Middle Cerebral Artery Resistance Index Research Articles

Middle Cerebral Artery Doppler before and after Fetal Spina Bifida Repair: An Indirect Sign of Hindbrain Compression and Decompression?

Reduced middle cerebral artery resistance indices (MCA-RI) in fetuses with spina bifida (fSB) are commonly observed. Compression of neuronal pathways in the brainstem due to hindbrain herniation (HH) and disturbed cerebrospinal fluid circulation likely cause an imbalance of the autonomic nervous system. This may increase systemic vasoconstriction and compensatory increase cerebral vasodilation (like brain sparing). The aim of this study was to systematically analyze all fetal MCA-RI before and after fSB repair and to compare their correlation with the presence and postsurgical resolution of HH. 173 patients were included. Standardized ultrasound examinations including MCA and umbilical artery (UA) Doppler as well as assessment of HH presence and regression were performed. Fetuses with MCA-RI <5th percentile (P) before fetal surgery were compared to the group with normal MCA-RI and correlated to the presence of HH before and its regression after fSB repair. 30% (49/161) fetuses showed RI's <5th P before fSB repair. All fetuses had normal UA-RI. 99.4% of fetuses (160/161) showed normal of MCA-RI before delivery. Normalization occurred within a mean of 1.3 ± 1.2 weeks. HH regression was observed in 97% in the group with normal MCA-RI and in 96% in the group with MCA-RI <5th P before surgery (p = 0.59). Time lapse to HH regression after fSB repair was 1.8 ± 1.7 and 1.9 ± 1.6 weeks, respectively. In fetuses with MCA-RIs <5 P before fSB repair, a parallel timely course of MCA-RI normalization and HH regression was noted. To suggest common pathogenic factor(s), more studies are needed. However, normalization of the fetal cerebral circulation could be a further benefit of fSB repair.

Assessment of Dynamic Cerebral Autoregulation During Long-Term Exposure to High Altitude in Normal Subjects by Ultrasonography.

To evaluate changes in dynamic cerebral autoregulation (CA) during short-term and long-term exposure to high altitude with ultrasonography, and also study the sex differences in the response of CA to altitude. We assessed the differences in dynamic CA and measured with Doppler ultrasound of the bilateral internal carotid artery (ICA), vertebral artery (VA), and middle cerebral artery (MCA) and the values of basic information within 48 hours and at 2 years after arrival at Tibet in 65 healthy Han young Chinese volunteers, meanwhile, we compared the resistance index (RI) and pulsatility index (PI) of the right MCA at inhale oxygen 8 minutes when a newcomer with 2 years after arrival at Tibet. With 2 years of altitude exposure, the SaO2 of all subjects was above 90%, the mean PEF, DAP, and HR values decreased, HGB increased compared within 48 hours in same-gender groups. Comparisons of cerebral hemodynamics between before 2 years and after 2 years within male and female groups, the mean RI and PI values of bilateral MCA after 2 years were significantly higher than before 2 years, at the same time, the mean RI and PI values of bilateral ICA were significant differences (P < .05) between male groups, with regard to female groups, showed that the mean RI and PI values of bilateral VA were significant differences (P < .05). Comparisons of Right MCA hemodynamics between after oxygen uptake 8 minutes and 2 years, the mean RI and PI values were no significant difference within male and female groups (P > .05). Acute mountain sickness could result from an alteration of dynamic autoregulation of cerebral blood flow, but the impaired autoregulation may be corrected with the extension of time, furthermore, the response of CA to altitude in males and females are different.

Effects of a high-sugar mixed-meal on cerebral hemodynamics in young versus middle-aged adults

