Doppler Assessment of the Aortic Isthmus in Intrauterine Growth-Restricted Fetuses

We aimed to evaluate the association of fetal aortic isthmus (AoI) Doppler flow measurements in intrauterine growth-restricted (IUGR) fetuses with fetal outcome. The data presented in this prospective cohort study were obtained from 74 IUGR and 71 appropriate-for-gestational-age (AGA) fetuses of singleton pregnancies with normal medical and obstetric histories that were between 26 and 40 weeks of gestation. All AoI Doppler scans were performed by the same observer. There were no statistical differences in maternal characteristics and gestational age or between AGA and IUGR fetuses at the inclusion time. No cases of reversed flow during diastole were detected. Aortic isthmus flow index was increased in growth-restricted fetuses. Absolute end-diastolic (EDV) and time-averaged maximum velocities were decreased in the IUGR fetuses. There was an association between AoI Doppler EDV measurements and prediction of neonatal intensive care unit requirement as well as AoI Doppler isthmic flow index and resistance index measurements and low 5-minute Apgar values. Aortic isthmus EDV was found to be independently associated with IUGR status. Because the AoI Doppler flow measurements of the IUGR fetuses were different from the AGA fetuses and predicted neonatal adverse outcome, Doppler imaging of the AoI could be used as a screening tool in the clinical surveillance of fetuses with IUGR after confirmation in larger prospective studies.