Echocardiographic Assessment of Maternal Cardiac Physiological Adaptation Across Trimesters in Chinese Pregnancies: A Comprehensive Investigation

Objective To comprehensively characterize trimester-specific echocardiographic changes in maternal cardiac morphology and function during normal pregnancy in healthy Chinese women, and to establish population-specific reference values for physiological cardiac adaptation. Methods In this prospective observational study, 412 healthy pregnant women with singleton gestations underwent standardized transthoracic echocardiography at Yichun Maternal & Child Health Hospital, China. Two-dimensional, Doppler, and tissue Doppler imaging were performed to assess left ventricular (LV) structure, systolic and diastolic function, and great artery hemodynamics across the first, second, and third trimesters. Group comparisons were analyzed using one-way ANOVA with Bonferroni correction. Results Progressive cardiac remodeling was observed throughout gestation. LV end-diastolic and end-systolic volumes increased significantly (86.96 ± 19.1 → 100.44 ± 20.6 mL and 32.13 ± 8.9 → 38.70 ± 9.3 mL, p < 0.001), with stable wall thickness and preserved geometry, indicating eccentric rather than concentric remodeling. Stroke volume and cardiac output rose significantly (55.26 ± 15.54 → 62.39 ± 12.65 mL; 4.77 ± 1.60 → 5.91 ± 1.47 L/min, p < 0.001), while ejection fraction remained within normal limits. Diastolic indices showed load-dependent modulation: E/A and e’/a’ ratios decreased and E/e’ increased modestly (p < 0.05), suggesting adaptive relaxation. Great artery velocities and pressure gradients exhibited mild, balanced increases consistent with vascular compliance. Conclusion Pregnancy in Chinese women induces physiologic eccentric ventricular remodeling, enhanced systolic performance, and adaptive diastolic and vascular changes that sustain maternal–fetal circulation. The trimester-specific reference data established provide crucial ethnicity-specific baselines for accurate echocardiographic assessment and early identification of cardiovascular maladaptation.