Forecasting temporal world recovery in air transport markets in the presence of large economic shocks: The case of COVID-19.

This paper estimates the relationship between the strength of economic shocks and temporal recovery in the world air transport industry. Our results show that world recovery of passenger demand to pre-COVID-19 levels is estimated to take 2.4 years (recovery by late-2022), with the most optimistic estimate being 2 years (recovery by mid-2022), and the most pessimistic estimate 6 years (recovery in 2026). Large regional differences are detected, Asia Pacific has the shortest estimated average recovery time 2.2 years, followed by North America 2.5 years and Europe 2.7 years. For air freight the results show a shorter average world recovery time of 2.2 years compared to passenger demand. At the regional level, Europe and Asia Pacific are comparable with average recovery times of 2.2 years while North America is predicted to recover faster in 1.5 years. The results show that the strength of economic shocks of various origins impacts the linear growth of passenger and freight traffic and the temporal recovery of the industry in a predictable transitory way. Hence, the impact of the COVID-19 recession will represent a temporary, although long-lasting, correction to previous growth levels.

Metabolomics comparison of red cells stored in four additive solutions reveals differences in citrate anticoagulant permeability and metabolism.

BACKGROUND AND OBJECTIVES: Metabolomics studies have revealed transition points in metabolic signatures of red cells during storage in SAGM, whose clinical significance is unclear. We set out to investigate whether these transition points occur independent of storage media and define differences in the metabolism of red cells in additive solutions. MATERIALS AND METHODS: Red cell concentrates were stored in SAGM, AS-1, AS-3 or PAGGSM, and sampled fourteen times spanning Day 1-46. Following quality control, the samples were split into extracellular and intracellular aliquots. These were analysed with ultra-high-performance liquid chromatography coupled to mass spectrometry analysis affording quantitative metabolic profiles of both intra- and extracellular red cell metabolites. RESULTS: Differences were observed in glycolysis, purine salvage, glutathione synthesis and citrate metabolism on account of the storage solutions. Donor variability however hindered the accurate characterization of metabolic transition time-points. Intracellular citrate concentrations were increased in red cells stored in AS-3 and PAGGSM media. The metabolism of citrate in red cells in SAGM was subsequently confirmed using 13 C citrate isotope labelling and shown to originate from citrate anticoagulant. CONCLUSION: Metabolic signatures that discriminate between 'fresh' and 'old' stored red cells are dependent upon additive solutions. Specifically, the incorporation and metabolism of citrate in additive solutions with lower chloride ion concentration is altered and impacts glycolysis.

A nonsense mutation in CEP55 defines a new locus for a Meckel-like syndrome, an autosomal recessive lethal fetal ciliopathy.

Mutations in genes involved in the cilium-centrosome complex are called ciliopathies. Meckel-Gruber syndrome (MKS) is a ciliopathic lethal autosomal recessive syndrome characterized by genetically and clinically heterogeneous manifestations, including renal cystic dysplasia, occipital encephalocele and polydactyly. Several genes have previously been associated with MKS and MKS-like phenotypes, but there are still genes remaining to be discovered. We have used whole-exome sequencing (WES) to uncover the genetics of a suspected autosomal recessive Meckel syndrome phenotype in a family with 2 affected fetuses. RNA studies and histopathological analysis was performed for further delineation. WES lead to identification of a homozygous nonsense mutation c.256C>T (p.Arg86*) in CEP55 (centrosomal protein of 55 kDa) in the affected fetus. The variant has previously been identified in carriers in low frequencies, and segregated in the family. CEP55 is an important centrosomal protein required for the mid-body formation at cytokinesis. Our results expand the list of centrosomal proteins implicated in human ciliopathies and provide evidence for an essential role of CEP55 during embryogenesis and development of disease.

Clinical symptoms in adults with selective IgA deficiency: a case-control study.

