Fetal Cerebral Circulation 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.

Fetal posterior cerebral artery in pediatric and adult moyamoya disease: A single-center experience of 480 patients

PurposeIn past pediatric and adult cohort studies of moyamoya disease, the fetal posterior cerebral artery has received less attention. Its relationship with the clinical manifestations and collateral circulation of moyamoya disease or ipsilateral cerebral hemispheres remains unclear. MethodWe summarize the clinical features of patients with and without fetal posterior cerebral artery moyamoya disease from consecutive cases.We explored the relationship between fetal posterior cerebral arteries and collateral circulation in the ipsilateral cerebral hemispheres, as well as differences among different subgroups of patients.According to the morphology, the fetal posterior cerebral artery is divided into complete fetal posterior cerebral artery and partial fetal posterior cerebral artery. Clinical features were classified as: infarction,hemorrhage,and non-stroke in unilateral/bilateral cerebral hemispheres. Collateral circulation is divided into extracranial vascular compensation and leptomeningeal collateral circulation. Digital subtraction angiography and CT/MR were used to evaluate the blood flow status and clinical characteristics of patients with moyamoya disease. ResultA total of 960 cerebral hemispheres from 142 pediatric patients and 338 adult patients were included in the study. A total of 273 (56.9%) patients had 399 cerebral hemispheres (41.6%) with fetal posterior cerebral arteries. Adults with fetal posterior cerebral arteries had lower rates of infarction (24.6%vs37.3%, P =0.005) and were less likely to have bilateral stroke (8.4%vs11.5%, P =0.038). Cerebral hemispheres with fetal posterior cerebral artery were more likely to have anterior cerebral artery and middle cerebral artery stenosis and less likely to have occlusion (P =0.002, 0.001), and less likely to involve the posterior circulation (P < 0.001). The cerebral hemispheres of the fetal posterior cerebral artery had higher leptomeningeal collateral circulation scores. There are significant differences in extracranial vascular compensation between cerebral hemispheres with and without fetal posterior cerebral artery. Adult patients with fetal posterior cerebral artery were more advanced in Suzuki stage (P =0.017). ConclusionsOur results suggest that fetal posterior cerebral artery is associated with infarct manifestations in pediatric and adult moyamoya disease. In the cerebral hemispheres, the fetal posterior cerebral artery is associated with ipsilateral hemispheric anterior and posterior circulation artery injury, extracranial vascular compensation, leptomeningeal collateral circulation compensation, and infarction. Adult patients with fetal posterior cerebral artery were more advanced in Suzuki stage.

Fetal cerebral three-dimensional power Doppler vascularization indices and their relationships with maternal glucose levels in pregnancies complicated with gestational diabetes.

ObjectivesWe aimed to evaluate fetal cerebral circulation using three-dimensional power Doppler (3DPD) vascular indices and to study their relationships with maternal lipid and glycaemic profiles.MethodsCase–control study in women with and without gestational diabetes mellitus (GDM) at 28–32 weeks in which feto-maternal Doppler study and 3DPD cerebral vascularization indices (FI, VI and VFI) were determined. Maternal lipid and glycaemic profiles were also analysed. Both groups were compared and the correlations of the 3DPD indices with studied variables were analysed.ResultsThere were significant differences between groups in cerebral FI (p= 0.02), mean maternal Uterine artery PI (p= 0.009) and glucose levels (p= 0.001), being higher in the GDM group. Significant negative correlations were found in GDM group between VFI and MCA PI (p = 0.02) and between VI and MCA PI (p= 0.01). In the GDM group we found a negative significant correlation between FI, VI, VFI and maternal glucose (r= −0.52, p<0.001; r= −0.32, p=0.03 and r= −0.36, p= 0.01, respectively).ConclusionsFetal cerebral FI values were higher in GDM pregnancies. All 3DPD vascular indices showed an inverse correlation with maternal glucose levels. These findings support the view that GDM may also represent a fetal vascular disorder influencing fetal neurodevelopment.