High-sugar mixed-meal consumption increases both glucose and insulin and elicits mixed vascular effects, with impairments in peripheral microvascular but improved conduit artery function. It is underexplored 1) if a high-sugar mixed-meal elicits vascular segment-specific effects within cerebrovasculature and 2) whether these responses are altered in middle-aged adults with cardiovascular disease (CVD) risk factors. This study sought to test the hypotheses that a high-sugar mixed-meal would elicit differential effects within the middle cerebral artery (MCA) versus downstream hemodynamics, and that changes in cerebral hemodynamics would be blunted among at-risk middle-aged adults compared to young adults. 21 young, healthy adults (24±6 years; 23.7±3.0 kg/m2) and 20 middle-aged adults (55±5 years; 28.2±5.2 kg/m2) with CVD risk factors (hypertension, obesity, or dyslipidemia) consumed a high-sugar mixed-meal consisting of 930 kcals (35.5 g fat, 129 g carbohydrates, 100.5 g sugar, 14 g protein). Vascular measures were taken prior to meal consumption and 30- and 60-min post-meal. MCA pulsatility index (PI), resistance index (RI), mean velocity, and conductance were assessed via transcranial Doppler. Mean arterial pressure (MAP) and common carotid artery diameter were assessed via automated oscillometric cuff and ultrasound, respectively. MCA PI and RI were taken as proxy measures of downstream vascular tone, while MCA mean velocity and conductance, and carotid artery diameter were taken as measures of larger artery cerebrovascular hemodynamics. MCA PI and RI were unchanged in middle-aged adults but increased at 30- (PI+Δ0.13±0.13 au; RI+Δ0.05±0.05 au) and 60-min (PI+Δ0.10 ±0.11 au; RI+Δ0.04±0.05 au) compared to baseline in young adults (p&lt;0.05). MCA conductance increased at 30-min (+Δ0.04±0.08 cm/s per mmHg, p&lt;0.05), carotid diameter increased at 60-min (+Δ0.13±0.20 mm, p&lt;0.05), and MAP tended (p=0.07-0.09) to decrease at 30- (-Δ2.01±5.7 mmHg) and 60-min (-Δ2.26±6.54 mmHg) compared to baseline in both groups. MCA mean velocity was not significantly different across timepoints in both groups. These data suggest a high-sugar mixed-meal may transiently dilate larger cerebral arteries in both young and middle-aged adults but elicit vasoconstriction downstream of the MCA in young adults only. As such, our data suggest that 1) cerebrovascular response to a high-sugar mixed-meal may be vascular segment-specific, and 2) age and risk-factor burden may alter the sensitivity of vasculature downstream of the MCA to a high-sugar mixed-meal. Further research is needed to dissect mechanisms underlying the complex cerebrovascular response to a high-sugar mixed-meal in young versus middle-aged adults with CVD risk factors. This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Correlation Between Fetal Umbilical Artery and Middle Cerebral Artery Doppler Indices in Preeclamptic and Normotensive Pregnancies

Objective: To assess the correlation between fetal umbilical artery (UA) and middle cerebral artery (MCA) Doppler indices in a cohort of preeclamptic and normotensive pregnancies. Materials and Methods: This cross-sectional analytical study recruited 70 pregnant women (28–40 weeks of gestation) using a non-probability convenient technique. The study included 33 patients with preeclampsia and 37 normotensive participants. Results: In the normotensive group, a significant ( P = .00) strong correlation ( r = 0.72) was observed between UA velocity, systolic/diastolic (S/D) ratio, and pulsatility index (PI), and MCA velocity; a significant ( P = .00) correlation ( r = 0.56) between UA, S/D ratio, and the MCA resistive index (RI); a significant ( P = .00) moderate correlation ( r = 0.66) between S/D ratio, UA velocity, and MCA velocity; a significant ( P = .00) negative correlation ( r = −0.50) between UA velocity, RI, and MCA PI; a significant ( P = .01) negative correlation ( r = −0.44) between UA velocity, RI, and MCA S/D ratio. In contrast, in the preeclamptic group, we observed a substantial ( P = .01) moderate correlation ( r = 0.43) between UA, PI, and MCA velocity; a significant ( P = .04) correlation ( r = 0.368) between UA, RI, and MCA PI; a significant ( P = .05) moderate correlation ( r = 0.35) between UA, PI, and MCA RI; a significant ( P = .00) strong correlation ( r = 0.83) between UA S/D ratio UA and MCA velocity. Conclusion: This study suggests potential diagnostic value in Doppler measurements for assessing preeclampsia-related vascular changes. However, caution is warranted owing to a split sample and limited statistical power, necessitating further research for validation.

Effect of delayed cord clamping on cerebral hemodynamics in preterm infants

BackgroundUnstable cerebral hemodynamics is an important cause of intracranial hemorrhage in premature infants. The increased blood flow of delayed cord clamping (DCC) compared to immediate cord clamping (ICC) is equivalent to 1/3-1/4 of newborn blood volume. Our objective was to assess whether the increased blood flow causes fluctuations in cerebral blood flow and how. MethodsThis experiment was a prospective, observational study. Neonatologists selected preterm infants eligible for inclusion and exclusion, and divided them into DCC group and ICC group according to the way of umbilical cord ligation performed by obstetrics department, and matched them 1:1 according to gestational age. The peak systolic velocity （PSV) ，end diastolic velocity (EDV)，and resistance index (RI) of middle cerebral artery was measured by Mindray M9 color ultrasonic diagnostic instrument within 1 h, 24±1 h, 48±1 h, 72±1 h, respectively. ResultsThere was no significant difference in PSV, EDV and RI in middle cerebral artery between DCC group and ICC group (P > 0.05). There were no significant differences between groups and time (P > 0.05). The hemoglobin and hematocrit in DCC group were higher than those in ICC group within 2 h after birth (P < 0.05). (P > 0.05). ConclusionDCC can increase hemoglobin and hematocrit in preterm infants, but does not cause cerebral blood flow fluctuation within a certain range. DCC is a safe method of placental transfusion.

