Doppler Blood Flow Velocimetry Research Articles

Can flavonoid-rich chocolate modulate arterial elasticity and pathological uterine artery Doppler blood flow in pregnant women? A pilot study

Introduction: Dark chocolate has shown beneficial effects on cardiovascular health and might also modulate hypertensive complications in pregnancy and uteroplacental blood flow. Increased uteroplacental resistance is associated with systemic arterial stiffness. We aimed to investigate the short-term effect of flavonoid-rich chocolate on arterial stiffness and Doppler blood flow velocimetry indexes in pregnant women with compromised uteroplacental blood flow.Methods: Doppler blood flow velocimetry and digital pulse wave analysis (DPA) were performed in 25 women pregnant in the second and third trimesters with uterine artery (UtA) score (UAS) 3–4, before and after 3 days of ingestion of chocolate with high flavonoid and antioxidant contents. UtA pulsatility index (PI), UtA diastolic notching, UAS (semiquantitative measure of PI and notching combined), and umbilical artery PI were calculated, and DPA variables representing central and peripheral maternal arteries were recorded.Results: Mean UtA PI (p = .049) and UAS (p = .025) significantly decreased after chocolate consumption. There were no significant changes in UtA diastolic notching or any DPA indexes of arterial stiffness/vascular tone.Conclusion: Chocolate may have beneficial effects on the uteroplacental circulation, but in this pilot study, we could not demonstrate effects on arterial vascular tone as assessed by DPA.

Pregnancy Related Complications in Patients with Systemic Lupus Erythematosus, An Egyptian Experience

BackgroundSystemic Lupus Erythematosus (SLE) has a tendency to occur in women in their reproductive years, causing complications during pregnancy and labour. Conversely, pregnancy can cause flares of disease activity, often necessitating immediate intervention.Aim of studyto study pregnancy related complications in patients with SLE.Patients and methodsThe study included 48 SLE pregnant females. 27 patients with 38 pregnancies, their data viewed retrospectively from medical records, and 21 patients with 21 pregnancies followed up prospectively. The laboratory data included ANA, DNA, APL antibodies and anti Ro/SSA. The disease activity was calculated according to the Systemic Lupus Activity Measure. Ultrasound was performed to confirm gestational age and assess for the presence of any congenital fetal malformations, and then repeated monthly to detect any abnormality including intrauterine growth restriction. At 30 weeks gestation and onwards, assessment of fetal wellbeing including daily fetal kick chart and once weekly non stress test was performed. Doppler blood flow velocimetry was done for those with abnormal fetal heart rate pattern. After labour, the neonate was examined for complications including complete heart block and neonatal lupus.ResultsAnti dsDNA was found in 95% of the patients, anti Ro/SSA in 6% and anti APL in 30%. 57% of the patients followed up prospectively had active disease in the 1st trimester, 24% in the 2nd and 62% in the 3rd trimester. The most common maternal complication was preeclampsia 33%, followed by spontaneous abortion 20%. Prematurity was the most common fetal complication 37%, followed by intrauterine growth restriction 29%. 2 neonates were born with congenital heart block and 1 with neonatal lupus.ConclusionPregnancy in SLE patients is associated with a higher risk of obstetric complications affecting both the mother and the fetus. Preeclampsia was the most common complication followed by prematurity. Preeclampsia was significantly associated with third trimester disease activity.