A Study of Fetal Umbilical Artery and Middle Cerebral Artery Doppler Velocimetry Before and after Treatment of Severe Maternal Iron Deficiency Anaemia

Background: Despite maternal iron deficiency anemia being a worldwide medical complication, very few studies have been performed to evaluate the efficacy of iron supplementations for treating and preventing adverse pregnancy sequelae. This study attempts to show the impact of maternal iron deficiency anemia on the mother and the fetus and whether treatment can reverse the physiological and pathological effects of anemia on the mother as well as the fetus. Objective: To evaluate the effect of vascular adaptation and extent of compensatory changes in the fetus with the change in maternal hemoglobin (Hb) levels and to study maternal and perinatal outcomes after treatment of maternal iron deficiency anemia. Methodology: The present study was an observational prospective study conducted on 50 pregnant women in GMC, Srinagar from January 2016 to June 2017. The study population was divided into two groups-Group A-Patients with moderate anemia – Hb 7–9 g/dl and Group B-Patients with severe anemia – Hb &lt;7 g/dl. Group A received parenteral iron preparation and Group B received blood transfusion or packed red blood cells until Hb exceeded 7 g/dL, then parenteral iron was used. Maternal Hb and color Doppler were performed before and after treatment of anemia. Results: There was a decrease in the umbilical artery resistivity index (RI) after treatment of maternal anemia in both the groups and the decrease was more in those who received blood transfusion. There was an improvement in middle cerebral artery RI in both the groups after treatment and the increase was statistically significant. The C/U ratio was normalized to &gt;1.1 in both the study groups after treatment of anemia. Conclusion: Our data support the fact that maternal Hb content of &lt;7 g/dl is strongly associated with marked fetal hemodynamic adaptation and must be treated with acute red cell transfusion. Moderate anemia (&gt;7 g/dl) is not sufficient to trigger fetal blood flow redistribution and can be treated with parenteral iron. Close monitoring of the fetal umbilical and cerebral circulation by Doppler examination in anemic pregnancies allows the measurement of the amplitude of fetal vascular response, early assessment of fetal damage and helps in improving fetal outcome as well.

The effect of nuchal umbilical cord on fetal cardiac and cerebral circulation-cross-sectional study.

The subject of our analysis is the influence of umbilical cord collision around the fetal neck on the fetal heart function and cerebral circulation. Our study was carried out on a group of 115 fetuses from single pregnancies with physiological course, during the 15th to 40th week of pregnancy. In our analysis, we examined the following parameters: Tei index for right ventricle, Tei index for left ventricle with Tei index components: isovolumetric contraction time, isovolumetric relaxation time, ejection time and cardiothoracic area ratio, middle cerebral artery peak systolic velocity (PS MCA), middle cerebral artery pulsatility index (PI MCA). Gestational age in our study was: 28+2±34. The study group of patients with fetal umbilical cord around neck group (fUCAN) included 38 fetuses (20 males, 18 females). The control group of patients with no fetal umbilical cord around neck group (NfUCAN) included 77 fetuses (43 males, 34 females). In our study, we found no significant differences in the values obtained: Tei LV in fUCAN: 0.5±0.1 vs. in NfUCAN: 0.5±0.1; p=0.42), Tei RV in fUCAN: 0.5±0.2 vs. in NfUCAN: 0.4±0.1; (p=0.2). Tricuspid valve regurgitation-TR was observed with the following frequency: fUCAN: 7/38, 18% vs. NfUCAN: 13/77, 17%; p=0.8. MCA PS in study fUCAN group was significantly higher than in NfUCAN (40.2±11.5 vs. 32.5±9.5; p=0.003), although other hemodynamic and clinical variables did not differ between the study and control groups. The fetal nuchal umbilical cord collision did not affect the fetal heart function expressed as Tei index, at the time of fetal heart examination (at mean gestational age 29+4weeks). The fUCAN group presented elevated PS MCA, which was not related to other hemodynamic and clinical variables between the study and control groups.

In utero hypoxia altered Ang II-induced contraction via PKCβ in fetal cerebral arteries.

