Umbilical Artery Doppler Velocimetry Indices in Fetuses with Single Umbilical Arteries

Backgrounds and

Doppler waveform analysis of the umbilical artery is a powerful tool to evaluate probable pregnancy risks. So far, huge amounts of data on fetuses with three-vessel umbilical cords have been collected. Our objective was to evaluate the value of umbilical artery Doppler velocimetry in fetuses with single umbilical arteries. In this respect, two evaluation indices of the Pulsatility Index and the Systolic/Diastolic Ratio were considered.

Fetuses between 16 and 40 week gestational age were studied. A set of information was obtained from 50 cases with single umbilical arteries. Data were analyzed using chi-square (χ²) test. P-values less than 0.05 was considered significant.

The Systolic/Diastolic Ratio in the umbilical artery was abnormal in 29 fetuses (58%) and normal in 21 fetuses (42%). Pulsatility Index in the umbilical artery was abnormal in 28 fetuses (56%) and normal in 22 fetuses (44%). Fetuses with abnormal Doppler waveform analysis in their umbilical arteries were significantly more likely to be growth restricted (38%) and to more have complex malformations (18%) than those with normal Doppler waveform analysis.

Fetuses with single umbilical arteries and abnormal umbilical Doppler velocimetry had a significantly increased risk of adverse fetal and neonatal outcomes compared with those with single umbilical arteries but normal Doppler studies. When the fetus with isolated umbilical artery is the only observed fetus anomaly and the results of Doppler velocimetry are normal, it might be suggested that the risk of disorder in fetus is so low.