This cross-sectional study investigated the circulatory profile of the donor and recipient fetuses in 20 pregnancies with twin-twin transfusion syndrome presenting with acute polyhydramnios at 17-27 (mean, 22) weeks' gestation. Doppler investigations of the arterial vessels and ductus venosus, inferior vena cava, right hepatic vein, tricuspid and mitral ventricular inflow ...

A prospective cohort study was conducted to determine whether preterm labor is associated with changes in the impedance to blood flow of the fetal middle cerebral artery. Doppler velocimetry studies were performed in 194 consecutive patients with preterm labor and intact membranes. Pulsatility indices of the middle cerebral artery and ...

The objective of this study was to evaluate the effect of fetal blood sampling on ductus venosus hemodynamics. A secondary objective was to establish the relationship between the amplitude of these changes, if any, and different variables related either to the procedure of sampling or to fetal characteristics. The ratio ...

Controversy continues regarding the clinical relevance of absent or reversed umbilical artery blood flow during diastole. The purpose of this study was to characterize the blood gas and lactate measurements of growth deficient fetuses with absent (ADF) or reversed (RDF) umbilical artery (UA) diastolic flow. In a descriptive study from ...

The objectives of this study were (1) to detect vasoactive intestinal polypeptide in fetal blood obtained by cordocentesis (2) to examine possible changes in growth retarded fetuses and to establish relationships between its levels and fetal blood acid-base status as well as fetal haemodynamics as assessed by Doppler ultrasonography. Vasoactive ...

OBJECTIVE: Our purpose was to investigate the three-dimensional architecture of placental villi from normal and growth-restricted fetuses and relate findings to umbilical artery blood flow velocity waveforms. STUDY DESIGN: Placentas from term (n = 15) and preterm (n = 5) appropriately grown and term (n = 9) and preterm (n ...

BACKGROUND: The aim of this study was to investigate the possible association between Doppler velocimetry and synthesis of prostacyclin (PGI2) and thromboxane A2 (TxA2) in umbilical cord vessels. The hypothesis was that an altered balance between PGI2 and TxA2 production is associated with a change of artery flow resistance. METHODS: ...

OBJECTIVE: To estimate the acid-base and oxygen status of fetal blood and compare with maternal placental venous blood. DATA SOURCES AND CALCULATIONS: We selected pH and blood gas data from the literature pertaining to umbilical vein and artery blood obtained by cordocentesis and estimated values for the 30th and 40th ...

OBJECTIVE: To investigate the effect of anemia on fetal venous, arterial, and intracardiac blood flows. METHODS: Color flow Doppler was used to record flow-velocity waveforms from the atrioventricular valves, ductus venosus, right hepatic vein, inferior vena cava, middle cerebral artery, and descending thoracic aorta from 38 cases of red blood ...

Glutathione S-transferase B1 (GST B1) concentration in blood and amniotic fluid from fetuses investigated for a variety of conditions including rhesus (Rh) allo-immunisation was assessed for its usefulness as a measure of liver damage caused by hypoxia in utero. The concentration in blood from the intrahepatic vein (IHV) was 10-fold ...

Newborns suffering from severe respiratory difficulties and not responding to conventional methods have been successfully treated by extracorporeal circulation with a membrane oxygenator (ECMO). However, the technique needs a highly specialized staff, excellent laboratory support, and continuous surveillance of the procedure to prevent complications. In a series of experiments on ...

BACKGROUND: Doppler studies of the fetal circulation in intrauterine growth retardation and hypoxia have demonstrated a compensatory redistribution of arterial blood flow with increased flow to the cerebrum and myocardium and decreased flow to the periphery. The aim of this study was to evaluate the significance of changes in fetal ...

A total of 1175 umbilical venous Doppler flow velocity waveforms were acquired from 449 normal pregnant women whose fetuses were delivered at term without neonatal asphyxia or anomalies. Arterial and venous flow velocity waveforms were acquired from a free loop of the umbilical cord. The incidence of umbilical venous pulsation ...