Predictive value of middle cerebral artery to uterine artery pulsatility index ratio in preeclampsia

To determine the predictive value of middle cerebral artery (MCA) to uterine artery pulsatility index (PI) ratio in preeclamptic patients. This prospective cross-sectional study was performed on 64 preeclamptic and 131 normal pregnancies at or beyond 26 weeks of gestation between June 2007-August 2008 in the high-risk pregnancy unit of Dr. Zekai Tahir Burak Women Health Teaching and Research Hospital, Ankara. Doppler blood flow velocimetry of the uterine and umbilical arteries and fetal MCA was measured. The ratios between the PI of MCA and the mean PI value of both uterine arteries were calculated and values below the fifth percentile were considered as brain-sparing. The ratios between the PI of MCA and PI of the umbilical artery were calculated and values lower than 1.08 were considered as brain-sparing and the results were related to perinatal outcome. Statistical analysis were performed using the SPSS Software (SPSS, Chicago, IL, USA) version 9.0 for Windows. Odds ratio with 95% confidence interval (95%) was also used for statistical analysis. In 11 (42.3%) of the preeclamptic pregnancies that had abnormal MCA/uterine artery PI, 4 of them had severe preeclampsia and 7 had mild preeclampsia. In the low MCA/uterine artery PI ratio group, a statistically significantly higher rate of Cesarean section (66 vs. 88.46%), NICU admission (26.3 vs. 57.6%), preterm birth (52.6 vs. 92.3%) was found. Abnormal MCA/uterine artery PI ratio and abnormal MCA/umbilical artery PI ratio in the prediction of adverse outcome of pregnancy was compared. In the prediction of preterm birth, which was better for the MCA/uterine artery, there was a significant difference between the ratios (P = 0.005). Our results suggest that MCA/uterine artery PI ratio is a good predictor of neonatal outcome in preeclamptic patients in the third trimester and could be used to identify fetuses at risk of morbidity and mortality.

Research and development of portable Doppler blood flow velocimetry for health care monitor: Epidemiological investigations

Research and development of portable Doppler blood flow velocimetry for health care monitor: Epidemiological investigations

Fetal middle cerebral to uterine artery pulsatility index ratios in normal and pre‐eclamptic pregnancies

To calculate the normal range for the fetal middle cerebral artery (MCA)/uterine artery pulsatility index (PI) ratio in the third trimester of pregnancy and to assess its value, compared with that of the MCA/umbilical artery PI ratio, in predicting an unfavorable outcome of pregnancies complicated by pre-eclampsia. Doppler blood flow velocimetry of the uterine and umbilical arteries and fetal MCA was performed. We calculated the ratios between 1) the PI of the MCA and the mean PI value of both uterine arteries and 2) the PI of the MCA and the PI of the umbilical artery. All women were examined at or beyond 26 weeks of gestation. A cross-sectional study of 231 normal pregnancies was conducted to construct the reference range. Values below the 5th percentile or an MCA/umbilical artery PI ratio lower than 1.08 were defined as brain-sparing. A further 115 pregnancies with pre-eclampsia (50 mild and 65 severe) were assessed prospectively and the results were related to perinatal outcome. The accuracy of MCA/uterine artery and MCA/umbilical artery PI ratios for prediction of unfavorable pregnancy outcome was compared. Normal MCA/uterine artery PI ratios decreased with advancing gestational age. Redistribution of the fetal circulation indicated by a low MCA/uterine artery PI ratio was seen in 30% of the mild (n=15) and 46% of the severe (n=30) pre-eclamptic cases. There was a significant difference between those without and those with signs of brain-sparing, respectively, in mean birth weight (2456.0 vs. 1424.5 g), gestational age at delivery (35.6 vs. 31.3 weeks) and gestational age at the time of examination (34.9 vs. 30.9 weeks). Furthermore, there was a significantly higher rate of small-for-gestational-age (SGA) neonates (57.8% vs. 25.7%), preterm delivery (100% vs. 81.8%) and Cesarean section (90.7% vs. 66.7%) in cases with an MCA/uterine artery PI ratio below the 5th percentile. However, there was no difference between the groups in the rate of low 5-min Apgar scores, admission to the neonatal intensive care unit, or deliveries before 34 weeks. The MCA/uterine artery and MCA/umbilical artery PI ratios were similar in the prediction of adverse perinatal outcome. Both ratios were better at predicting the outcome of pregnancy than were signs of increased vascular impedance in either the umbilical or uterine arteries. Normal MCA/uterine artery PI ratio decreases with gestational age. Abnormally low MCA/ uterine artery PI ratios are related to unfavorable pregnancy outcome. The predictive value of the MCA/uterine artery PI ratio is similar to that of the MCA/umbilical artery PI ratio.