Selective IgA deficiency (SIgAD) is the most common primary immunodeficiency in Caucasians with a prevalence of 1/600 and is generally considered a mild disorder. In this study, the clinical status of 32 adults with SIgAD was investigated and compared to 63 age- and gender matched controls, randomly selected from a population database. The SIgAD individuals reported significantly more often contracting various upper and lower respiratory infections, with 8 (25.0 %) having been diagnosed with ≥1 pneumonia in the preceding two years, compared to one (1.6 %) control (p < 0.001). Furthermore, the SIgAD individuals were found to have increased proneness to infections and increased prevalence of allergic diseases and autoimmunity, with a total of 84.4 % being affected by any of these diseases, compared to 47.6 % of the controls (p < 0.01). This study challenges the common statement of SIgAD being a mild form of immunodeficiency. It also highlights the importance of using matched controls in PID clinical research to better detect clinically important manifestations.

Abnormal ductus venosus pulsatility index in the absence of concurrent umbilical vein pulsations does not indicate worsening fetal condition.

OBJECTIVE: Recordings of blood flow velocity waveforms in the ductus venosus (DV) and umbilical vein (UV) are routinely used in order to predict fetal condition in high-risk pregnancies. The aim of this study was to investigate the relationship between pathological blood flow in the two vessels and perinatal outcome. METHODS: High-risk pregnancies (n = 11 863) admitted from 1993 to 2011 for blood-flow examination, including recordings of DV pulsatility index for veins (DV-PIV) and UV pulsations, were included. The results were related to perinatal outcome, using the last Doppler examination prior to delivery in the analysis. RESULTS: Abnormal DV-PIV was observed in 3.9% of cases, intra-abdominal UV pulsations in 1.3% and pulsations in the cord in 0.7%. As expected, the rate of UV pulsations increased with increasing DV-PIV Z-score. Fetuses with a pathological DV-PIV, but without UV pulsations, showed fewer signs of compromise. This was also true for cases with a DV-PIV ≥ 4 SDs above the mean (53.7% had steady flow in the UV). In contrast, the occurrence of UV pulsations seemed to be an indicator of fetal compromise, regardless of level of DV-PIV. CONCLUSIONS: Abnormal fetal venous blood velocity is related to adverse outcome in high-risk pregnancies. However, abnormal DV-PIV is not a reliable indicator of fetal compromise unless UV pulsations are concurrently present, and should not be regarded an indication for emergency delivery.

Association of HLA-DRB1*01 with Dupuytren's disease.

OBJECTIVES: To explore the human leucocyte antigen (HLA)-DRB1 allele frequency in Dupuytren's disease (DD). METHOD: HLA-DRB1 genotypes were analysed by sequence-specific primers (SSPs) in samples collected from 172 men participating in a nested case-control study on the clinical manifestations and progression of DD. Of those, 121 had signs of DD while 51 did not. Of the 121 men with DD, 49 had contracted fingers or had been operated on, while 72 had nodules or fibrous cords in the palms. Odds ratios (ORs) and 95% confidence interval (CIs) were used to evaluate the results. RESULTS: The HLA-DRB1*01 allele was observed in 26 of the 121 affected men (23.7%) but in only four of the controls (7.8%) (OR 3.22, 95% CI 1.06-9.75). The HLA-DRB1*01 allele frequency in those affected was 11%, while in the control group it was 4% (OR 3.07, 95% CI 1.05-9.03). CONCLUSIONS: This observation indicates a possible association of HLA-DRB1*01 with DD, but further studies are needed for confirmation.

Hepatic venous Doppler in the evaluation of fetal extrasystoles.

OBJECTIVES: To evaluate the use of fetal hepatic venous Doppler in the diagnosis of fetal extrasystoles, to estimate the prevalence and persistence of extra atrial and ventricular heart beats throughout pregnancy, labor and delivery, and to estimate the frequency of coexisting congenital heart disease. METHODS: This was a retrospective study of 256 singleton pregnancies attending our hospital as outpatients due to fetal extrasystoles. Hepatic venous Doppler and detailed fetal echocardiography were performed. Information on fetal heart rate patterns during labor and neonatal conditions was collected. Congenital heart malformations and the frequency and persistence of fetal extrasystoles were noted. RESULTS: On venous Doppler examination, 228 (89%) of the fetuses showed signs of supraventricular extrasystoles (SVES) and 28 (11%) had ventricular extrasystoles (VES). One fetus with SVES developed atrial flutter during pregnancy and another case developed supraventricular tachycardia postnatally. SVES persisted until labor and delivery in 28 (12.3%) fetuses and VES persisted in six (21.4%). In 31 of 34 (91.2%) fetuses with extrasystoles during labor and delivery, the conduction pattern normalized within 3 days. Five neonates were referred for evaluation by a pediatric cardiologist. Two cases had congenital heart disease. Extrasystoles persisted until labor and delivery more frequently in male fetuses (P < 0.0001). CONCLUSION: Hepatic venous Doppler can differentiate between SVES and VES. Despite being the more uncommon of the two, VES persists throughout pregnancy more often. Our results strongly support the suggestion that extrasystoles are a benign finding, with very few cases developing tachycardia or having a coexisting congenital heart malformation.

