± 18.01, p=0.003) and ESV (33.11 ± 13.04 vs. 27.92 ± 9.04, p=0.009), which were not significantly different in early pregnancy but became prominent in the late second/third trimester, suggesting progressive volume overload.

Temporal Changes: EDV, ESV, GLS, and E/e' lat showed progressive changes, becoming more pronounced at the second timepoint, highlighting the evolving cardiac impact of both HDP and GDM throughout pregnancy.

HDP primarily affects LV structure, atrial enlargement, and diastolic function, while GDM is characterized by myocardial strain impairment and increased ventricular volumes. These findings establish an echocardiographic reference framework for pregnancy and underscore the need for longitudinal monitoring in cardiometabolic complications to guide early cardiovascular risk management.