Antenatal prediction of pulmonary hypoplasia by acceleration time/ejection time ratio of fetal pulmonary arteries by Doppler blood flow velocimetry

Objective: The purpose of this study was to develop a new method for the antenatal prediction of pulmonary hypoplasia by Doppler blood flow velocimetry. Study Design: One hundred seventy-seven fetuses (160 normal fetuses and 17 fetuses with congenital anomalies that may affect fetal lung growth and/or development) were studied. Blood flow waveforms at the main branches of the pulmonary arteries were recorded by Doppler echocardiography from 20 to 39 weeks of gestation. The ratio of acceleration time to ejection time was calculated from the waveform as a parameter to predict pulmonary hypoplasia. Results: Doppler waveform of normal fetal pulmonary artery showed a “spike-and-dome” pattern. The normal values of acceleration time/ejection time ratio from the right and left pulmonary arteries were 0.17 ± 0.04 and 0.15 ± 0.04, respectively. These values were not significantly altered through the gestational age observed in this study. The acceleration time/ejection time ratio of either right or left pulmonary artery was measured successfully in all cases of fetal congenital anomalies. In 8 of 17 fetuses, acceleration time/ejection time ratio was measured at both of the pulmonary arteries. Because of a congenital anomaly that affected the fetal lung or thorax asymmetrically (as in congenital diaphragmatic hernia or congenital cystic adenomatoid malformations of the lung), the acceleration time/ejection time ratio of both of the pulmonary arteries could be measured in only 5 of 13 fetuses. The technical difficulties for the measurement always existed in the affected side. Eleven of the 17 fetuses with congenital anomalies survived without signs of clinical pulmonary hypoplasia or persistent pulmonary hypertension of the newborn infant. The fetuses revealed normal acceleration time/ejection time ratio from at least one pulmonary artery. The remaining 6 fetuses died of pulmonary hypoplasia, and the diagnosis was confirmed by autopsy or clinical findings. Of those 6 fetuses, 5 fetuses demonstrated the acceleration time/ejection time ratio below normal in one side, and the ratio could not be obtained on the other side; 1 fetus showed the acceleration time/ejection time ratio below the normal range in both sides. Conclusion: The acceleration time/ejection time ratio by Doppler velocimetry that was obtained at the main branches of fetal pulmonary artery was consistent throughout gestational age from 20 to 39 weeks. This ratio appears to be an accurate parameter with which to predict the subsequent development of pulmonary hypoplasia and clinical outcomes of the newborn infants with high positive and negative predictive values (positive predictive value, 100%; negative predictive value, 100%). Am J Obstet Gynecol 2003;188:228-33.

OC227a: Abnormal DV blood flow in the first trimester and detection of complications in monochorionic twins

Abnormal nuchal translucency and the reversed flow in the ductus venosus (DV) seem to be a good predictor of certain complications of monochorionic pregnancies, namely: twin-to-twin transfusion syndrome (TTTS), congenital heart diseases or early fetal demise. We analysed 19 monochorionic twin pregnancies at 12–14 weeks of pregnancy. Nuchal translucency thickness (NT1, NT2) was measured and the difference between both twins (NT1–NT2) was calculated. We also studied Doppler blood flow velocimetry in the ductus venosus (ACUSON 128 XP). The appearance of reversed blood flow in the DV during atrial systole was marked. We were able to visualize the DV by colour Doppler facilities and measure the blood flow by applying pulsed wave Doppler (angel of insonation < 30.0). A right ventral mid-sagittal plane of the fetal body was obtained and pulsed wave Doppler was performed in order to record the Doppler blood flow waveforms in the DV. A biweekly ultrasound scanning of the patients followed. We found four cases of abnormal blood flow in the DV and/or abnormal NT1-NT2 (> 0.5). Three of them were associated with cardiac anomaly, TTTS and fetal demise. Abnormal flow in the DV may be an early sign of not only chromosomal abnormalities but also cardiac anomalies or early cardiac dysfunction resulting in TTTS development.

