Altered Transmission of Cardiac Cycles to Ductus Venosus Blood Flow in Fetal Growth Restriction: Why Ductus Venosus Reflects Fetal Circulatory Changes More Precisely

Abstract

We aimed to investigate the relation between the time intervals of the flow velocity waveform of ductus venosus (DV-FVW) and cardiac cycles. We defined Delta A as the difference in the time measurements between DV-FVW and cardiac cycles on the assumption that the second peak of ductus venosus (D-wave) starts simultaneously with the opening of the mitral valve (MV). As well, we defined Delta B as the difference of the time measurements between DV-FVW and cardiac cycles on the assumption that the D-wave starts simultaneously with the closure of the aortic valve (AV). We then compared Delta A and Delta B in the control and fetal growth restriction (FGR) groups. In the control group of healthy fetuses, Delta A was strikingly shorter than Delta B. On the other hand, in all FGR cases, no difference was observed. The acceleration of the D-wave is suggested to be generated by the opening of the MV under normal fetal hemodynamics, whereas it precedes the opening of the MV in FGR. Our results indicate that the time interval of DV analysis might be a more informative parameter than the analysis of cardiac cycles.

Correlation analysis of time-interval parameter of ductus venosus and neonatal blood pressure at birth in fetal growth restriction

“…Interestingly, the DV-S/D more precisely represents fetal pH than other parameters of cardiac cycles, likely because the DV-S/D might also be affected not only by cardiac cycles but also by altered vascular resistance and blood viscosity in FGR [21,22]. As such, the DV-S/D might more likely re ect fetal circulation volume, although the DV-PI might rather re ect cardiac congestion and/or myocardial compliance in at-risk fetuses.…”