Altered Cerebral Vasoreactivity on Transcranial Color-Coded Sonography Related to Akinetic-Rigid Phenotype of Parkinson's Disease: Interim Analysis of a Cross-Sectional Study.

A correlation between worse functional outcomes in Parkinson's disease (PD) patients with cerebrovascular disease (CVD) or the Akinetic-rigid phenotype has been argued in recent studies. We aimed to evaluate the association of cerebral hemodynamics impairments, assessed by Transcranial Color-coded Doppler sonography (TCCS), on PD patients with different phenotypes of the disease and with risk factors for CVD. Idiopathic PD patients (n = 51) were divided into motor subtypes: Akinetic-rigid (AR) (n = 27) and Tremor-dominant (TD) (n = 24) and into two groups regarding vascular risk factors: when ≥2 were present (PDvasc) (n = 18) and <2 (PDnvasc) (n = 33). In a parallel analysis, the Fazekas scale on brain magnetic resonance imaging (MRI) was applied to a sample to assess the degree of leukoaraiosis. TCCS examinations were prospectively performed obtaining middle cerebral artery Mean Flow Velocities (Vm), Resistance Index (RI), and Pulsatility Index (PI). The Breath-Holding Index (BHI) was calculated to assess cerebrovascular reactivity (cVR). Standardized functional scales were administered (UPDRS III and Hoehn&Yahr). The phenotype groups were similar in age, disease duration and demographic parameters, but there were significantly higher H&Y scores than TD group. cVR was impaired in 66.7% of AR vs. 37.5% of TD. AR group exhibited lower BHI (0.53 ± 0.31 vs. 0.91 ± 0.62; p = 0.000), lower Vm after apnea (44.3 ± 9.0 cm/s vs. 53.4 ± 11.4 cm/s; p = 0.003), higher PI (0.91 ± 0.26 vs. 0.76 ± 0.12; p = 0.000) and RI (0.58 ± 0.11 vs. 0.52 ± 0.06; p = 0.021). PDvasc group showed higher PI (0.98 vs. 0.76; p = 0.001) and higher frequency of altered cVR (72.2% vs. 42.2%; p = 0.004). There was a significant predominance of higher values on Fazekas scale in the PDvasc group. We found no difference between the Fazekas scale when comparing motor subtypes groups but there was a trend toward higher scores in the AR phenotype. TCCS, a cost-effective method, displayed impaired cVR in Parkinsonian patients with risk factors for CVD with higher degree of MRI leukoaraiosis. PD patients with the AR disease phenotype also presented impaired cVR on TCCS and greater functional impairment, although with just a trend to higher scores on MRI Fazekas.

An exploratory study to identify neonatal arterial ischemic stroke: A single-center study

BackgroundNeonatal arterial ischemic stroke (NAIS) presents as seizures, including convulsions, subtle seizures, and apnea, and most patients experience neurological sequelae. Diagnosis is often delayed owing to low test sensitivity. The present study aimed to identify the early clinical diagnostic factors for NAIS in neonates with seizures. MethodsThe present study included 54 patients born at ≥36 weeks of gestation during the last 15 years who presented to the neonatal intensive care unit with neonatal seizures and underwent brain magnetic resonance imaging (MRI), 6 of whom were diagnosed with NAIS. Maternal background, clinical characteristics, and transcranial pulsed Doppler sonography results were retrospectively reviewed. ResultsOf the 24 patients who presented with convulsions or subtle seizures, 3 (13%) were diagnosed with NAIS and 3 of 30 patients (10%) presented with apnea. Maternal premature ventricular contraction complications were higher in the NAIS group than in the non-NAIS group (p = 0.01). NAIS group showed lower mean middle cerebral artery (MCA) resistance index (RI) was lower the non-NAIS group (p = 0.009), while the left–right RI difference (p = 0.019), mean MCA blood velocity (MnV; p = 0.04), and left–right MnV difference (p < 0.001) in cerebral blood flow velocities (CBFVs) were higher in the NAIS group. ConclusionsOur results revealed that maternal arrhythmia may be a diagnostic factor for NAIS in neonates with seizures. Early brain MRI is essential in neonates with seizures and findings of low MCA-RI, high MCA-MnV, or high left–right difference in CBFVs to distinguish between NAIS and non-NAIS.

Analysis of Causes and Results of Fetal Growth in Utero Caused by Genetic Factors Detected by Ultrasound.