Venous Doppler in the evaluation of fetal hydrops.

Objective. To examine venous blood flow velocity in different types of fetal hydrops and its value in the prediction of outcome of pregnancies. Methods. Venous Doppler sonography was performed in 100 hydropic fetuses from 15 to 37 weeks of gestation. Blood velocity was recorded in the right hepatic vein (HV), the ductus venosus (DV) and in the intra-abdominal part of the umbilical vein (UV). Blood velocity indices were calculated and pulsations in the umbilical vein noted and grouped into a single, double or triple flow pattern. Blood velocity was related to cause of hydrops. Results. Mortality was noted in 51 cases of which 19 were by termination of pregnancy. Mortality in the 30 with normal venous blood velocity was 35%, but 58% in cases of abnormal Doppler. Abnormal HV and DV blood velocities were recorded in 39 and 34 cases, respectively and were strongly related to mortality (P < .04 and P < .003, resp.). UV pulsations were noted in 49 fetuses and were significantly related to mortality (P < .04). Mortality and abnormal venous velocities were most frequent in the low-output hydrops group (79% and 75%, resp.). Conclusions. Abnormal venous blood velocity is related to mortality in pregnancies complicated by fetal hydrops. Venous Doppler sonography should be a part of the routine work-up of pregnancies complicated by fetal hydrops.

Ductus venosus blood flow velocity waveform in diabetic pregnancies.

OBJECTIVE: Maternal diabetes during pregnancy is associated with congenital cardiac malformations and hypertrophic cardiomyopathy. Blood flow in the ductus venosus (DV) has been postulated to reflect cardiac function. The aim of our study was to investigate if diabetic pregnancies exhibit abnormal DV hemodynamics, hence indicating changes in fetal cardiac function. METHODS: The pulsatility index of the DV (DV-PI) was analyzed retrospectively in 142 diabetic patients and compared to previously published DV-PI reference values from a non-diabetic low-risk population. DV values were then correlated with maternal glycosylated hemoglobin (HbA1c). RESULTS: DV-PI was significantly higher in pregnancies complicated by either pre-existing insulin-dependent (DM) or gestational diabetes when compared with normal reference values. Increased DV-PI values were still evident in both diabetic groups when neonates that were small-for-gestational age and neonates with pathological umbilical blood flow pattern were excluded from the analysis. In DM pregnancies a statistically significant correlation was found between DV-PI and maternal HbA1c. CONCLUSION: Diabetic pregnancies exhibit increased DV-PI values when compared to a normal low-risk pregnant population, possibly indicating a fetal cardiac effect.

The use of EEG in Alzheimer's disease, with and without scopolamine - a pilot study.

OBJECTIVE: To use multivariate statistical analysis of EEG data in order to separate EEGs of patients with Alzheimer's disease (AD) from controls. A group of individuals with mild cognitive impairment (MCI) was evaluated using the same methodology. Additionally, the effects of scopolamine on this separation are studied. METHODS: Statistical pattern recognition (SPR) is used in conjunction with information extracted from EEGs before and after administration of scopolamine. RESULTS: There was complete separation of the AD group and controls before administration of scopolamine. The separation increased after scopolamine had been given. Of the 10 MCI individuals, five seemed to belong to the AD group. Three of those progressed to AD within 1 year and one after 3 years. CONCLUSIONS: Using SPR on EEG recordings it is possible to separate AD from controls. This separation can be increased by the use of scopolamine but the medication is not a prerequisite for classification. The results indicate that SPR is useful for predicting progress of MCI to AD. SIGNIFICANCE: EEG registration is a simple and noninvasive method. If these results are confirmed in other studies, this method could be more widely applied than the highly specialized methods used today in detection of early AD.

