Assessment of fetal cardiac morphology and functional changes in early-onset and late-onset fetal growth restriction.

Objective: To compare the fetal cardiac morphology and functions of early-onset fetal growth restriction (EO-FGR) and late-onset fetal growth restriction (LO-FGR) groups with gestational weeks-matched controls.

Methods: A total of 164 pregnant women were included, 28 of whom were in the EO-FGR group, 54 in the LO-FGR group, and 82 in the control group. Fetal echocardiographic evaluation was performed with two-dimensional, M-mode, tissue Doppler imaging (TDI), and pulsed wave Doppler.

Results: Fetal cardiac morphologic measurements and diastolic and systolic functions changed in EO-FGR and LO-FGR fetuses compared with controls. The EO- and LO-FGR fetuses had reduced right and left cardiac output, increased myocardial performance index, and significantly higher mitral and tricuspid E/E' ratios compared with controls. The EO-FGR fetuses had lower mitral and tricuspid E and E' values. In LO-FGR fetuses, mitral and tricuspid E' values were lower than in their controls (P = 0.001 and P < 0.001). On the other hand, the mitral and tricuspid E values were not significantly changed (P = 0.107 and P = 0.196).

Conclusion: We hypothesized that EO-FGR and LO-FGR fetuses had insufficient myocardial maturation. Especially in the LO-FGR fetuses, TDI is the earliest and most sensitive technique to show subtle changes in fetal cardiac functions.