In order to investigate the value of the ultrasonic monitoring of maternal and fetal vascular parameters, serum vitamin D, and placental growth factor (PLGF) in predicting fetal growth restriction (FGR), a method of ultrasonic detection of genetic factors causing fetal growth in utero was proposed. 125 pregnant women with FGR diagnosed in our hospital from June 2018 to June 2021 (the FGR group) and 125 pregnant women with a normal prenatal examination (the control group) were collected retrospectively. The systolic/diastolic blood flow ratio (S/D), pulsatile index (PI), and resistance index (RI) of the fetal umbilical artery (UA), middle cerebral artery (MCA), and maternal uterine artery (UtA) were monitored by ultrasound at 20 to 24 weeks of gestation, and the levels of serum vitamin D and PLGF were detected. The receiver operating characteristic curve (ROC curve) was used to evaluate the predictive value of FGR. The results showed that the S/D, PI, and RI of UA in the FGR group were higher than those in the control group, the areas under the curve (AUC) were 0.866, 0.817, and 0.849, and the sensitivity and specificity were (72.8%, 91.2%), (50.4%, 100%), and (72.8%, 91.2%), respectively. The S/D, PI, and RI of MCA were lower than those of the control group. The AUC was 0.882, 0.869, and 0.834, respectively; the sensitivity and specificity were (92.0%, 74.4%), (88.8%, 81.6%), and (90.4%, 72%), respectively. The S/D, PI, and RI of UtA were higher than those of the control group; the AUC was 0.768, 0.729, and 0.732; the sensitivity and specificity were (91.2%, 52%), (48%, 90.4%), and (48.8%, 90.4%), respectively. The serum levels of vitamin D and PLGF were lower than those of the control group (AUC 0.784 and 0.807), and the sensitivity and specificity were (54.4%, 91.2%) and (99.2%, 52%), respectively. It was concluded that the ultrasound monitoring of UA, MCA, and UtA in pregnant women in the middle of pregnancy and detection of serum vitamin D and PLGF levels had a certain predictive value for FGR. Moreover, the comprehensive evaluation could reduce the occurrence of FGR in high-risk pregnant women.

Role of Doppler Waveforms in Pregnancy-Induced Hypertension and Its Correlation With Perinatal Outcome.

ObjectivesThe present study aims to measure the role of Doppler waveforms in pregnancy-induced hypertension (PIH) and its relationship with the perinatal outcome.MethodsWe have studied 50 pregnant women with PIH with gestational age (GA) 30-40 weeks for Umbilical Artery (UmA), Middle Cerebral Artery (MCA) and Uterine Artery (UtA) Doppler waveforms. Comparison between the various Doppler indices, i.e., Pulsatility Index (PI), Resistive Index (RI) and S/D ratio, with the severity of the disease and the perinatal outcomes were evaluated using appropriate statistical tests considering a threshold value of p-value <0.05 as significant. The Statistical Package for the Social Sciences (SPSS) version-16 (SPSS Inc, Chicago, USA) and MedCalc software (MedCalc Software Ltd, Ostend, Belgium) were used for data analysis.ResultsHalf (50%) of the cases attributed to the 26 to 30 years age group were at 38 to 40 weeks of gestation. Out of the 50 patients, 68% were primigravida, and 74% had severe PIH. Mean UmA PI, mean MCA PI, mean MCA RI, and mean Cerebro Placental Ratio (CPR) were differed significantly among mild and severe PIH patients (p-value<0.05). Perinatal outcomes in 33 (66%) cases were adverse. The abnormal UmA RI, MCA RI, MCA PI, MCA S/D were significantly linked with poor pregnancy outcomes (p-value <0.05). PIH cases with the presence of early diastolic notch of UtA (p-value <0.01), abnormal PI CPR (p-value <0.001) and S/D CPR (p-value <0.003) were observed to have more adverse outcomes. PI CPR had the highest sensitivity (84.8%), and the existence of early diastolic notch of UtA and MCA-PI were most specific in diagnosing adverse perinatal outcomes.ConclusionCPR-PI is a valuable indicator of adverse perinatal outcomes in PIH. Doppler studies of multiple vessels may help manage high-risk pregnancies as it may provide helpful information about the fetus at risk of hypoxia and placental insufficiency.

Differences in Biometric Fetal Weight Estimation Accuracy and Doppler Examination Results in Uncomplicated Term Singleton Pregnancies between Vertex and Breech Presentation.

