Dataset Information

Understanding abnormal uterine artery Doppler waveforms: A novel computational model to explore potential causes within the utero-placental vasculature.

ABSTRACT: INTRODUCTION:Uterine artery (UtA) Doppler indices are one of the most commonly employed screening tests for pre-eclampsia worldwide. Abnormal indices appear to result from increased uterine vascular resistance, but anatomical complexity and lack of appropriate animal models mean that little is known about the relative contribution of each of the components of the uterine vasculature to the overall UtA Doppler waveform. Previous computational models suggested that trophoblast-mediated spiral artery remodeling has a dominant effect on the UtA Doppler waveform. However, these models did not incorporate the myometrial arterio-venous anastomoses, which have significant potential to affect utero-placental haemodynamics. METHODS:We present a more anatomically complete computational model, explicitly incorporating a structural description of each component of the uterine vasculature, and crucially including myometrial arterio-venous anastomoses as parallel pathways for blood-flow away from the placental bed. Wave transmission theory was applied to the network to predict UtA waveforms. RESULTS:Our model shows that high UtA resistance indices, combined with notching, reflect an abnormal remodeling of the entire uterine vasculature. Incomplete spiral artery remodeling alone is unlikely to cause abnormal UtA Doppler waveforms as increased resistance in these arteries can be 'buffered' by upstream anastomoses. Critically, our results indicate that the radial arteries, may have a more important effect on utero-placental flow dynamics, and the UtA Doppler waveform than previously thought. CONCLUSIONS:This model suggests that to appropriately interpret UtA Doppler waveforms they must be considered to be reflecting changes in the entire system, rather than just the spiral arteries.

SUBMITTER: Clark AR

PROVIDER: S-EPMC6511649 | biostudies-literature | 2018 Jun

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Understanding abnormal uterine artery Doppler waveforms: A novel computational model to explore potential causes within the utero-placental vasculature.

Clark Alys R AR James Joanna L JL Stevenson Gordon N GN Collins Sally L SL

Placenta 20180509

<h4>Introduction</h4>Uterine artery (UtA) Doppler indices are one of the most commonly employed screening tests for pre-eclampsia worldwide. Abnormal indices appear to result from increased uterine vascular resistance, but anatomical complexity and lack of appropriate animal models mean that little is known about the relative contribution of each of the components of the uterine vasculature to the overall UtA Doppler waveform. Previous computational models suggested that trophoblast-mediated spi ...[more]

PMID: 29884305

Similar Datasets

Project description:BACKGROUND:Intrauterine growth restriction is defined as a fetal weight below the 10th percentile for a given gestational age and can be identified using umbilical artery Doppler velocimetry which is a non-invasive technique. The objective of this study was to determine the perinatal outcome of growth-restricted fetuses with abnormal umbilical artery Doppler study compared to those with normal umbilical artery Doppler waveforms at a tertiary referral hospital in Ethiopia. METHODS:A prospective cohort study was conducted among pregnant mothers with fetal growth restriction admitted for labour and delivery from September 2018-February 2019. The data were entered and analyzed using SPSS version 23. After conducting descriptive analysis, exploring the entire data, and checking for, statistical associations between abnormal umbilical artery Doppler and outcome variables, multiple logistic regression was conducted to control for confounders. RESULTS:A total of 170 pregnant mothers complicated with growth-restricted fetuses were included in the study, among which 133 were with normal umbilical artery Doppler studies and 37 were with abnormal umbilical artery Doppler studies. Four (3%) of normal and 9(24.3%) of abnormal umbilical artery Doppler studies ended in perinatal death-value = 0.001. Twenty (15%) of normal and 24(64.9%) of abnormal umbilical artery Doppler study neonates required neonatal intensive care admission-value = 0.002. Growth restricted fetuses complicated with abnormal Doppler were two times more likely to require neonatal intensive care unit admissions compared to growth-restricted fetuses with normal umbilical artery Doppler flow, P-value 0.002, (OR = 2.059,95%CI 1.449-2.926). Growth restricted fetuses complicated with abnormal Doppler were four times more likely to end in early neonatal death compared to growth-restricted fetuses with normal umbilical artery Doppler flow, P-value 0.001, (OR = 4.136, 95%CI 3.423-4.998). However, the study is unmatched and there is a possibility of gestational age confounding the result and should be seen with the context of preterm morbidity and mortality. CONCLUSION:The abnormal umbilical artery Doppler waveform is associated with cesarean section delivery, neonatal intensive care unit admission, respiratory distress syndrome, neonatal sepsis, neonatal hyperbilirubinemia, and early neonatal death compared to normal umbilical artery Doppler flow.