The role of Doppler blood flow velocimetry in multiple pregnancy

This article focuses on Doppler velocimetry in the assessment of fetal growth, placental insufficiency, management of intrauterine growth restriction, discordant growth and twin-twin transfusion syndrome. Problems specific to multiple pregnancy such as twin reversed arterial perfusion, cord entanglement and visualization of anastomoses are also reviewed. Doppler sonography seems to be superior to other tests for early detection of placental insufficiency during surveillance of multiple pregnancies. It is suggested that Doppler sonography helps to select multiple fetuses who are at higher than normal risk, and might reduce perinatal mortality and morbidity. Fetal echocardiography may provide an accurate assessment of cardiovascular adaptation to intertwin transfusion, early recognition of deterioration and evaluation of antenatal management. In the management of the twin-twin transfusion syndrome, Doppler echocardiography and Doppler ultrasound examination of the venous circulation appear to be useful tools for improved perinatal management. Doppler sonography is an important adjunct in monitoring high-risk multiple pregnancies.

Changes in fetal blood flow in hypoxemia during labor

Objective: The aim of this study was evaluation of intrapartum Doppler velocimetry changes in fetuses with signs of fetal hypoxemia in fetal pulse oximetry (arterial hemoglobin saturation &lt;30%).Study design: Examinations were performed on 44 women in labor with singleton pregnancies. The subject of analysis was Doppler blood flow velocimetry in umbilical cord, fetal brain and lung. In all cases the following examinations were performed: blood flow velocimetry in middle cerebral artery (MCA), umbilical artery (UA), and pulmonary vein (PV). Among fetuses with normal Doppler velocimetry at the time of admission, we selected those with cephalic presentation and non‐reassuring fetal heart rate pattern during labor. The fetuses were included to the group of fetal pulse oximetry monitoring. All cases with signs of fetal distress in ctg and intrapartum fetal arterial oxygen saturation &lt;30% for at least 5 min were included to the study group. Fetuses with abnormal ctg and fetal oxygen saturation &gt;30% constituted the control group.Results: Doppler indices (PI, RI) in MCA were significantly lower in the presence of reduced oxygen saturation. Pulsatility and resistance index in UA in the study group were higher, comparing to the control group. But, there was no statistically significant difference between both groups in analyzing parameters. There were no statistically significant changes in parameters describing blood flow in pulmonary veins in both studied groups.Comments: The combined intrapartum fetal monitoring, including pulse oximetry and Doppler blood flow velocimetry, proved that the reduction of fetal arterial oxygen saturation (&lt;30%) is associated with changes in hemodynamics of fetal cerebral circulation. It has been not observed any changes in blood flow in umbilical artery and pulmonary vein in the presence of decreased fetal saturation.

The role of Doppler blood flow velocimetry in multiple pregnancy

ABSTRACTThis article focuses on Doppler velocimetry in the assessment of fetal growth, placental insufficiency, management of intrauterine growth restriction, discordant growth and twin-twin transfusion syndrome. Problems specific to multiple pregnancy such as twin reversed arterial perfusion, cord entanglement and visualization of anastomoses are also reviewed. Doppler sonography seems to be superior to other tests for early detection of placental insufficiency during surveillance of multiple pregnancies. It is suggested that Doppler sonography helps to select multiple fetuses who are at higher than normal risk, and might reduce perinatal mortality and morbidity. Fetal echocardiography may provide an accurate assessment of cardiovascular adaptation to intertwin transfusion, early recognition of deterioration and evaluation of antenatal management. In the management of the twin-twin transfusion syndrome, Doppler echocardiography and Doppler ultrasound examination of the venous circulation appear to be use...