Doppler examination of the umbilical artery and the fetal middle cerebral artery is evaluated predominantly in pregnancies with fetuses in cephalic presentation and never has been elucidated in breech presentation. Evidence on the accuracy of fetal weight estimation in dependence of the fetal presentation is controversial. Nevertheless, clinical decisions including recommendations for a cesarean section or labor induction based on these examinations are applied to pregnancies with fetuses in breech presentation. The objective of this study was to investigate the influence of the fetal presentation on fetal weight estimation accuracy, umbilical artery and middle cerebral artery resistance indices (RI) in a prospective case control study. Ultrasound examinations in 305 uncomplicated term pregnancies (153 vertex presentations, 152 breech) were investigated. Non-parametric variables were compared using Pearson’s chi2 test and Wilcoxon chi2 test, depending on variable scaling. Fetal weight estimation accuracy was not significantly different between vertex presentation group (VP) (6.97%) and breech presentation group (BP) (7.96%, p = 0.099). Fetal head circumference measurements were significantly larger in BP (350 mm vs. 341 mm in VB, p > 0.0001) while abdominal circumferences were significantly smaller (VP: 338 mm, BP: 331 mm, p = 0.0039) and weight estimation was not significantly different. Umbilical artery RIs were not significantly different between VP (54.5) and BP (55.3, p = 0.354). Fetal middle cerebral artery RIs also showed no significant differences (VP: 71.2, BP: 70.7, p = 0.335). Our study shows that fetal Doppler (RI) and weight estimation ultrasound originally calibrated in cephalic pregnancies are applicable to pregnancies with fetuses in breech presentation.

Value of Middle Cerebral/Umbilical Artery Resistance Index Ratio in Neonatal Outcome in Patients with Intrauterine Growth Restriction (Prospective Study)

Background: Fetal growth disorders are usually associated with perinatal morbidity and mortality. Accurate assessment of intrauterine fetal growth is difficult, but recent advances have improved with positive implications for antenatal care.Aim of the work: The aim of this study was to assess the accuracy of the umbilical and middle cerebral artery resistance index in prediction of fetal outcome in pregnancies with intra-uterine growth restriction (IUGR).Patients and Methods: Forty-five pregnant females had been included in a prospective study. All had a confirmed diagnosis of intra-uterine growth restriction (IUGR). Doppler ultrasound had been performed to record fetal umbilical and middle cerebral artery (MCA) resistance indices every one week (from 32 weeks onwards). Post-delivery birth weight of the baby, Apgar score at 0 and 5 minutes had been documented and correlated with doppler indices. Results: One-fifth of the mothers participating in the study (20%) had pre-term birth and 6.7% missed the follow-up. Umbilical artery resistance index (RI) at a cut off value of (0.79) had a diagnostic accuracy of 93%. MCA RI best cut off value was 0.63 with diagnostic accuracy of 73.9%. Also, for C/U ratio had diagnostic accuracy of 92.9%. Finally, there was significant, proportional correlation between MCA RA and C/U ratio from one side and APGAR score at 0 and 5 minutes from the other side. However, the correlation between UARI and Apgar score was inverse and statistically significant. Conclusion: Doppler velocimetry of fetal circulation can provide important information regarding fetal well-being, with subsequent impact on fetal outcome.

Effect of injecting mouse nerve growth factor in different ways on motor development, cerebral hemodynamics and biochemical metabolism in children with cerebral palsy

To compare the effect of acupoint injection and intramuscular injection with mouse nerve growth factor (mNGF) on gross motor function development of children with cerebral palsy (CP), and explore the treatment mechanism. A total of 63 children with CP were randomly divided into an observation group (32 cases, 4 cases dropped off ) and a control group (31 cases, 3 cases dropped off). Based on the routine rehabilitation therapy, the control group received intramuscular injection of mNGF(18 µg/2 mL), and the observation group received acupoint injection of mNGF at Xinshu (BL 15), Ganshu (BL 18), Pishu (BL 20), Shenshu (BL 23), Sanjiaoshu (BL 22), Shenting (GV 24), Baihui (GV 20), Fengfu (GV 16), Dazhui (GV 14), etc. Of them, 5-6 acupoints alternately were selected each time, and each acupoint was given 0.3-0.5 mL, totally 18 µg/2 mL. Both treatment were carried out once every other day for six months. Before and after treatment, the children's development of brain function was assessed using gross motor function classification system (GMFCS). Before treatment (T0), after 2 (T2), 4 (T4) and 6 (T6) months of treatment, the motor function was evaluated by gross motor function measure (GMFM-88). The systolic peak velocity (Vs), mean velocity (Vm) and vascular resistance index (RI) of anterior cerebral artery (ACA) and middle cerebral artery (MCA) were measured, and the level of N-acetyl aspartate acid (NAA), choline (Cho), lactate (Lac) and creatine (Cr) from the basal ganglia, thalamus and periventricular white mater were detected by magnetic resonance spectroscopy (MRS) technology with MAGNETOM Skyra3.0T magnetic resonance imaging system before and after treatment. Compared with before treatment, the GMFCS classification of the observation group after treatment was significantly improved (P<0.05); after treatment, the difference of GMFCS classification between the two groups was not significant (P>0.05), however, the observation group had a 3.142 times of feasibility for good gross motor function development by more than level 1 compared to the control group (P<0.05). After 2, 4, and 6 months of treatment, the GMFM-88 scores of the two groups showed an upward trend (P<0.01), and the increase of the observation group was greater than that of the control group (P<0.05). Compared with before treatment, in the ACA and MCA, the Vs and Vm increased, RI decreased in both groups after treatment (P<0.01), and in the brain, NAA/Cr increased, Cho/Cr and Lac/Cr decreased (P<0.01), and after treatment, the Vs, Vm of ACA and MCA and NAA/Cr of brain in the observation group were higher than those in the control group (P<0.05), and the RI of ACA and MCA and Cho/Cr and Lac/Cr of brain in the observation group were lower than those in the control group (P<0.05). The mNGF acupoint injection has a better effect on the gross motor function in the children with cerebral palsy compared with the intramuscular injection, and the mechanism may be associated with exhibiting the double effects of acupoint effect and the targeting therapy of drug, which can effectively improve the cerebral hemodynamics and the metabolism of cerebral nervous substances.