Pulsations in the umbilical vein during labor are associated with increased risk of operative delivery for fetal distress.

OBJECTIVES: Under physiological conditions the blood flow velocity waveform in the umbilical vein (UV) has an even non-pulsating pattern. Pulsations in the UV have been described in human fetuses exposed to chronic hypoxia and heart failure. Current techniques for fetal surveillance during labor and delivery involve a risk of both over- and underestimation of fetal hypoxia. We aimed to examine whether pulsations in the UV appear in the human fetus during suspected intrapartum hypoxia, and if so whether they are associated with increased risk of operative delivery for fetal distress (ODFD). METHODS: This was a prospective double blind study including 52 normal pregnancies. A Doppler examination of the UV was performed on 26 fetuses with pathological and 26 fetuses with normal cardiotocography (CTG) during labor. Presence or absence of pulsations in the UV were noted and related to perinatal outcome. RESULTS: Pulsations in the UV were seen in eight (30.8%) of the fetuses with pathological CTG, of which six (75%) underwent ODFD. No pulsations were seen in the other 18 (69.2%) fetuses with pathological CTG and these were all delivered without ODFD. No pulsations were seen in the UV in the fetuses with normal CTG and these were all delivered without ODFD. Among the fetuses with pathological CTG, there was an increased risk of ODFD in fetuses with vs. those without pulsations in the UV (P < 0.0001). CONCLUSIONS: Pulsations in the UV can be observed in human fetuses during suspected intrapartum hypoxia and these pulsations are associated with an increased risk of ODFD. Doppler examination of the UV might give important additional information on fetal condition during labor and delivery.

Uterine and umbilical artery Doppler are comparable in predicting perinatal outcome of growth-restricted fetuses.

OBJECTIVE: To compare umbilical and uterine artery Doppler in predicting outcome of pregnancies suspected of fetal growth restriction (FGR). DESIGN: A prospective study included 353 singleton pregnancies complicated by an FGR fetus. SETTING: University Hospital setting. SAMPLE: Pregnancies suspected of FGR diagnosed by ultrasound fetal biometry during a 5-year period. MAIN OUTCOME MEASURE: Perinatal outcome in relation to uterine and umbilical artery Doppler. METHODS: The women underwent Doppler examination of the umbilical and uterine arteries. Results from the uterine, but not the umbilical artery, were blind to the woman and managing obstetrician. The Doppler results were related to perinatal outcomes including small for gestational age newborns, caesarean delivery, premature delivery (<37 weeks of gestation) and admission of the newborn to a neonatal intensive care unit. RESULTS: Abnormal uterine artery Doppler velocimetry was seen in 120 (33.4%) pregnancies and abnormal umbilical artery Doppler in 102 (28.4%). There was a statistically significant correlation between abnormal Doppler of both the umbilical and uterine arteries and adverse outcome of pregnancy. The two vessels were comparable in predicting adverse outcome. Women with normal umbilical artery Doppler (251) were analysed separately. Abnormal uterine artery Doppler, seen in 61 (24.3%) of those women, showed a statistically significant correlation for adverse outcome of pregnancy. CONCLUSIONS: Doppler examinations of the uterine and/or the umbilical arteries seem to be comparable as predictors of outcome in pregnancies complicated by FGR. Including uterine artery Doppler in the surveillance of growth-restricted fetuses might detect a group of pregnancies at high risk, even though the umbilical artery Doppler was normal.

Risk factors and outcome in ICU-acquired infections.