Cerebral circulation is important in fetal brain development, and angiotensin II (Ang II) plays vital roles in regulation of adult cerebral circulation. However, functions of Ang II in fetal cerebral vasculature and influences of in utero hypoxia on Ang II-mediated fetal cerebral vascular responses are largely unknown. This study investigated the effects and mechanisms of in utero hypoxia on fetal middle cerebral arteries (MCA) via Ang II. Near-term ovine fetuses were exposed to in utero hypoxia, and fetal MCA responses to Ang II were tested for vascular tension, calcium transient, and molecular analysis. Ang II caused significant dose-dependent contraction in control fetal MCA. Ang II-induced MCA constriction was decreased significantly in hypoxic fetuses. Neither losartan (AT1R antagonist, 10-5 mol/L) nor PD123,319 (AT2R antagonist, 10-5 mol/L) altered Ang II-mediated contraction in fetal MCA. Phenylephrine-mediated constriction was also significantly weaker in hypoxic fetuses. Bay K8644 caused similar contractions between the two groups. Protein expression of L-type voltage-dependent calcium channels was unchanged. There were no differences in caffeine-mediated vascular tension or calcium transients. Contraction induced by PDBu (PKC agonist) was obviously weaker in hypoxic MCA. Protein expression of PKCβ was reduced in the hypoxic compared with the control, along with no differences in phosphorylation levels. The results showed that fetal MCA was functionally responsive to Ang II near term. Intrauterine hypoxia reduced the vascular agonist-mediated contraction in fetal MCA, probably via decreasing PKCβ and its phosphorylation, which might play protective effects on fetal cerebral circulation against transient hypoxia.

Effect of pregestational diabetes mellitus on fetal cerebral artery Doppler changes and its correlation with fetal weight

Background Pregestational diabetes mellitus (PDM) is one of the causes of many gestational complications. This study aimed to review the effect of maternal pregestational diabetes on fetal cerebral circulation through assessment of fetal middle cerebral artery (MCA) and vertebral artery (VA) Doppler study as well as cerebroplacental ratio using MCA pulsatility index (PI)/uterine artery PI and VA PI/uterine artery PI, and to find its correlation with fetal weight. Patients and methods This prospective study was conducted on 40 cases, comprising 20 pregestational diabetic women and 20 comparison pregnant nondiabetic women (comparison cases). Fetal Doppler studies were done twice for pregestational diabetic patients and the comparison group. The Doppler indices such as fetal MCA, VA, and umbilical artery were assessed along with the routine obstetric ultrasound examination. Results Statistically significant differences were detected between pregestational diabetic and comparison cases regarding MCA peak systolic volume and VA resistivity index at mid/end of the second trimester and VA resistivity index, VA PI, and VA cerebroplacental ratio at the beginning of the third trimester. There was no correlation in PDM cases between Doppler indices and fetal weight. Conclusion PDM was associated with VA and MCA Doppler changes. VA Doppler is recommended along with MCA Doppler in fetal screening in high-risk pregnancies.

Effect of antenatal maternal anxiety on the reactivity of fetal cerebral circulation to auditory stimulation, and early child development

Introduction/Objective. Antenatal maternal anxiety (AMA) can have negative impact on a child?s preand postnatal development. The aim of the study was to examine the effect of AMA on changes in fetal blood flow through the middle cerebral artery (MCA) after acoustic stimulation, on birth outcome, and on early child development. Methods. Forty-three women in the third trimester of pregnancy and their children were enrolled into a longitudinal prospective study. The AMA (state and trait) was assessed using Spielberger?s questionnaire. The MCA blood flow was assessed using Doppler ultrasound before and after the defined acoustic stimulus. The data regarding neonatal body weight, Apgar score, first step and word appearance, estimated speech?language (ESLD), sensory-motor (ESMD), and social-emotional (ESED) development at the age of three were collected. Results. Fetuses from mothers with high state and trait anxiety had slower reaction time and higher relative pulsatility index after defined auditory stimulation. There are more preterm deliveries, lower scores on ESLD, ESMD, and ESED in mothers with high State-Trait Anxiety Inventory personality trait (STAI-T) compared to low. There is a negative correlation between reaction time, relative pulsatility index, STAI-T and ESLD. Conclusions. High levels of antenatal maternal trait anxiety could have a negative effect on both fetal reactivity to sound stimulation and early child development.

Fetal Cerebral Circulation as Target of Maternal Alcohol Consumption.