ULTRA-SOUND ASSESSMENT OF FETAL KIDNEY VOLUME AND RENAL BLOOD FLOW VELOCIMETRY IN INTRAUTERINE GROWTH RESTRICTION

Background: Intrauterine growth restriction ( IUGR ) refers to a condition in which an unborn baby is smaller than it should be because it is not growing at a normal rate inside the womb. Delayed growth puts the baby at risk of certain health problems during pregnancy, delivery and after birth. Objective: To investigate the correlation between kidney volume and renal artery Doppler in intra-uterine growth restriction. Patients and Methods: This was a prospective randomized descriptive study on 64 pregnant females devided in to two equal groups: Group A: Pregnant females with restricted fetal growth and Group B: females with normal pregnancy. Fetal renal volume was measured by 3-D ultrasound. Renal artery, umbilical artery and middle cerebral artery Doppler indices were measured for each fetus in both groups. Results: The mean total fetal renal volume was 10.26±2.62 in group A and 16.85±5.35 in group Head circumference, abdominal circumference and estimated fetal weight were positively correlated with the total renal volume in both groups, with a statistically significant of group B. Umbilical artery resistance index was inversely correlated with the total renal volume in group The middle cerebral artery resistance index did not show a significant correlation with the TRV in group A in contrast to the control group where a significant negative correlation existed between the two parameters. Conclusion: Intrauterine growth restriction appears to be associated with a decrease in the fetal renal volume.

ULTRA-SOUND ASSESSMENT OF FETAL KIDNEY VOLUME AND RENAL BLOOD FLOW VELOCIMETRY IN INTRAUTERINE GROWTH RESTRICTION

Background: Intrauterine growth restriction ( IUGR ) refers to a condition in which an unborn baby is smaller than it should be because it is not growing at a normal rate inside the womb. Delayed growth puts the baby at risk of certain health problems during pregnancy, delivery and after birth. Objective: To investigate the correlation between kidney volume and renal artery Doppler in intra-uterine growth restriction. Patients and Methods: This was a prospective randomized descriptive study on 64 pregnant females devided in to two equal groups: Group A: Pregnant females with restricted fetal growth and Group B: females with normal pregnancy. Fetal renal volume was measured by 3-D ultrasound. Renal artery, umbilical artery and middle cerebral artery Doppler indices were measured for each fetus in both groups. Results: The mean total fetal renal volume was 10.26±2.62 in group A and 16.85±5.35 in group B. Head circumference, abdominal circumference and estimated fetal weight were positively correlated with the total renal volume "TRV" in both groups, with a statistically significant of group B". Umbilical artery resistance index was inversely correlated with the total renal volume in group B. The middle cerebral artery resistance index did not show a significant correlation with the TRV in group A in contrast to the control group where a significant negative correlation existed between the two parameters. Conclusion: Intrauterine growth restriction appears to be associated with a decrease in the fetal renal volume.

Impact of Skin-to-Skin Parent-Infant Care on Preterm Circulatory Physiology

To ascertain the impact of skin-to-skin care between parents and infants on cardiac function and cerebral blood flow in preterm infants. We undertook a prospective study of 40 self-ventilating preterm infants at a quaternary center and assessed cardiac performance and cerebral blood flow. Assessments were carried out two hours before skin-to-skin care and then 60minutes after skin-to-skin care (with the infant still on parent and turned supine). Infants were 30.5±0.6weeks' gestational age and 1378±133g birthweight. Axillary temperature noted a nonsignificant increase during skin-to-skin care from 36.7±0.07°C to 36.9±0.07°C (P=.07). Cardiac contractility (right ventricular fractional area change [26.5%±0.3% vs 27.8%±0.4; P<.001] and tricuspid annular plane systolic excursion [0.73±0.03cm vs 0.77±0.03cm; P=.02]) increased significantly, coincident with decreased measures of pulmonary vascular resistance. An increase in systemic cardiac output was associated with increased cerebral blood flow and reduced middle cerebral artery resistive index (0.81±0.02 vs 0.74±0.02; P=.0001). We documented a significant circulatory beneficial adaptation to a common neonatal practice. These findings align with previously documented physiologic benefits in cardiorespiratory stability and cardiac rhythm in preterm infants, and may be mediated through modulation of the autonomic nervous system.

