Qualitative Venous Doppler Flow Waveform Analysis in Preterm Intrauterine Growth-Restricted Fetuses with ARED Flow in the Umbilical Artery???Correlation With Short-Term Outcome

Abstract

Controversy continues about the best time for delivery when intrauterine growth restriction (IUGR) is present. Although many practitioners use arterial and venous Doppler, biophysical parameters, and fetal heart tracings,there is no standard management. The risk of prematurity-usually before 32 weeks gestation-must be balanced against the risks of prolonged fetal exposure to hypoxemia and acidemia with their possible consequences of persistent fetal damage, stillbirth, and neonatal death. This retrospective study enrolled 74 fetuses with IUGR and absent or reversed end-diastolic (ARED) flow in the umbilical artery (UA) with delivery taking place at 24 to 34 weeks gestation. Perinatal outcomes were related to absent or reversed flow during atrial contraction (a-wave) in the ductus venosus (DV) and pulsatile flow in the umbilical vein (UV). Color Doppler imaging was performed, and flow velocity waveforms were recorded from the UA, DV, UV, and middle cerebral artery. End-diastolic flow in the UA was absent in 43% of fetuses and reversed in 57%. Brain sparing was observed in 53% and 90.5% of fetuses, respectively. Flow was absent or reversed during the a-wave in the DV in 41% of cases and UV pulsations in 31%. In 18% of fetuses, Doppler waveforms were abnormal in both the DV and the UV. More than half (54%) of fetuses were acidotic at birth and 6.5% had birth asphyxia. Perinatal mortality was 19% with 12 perinatal and 2 neonatal deaths. Eight of these 12 fetuses were stillborn. On logistic regression analysis, the strongest predictors of perinatal death were abnormal. Only gestational age correlated significantly with neonatal deaths. Abnormal venous Doppler waveforms were more frequent in fetuses with acidemia, oligohydramnios, or intraventricular hemorrhage at birth. In this series, venous Doppler flow patterns predicted stillbirths and perinatal deaths with better specificity and higher positive predictive values than did reversed flow in the UA or brain sparing. Fetal and perinatal deaths were significantly associated with an absent or reversed DV a-wave or UV pulsations, especially before 32 weeks gestation. Preterm IUGR fetuses in this study with severe venous Doppler flow abnormalities were delivered at a time when multiorgan failure and persistent damage were already present. These translate into a high number of stillbirths and perinatal/neonatal deaths. The question of when to deliver preterm infants with IUGR will be addressed in a planned prospective, randomized multicenter trial, the TRUFFLE study.