480: Umbilical artery Doppler discordance in fetal growth restriction

Abstract

Contemporary antepartum surveillance for fetal growth restriction (FGR) consists of serial umbilical artery Doppler waveform assessments from a “free loop” (FL) of cord without regard to the specific artery being sampled. The primary objective of this study was to establish the frequency of discordant blood flow patterns between right and left umbilical arteries at the abdominal wall insertion site (AWI). Secondary aims included determining the frequency of discordance between FL and AWI patterns, and whether deterioration of Doppler waveforms occurred in a synchronous pattern. A descriptive prospective cohort study of patients diagnosed with IUGR between 23 0/7 -36 6/7 weeks gestation. Umbilical artery FL Doppler was obtained per routine clinical practice, with additional study waveforms acquired of both right and left umbilical arteries at the AWI. Doppler patterns were assigned 1 of 6 classifications. Baseline maternal demographics, obstetrical complications, gestational age at delivery, and neonatal birthweights were abstracted from medical records. Median gestational age at IUGR diagnosis was 31.4 weeks. Among the 70 participants, 50 (71.4%) had more than 1 Doppler measurement recorded, for a total of 238 examinations. At the initial study measurement, 14 patients (20%) had discordant AWI waveforms. When comparing AWI to FL measurements, discordance was found in 23 cases (33%). Progression of at least 1 AWI Doppler occurred in 23 patients (33%), and progression was discordant in 20 cases (29%; Table1). Frequent variability exists between arterial umbilical Doppler flow patterns in growth restricted fetuses, both at time of diagnosis and during subsequent measurements. The current study was descriptive, thus the clinical significance of this finding is indeterminate at present. Further investigations are needed to determine if umbilical artery Doppler discordance could conceivably represent an additional parameter for antepartum monitoring in fetal growth restriction.