Alterations in time intervals of ductus venosus and atrioventricular flow velocity waveforms in growth‐restricted fetuses

Objective To investigate time intervals of the ductus venosus ( DV ) flow velocity waveform ( FVW ) and those of the cardiac cycle that correspond with each DV‐FVW component in fetuses with intrauterine growth restriction ( IUGR ) due to placental insufficiency. Methods Women with a pregnancy complicated by IUGR were recruited into the study, as was a normal control group. Time intervals for systolic (S) and diastolic (D) components were measured in DV‐FVW as follows: S DV , from the nadir of the a‐wave during atrial contraction to the nadir between the S‐wave and D‐wave; D DV , from the nadir between S‐wave and D‐wave to the nadir of the a‐wave. Regarding cardiac cycles, the following variables were measured from ventricular inflow through the tricuspid valve ( TV ) and mitral valve ( MV ): S TV and S MV , from the second peak of ventricular inflow caused by atrial contraction (A‐wave) to the opening of the atrioventricular valve; D TV and D MV , from the opening of the atrioventricular valve to the peak of the A‐wave. In the IUGR group, only the last examination performed within 1 week of delivery was used for analysis. All variables were analyzed statistically using Z ‐scores. Results Data were obtained from 249 normal fetuses and 26 fetuses with IUGR . Compared to normal fetuses, S DV showed a significant decrease ( P  < 0.001), while D DV showed a significant increase ( P  < 0.001) in the IUGR group. Regarding cardiac cycles, S TV and S MV showed significant decreases ( P  = 0.014 and P  < 0.001, respectively) and D TV and D MV showed significant increases ( P  = 0.008 and P  = 0.002, respectively) in fetuses with IUGR . Conclusion Time‐interval alterations of DV‐FVW in growth‐restricted fetuses reflect the hemodynamic events caused by placental insufficiency. Copyright © 2014 ISUOG. Published by John Wiley & Sons Ltd.