F Bahlmann 1 , M Fittschen 1 , I Reinhard 2 , S Wellek 3 , A Puhl 4 Show Affiliations »
Abstract
PURPOSE: The aim of the present study was to calculate new Doppler reference ranges for systolic, intensity-weighted mean, and end-diastolic blood flow velocities (Vmax, Vmean, Vmin) and fetal heart rate and impedance indices (PI, RI) of the umbilical artery by automatic waveform analysis. MATERIALS AND METHODS: A cross-sectional prospective study of 1926 low-risk pregnancies was performed at 18 - 42 weeks of gestation. The measurements were carried out in the region of a free floating loop of cord. Reference ranges for the individual measuring parameters were constructed based on a growth function from a four-parameter class of monotonic continuous functions according to the smallest square principle. The intraobserver reliability was also assessed. RESULTS: A significant increase in umbilical blood flow velocity was observed at 18 - 42 weeks of gestation (Vmax = 33.7 cm/sec to 65 cm/sec (p < 0.001), Vmean = 18.2 cm/sec to 38.7 cm/sec (p < 0.001) and Vmin = 8.2 to 31 cm/sec (p < 0.001). Reference curves for the pulsatility and the resistance index were associated with significant decreases with increasing gestational age (PI: 18 weeks: 1.3; 28 weeks: 1.1; 42 weeks: 0.8 and RI: 18 weeks: 0.7; 28 weeks: 0.6; 42 weeks: 0.5). The fetal heart rate decreased from 147 - 134 bpm. The intraobserver reliability was low, but of no clinical relevance. CONCLUSION: The reference ranges for blood flow velocities and resistance indices in the umbilical artery calculated by the authors serve as the basis for Doppler ultrasound antenatal examinations in a normal patient population and enable the early diagnosis of fetal risk. © Georg Thieme Verlag KG Stuttgart · New York.
PURPOSE: The aim of the present study was to calculate new Doppler reference ranges for systolic, intensity-weighted mean, and end-diastolic blood flow velocities (Vmax, Vmean, Vmin) and fetal heart rate and impedance indices (PI, RI) of the umbilical artery by automatic waveform analysis. MATERIALS AND METHODS: A cross-sectional prospective study of 1926 low-risk pregnancies was performed at 18 - 42 weeks of gestation. The measurements were carried out in the region of a free floating loop of cord. Reference ranges for the individual measuring parameters were constructed based on a growth function from a four-parameter class of monotonic continuous functions according to the smallest square principle. The intraobserver reliability was also assessed. RESULTS: A significant increase in umbilical blood flow velocity was observed at 18 - 42 weeks of gestation (Vmax = 33.7 cm/sec to 65 cm/sec (p < 0.001), Vmean = 18.2 cm/sec to 38.7 cm/sec (p < 0.001) and Vmin = 8.2 to 31 cm/sec (p < 0.001). Reference curves for the pulsatility and the resistance index were associated with significant decreases with increasing gestational age (PI: 18 weeks: 1.3; 28 weeks: 1.1; 42 weeks: 0.8 and RI: 18 weeks: 0.7; 28 weeks: 0.6; 42 weeks: 0.5). The fetal heart rate decreased from 147 - 134 bpm. The intraobserver reliability was low, but of no clinical relevance. CONCLUSION: The reference ranges for blood flow velocities and resistance indices in the umbilical artery calculated by the authors serve as the basis for Doppler ultrasound antenatal examinations in a normal patient population and enable the early diagnosis of fetal risk. © Georg Thieme Verlag KG Stuttgart · New York.
Entities: Chemical
Mesh： See more »
Year: 2012
PMID： 22331834 DOI： 10.1055/s-0031-1299294
Source DB: PubMed Journal: Ultraschall Med ISSN： 0172-4614 Impact factor: 6.548