280: The doppler transitional phase in severely premature IUGR fetuses


      We recently demonstrated Doppler changes in the Ductus Venosus (DV) progress through an intermittent transitional phase before absent/reversed flow is persistent that can last from 1 to 57 days. The hypothesis for this work is that this phenomenon is not specific to the DV, but is a systemic pattern in worsening IUGR

      Study Design

      Multivessel serial Doppler studies were prospectively performed in 15 IUGR fetuses (EFW < 10th percentile and umbilical artery pulsatility index > 95th percentile) from diagnosis until demise or delivery. At least 3 studies were performed in each fetus, each consisting of 3 different sets of waveforms for a total of at least 100 waveforms for each vessel. MCA Doppler waveforms assessed pulsatility index and peak systolic velocity, while umbilical artery, umbilical vein, and DV Doppler waveforms qualitatively assessed forward, absent, or reversed flow in diastole for UA and DV, and presence or absence of pulsation in the UV. A transitional phase for each vessel was defined when normal and abnormal flow patterns were identified during the same exam for that vessel.


      This data indicates the transitional phase previously identified in the DV is demonstrated throughout the fetal vascular tree in severely premature IUGR fetuses and emphasizes the importance of revisiting the way Doppler ultrasound is performed in the fetus.