Alcohol (ethanol [EtOH]) is one of the most widely used psychoactive substances worldwide. Alcohol consumption during pregnancy may result in a wide range of morphological and neurodevelopmental abnormalities termed fetal alcohol spectrum disorders (FASD), with the most severe cases diagnosed as fetal alcohol syndrome (FAS). FAS and FASD are not readily curable and currently represent the leading preventable causes of birth defect and neurodevelopmental delay in the United States. The etiology of FAS/FASD remains poorly understood. This review focuses on the effects of prenatal alcohol exposure (PAE) on fetal cerebrovascular function. A brief introduction to the epidemiology of alcohol consumption and the developmental characteristics of fetal cerebral circulation is followed by several sections that discuss current evidence documenting alcohol-driven alterations of fetal cerebral blood flow, artery function, and microvessel networks. The material offers mechanistic insights at the vascular level itself into the pathophysiology of PAE.

Effects of betamethasone on fetoplacental and maternal hemodynamics in preterm pregnancies.

To evaluate the possible effects of prenatal steroid administration onDoppler parameters of the umbilical artery, uterine artery, middle cerebral artery, and ductus venosus, the cerebroplacental ratio, and the amniotic fluid index in pretermfetuses. The present prospective observational study was performed at the Perinatology Department of Trakya University, Edirne, Turkey, between June 1, 2015, and September 1, 2016. It included patients with healthy singleton pregnancies who had received betamethasone at 24-34weeks of pregnancy. Doppler parameters were measured before (0hours) and 24, 48, and 72hours after the administration of betamethasone (two intramuscular doses of 12mg each, administered 24hours apart). There were 68 patients included. Pairwise comparisons demonstrated that, at 72hours after betamethasone administration, the umbilical artery resistance index (P=0.038), the middle cerebral artery systolic/diastolic velocity ratio (P=0.007), and the amniotic fluid index (P=0.017) were reduced, whereas the end-diastolic velocity of the middle cerebral artery was increased (P=0.012), compared with baseline values. Betamethasone had favorable effects on fetal cerebral circulation, with increased end-diastolic velocity in the middle cerebral artery; this could represent a positive effect on cerebral blood circulation and decreased flow resistance in the umbilical artery.

Correlation between maternal anxiety, reactivity of fetal cerebral circulation to auditory stimulation, and birth outcome in normotensive and gestational hypertensive women.

This study investigated the correlation between maternal anxiety and blood flow changes through the fetal middle cerebral artery (MCA) after defined acoustic stimulation in 43 normotensive (C) and 40 gestational hypertensive (GH) subjects. Neonatal outcomes (gestational age at birth, Apgar score, birth weight) in the C and GH groups were analyzed. State (STAI-S) and trait (STAI-T) anxiety was assessed using Spielberger's questionnaire. The MCA blood flow was assessed once between 28 and 41 weeks of gestation using color Doppler ultrasound before and after application of defined acoustic stimulus. Relative size of the Pulsatility index (Pi) change (RePi) was calculated. The general hypotheses were: (1) women in GH group would have higher anxiety; (2) higher anxiety correlates with higher RePi change and poorer neonatal outcome; (3) fetuses from the GH group would have poorer neonatal outcome. Subjects from the GH group had higher STAI-T and RePi compared to the C group. A positive correlation between RePi and STAI-S, STAI-T, and systolic/diastolic blood pressure was found in both groups. There were more preterm deliveries in the GH group compared to the C group. A significant effect of STAI-T on body weight was observed in the C and GH group. There was a predictive effect of STAI-T and RePi on the C group, and STAI-S, STAI-T, diastolic blood pressure, and RePi on the GH group in terms of neonatal body weight. This study demonstrates an association between antenatal anxiety in GH women and increased fetal cerebral circulation in response to defined auditory stimulation.

Oxygen supply to the fetal cerebral circulation in hypoplastic left heart syndrome: a simulation study based on the theoretical models of fetal circulation.

