730: Doppler velocimetry: A comparison of the intrafetal to extrafetal segments of the umbilical artery(UA) (original) (raw)
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Journal of Clinical Ultrasound, 1993
A range-gated Doppler ultrasound system combined with a real-time imaging system was used to determine arterial blood velocity values from the fetal and placental ends of the umbilical cord in 269 normal pregnancies between 17 and 40 weeks, menstrual age. The systolic-diastolic ratio (S/D), pulsatility index (PI), and resistance index (RI) were higher at the fetal end compared to the placental end of the cord. The individual differences in these Doppler indices, obtained between the fetal and placental recording sites, were inversely related to menstrual age: S/D: r =-0.38, p < 0.001; PI: r =-0.25, p < 0.001; and RI: r =-0.15, p < 0.01. After normalization for the angle of insonation, the peak systolic velocity was higher and the enddiastolic velocity was lower at the fetal than at the placental end of the cord. It is concluded that routine recordings for Doppler velocimetric indices should take into account the recording site on the umbilical cord in order to reduce methodological sources of variance, especially during midgestation. Furthermore, the data presented here in the form of the median and percentile values are proposed as normal reference values to facilitate this procedure.
The relationship between umbilical artery Doppler velocimetry and fetal biometry
American Journal of Obstetrics and Gynecology, 1991
The relationship between peak-systolic/ end-diastolic ratio of the umbilical artery waveform and fetal biometry was studied in 127 uncomplicated pregnancies with established dates between 20 and 40 weeks' gestation. At each ultrasonographic examination fetal biometry included measurement of the biparietal diameter, head circumference, abdominal circumference, and femur length. The peak-systolic/end-diastolic ratio was measured by either a continuous or a pulsed-wave method. There were significant linear negative correlations between all the biometric parameters, as well as between the ultrasonographically estimated fetal weight and peak-systolic/end-diastolic ratio. Of the individual ultrasonographic parameters the femur length (for gestations <30 weeks) and the abdominal circumference (for gestations 2:30 weeks) were found to be best correlated with the peak-systolic/end-diastolic ratio. Regression curves, including the 10th and the 90th percentile, were developed between each biometric parameter (biparietal diameter, head circumference, abdominal circumference, and femur length), as well as between estimated fetal weight and peak-systolic/end-diastolic ratio. The estimated fetal weight nomogram had the best sensitivity (48%) in predicting intrauterine growth retardation. These nomograms should prove most useful in assessing downstream placental vascular resistance in high-risk patients with unknown dates. (AM J
American Journal of Obstetrics and Gynecology, 1987
Fifty-four women who were delivered of small for gestational age infants were studied antenatally by serially continuous-wave Doppler velocimetry. Outcomes were compared in the normal and abnormal systolic/diastolic ratio groups. Seventy-eight percent had an abnormal systolic/diastolic ratio. The group with an elevated systolic/diastolic ratio had a significantly higher incidence of abnormal fetal heart rate, pregnancy-induced hypertension, oligohydramnios, cesarean section for fetal distress, and admission into the neonatal intensive care unit. One third of the newborns required intermittent positive pressure ventilation. Average birth weight and gestational age at delivery were significantly lower and there were six perinatal deaths in the group with an elevated systolic/diastolic ratio and none in the group with a normal systolic/diastolic ratio. These data suggest that the small for gestational age fetus with normal umbilical artery velocimetry is at significantly lower risk than are those with abnormal ratios. This implies that management of the small for gestational age fetus may now be aided by a functional classification based on the umbilical artery velocity waveform.
Doppler Velocimetry of Umbilical Artery in Normal and Growth Restricted Pregnancy
Bangladesh Journal of Obstetrics & Gynaecology, 2022
Objectives: To evaluate the umbilical arterial blood flow velocity and its various indices during 3rd trimester of pregnancy and to compare these indices in normal and growth restricted pregnancies. Methods: In this study, 50 women with normal singleton pregnancy and 50 women with intrauterine growth restricted (IUGR) pregnancy with expected birth weight <10th percentile of the normal for the gestational age were studied by Doppler evaluation of their umbilical artery, Pulsality Index (PI), Resistance Index (RI) and S/D ratio of the control group and IUGR group were calculated and reference range constructed. Values of Doppler indices of IUGR group were compared with those of the control group. Perinatal outcome was evaluated in relation to the indices. Results: Doppler velocimetry of umbilical artery showed elevated indices in 33 out of 50 cases of IUGR group showing its high sensitivity in diagnosing haemodynamically compromised growth restricted fetuses. Absent end diastolic v...