Current concepts of fetal growth restriction: part II. diagnosis and management

Objective: To update diagnostic concepts and management strategies of fetal growth restriction (FGR). Data source: An English literature search was conducted for pertinent articles related to FGR from 1976 to 1997 including original research articles, review articles, and book chapters. Methods of study selection: In part II, clinical studies involving both diagnostic and therapeutic approaches to the management of FGR were included. Throughout the study period, the evolution of concepts is demonstrated. Tabulation, integration, and results: Diagnostic methods including two- and three-dimensional ultrasound for diagnosis of fetal structural abnormalities, organ volumetry, and estimating fetal weight are presented. Clinical tools to assess fetal well-being such as nonstress tests, contraction stress tests, biophysical profile scores, and Doppler blood flow velocimetry of fetal circulation and funicentesis are discussed. Correlations between these indirect fetal evaluations and fetal blood biochemical parameters obtained by funicentesis are also reviewed. Finally, various therapeutic approaches, especially timing of delivery of growth-restricted fetuses, are formulated. Conclusion: We suggest that both diagnostic and therapeutic approaches to FGR should be modified. With the current development of technology, newly available three-dimensional ultrasound might offer more precise diagnostic data than conventional two-dimensional ultrasonography in the near future. From current concepts of pathophysiology of FGR, morphometric measurement abnormality alone should not be a basis for intervention. Combined use of morphometric measurements and functional evaluation tests and good clinical judgment using flexibility and individualization are the key elements in successful management of FGR.

Cerebral Doppler blood flow velocimetry and central hemodynamics in the ovine fetus during hypoxemia-acidemia.

The purpose of this study was to assess the effects of hypocapnic hypoxia, acidemia and the combination of hypoxia/acidemia on blood flow velocity variables in the fetal cerebral circulation. Chronically instrumented fetal sheep were used and the ewes were induced to breathe a hypoxic gas mixture for about 90 min. This caused an initial period of hypoxemia followed by a period of mixed hypoxemia/acidemia. When the ewe was reoxygenated, the fetus experienced a period of normoxic acidemia. The fetal cerebral circulation was assessed by recording Doppler blood flow velocity waveform variables in a cerebral vessel and the umbilical artery, using standard ultrasound equipment. External carotid artery blood flow was maintained during hypoxic and hypoxic/acidotic periods despite a fall in cardiac output. In the cerebral vessel, mean maximum velocity (time-averaged maximum velocity), minimum diastolic velocity and maximum systolic velocity manifested increases during hypoxic and hypoxic-acidotic periods, but pulsatility index did not change due to the effect of reduced heart rate on pulsatility index. Umbilical artery pulsatility index increased in the hypoxic and hypoxic-acidotic periods, despite unchanged mean maximum velocity, minimum diastolic velocity and maximum systolic velocity. With acute hemodynamic changes, the measurement of pulsatility index can yield misleading results. For clinical and experimental research on the fetal cerebral circulation, more attention should be paid to the individual Doppler variables, especially to the mean maximum velocity, than to the pulsatility index alone. Changes in mean maximum velocity recorded from the cerebral artery seem to reflect changes in the cerebral arterial flow.

Simultaneous pulsed Doppler velocimetry of fetal aorta and inferior vena cava. Diagnosis of fetal congenital heart block; two case reports

A simple technique for the diagnosis of fetal congenital heart block by simultaneous Doppler blood-flow velocimetry of the fetal abdominal aorta and inferior vena cava is described. Furthermore, a simple method of monitoring the fetal atrial reactivity during the antenatal period; and simultaneous recording of atrial and ventricular rates during labour are also described. These simple techniques can be applied for the diagnosis and monitoring of the fetus in other types of cardiac arrhythmias.