Hypoxia due to congenital heart diseases (CHDs) adversely affects brain development during the fetal period. Head circumference at birth is closely associated with neuropsychiatric development, and it is considerably smaller in newborns with hypoplastic left heart syndrome (HLHS) than in normal newborns. We performed simulation studies on newborns with CHD to evaluate the cerebral circulation during the fetal period. The oxygen saturation of cerebral blood flow in newborns with CHD was simulated according to a model for normal fetal circulation in late pregnancy. We compared the oxygen saturation of cerebral blood flow between newborns with tricuspid atresia (TA; a disease showing univentricular circulation and hypoplasia of the right ventricle), those with transposition of the great arteries (TGA; a disease showing abnormal mixing of arterial and venous blood), and those with HLHS. The oxygen saturation of cerebral blood flow in newborns with normal circulation was 75.7%, whereas it was low (49.5%) in both newborns with HLHS and those with TA. Although the oxygen level is affected by the blood flow through the foramen ovale, the oxygen saturation in newborns with TGA was even lower (43.2%). These data, together with previous reports, suggest that the cerebral blood flow rate is decreased in newborns with HLHS, and the main cause was strongly suspected to be retrograde cerebral perfusion through a patent ductus arteriosus. This study provides important information about the neurodevelopmental prognosis of newborns with HLHS and suggests the need to identify strategies to resolve this unfavorable cerebral circulatory state in utero.

Association between maternal psychological status and fetal hemodynamic circulation in late pregnancy

Background The prevalence reported of maternal depression from the first to the third trimester was 7.4%, 12.8%, 12.0% respectively, which implies that around one-tenth of pregnant women suffer from psychological disorder during the whole pregnancy. It is assumed that during pregnancy the maternal-fetal circulation unit is also affected by maternal psychological status. The aim of this study is to explore the association between maternal psychological status and fetal dynamic blood flow circulation during pregnancy. Methods We recruited 102 singleton low risk pregnant women between 30 to 33 gestational weeks. The Symptom Checklist-90 (SCL-90) was used to assess maternal psychological status. Ultrasound Doppler was used to measure blood flow changes in maternal-fetal circulation. Pulsatility index (PI) value was measured in umbilical artery (UA), fetal middle cerebral artery (MCA) and maternal uterine arteries (UTA). Peak systolic velocity (PSV) was measured in MCA and velocity was measured in umbilical vein (UV). Statistical analysis was performed with standard nonparametric Mann-Whitney U tests. Two-tailed P values &lt;0.05 were considered statistical significance. Results Of the 102 pregnant women, 12 patients show high levels of poor mental health. Women with poor mental health have higher umbilical artery PI values than good mental health patients (P=0.020). A higher MCA PI value is found in poor mental health patients but this does not reach statistical significance (P=0.053). Women with hostility show lower placental scores (P=0.030). Women with somatization demonstrate higher values in UA PI, MCA PI and MCA PSV (P=0.049, 0.030 and 0.035 respectively). A higher MCA PSV value is also found in phobic anxiety patients (P=0.046). Conclusions Poor mental health during pregnancy is found to have an adverse effect on maternal-fetal circulation. Umbilical artery and fetal cerebral circulation are more sensitive and affected by maternal psychological disorder.

NPY ő a regulator of hypoxic cerebrovascular remodeling in fetal lambs (853.4)

Prenatal, intra‐partum or post partum exposure of a fetus to hypoxia results in structural and functional changes in cerebral arteries, known as remodeling. Sympathetic nerves have been suggested to contribute to this process. Whereas NE is suggested as the major mediator of adrenergic effects, our preliminary experiments show that there is a guanethidine‐resistant (norepinephrine‐independent) component. This study explores the hypothesis that NPY contributes to hypoxic cerebrovascular remodeling in the fetal cerebral circulation. Chronic hypoxia (CH) produced a 254% ↑ in K‐induced tone and a 30% ↓ in stretch‐induced myogenic tone in fresh nerve‐intact fetal cerebral arteries. CH also increased the magnitude of nerve stimulation induced guanethidine‐resistant contractile tone. Immunohistochemistry revealed that CH significantly ↑ cerebrovascular NPY whereas sympathectomy (SANX) ablated this effect. Likewise, Western blot quantification of NPY‐Y1 receptors revealed that CH increased Y1 receptors 73%. Whereas SANX in normoxic tissues had no significant effect, SANX produced a 30% ↓ in Y1 receptors in hypoxic arteries. Together these results suggest that NPY released from sympathetic cerebrovascular nerves contributes to hypoxic remodeling through increased NPY content/release and Y1 receptor density.Grant Funding Source: Supported by NIH Grants HD‐31266 and NS‐076945

Can anomalies of fetal brain circulation be useful in the management of growth restricted fetuses?