American Journal of Obstetrics and Gynecology, 2005
Objective: The purpose of this study was to construct new reference ranges for serial measurements of commonly used umbilical artery Doppler indices (pulsatility index, resistance index, and systolic:diastolic ratio). Study design: This was a prospective longitudinal study of the umbilical artery Doppler indices that were obtained serially at the free-loop of umbilical cord at 4-week intervals at 19 to 42 weeks of gestation in 130 low-risk singleton pregnancies. A total of 513 observations were used to construct the reference ranges with the use of multilevel modeling. Results: Longitudinally established percentiles of Doppler indices from the present study show a continuous reduction throughout the second half of pregnancy without any plateau or increase near term, as reported previously. There was a significant negative association between Doppler indices and placental weight and neonatal birth weight, but not with gender. The intraobserver coefficients of variation for the umbilical artery pulsatility index, resistance index, and systolic:diastolic ratio were 10.5%, 6.8 %, and 13.0 %, respectively. Conclusion: New reference ranges for umbilical artery Doppler indices that are based on longitudinal observations appear to be slightly different from cross-sectional studies and are more appropriate for serial evaluation of fetal hemodynamics.
Umbilical artery Doppler velocimetry in the prediction of intrapartum fetal compromise
South African medical journal = Suid-Afrikaanse tydskrif vir geneeskunde, 1992
The value of early intrapartum umbilical artery Doppler velocimetry in the prediction of fetal compromise was studied. One hundred patients were recruited into the study and fetal compromise was diagnosed by abnormal first- or second-stage fetal heart rate traces, a 5-minute Apgar score less than 7, or the development of hypoxic ischaemic encephalopathy. Fetal compromise developed in 30 patients. An umbilical artery resistance index (RI) of 0.66 or less did not predict fetal compromise (sensitivity 13%, specificity 89%, positive predictive value 25%, negative predictive value 70%). Since the mean umbilical artery RI was identical in the compromised and the non-compromised groups, we conclude that early intrapartum Doppler velocimetry is of very little clinical value in predicting fetal compromise at term.
Umbilical Artery Doppler Waveform Indices at Term
Donald School Journal of Ultrasound in Obstetrics and Gynecology, 2018
Aim: This study was designed to evaluate umbilical artery Doppler indices [systolic/diastolic (S/D) ratio and pulsatility index (PI)] in normal fetus at term. Doppler ultrasound of umbilical arteries is widely accepted as a primary tool for quantitative analysis of fetoplacental and uteroplacental blood flow in highrisk pregnancies. Materials and methods: A total of 100 normal singleton pregnant women were recruited in this study from the Radiology Department Fatima Memorial Hospital (FMH) from August 3, 2012 to November 30, 2012. Their gestational ages were from 37 to 40 weeks. Results: A total of 100 Doppler indices measurements were performed. The values of S/D ratio were less than 3 and the values of mean PI were less than 1 from 37 to 40 weeks of gestation. Conclusion: Umbilical artery Doppler indices among normal pregnant women in our population are similar to most published reference values from other parts of the world. Clinical significance: This normative data will serve as a basis for the evaluation of the umbilical artery circulation in our population.
Umbilical Artery Doppler Velocimetry in Fetuses with a Single Umbilical Artery
Journal of Diagnostic Medical Sonography, 1997
Objective: Doppler waveform analysis of the umbilical artery is an important tool for the evaluation of high-risk pregnancies. Yet, available data are based on normal values from three-vessel umbilical cords. Our purpose was to evaluate the value of umbilical artery Doppler velocimetry in fetuses with a single umbilical artery.
International Journal of Reproduction, Contraception, Obstetrics and Gynecology, 2017
Background: Early detection of fetoplacental compromise with Umbilical Artery Doppler indices and to know the predictive value of each indices in predicting perinatal outcome and interventional strategies in these patients.Methods: The present prospective study was conducted on 200 women with hypertensive disorder of pregnancy. Umbilical artery doppler evaluation done in all the patients at (28-32) weeks, (33-36) weeks and (37-40) weeks of gestation and more frequently in those patients having deranged Doppler. Patients divided into two groups women with abnormal Umbilical artery indices (group B) and normal indices (group A). Perinatal outcome of both the groups were compared, analyzed statistically using Chi-square test. Multiple pregnancy, chronic hypertension, fetal congenital anomalies, systemic disease and those lost to follow up till delivery were excluded from study.Results: A total of 200 pregnant women with hypertensive disorder, 64% were primgravida. Abnormal umbilical ar...