167: Maternal hyperoxia leads to changes in the fetal aortic isthmus doppler waveform

The doppler velocity pattern in the aortic isthmus (AoI) has been shown to be a valid indicator of cardiac and peripheral circulatory conditions during fetal life. We sought to evaluate changes in the AoI doppler following maternal hyperoxygenation (MH) in utero, during the third trimester of pregnancy. Forty six women with a singleton gestation ≥31 weeks gestational age were prospectively recruited to the study. A fetal echocardiogram was performed on all subjects. Pulsatility index (PI) and Resistance index (RI) were obtained from the AoI. Measurements were also taken of the umbilical artery (UAD), middle cerebral artery (MCA), ductus arteriosus (DA) and pulmonary artery (PA). Doppler measurements were taken at baseline and repeated following MH for 10 minutes at a rate of 12L/min. The median gestational age was 35 [33 – 37] weeks. A decrease in fetal AoI PI following MH was observed (from 2.61 [2.33-2.89] to 2.46 [2.1-2.82], p=0.04). following MH. The resistance index of the AoI decreased from 0.88 to 0.86, p=0.03. There was a decrease in PA PI following hyperoxygenation (from 2.47 [2.11 – 2.80] to 2.08 [1.75 – 2.49], p=0.02). There was no significant change in fetal heart rate or in the resistance indices of the UAD or DA over the study period. There was a significant increase in MCA blood flow, but not in MCA resistance indices. Our findings indicate a reduction in fetal pulmonary vascular resistance with secondary increased fetal pulmonary blood flow in response to MH. This was not achieved at the expense of ductal constriction. There was evidence of improved MCA peak systolic velocity parameters; this was likely due to the positive impact of improved pulmonary venous return on left ventricular preload, leading to improvement of flow in the aorta as demonstrated by the reduced PI in the AoI. The AoI is a fascinating arterial watershed that offers potential to further improve our understanding of fetal hemodynamic physiology. Continued investigation into the use of maternal hyperoxygenation for evaluating fetal cardiovascular physiology is warranted.

Impaired Right Ventricular Performance Is Associated with Adverse Outcome after Hypoxic Ischemic Encephalopathy.

Rationale: Asphyxiated neonates with hypoxic ischemic encephalopathy (HIE) are at risk of myocardial dysfunction; however, echocardiography studies are limited and little is known about the relationship between hemodynamics and brain injury.Objectives: To analyze the association between severity of myocardial dysfunction and adverse outcome as defined by the composite of death and/or abnormal magnetic resonance imaging.Methods: Neonates with HIE undergoing therapeutic hypothermia were enrolled. Participants underwent echocardiography at 24 hours, 72 hours (before rewarming), and 96 hours (after rewarming). Cerebral hemodynamics were monitored by near-infrared spectroscopy and middle cerebral artery Doppler.Measurements and Main Results: Fifty-three patients with a mean gestation and birthweight of 38.8 ± 2.0 weeks and 3.33 ± 0.6 kg, respectively, were recruited. Thirteen patients (25%) had mild encephalopathy, 27 (50%) had moderate encephalopathy, and 13 (25%) had severe encephalopathy. Eighteen patients (34%) had an adverse outcome. Severity of cardiovascular illness (P < 0.001) and severity of neurologic insult (P = 0.02) were higher in neonates with adverse outcome. Right ventricle (RV) systolic performance at 24 hours was substantially lower than published normative data in all groups. At 24 hours, lower tricuspid annular plane systolic excursion (P = 0.004) and RV fractional area change (P < 0.001), but not pulmonary hypertension, were independently associated with adverse outcome on logistic regression. High brain regional oxygen saturation (P = 0.007) and low middle cerebral artery resistive index (P = 0.04) were associated with RV dysfunction on post hoc analysis.Conclusions: RV dysfunction is associated with the risk of adverse outcome in asphyxiated patients with HIE undergoing hypothermia. Echocardiography may be a valuable diagnostic and prognostic tool in this vulnerable population.