BACKGROUND: Nosocomial infections are common in intensive care units (ICU). The objectives of this study were to determine risk factors of ICU-acquired infections, and potential mortality attributable to such infections. METHODS: An observational study was performed in a 10-bed multidisciplinary ICU. For a period of 27 months, all patients admitted for >or=48 h were included. Infections were diagnosed according to Centers for Disease Control and Prevention definitions. Airway colonization was explored by molecular typing. Risk factors for infection were determined by multivariable logistic regression. Survival was analyzed with time-varying proportional hazards regression. RESULTS: Of 278 patients, 81 (29%) were infected: urinary tract infections in 39 patients (14%), primary bloodstream infections in 25 (9%), surgical site infections in 22 (8%) and pneumonia in 21 (8%). Of the total of 147 episodes, Gram-negative bacilli were isolated in 90, Gram-positive cocci in 49 and Candida sp. in 25. Risk factors for pneumonia were mechanical ventilation [odds ratio (OR=7.9, CI 1.8-35), lack of enteral nutriment (OR=8.0, CI 1.4-45) and length of time at risk (OR=1.8, CI 1.2-2.8), while gastric acid inhibitors did not affect the risk (OR=0.99, CI 0.32-3.0). Transmission of bacteria from the stomach to the airway was not confirmed. The risk of death was increased as patients were infected with pneumonia [hazard ratio (HR)=3.6; CI: 1.6-8.1], or primary bloodstream infection (HR=2.5; CI: 1.2-5.4), independent of age and disease severity. CONCLUSIONS: Mortality was increased by ICU-acquired pneumonia and primary bloodstream infections. Our findings did not support the gastro-pulmonary hypothesis of ICU-acquired pneumonia. The proposition that blood transfusions increase the risk of ICU-acquired nosocomial infections was not supported.

Inflammatory cytokines in relation to adrenal response following total hip replacement.

Our objective was to investigate the initiation and course of pro- and anti-inflammatory cytokines in early inflammatory response and to elucidate the cytokine system in relation to the adrenal response caused by stress. Seven blood samples were collected, pre- and postoperatively (0-72 h) after total hip replacement (THR) due to osteoarthritis. The following cytokines were measured using Cytometric Bead Array: interleukin-1beta (IL-1beta), IL-6, tumour necrosis factor-alpha, IL-8, IL-12 and IL-10 (B&D). Thirteen patients took part in the study (67 +/- 9 years). C-reactive protein increased from <6 to over 200 mg/l on the second post-op day. The concentration of IL-6 increased 10-fold just 3 h post-op (4-47 pg/ml) and reached its maximum value 6 h post-op (77 pg/ml; Wilcoxon test P < 0.01) Repeated measurements were also significant (Friedman P < 0.05). The concentration of IL-8 doubled the day of surgery but did not reach a significant level (Friedman test =0.069). None of the other cytokines showed any significant changes. The diurnal cortisol rhythm was interrupted after the surgery and there was a significant correlation between the cortisol secretion and IL-6 response. This study demonstrates an isolated elevation in IL-6 levels with only a minor elevation in IL-8 following THR. This pro-inflammatory response seemed to decline without activation of anti-inflammatory cytokines (IL-10), but cortisol seemed to play a complicated role in halting the acute inflammatory response.

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

OBJECTIVES: 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. METHODS: 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. RESULTS: 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. CONCLUSIONS: 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.

Evaluation of third trimester uterine artery flow velocity indices in relationship to perinatal complications.

OBJECTIVE: Uterine artery Doppler is becoming a routine part of pregnancy surveillance in high-risk pregnancies. Which blood flow velocity waveform index to measure is debated and the 'notch' in early diastole is not widely accepted, as it is a subjective measure. The aim of the present study was to evaluate the different indices in the prediction of adverse outcome of pregnancies suspected for intrauterine fetal growth restriction (IUGR). METHODS: Uterine artery blood flow was recorded in 217 pregnancies admitted for Doppler ultrasound surveillance due to suspected IUGR. The median gestational age at examination was 38 weeks (range 25-42 weeks). Only cases having bilateral uterine artery notching were included in the evaluation. The uterine artery Doppler spectrum was analyzed for different indices, including evaluation of notch and end-diastolic velocities. Umbilical artery Doppler velocimetry was also performed. The outcome variables chosen were: a small-for-gestational-age (SGA) newborn, preterm birth, and abdominal delivery. ROC-curve calculations were used to compare the different indices. RESULTS: The uterine artery blood velocity pulsatility index (PI) and resistance indices (RI) were the best predictors of adverse outcome of pregnancy. Apart from premature birth, the systolic/end-diastolic ratio was less predictive of adverse outcome. The indices including only diastolic blood velocities were the least predictive of adverse outcome. The group with notch velocity above end-diastolic velocity was compared with those having notch velocity below the end-diastolic velocity. No difference in outcome was seen between the two groups. CONCLUSIONS: RI and PI as measures of third trimester utero-placental vascular impedance are the best predictors of adverse outcome of IUGR-suspected pregnancies.