Assessment of the fetal cerebral circulation provides important information on the hemodynamic changes associated with chronic hypoxia and intrauterine growth restriction. Despite the incorporation of new US parameters, the landmark for the fetal brain hemodynamic evaluation is still the middle cerebral artery. However, new vascular territories, such as the anterior and posterior cerebral arteries, might provide additional information on the onset of the brain sparing effect. The fractional moving blood volume estimation and three-dimensional power Doppler ultrasound indices are new techniques that seem to be promising in identifying cases at earlier stages of vascular deterioration; still, they are not available for clinical application and more information is needed on the reproducibility and advantages of three-dimensional power Doppler ultrasound blood flow indices. In the past, the brain sparing effect was considered as a protective mechanism; however, recent information challenges this concept. There is growing evidence of an association between brain sparing effect and increased risk of abnormal neurodevelopment after birth. Even in mild late-onset intrauterine growth restriction affected fetuses with normal umbilical artery blood flow, increased cerebral blood perfusion can be associated with a substantial risk of abnormal neuroadaptation and neurodevelopment during childhood.

Ethanol Exposure During Pregnancy Persistently Attenuates Cranially Directed Blood Flow in the Developing Fetus: Evidence from Ultrasound Imaging in a Murine Second Trimester Equivalent Model

Ethanol (EtOH) consumption during pregnancy can lead to fetal growth retardation, mental retardation, and neurodevelopmental delay. The fetal brain initiates neurogenesis and vasculogenesis during the second trimester, and depends on maternal-fetal circulation for nutrition and growth signals. We used high-resolution in vivo ultrasound imaging to test the hypothesis that EtOH interferes with fetal brain-directed blood flow during this critical developmental period. Pregnant mice were lightly anesthetized on gestational day 12 with an isoflurane/oxygen mixture. We assessed the effect of single and repeated binge-like maternal EtOH exposures at 3 g/kg, administered by intragastric gavage or intraperitoneal injection, on maternal circulation and fetal umbilical, aortic, internal carotid, and middle cerebral arterial circulation. Binge maternal EtOH exposure, regardless of exposure route, significantly reduced fetal arterial blood acceleration and velocity time integral (VTI), from umbilical to cerebral arteries, without a change in fetal heart rate and resistivity indices. Importantly a single maternal binge EtOH exposure induced persistent suppression of fetal arterial VTI for at least 24 hours. Repeated binge episodes resulted in a continuing and persistent suppression of fetal VTI. Qualitative assessments showed that maternal EtOH exposure induced oscillatory, nondirectional blood flow in fetal cerebral arteries. Maternal cardiac and other physiological parameters remained unaltered. These data show that binge-type maternal EtOH exposure results in rapid and persistent loss of blood flow from the umbilical artery to the fetal brain, potentially compromising nutrition and the maternal/fetal endocrine environment during a critical period for neuron formation and angiogenesis in the maturing brain.

Impact of passive smoking on uterine, umbilical, and fetal middle cerebral artery blood flows

The aim of this study was to evaluate the influence of passive maternal smoking on blood flow velocities in arteries of the fetal-placental-maternal circulation. A total of 79 pregnant women in their third trimester, including 33 passive smokers, 23 active smokers, and 23 nonsmoking controls, were enrolled in the study. Fetal biophysical indices were evaluated with B-mode scanning, whereas blood flow waveforms of uterine, umbilical, and fetal middle cerebral (MCA) arteries were analyzed with Doppler ultrasonography. There were significant differences among active smokers vs. passive smokers vs. controls with regard to the presence of a uterine artery diastolic notch (39.1% vs. 18.2% vs. 4.3%; P = 0.012); ratio of peak systolic/end-diastolic velocity of fetal MCA [3.73 ± 1.27 vs. 4.26 ± 1.20 vs. 5.00 ± 2.15, analysis of variance (ANOVA) P = 0.026]; resistance index of fetal MCA (0.74 ± 0.08 vs. 0.75 ± 0.07 vs. 0.80 ± 0.09; ANOVA P = 0.014); ratio of fetal MCA/umbilical artery resistance index (1.27 ± 0.20 vs. 1.24 ± 0.14 vs. 1.39 ± 0.21; ANOVA P = 0.011); and ratio of fetal MCA/umbilical artery pulsatility index (1.56 ± 0.44 vs. 1.63 ± 0.43 vs. 1.97 ± 0.54; ANOVA P = 0.046). Effects of passive maternal smoking on the fetal-placental-maternal unit were comparable to those with active maternal smoking as determined by the means of increased resistance in the maternal vasculature and adaptive changes of cerebroplacental circulation for maintaining fetal cerebral circulation.

