Analysis of the Effect of Sampling Site of Umbilical Artery Doppler on the Variability of Umbilical Artery Pulsatility Index

Abstract

Background: Analysis of the umbilical artery (UA) flow by means of pulsed Doppler has become a standard for antenatal care of high-risk pregnancies.Aim: The aim of the present study was to test the hypothesis that standardizing the site of sampling of umbilical artery Doppler reduces the variability of umbilical artery Pulsatility Index (PI).Materials and Methods: The present study was Prospective study included 120 pregnant women - with singleton fetuses of 28 week of gestation till term and delivery-attending outpatient clinic at Helwan University Hospitals. All pregnant females were followed up monthly minimum for 3 occasions till delivery.Results: The present study revealed the presence of significant variability in the measurements of umbilical artery PI among the sampling sites as well as among the different time points at which the measurements were taken, with poor repeatability and reproducibility of the umbilical artery PI measurements. Variability in umbilical artery PI among the sampling sites was demonstrated in our study. There were significant differences in the mean umbilical artery PI among the four sampling sites, with higher mean umbilical artery PI at PVC site, followed by AI, FL and PL sites. Intraclass correlation was computed to test reliability, showing poor agreement among the four sampling sites. These findings suggest that standardization of the site of sampling may reduce variability and increase reliability of measurements.Conclusion:Standardization of the site of sampling of umbilical artery Doppler may reduce variability and increase reliability of measurements of umbilical artery Pulsatility Index.