418: Changes in fetal pulmonary artery doppler indices in response to maternal hyperoxygenation

The reactivity of the pulmonary vascular bed to the administration of oxygen is well established in the post-natal circulation. We sought to evaluate changes in the pulmonary artery doppler following maternal hyperoxygenation in utero, during the third trimester of pregnancy. Forty six women with a singleton gestation greater than or equal to 31 weeks gestational age were prospectively recruited to the study. A fetal echocardiogram was performed on all subjects to exclude congenital heart disease. Pulsatility index (PI), Resistance index (RI), Peak systolic (PSV) and end diastolic velocity (EDV), acceleration time (AT), and ejection time (ET) were taken within the proximal portion of the fetal main pulmonary artery (PA). AT:ET was used to assess pulmonary vascular resistance (PVR). Doppler measurements were taken at baseline and repeated immediately following maternal hyperoxygenation for 10 minutes (O2 100% v/v inhalational gas) at a rate of 12L/min via a partial non-rebreather mask. Doppler waveform measurements were also taken of the umbilical artery (UAD), middle cerebral artery (MCA) and the ductus arteriosus (DA). The median gestational age was 35 [33 – 37] weeks. There was a decrease in fetal PA PI following maternal hyperoxygenation (from 2.37 [2.04 – 2.70] to 2.05 [1.69 – 2.41], p=0.001). The resistance index of the PA decreased from (0.86 [0.81- 0.91] to 0.78 [0.69-0.87]. There was an increase in PA AT (57 [42-71] to 66 [49 – 82] ms, leading to an increase in AT:ET following maternal hyperoxygenation (0.32 to 0.34], p=0.001) (Table 1). There were no significant changes in the resistance indices of the UAD and DA. There was a significant increase in MCA blood flow, but not in MCA resistance indices. Maternal hyperoxygenation offers the opportunity to assess the reactivity of the pulmonary vasculature before birth. Our findings would indicate a reduction in fetal pulmonary vascular resistance with secondary increased fetal pulmonary blood flow. This was not achieved at the expense of ductal constriction. There was evidence of improved MCA peak systolic velocity parameters; this was likely due to the positive impact of improved pulmonary venous return on left ventricular preload. The hyperoxygenation test can inform us of functional rather than anatomical information in relation to the pulmonary arteries and this warrants further exploration in a larger cohort.

Doppler Ultrasonography of Foetal Middle Cerebral and Umbilical Arteries in High Risk Pregnancy

AbstractBackground: Foetal hypoxemia is associated with in-creased impedance to flow in the umbilical artery (UA) and decreased impedance in the fetal middle cerebral artery (MCA).Aim of Study: To evaluate Doppler of foetal Middle cerebral (MCA) and Umbilical (UMA) arteries in high risk pregnancies.Patients and Methods: This prospective cross-sectional study was carried on 100 patients at Menoufia university hospital in the period from March 2017 to Febraury 2018 using a 2-5MHz transabdominal probe (GE LOGIC p5 and GE LOGIC p7). The study including two groups, group (A) High risk group: Including 50 patients with pregnancy above 27 weeks presenting with high risk pregnancy, and group (B) control group: Including 50 patients with normal pregnancy above 27 weeks, Doppler examination for both MCA and UMA was done.Results: Out of the fifty pregnant women in Group A, there were 18 cases with abnormal UMA Doppler, 14 cases with abnormal MCA Doppler indices and 10 cases with abnormal cerbroplacental (CPR ). For estimating the associ-ation between high risk pregnancy and resistive index ( RI ) and pulsatility index (PI) of both UMA and MCA for predicting foetal outcome, RI of UMA showed sensitivity and specificity of 70% and 60% and accuracy of 63% and MCA RI showed sensitivity of 74%, specificity of 48% and accuracy of 61%.Conclusion: Doppler ultrasonography of foetal middle cerebral and umbilical arteries plays important role in high risk pregnancies and predicting foetal outcome.

Foetal Doppler Parameters as a Prognostic Marker Before Induction of Labour.

Introduction The value of foetal Doppler ultrasonography before induction of labour for prognostic assessment of the duration of labour and foetal outcome is presented. Patients and Methods Doppler ultrasound of the foetal middle cerebral artery (MCA) and of the umbilical artery (UA) was performed in addition to evaluation of the Bishop score in 49 women around the expected date of confinement (38 + 0 – 42 + 0 weeks of gestation) prior to planned pharmacological induction of labour. These parameters were studied using non-parametric statistical methods for associations with the duration of induction until delivery, the mode of delivery and foetal outcome. Results The resistance index (RI) of the MCA (rs = 0.547, p < 0.001), but not the RI of the UA (rs = − 0.055, p = 0.707) correlated positively with the duration of induction. Moreover, a negative correlation was found between the RI of the UA and the babyʼs arterial cord pH at birth (rs = − 0.287, p = 0.046). No differences in the RI of MCA or UA were found between babies born vaginally and those delivered by secondary section. Conclusion The present data show that Doppler measurement of the foetal MCA and UA before pharmacological induction of labour at term can be a further parameter for prognostic estimation of the duration and success of induction and of foetal outcome in addition to the established Bishop score.