Polymorphism of PRNP codons in the normal Icelandic population.

OBJECTIVES: Polymorphisms in the prion protein gene in humans influence susceptibility to, and phenotype of, prion diseases. Methionine-methionine (MM) homozygosity at codon 129 is a risk factor for sporadic Creutzfeldt-Jakob disease (CJD). Polymorphism at codon 117 and changes in the octapeptide repeat region have been associated with genetic CJD. Knowledge of genetic background in normal populations may contribute to better understanding of prion diseases. MATERIALS AND METHODS: Polymorphism at codon 129, codon 117 and deletions of octapetide repeats were studied in 208 healthy blood donors of both genders and of different age. RESULTS: Polymorphism at codon 129 was: MM 46.6%, methionine-valine 44.7%, valine-valine 8.7%. Polymorphism at codon 117 was observed in 4.8%. Deletions of octapeptide repeats were not detected. There were no gender or age differences in the distribution of codon 129 polymorphism. The frequency of codon 129 polymorphisms was, with one exception, not significantly different from that observed elsewhere in Europe.

Increased uterine artery vascular impedance is related to adverse outcome of pregnancy but is present in only one-third of late third-trimester pre-eclamptic women.

OBJECTIVE: Signs of increased uterine artery vascular impedance in mid-gestation are strongly related to pre-eclampsia later in pregnancy. Whether this is true for the late third trimester is, however, unclear. The aim of the present study was to analyze the frequency of increased uterine artery vascular impedance in the third trimester, and its relationship to abnormal umbilical artery Doppler and adverse outcome of pregnancy. METHODS: This was a retrospective study of uterine and umbilical artery Doppler velocimetry in 570 pregnancies complicated by pre-eclampsia. The managing clinician was informed only about the umbilical artery flow. The Doppler recordings were related to severity of pre-eclampsia, prematurity, fetal growth restriction, and rates of Cesarean section and admission to neonatal intensive care. RESULTS: Increased umbilical artery vascular impedance was seen in 59 cases (10.4%), seven having absent or reversed end-diastolic flow. Uterine artery notching was seen in 145 cases (25%), 88 (15%) having bilateral notches. Either increased uterine artery pulsatility index (PI) or notching, or both, were seen in 207 women (36.3%). In 108 women with severe pre-eclampsia, 38 (35.2%) had uterine artery notching. Signs of increased uteroplacental vascular impedance were more common in severe than in mild pre-eclampsia (57.4% vs. 31.4%), in premature than in term pregnancies (70.9% vs. 28.4%), and were more prevalent than abnormality in the umbilical artery (36.3% vs. 10.4%). CONCLUSION: Only one-third of pre-eclamptic cases showed signs of increased uterine artery vascular impedance in the third trimester. However, signs of increased vascular impedance were much more frequent in the uterine than in the umbilical arteries and were strongly related to adverse outcome of pregnancy.

Acute changes of cerebral venous blood flow in growth-restricted human fetuses in response to uterine contractions.

OBJECTIVE: The fetal cerebral venous circulation during acute hypoxic stress provoked by uterine contractions has not been studied previously. The aim of this study was to explore the cerebral venous circulation during an oxytocin challenge test (OCT) in intrauterine growth-restricted (IUGR) fetuses. METHODS: Doppler recordings of blood flow in the vein of Galen (GV), straight sinus (SS) and transverse sinus (TS) before and during uterine contractions and relaxation were obtained at the same time as electronic fetal heart rate (FHR) monitoring in 44 term IUGR fetuses. The OCT was classified as negative (normal FHR) or positive (late FHR decelerations). Non-parametric statistics were used to test differences between OCT groups. RESULTS: In OCT-negative cases (n = 39), de novo pulsations occurred in the GV, and SS flow velocities increased during contractions compared with basal measurements. There were no significant differences in TS flow. Flow recordings were less often obtained from OCT-positive cases (n = 5), making comparisons with OCT-negative cases uncertain. CONCLUSIONS: In uncompromised IUGR fetuses an acute cerebral venous hyperperfusion develops in response to uterine contractions. Pulsations in the GV are detected but are unlikely to be an ominous sign in this situation. The more centrally located TS was less discriminating for acute cerebral venous blood flow changes.