OP16.03: Fetal cerebral perfusion in the third trimester of pregnancies with controlled maternal insulin‐dependent‐diabetes (IDD)

Insulin dependent diabetes has been described to have an impact during pregnancy on the fetal heart and blood rheology. A fetal diabetes-induced cardiopathy is described. The present study assesses the fetal cerebral perfusion in pregnancies complicated by maternal IDD, asses the fetal middle cerebral artery (MCA) Doppler for 3rd trim. Cross-sectional study incl singleton pregnancies complicated by pre-gestational IDD after 20 weeks of gestation, followed-up in the Nat Inst for Diabetes “Nic Paulescu” Buc in collaboration with the Cantacuzino Hosp-Prenatal Diagnosis Unit. Exclusion criteria were: pre-eclampsia, IUGr < 10°P and treatment with beta-mimetics or calcium channel blockers. Recorded data, using Voluson730ProV Ultrasound System. Twenty-one patients (n = 21), aged 24–35 years with pre-gestational IDD, with an onset 2–10 years prior to pregnancy, without specific diabetes complications were matched with 20 non-complic pregnancies between 20–39 weeks. In diabetes, HbA1c levels were 5.54% ± 0.6%, (min. 4.4%–6.8%). Diabetic pregnancies have significant higher EFW in average 78° percentile (min 41°P-max 99°P). 35.3% above 90°P (P < 0.001). Hydramnios in diabetes is 14.3%. MCA PSV in diabetes was 1.04 ± 0.25 MoM, (min. 0.59 MoM-max. 1.53 MoM), not significantly different from the normal controls. Compared to the normal distribution of PSV MCA published by Kurmanavicius et al: 4/21diabetic cases (19%) were above 95′P. Well controlled maternal IDD, although is known to influence fetal cardiac morphology and blood rheology, does not influence fetal cerebral circulation at the level of the MCA PSV. It can be argued that the modifications at the level of the fetal heart, described as diabetic cardiac fetopathy, are only adaptation changes in order to preserve normal cerebral perfusion. This work was supported by CNCSIS -UEFISCSU, project number PNII-IDEIcode 1331/2008.

Three-Dimensional Power Doppler Analysis of Cerebral Circulation in Normal and Growth-Restricted Fetuses

The objective of the present study was to evaluate fetal cerebral circulation by using three-dimensional (3D) power Doppler ultrasound in normal and growth-restricted fetuses. A total of 100 normal grown fetuses were compared with other 25 with growth restriction (FGR). Three-dimensional power Doppler ultrasound was used to assess fetal cerebral 3D vascular indices: vascularization index, flow index (FI), and vascularization flow index (VFI). Both FI and VFI correlated positively with gestational age. On average, all the 3D vascular indices were increased in fetuses with FGR. The proportion of fetuses detected as having hemodynamic redistribution was higher when using 3D power Doppler indices than by means of the middle cerebral artery pulsatility index (52% versus 20%, P=0.002). In conclusion, two of the three indices increased during gestation. All the fetal cerebral 3D vascular indices are increased in fetuses with FGR. In these fetuses, there were more cases suggesting hemodynamic redistribution than expected by conventional Doppler studies.

OC163: The relationships between three‐dimensional power Doppler indices of fetal cerebral circulation and hemoglobin concentration in non‐anemic fetuses

OC163: The relationships between three‐dimensional power Doppler indices of fetal cerebral circulation and hemoglobin concentration in non‐anemic fetuses