The objective of this study was to examine the acid-base status in blood obtained at cordocentesis in growth-retarded fetuses with absent end-diastolic velocity in the umbilical artery and divided according to the presence or absence of pulsations in the umbilical vein. Twenty-six growth-retarded fetuses free from structural and chromosomal abnormalities ...

For chronic fetal hypoxia due to maternal Ebstein's anomaly, oxygen was administered daily to the mother by mask for 105 days. At 20 weeks of gestation, umbilical venous blood gases in room air showed pH 7.42, PO2 25.7 mm Hg, PCO2 33.7 mm Hg and O2 saturation 48.7%, and changed ...

OBJECTIVE: Our purpose was to compare the ovine fetal response to severe, damaging asphyxia resulting from umbilical cord occlusion with that seen in uterine artery occlusion. STUDY DESIGN: Six ovine fetuses were exposed to severe asphyxia produced by partial umbilical cord occlusion for 90 minutes. Fetal blood pressure and heart ...

A possible association of limb reduction defects with chorionic villus sampling (CVS) may be related to compromised umbilical blood flow from the trauma of the procedure. We hypothesized that because CVS may disrupt or compromise umbilical blood flow to the fetus, either by vasoconstriction, bradycardia, or emboli, we would detect ...

We compared arterial growth to hemodynamic changes in the perinatal period in lambs. Blood pressure did not change significantly from 120 days gestation to 3 days postpartum, when it was 45.4 +/- 1.9 mmHg; however, pressure rose to 64.8 +/- 2.5 mmHg at 21 days postpartum. Thoracic and abdominal aortic ...

OBJECTIVE: We examined intraplacental color Doppler flow patterns and spectral Doppler flow velocity waveforms of villous arteries in pregnancies with intrauterine growth retardation. STUDY DESIGN: A total of 192 uncomplicated pregnancies and 29 pregnancies with intrauterine growth retardation between 26 and 41 weeks' gestation were examined in this cross-sectional study. ...

OBJECTIVE: To study possible relationships between abnormal placental perfusion, hypoxemia and impaired fetal nutrient supply. STUDY DESIGN: Umbilical artery flow velocity waveforms were assessed in high risk pregnancies and compared with controls. Three groups were studied. In group I (n = 13) the pulsatility index (PI) was within normal limits, ...

OBJECTIVE: Pre-eclampsia is characterized by an increased vascular tone which might be related to an abnormal endothelial cell function. As representatives of the fetal circulation, we compared the nitric oxide (NO)-releasing capacity of human umbilical vessels from normal and pre-eclamptic pregnancies. METHODS: Normal and pre-eclamptic umbilical vessels were mounted in ...

To assess the stability of different measures of receptor occupancy from [11C]raclopride (a D2 antagonist) studies with positron emission tomography, we analyze data from five test/retest studies in normal volunteers in terms of individual model parameters from a three-compartment model, the distribution volume (DV) and the ratio of DVs from ...

This prospective study was completed to determine the influence of epidural anaesthesia on the fetoplacental circulation of normal subjects. Thirty-seven normal pregnant patients at term, undergoing elective Caesarean section, had Doppler measurements of the fetal umbilical artery blood flow velocity before and after epidural anaesthesia using lidocaine 2% without epinephrine. ...

The reversal of diastolic cerebral blood flow has been regarded as a characteristic waveform of brain death and a useful confirming sign. We report 2 patients who had diastolic flow reversal but survived. One, a 1-month-old boy with status epilepticus, had reversal of diastolic cerebral blood flow detected by Doppler ...

Experimental and clinical evidence have demonstrated that an increase in resistance to placental blood flow causes changes in aortic isthmic diastolic flow profile before any significant modification is observed in umbilical artery Doppler waveforms. To identify these abnormal flow profiles, the objective of this study was to document the normal ...

OBJECTIVE: To define the histological lesions in the placenta associated with abnormal blood flow findings and to evaluate their possible clinical significance. DESIGN: A prospective blind study. SETTING: A clinical study at a teaching hospital, Malm? General Hospital, University of Lund, Sweden, morphological studies of placentas being performed at the ...

Umbilical venous blood pressure (UVP) was measured at fetal blood sampling using cordocentesis in 113 fetuses. Among these, both inferior vena cava (IVC) Doppler flow pattern, when the preload index was set as a parameter of reversed flow, and UVP were measured in 50 fetuses. We evaluated whether direct measurement ...

Fetal ultrasound studies were performed on 24 fetuses with non-immune hydrops to evaluate echocardiographic and cardiovascular Doppler parameters that may be useful in assessing hemodynamics and in predicting outcome. Of all cardiovascular parameters analyzed, only the presence of abnormal pulsations in the umbilical vein (p < 0.001) was found to ...

OBJECTIVE: To investigate the relation between the biochemical markers of umbilical venous erythropoietin and umbilical arterial pH and morphologic placental abnormalities in fetal hypoxia. METHODS: Placentas from 300 high-risk newborn infants (gestational age 24-42 weeks) were examined macroscopically and microscopically following standardized criteria. The morphologic findings were correlated with the ...

Blood flow across the atrioventricular valves and outflow tracts was measured in 55 normal fetuses and 32 fetuses with haemoglobin (Hb) Bart's disease between 18 and 26 weeks of gestation. The mean velocities remained unchanged in both normal and affected fetuses over the gestations studied. The volume flow across both ...

OBJECTIVE: Sampling of the umbilical artery for determination of acid-base status is performed within 60 minutes of birth, but is not feasible in all hospitals on a 24-hour basis. A desirable alternative would be to perform the arterial cord blood gas analysis hours after the sample was obtained at delivery ...

OBJECTIVE: To assess with Doppler colour flow imaging whether a brain-sparing effect is present in all cerebral arteries of the circle of Willis in the small for gestational age fetus, to determine which cerebral flow velocity parameter is most discriminating in this pathological condition, and to relate this parameter to ...

OBJECTIVE: Our purpose was to evaluate Doppler-detectable differences in the fetal circulation of discordant twins with a growth defect resulting from either placental insufficiency or twin-to-twin transfusion syndrome. STUDY DESIGN: Serial weekly Doppler recordings were performed for at least 3 weeks preceding delivery in 15 pairs of dichorionic twins (group ...

The study group consisted of 75 high risk singleton pregnancies in whom color duplex Doppler evaluation of the uteroplacental circulation was determined and correlated with perinatal outcome. Uterine, umbilical and middle cerebral artery flow velocity waveforms (FVW) were analysed and the resistance index (RI), pulsatility index (PI) and the systolic/diastolic ...

Umbilical artery flow curves were obtained by Doppler ultrasonography before, during, and after episodes of fetal bradycardia in the active stage of labor in 6 women. Between 126 and 1,607 Doppler wave forms were analyzed for each patient. During the periods of bradycardia all the umbilical artery resistance flow parameters ...

The purpose of this study was to determine regional cerebral flow velocity waveforms in the human fetus. Flow velocity waveforms were determined at the level of the middle cerebral artery, vertebral artery, and intracerebellar arteries in 25 fetuses between 23 and 39 weeks' gestation. The pulsatility index was used to ...

OBJECTIVE: We conducted a cohort study in growth-retarded fetuses to establish if absent or reverse end-diastolic flow in the umbilical artery was associated with increased perinatal mortality and morbidity and neurologic damage at long-term follow-up. STUDY DESIGN: Thirty-one fetuses with intrauterine growth retardation and absent or reverse end-diastolic flow in ...

Based on the assumption that the ductus venosus is regulator of oxygenated blood in the fetus, the present study investigated the blood flow velocity of the ductus venosus in relation to the umbilical circulation in the that seriously growth-retarded fetus. The study group of 38 fetuses (gestational week 17-39) had ...

Arachidonic acid metabolites were investigated in umbilical arteries of 16 normal pregnancies. Several prostaglandins (PGs) and hydroxyacids were synthesized by the umbilical artery. Prostaglandin I2, PGF2 alpha, PGE2 and PGD2 were found in the products, and PGI2 was the most abundant metabolite in the umbilical artery. The conversion rate of ...

Although fetal heart rate (FHR) monitoring is widely used for fetal surveillance, there is still disagreement about the value of cardiotocography and the interpretation of FHR patterns. We addressed this in a prospective study in which umbilical cord blood gas and pH values at the time of cesarean section were ...

We studied the effects of spinal anaesthesia (Group S), epidural anaesthesia (Group E), and combined spinal and epidural anaesthesia (Group SE), on maternal and fetal blood flow in 24 healthy parturients (n = 8/group) with uncomplicated singleton pregnancies using Doppler technique. Prior to the induction of anaesthesia, the patients were ...

Doppler velocity waveform analysis has been introduced as part of antenatal fetal biophysical assessment. Abnormal waveforms are associated with maternal and fetal complications. The most severe waveform patterns observed, absent end-diastolic velocity (AEDV) and reversed end-diastolic velocity (REDV), are of ominous significance in many cases but the incidence of these ...

The purpose of this study is to determine the levels of brain type isoenzyme of creatine kinase (CK-BB) as a possible indicator of a pre-existing intrauterine brain-cell damage in cord blood sera of fetuses with preceding absent or reverse end-diastolic flow velocities of the umbilical arteries (AREDFV). CK-BB isoenzyme activities ...

Pulsed Doppler blood-flow velocity waveforms in the umbilical arteries, as well as blood gases, hematocrit, and lactate concentration in umbilical venous blood, were examined in 21 patients undergoing 49 cordocentesis, 34 of which were followed by fetal blood transfusion into the umbilical vein. The aim of the study was to ...

Pulsed-Doppler examinations of blood-flow velocities in the umbilical artery were carried out before and after 15 diagnostic cordocenteses and 34 fetal blood transfusions into the umbilical vein. There were decreases in the systolic/diastolic ratio (A/B) (p < 0.01), the pulsatility index (PI) (p < 0.05), and the resistance index (RI) ...

To evaluate the efficiency of the Doppler examination of umbilical arterial blood flow for the antenatal diagnosis and the monitoring of fetal condition during intrauterine treatment of twin-to-twin transfusion syndrome (TTTS), we studied 33 pairs of twins including 5 TTTS cases. In all cases umbilical arterial blood flow was examined ...

This paper reports two cases of abruptio placentae assessed using pulsed Doppler at 29 and 30 weeks of gestation. Transvaginal pulsed Doppler showed abnormal uterine artery FVWs in both cases. One fetus with normal umbilical and normal middle cerebral artery FVWs was not acidotic and only midly hypoxic, whereas the ...

Reproducibility and inter-observer variability of intra- and extra-abdominal umbilical venous flow velocity and left portal venous flow velocity as well as heart-synchronous waveform pulsations in these vessels were studied in 23 women at 34-38 weeks of normal pregnancy.Limited reproducibility, expressed by large intra-patient coefficients and limits of agreement between two ...

Blood flow velocity investigations by applying Doppler method have emerged as a useful tool in obstetrics and gynaecology. The final role of the method is still to be established. Thus far, the umbilical artery Doppler indices have been preferred to the utero-placental indices. We have analysed the Doppler indices from ...

We attempted to assess feto-placental circulation in fetuses with intrauterine growth retardation (IUGR) by calculating the pulsatility index of flow volume (PIQ) based on the quantitative measurement of blood flow. Doppler sound was processed by an analog to digital converter and a frequency analyzer. Multiplication of frequency and signal strength ...