Project description:INTRODUCTION:Mid-trimester uterine artery resistance measured with Doppler sonography is predictive for iatrogenic preterm birth. In view of the emerging association between hypertensive disease in pregnancy and spontaneous preterm birth, we hypothesized that uterine artery resistance could also predict spontaneous preterm birth. MATERIAL AND METHODS:We performed a cohort study of women with singleton pregnancies. Uterine artery resistance was routinely measured at the 18-22 weeks anomaly scan. Pregnancies complicated by congenital anomalies or intrauterine fetal death were excluded. We analyzed if the waveform of the uterine artery (no notch, unilateral notch or bilateral notch) was predictive for spontaneous and iatrogenic preterm birth, defined as delivery before 37 weeks of gestation. Furthermore, we assessed whether the uterine artery pulsatility index was associated with the risk of preterm birth. RESULTS:Between January 2009 and December 2016 we collected uterine Doppler indices and relevant outcome data in 4521 women. Mean gestational age at measurement was 19+6 weeks. There were 137 (3.0%) women with a bilateral and 213 (4.7%) with a unilateral notch. Mean gestational age at birth was 38+6 weeks. Spontaneous and iatrogenic preterm birth rates were 5.7% and 4.9%, respectively. Mean uterine artery resistance was 1.12 in the spontaneous preterm birth group compared with 1.04 in the term group (P = 0.004) The risk of preterm birth was increased with high uterine artery resistance (OR 2.9 per unit; 95% CI 2.4-3.9). Prevalence of spontaneous preterm birth increased from 5.5% in women without a notch in the uterine arteries to 8.0% in women with a unilateral notch and 8.0% in women with a bilateral notch. For iatrogenic preterm birth, these rates were 3.9%, 13.6% and 23.4%, respectively. Likelihood ratios for the prediction of spontaneous preterm birth were 1.6 (95% CI 1.0-2.6) and 1.9 (95% CI 1.0-3.5) for unilateral and bilateral notches, respectively, and for iatrogenic preterm birth they were 3.6 (95% CI 2.5-5.2) and 6.8 (95% CI 4.7-9.9) for unilateral and bilateral notches, respectively. Of all women with bilateral notching, 31.4% delivered preterm. CONCLUSIONS:Mid-trimester uterine artery resistance measured at 18-22 weeks of gestation is a weak predictor of spontaneous preterm birth.

Project description:IntroductionEarly-onset fetal growth restriction is a pregnancy complication often coinciding with abnormal Doppler flow in the umbilical artery. Absent or reversed end-diastolic flow in the umbilical artery is associated with adverse perinatal outcome. As the optimal management of this condition is unclear, the objective of this study was to analyze the time interval from admission to delivery of pregnancies with early-onset fetal growth restriction, while pursuing a policy of postponing delivery unless active management of labor would be required because of fetal distress or maternal condition. We also assessed short- and long-term perinatal outcome.Material and methodsIn this historical cohort study, all pregnant women with singleton pregnancies, admitted during 2004-2015 with early-onset fetal growth restriction were included. Pregnancies with absent or reversed end-diastolic flow (AREDF) were compared with pregnancies with a positive end-diastolic Doppler flow (PEDF). Time until delivery was determined and perinatal outcome was assessed for both groups.ResultsIn our study, 111 women were allocated to the PEDF group and 109 to the AREDF group. In the AREDF group, fetal distress was more often an indication for delivery, in comparison with the PEDF group (p = .004). Median time until delivery in patients admitted between 26 and 28 weeks' gestation was 6+5 weeks in the PEDF group and 1+4 weeks in the AREDF group (p = .001). No statistically significant difference was found between the Doppler groups in the composite adverse neonatal outcome, which includes at least one of the following outcomes: infant respiratory distress syndrome, sepsis, bronchopulmonary dysplasia, necrotizing enterocolitis, intraventricular hemorrhage >grade 2, periventricular leukomalacia and perinatal death (p = .63).ConclusionsIn this study, comprising pregnancies with early-onset fetal growth restriction, fetal distress was observed more frequently in the AREDF group with the consequence of delivery at an earlier stage of gestation, compared with the PEDF group. AREDF was not associated with increased perinatal morbidity and mortality compared with PEDF.

Dataset Information

Understanding abnormal uterine artery Doppler waveforms: A novel computational model to explore potential causes within the utero-placental vasculature.

Publications

Understanding abnormal uterine artery Doppler waveforms: A novel computational model to explore potential causes within the utero-placental vasculature.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets