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BACKGROUND: Although fetal size is associated with adverse perinatal outcome, the relationship between fetal growth velocity and adverse perinatal outcome is unclear. OBJECTIVE: This study aimed to evaluate the relationship between fetal growth velocity and signs of cerebral blood flow redistribution, and their association with birthweight and adverse perinatal outcome. STUDY DESIGN: This study was a secondary analysis of the TRUFFLE-2 multicenter observational prospective feasibility study of fetuses at risk of fetal growth restriction between 32+0 and 36+6 weeks of gestation (n=856), evaluated by ultrasound biometry and umbilical and middle cerebral artery Doppler. Individual fetal growth velocity was calculated from the difference of birthweight and estimated fetal weight at 3, 2, and 1 week before delivery, and by linear regression of all available estimated fetal weight measurements. Fetal estimated weight and birthweight were expressed as absolute value and as multiple of the median for statistical calculation. The coefficients of the individual linear regression of estimated fetal weight measurements (growth velocity; g/wk) were plotted against the last umbilical-cerebral ratio with subclassification for perinatal outcome. The association of these measurements with adverse perinatal outcome was assessed. The adverse perinatal outcome was a composite of abnormal condition at birth or major neonatal morbidity. RESULTS: Adverse perinatal outcome was more frequent among fetuses whose antenatal growth was <100 g/wk, irrespective of signs of cerebral blood flow redistribution. Infants with birthweight <0.65 multiple of the median were enrolled earlier, had the lowest fetal growth velocity, higher umbilical-cerebral ratio, and were more likely to have adverse perinatal outcome. A decreasing fetal growth velocity was observed in 163 (19%) women in whom the estimated fetal weight multiple of the median regression coefficient was <-0.025, and who had higher umbilical-cerebral ratio values and more frequent adverse perinatal outcome; 67 (41%; 8% of total group) of these women had negative growth velocity. Estimated fetal weight and umbilical-cerebral ratio at admission and fetal growth velocity combined by logistic regression had a higher association with adverse perinatal outcome than any of those parameters separately (relative risk, 3.3; 95% confidence interval, 2.3-4.8). CONCLUSION: In fetuses at risk of late preterm fetal growth restriction, reduced growth velocity is associated with an increased risk of adverse perinatal outcome, irrespective of signs of cerebral blood flow redistribution. Some fetuses showed negative growth velocity, suggesting catabolic metabolism.
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Retardo do Crescimento Fetal , Peso Fetal , Recém-Nascido , Lactente , Gravidez , Feminino , Humanos , Masculino , Peso ao Nascer/fisiologia , Retardo do Crescimento Fetal/diagnóstico , Estudos Prospectivos , Artérias Umbilicais/fisiologia , Desenvolvimento Fetal , Feto , Redução de Peso , Ultrassonografia Pré-Natal , Ultrassonografia DopplerRESUMO
PURPOSE: To investigate the effects of the antenatal administration of betamethasone on fetal Doppler and short term fetal heart rate variation (CTG-STV) in early growth restricted (FGR) fetuses. MATERIALS AND METHODS: Post hoc analysis of data derived from the TRUFFLE study, a prospective, multicenter, randomized management trial of severe early onset FGR. Repeat Doppler and CTG-STV measurements between the last recording within 48 hours before the first dose of betamethasone (baseline value) and for 10 days after were evaluated. Multilevel analysis was performed to analyze the longitudinal course of the umbilico-cerebral ratio (UC ratio), the ductus venosus pulsatility index (DVPIV) and CTG-STV. RESULTS: We included 115 fetuses. A significant increase from baseline in CTG-STV was found on day +â1 (pâ=â0.019) but no difference thereafter. The DVPIV was not significantly different from baseline in any of the 10 days following the first dose of betamethasone (pâ=â0.167). Multilevel analysis revealed that, over 10 days, the time elapsed from antenatal administration of betamethasone was significantly associated with a decrease in CTG-STV (pâ=â0.045) and an increase in the DVPIV (pâ=â0.001) and UC ratio (pâ<â0.001). CONCLUSION: Although steroid administration in early FGR has a minimal effect on increasing CTG-STV one day afterwards, the effects on Doppler parameters were extremely slight with regression coefficients of small magnitude suggesting no clinical significance, and were most likely related to the deterioration with time in FGR. Hence, arterial and venous Doppler assessment of fetal health remains informative following antenatal steroid administration to accelerate fetal lung maturation.
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Betametasona , Cardiotocografia , Retardo do Crescimento Fetal , Glucocorticoides , Frequência Cardíaca Fetal , Ultrassonografia Pré-Natal , Betametasona/farmacologia , Feminino , Retardo do Crescimento Fetal/diagnóstico por imagem , Coração Fetal , Feto , Glucocorticoides/farmacologia , Humanos , Gravidez , Resultado da Gravidez , Estudos ProspectivosRESUMO
BACKGROUND: The mechanism underlying fetal-placental Doppler index changes in preeclampsia and/or fetal growth restriction are unknown, although both are associated with maternal cardiovascular dysfunction. OBJECTIVE: We sought to investigate whether there was a relationship between maternal cardiac output and vascular resistance and fetoplacental Doppler findings in healthy and complicated pregnancy. STUDY DESIGN: Women with healthy pregnancies (n=62), preeclamptic pregnancies (n=13), preeclamptic pregnancies with fetal growth restriction (n=15), or fetal growth restricted pregnancies (n=17) from 24-40 weeks gestation were included. All of them underwent measurement of cardiac output with the use of an inert gas rebreathing technique and derivation of peripheral vascular resistance. Uterine and fetal Doppler indices were recorded; the latter were z scored to account for gestation. Associations were determined by polynomial regression analyses. RESULTS: Mean uterine artery pulsatility index was higher in fetal growth restriction (1.37; P=.026) and preeclampsia+fetal growth restriction (1.63; P=.001) but not preeclampsia (0.92; P=1) compared with control subjects (0.8). There was a negative relationship between uterine pulsatility index and cardiac output (r2=0.101; P=.025) and umbilical pulsatility index z score and cardiac output (r2=0.078; P=.0015), and there were positive associations between uterine pulsatility index and peripheral vascular resistance (r2=0.150; P=.003) and umbilical pulsatility index z score and peripheral vascular resistance (r2= 0.145; P=.001). There was no significant relationship between cardiac output and peripheral vascular resistance with cerebral Doppler indices. CONCLUSION: Uterine artery Doppler change is abnormally elevated in fetal growth restriction with and without preeclampsia, but not in preeclampsia, which may explain the limited sensitivity of uterine artery Doppler changes for all these complications when considered in aggregate. Furthermore, impedance within fetoplacental arterial vessels is at least, in part, associated with maternal cardiovascular function. This relationship may have important implications for fetal surveillance and would inform therapeutic options in those pathologic pregnancy conditions currently, and perhaps erroneously, attributed purely to placental maldevelopment. Uterine and fetal placental Doppler indices are associated significantly with maternal cardiovascular function. The classic description of uterine and fetal Doppler changes being initiated by placental maldevelopment is a less plausible explanation for the pathogenesis of the conditions than that relating to maternal cardiovascular changes.
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Débito Cardíaco/fisiologia , Desenvolvimento Fetal/fisiologia , Retardo do Crescimento Fetal/etiologia , Placenta/diagnóstico por imagem , Pré-Eclâmpsia/etiologia , Artéria Uterina/diagnóstico por imagem , Adulto , Doenças Cardiovasculares/diagnóstico por imagem , Doenças Cardiovasculares/etiologia , Doenças Cardiovasculares/fisiopatologia , Estudos de Coortes , Feminino , Retardo do Crescimento Fetal/diagnóstico por imagem , Idade Gestacional , Testes de Função Cardíaca , Humanos , Recém-Nascido Pequeno para a Idade Gestacional , Saúde Materna , Placenta/irrigação sanguínea , Circulação Placentária/fisiologia , Pré-Eclâmpsia/diagnóstico por imagem , Gravidez , Estudos Prospectivos , Fluxo Pulsátil/fisiologia , Valores de Referência , Medição de Risco , Ultrassonografia Doppler , Ultrassonografia Pré-NatalRESUMO
BACKGROUND: Phase-rectified signal averaging, an innovative signal processing technique, can be used to investigate quasi-periodic oscillations in noisy, nonstationary signals that are obtained from fetal heart rate. Phase-rectified signal averaging is currently the best method to predict survival after myocardial infarction in adult cardiology. Application of this method to fetal medicine has established significantly better identification than with short-term variation by computerized cardiotocography of growth-restricted fetuses. OBJECTIVE: The aim of this study was to determine the longitudinal progression of phase-rectified signal averaging indices in severely growth-restricted human fetuses and the prognostic accuracy of the technique in relation to perinatal and neurologic outcome. STUDY DESIGN: Raw data from cardiotocography monitoring of 279 human fetuses were obtained from 8 centers that took part in the multicenter European "TRUFFLE" trial on optimal timing of delivery in fetal growth restriction. Average acceleration and deceleration capacities were calculated by phase-rectified signal averaging to establish progression from 5 days to 1 day before delivery and were compared with short-term variation progression. The receiver operating characteristic curves of average acceleration and deceleration capacities and short-term variation were calculated and compared between techniques for short- and intermediate-term outcome. RESULTS: Average acceleration and deceleration capacities and short-term variation showed a progressive decrease in their diagnostic indices of fetal health from the first examination 5 days before delivery to 1 day before delivery. However, this decrease was significant 3 days before delivery for average acceleration and deceleration capacities, but 2 days before delivery for short-term variation. Compared with analysis of changes in short-term variation, analysis of (delta) average acceleration and deceleration capacities better predicted values of Apgar scores <7 and antenatal death (area under the curve for prediction of antenatal death: delta average acceleration capacity, 0.62 [confidence interval, 0.19-1.0]; delta short-term variation, 0.54 [confidence interval, 0.13-0.97]; P=.006; area under the curve for prediction Apgar <7: average deceleration capacity <24 hours before delivery, 0.64 [confidence interval, 0.52-0.76]; short-term variation <24 hours before delivery, 0.53 [confidence interval, 0.40-0.65]; P=.015). Neither phase-rectified signal averaging indices nor short-term variation showed predictive power for developmental disability at 2 years of age (Bayley developmental quotient, <95 or <85). CONCLUSION: The phase-rectified signal averaging method seems to be at least as good as short-term variation to monitor progressive deterioration of severely growth-restricted fetuses. Our findings suggest that for short-term outcomes such as Apgar score, phase-rectified signal averaging indices could be an even better test than short-term variation. Overall, our findings confirm the possible value of prospective trials based on phase-rectified signal averaging indices of autonomic nervous system of severely growth-restricted fetuses.
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Cardiotocografia/métodos , Retardo do Crescimento Fetal/diagnóstico , Frequência Cardíaca Fetal/fisiologia , Processamento de Sinais Assistido por Computador , Adulto , Índice de Apgar , Deficiências do Desenvolvimento/diagnóstico , Deficiências do Desenvolvimento/etiologia , Feminino , Retardo do Crescimento Fetal/fisiopatologia , Humanos , Recém-Nascido , Estudos Longitudinais , Masculino , Valor Preditivo dos Testes , Gravidez , Prognóstico , Curva ROCRESUMO
The key determinant to a fetus maintaining its health is through adequate perfusion and oxygen transfer mediated by the functioning placenta. When this equilibrium is distorted, a number of physiological changes, including reduced fetal growth, occur to favor survival. Technologies have been developed to monitor these changes with a view to prolong intrauterine maturity while reducing the risks of stillbirth. Many of these strategies involve complex interpretation, for example Doppler ultrasound for fetal blood flow and computerized analysis of fetal heart rate changes. However, even with these modalities of fetal assessment to determine the optimal timing of delivery, fetal movements remain integral to clinical decision-making. In high-risk cohorts with fetal growth restriction, the manifestation of a reduction in perceived movements may warrant an expedited delivery. Despite this, there has been little evolution in the development of technologies to objectively evaluate fetal movement behavior for clinical application. This review explores the available literature on the value of fetal movement analysis as a method of assessing fetal wellbeing, and demonstrates how interdisciplinary developments in this area may aid in the improvement of clinical outcomes.
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Monitorização Fetal/métodos , Movimento Fetal , Adaptação Fisiológica , Cardiotocografia , Feminino , Retardo do Crescimento Fetal/fisiopatologia , Hipóxia Fetal/diagnóstico , Frequência Cardíaca Fetal , Humanos , Gravidez , Resultado da Gravidez , Natimorto , Ultrassonografia Doppler , Ultrassonografia Pré-NatalRESUMO
BACKGROUND: Preeclampsia continues to be a prevalent pregnancy complication and underlying mechanisms remain controversial. A common feature of preeclampsia is utero-placenta hypoxia. In contrast to the impact of hypoxia on the placenta and fetus, comparatively little is known about the maternal physiology. METHODS: We adopted an integrative approach to investigate the inter-relationship between chronic hypoxia during pregnancy with maternal, placental, and fetal outcomes, common in preeclampsia. We exploited a novel technique using isobaric hypoxic chambers and in vivo continuous cardiovascular recording technology for measurement of blood pressure in sheep and studied the placental stress in response to hypoxia at cellular and subcellular levels. RESULTS: Chronic hypoxia in ovine pregnancy promoted fetal growth restriction (FGR) with evidence of fetal brain-sparing, increased placental hypoxia-mediated oxidative damage, and activated placental stress response pathways. These changes were linked with dilation of the placental endoplasmic reticulum (ER) cisternae and increased placental expression of the antiangiogenic factors sFlt-1 (soluble fms-like tyrosine kinase 1) and sEng (soluble endoglin), combined with a shift towards an angiogenic imbalance in the maternal circulation. Chronic hypoxia further led to an increase in uteroplacental vascular resistance and the fall in maternal blood pressure with advancing gestation measured in normoxic pregnancy did not occur in hypoxic pregnancy. CONCLUSIONS: Therefore, we show in an ovine model of sea-level adverse pregnancy that chronic hypoxia recapitulates physiological and molecular features of preeclampsia in the mother, placenta, and offspring.
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Pré-Eclâmpsia , Animais , Biomarcadores/metabolismo , Feminino , Humanos , Hipóxia/metabolismo , Mães , Placenta/metabolismo , Fator de Crescimento Placentário , Gravidez , Ovinos , Receptor 1 de Fatores de Crescimento do Endotélio VascularRESUMO
OBJECTIVE: To investigate the relationship between the difference in estimated fetal weight and birthweight at or close to term, and in relation to Doppler parameters. STUDY DESIGN: A cohort study of all term singleton pregnancies who underwent an ultrasound within two weeks of delivery after 36 weeks at one institution in one calendar year. When available, Doppler measurements of umbilical and middle cerebral artery pulsatility index were recorded. Data were analysed by Pearson rank correlation. RESULTS: Of 8517 eligible deliveries, 885 women had an ultrasound scan within 2 weeks of delivery. Mean daily differences between estimated fetal weight and birth weight were: those born <10th percentile lost 26 g per day (95 % CI -36 to -16), 10-50th percentile gained 7 g per day (95 % CI -2 to 15), 50th-90th percentile gained 27 g per day (95 % CI 19-35) and >90th percentile gained 48 g per day (95 % CI 32-64). There was a negative correlation between umbilical: middle cerebral artery pulsatility index and the change in weight per day (n = 348, p = 0.001, r = 0.17). CONCLUSIONS: Difference in the estimated fetal weight and birthweight, expressed as grams growth per day, is proportional to the birthweight percentile. Fetuses with a birthweight >10th percentile gain weight, while those with a birthweight <10th percentile apparently decline in weight between their final ultrasound estimated fetal weight and delivery. In babies with the smallest or apparent negative weight gain there was an association with Doppler parameters that signified hypoxia indicating fetal growth at term may be restricted by impaired placental function. Estimated fetal weight may be a poor predictor of birthweight for reasons other than ultrasound or algorithmic error.
Assuntos
Peso Fetal , Artérias Umbilicais , Peso ao Nascer , Estudos de Coortes , Feminino , Retardo do Crescimento Fetal/diagnóstico por imagem , Feto , Idade Gestacional , Humanos , Recém-Nascido , Recém-Nascido Pequeno para a Idade Gestacional , Gravidez , Ultrassonografia Pré-Natal , Artérias Umbilicais/diagnóstico por imagemRESUMO
OBJECTIVE: To investigate and compare the effect of simulator training on quantitative scores for ultrasound-related skills for trainees with novice level ultrasound experience and expert ultrasound operators. METHODS: Three novice (comprising of 11, 32, 23 participants) and one expert (10 participants) subgroups undertook an ultrasound simulation training session. Pre- and post-training test scores were collected for each subgroup. Outcome measures were as follows: mean accuracy score for obtaining the correct anatomical plane, percentage of correctly acquired target planes, mean number of movements, time to achieve image, distance travelled by probe and accumulated angling of the probe. RESULTS: The novices showed improvement in image acquisition after completion of the simulation training session with an improvement in the rate of correctly acquired target planes from 28-57% to 39-83%. This was not replicated in the experts. The novice's individual ratios based on pre- vs. post-training metrics improved between 1.7- and 4.3-fold for number of movements, 1.9- and 6.7-fold for distance, 2.0- and 5.2-fold for time taken and 1.8- and 7.3-fold for accumulated angling. Among the experts, there was no relationship between pre-training simulator metrics and years of ultrasound experience. CONCLUSIONS: The individual simulation metrics suggest the sessions were delivered at an appropriate level for basic training as novice trainees were able to show demonstrable improvements in both efficiency and accuracy on the simulator. Experts did not improve after the simulation modules, and the novice scores post-training were similar to those of experts, suggesting the exercises were valid in testing ultrasound skills at novice but not expert level.
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A cohort study of 6,500,000 human pregnancies showed an increased risk of adverse fetal outcomes following abdominal but not non-abdominal surgery under general anesthesia. This may be the consequence of uterine handling during abdominal surgery. However, there are no data on any effects on the cardiometabolic physiology of the fetus or mother in response to uterine manipulation in otherwise healthy pregnancy. Consequently, 9 sheep in late gestation were anesthetized with isofluorane and maternal and fetal catheters and flow probes were implanted to determine cardiovascular and metabolic changes during uterine handling. Uterine handling led to an acute increase in uterine artery vascular resistance, fetal peripheral vasoconstriction, a reduction in oxygen delivery to the femoral circulation, worsening fetal acidosis. There was no evidence of systemic fetal hypoxia, or changes in fetal heart rate, carotid blood flow or carotid oxygen delivery. Therefore, the data support that uterine handling during abdominal surgery under general anesthesia can impact adversely on fetal cardiometabolic health. This may provide a potential explanation linking adverse fetal outcomes in abdominal compared with non-abdominal surgery during pregnancy. The data have important implications for human fetal surgery where the uterus is handled, as operative procedures during late gestation under general maternal anesthesia become more prevalent.
Assuntos
Anestesia Geral/métodos , Sistema Cardiovascular/fisiopatologia , Doenças Fetais/fisiopatologia , Hipóxia Fetal/fisiopatologia , Útero/irrigação sanguínea , Resistência Vascular , Anestesia Geral/efeitos adversos , Animais , Feminino , Cuidados Intraoperatórios , Gravidez , Fluxo Sanguíneo Regional , Ovinos , Útero/cirurgiaRESUMO
In mammals, pregnancy complicated by chronic hypoxia can program hypertension in the adult offspring. However, mechanisms remain uncertain because the partial contributions of the challenge on the placenta, mother, and fetus are difficult to disentangle. Here, we used chronic hypoxia in the chicken embryo-an established model system that permits isolation of the direct effects of developmental hypoxia on the cardiovascular system of the offspring, independent of additional effects on the mother or the placenta. Fertilized chicken eggs were exposed to normoxia (N; 21% O2) or hypoxia (H; 13.5%-14% O2) from the start of incubation (day 0) until day 19 (hatching, ≈day 21). Following hatching, all birds were maintained under normoxic conditions until ≈6 months of adulthood. Hypoxic incubation increased hematocrit (+27%) in the chicken embryo and induced asymmetrical growth restriction (body weight, -8.6%; biparietal diameter/body weight ratio, +7.5%) in the hatchlings (all P<0.05). At adulthood (181±4 days), chickens from hypoxic incubations remained smaller (body weight, -7.5%) and showed reduced basal and stimulated in vivo NO bioavailability (pressor response to NG-nitro-L-arginine methyl ester, -43%; phenylephrine pressor response during NO blockade, -61%) with significant hypertension (mean arterial blood pressure, +18%), increased cardiac work (ejection fraction, +12%; fractional shortening, +25%; enhanced baroreflex gain, +456%), and left ventricular wall thickening (left ventricular wall volume, +36%; all P<0.05). Therefore, we show that chronic hypoxia can act directly on a developing embryo to program hypertension, cardiovascular dysfunction, and cardiac wall remodeling in adulthood in the absence of any maternal or placental effects.
Assuntos
Coração/fisiopatologia , Hipertensão/etiologia , Hipóxia/complicações , Animais , Sistema Cardiovascular/fisiopatologia , Galinhas , Feminino , Hipertensão/fisiopatologia , Hipóxia/fisiopatologia , Estresse Oxidativo/fisiologia , GravidezRESUMO
The hypoxic fetus is at greater risk of cardiovascular demise during a challenge, but the reasons behind this are unknown. Clinically, progress has been hampered by the inability to study the human fetus non-invasively for long period of gestation. Using experimental animals, there has also been an inability to induce gestational hypoxia while recording fetal cardiovascular function as the hypoxic pregnancy is occurring. We use novel technology in sheep pregnancy that combines induction of controlled chronic hypoxia with simultaneous, wireless recording of blood pressure and blood flow signals from the fetus. Here, we investigated the cardiovascular defense of the hypoxic fetus to superimposed acute hypotension. Pregnant ewes carrying singleton fetuses surgically prepared with catheters and flow probes were randomly exposed to normoxia or chronic hypoxia from 121±1 days of gestation (term ≈145 days). After 10 days of exposure, fetuses were subjected to acute hypotension via fetal nitroprusside intravenous infusion. Underlying in vivo mechanisms were explored by (1) analyzing fetal cardiac and peripheral vasomotor baroreflex function; (2) measuring the fetal plasma catecholamines; and (3) establishing fetal femoral vasoconstrictor responses to the α1-adrenergic agonist phenylephrine. Relative to controls, chronically hypoxic fetal sheep had reversed cardiac and impaired vasomotor baroreflex function, despite similar noradrenaline and greater adrenaline increments in plasma during hypotension. Chronic hypoxia markedly diminished the fetal vasopressor responses to phenylephrine. Therefore, we show that the chronically hypoxic fetus displays markedly different cardiovascular responses to acute hypotension, providing in vivo evidence of mechanisms linking its greater susceptibility to superimposed stress.
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Barorreflexo/fisiologia , Hipóxia Fetal/fisiopatologia , Hipotensão/fisiopatologia , Resistência Vascular/fisiologia , Vasoconstrição/fisiologia , Agonistas de Receptores Adrenérgicos alfa 1/farmacologia , Animais , Catecolaminas/sangue , Feminino , Hipóxia Fetal/sangue , Hemodinâmica , Hipotensão/sangue , Hipotensão/induzido quimicamente , Nitroprussiato , Fenilefrina/farmacologia , Fluxo Sanguíneo Regional/efeitos dos fármacos , Fluxo Sanguíneo Regional/fisiologia , Ovinos , Resistência Vascular/efeitos dos fármacos , Vasoconstrição/efeitos dos fármacosRESUMO
INTRODUCTION: Data on the outcomes of early-onset twin-twin transfusion syndrome (TTTS), diagnosed before 18 weeks gestational age (GA), are sparse. We aimed to review the diagnosis, management and outcomes of early-onset TTTS. MATERIAL AND METHODS: Pregnancy records at a single referral unit 2010-6 were reviewed. In early-onset TTTS cases, data for pregnancy characteristics, interventions and outcomes were collected. PubMed and Scopus databases were searched for studies including pregnant women with early-onset TTTS. The primary outcome measure was livebirths. RESULTS: Case series: 58 cases of early-onset TTTS 2010-6, with full outcome data in 44. Diagnostic criteria were variable. Median GA at intervention was 17+4 (range 15+0-28+1); 67% of patients had laser therapy (39/58). Overall survival: 60% (53/88). At least one livebirth: 86% (38/44), Two livebirths: 34% (15/44); No survivors: 14% (6/44). GA at delivery was 32+1.5 (range 16+2-37+4). Systematic review: 16 studies included (n = 171 pregnancies). Diagnostic criteria varied widely: 79% of studies used Quintero staging. Most offered laser (89%) at median 17+0 weeks (range 16+0-21+6). GA at delivery was 23+0-39+5 weeks. Overall survival: 69% (129/186). At least one livebirth: 74% (127/171). Two livebirths: 59% (55/93). No survivors: 26% (44/171). CONCLUSIONS: In comparison with the commonly accepted overall survival for TTTS treated after 18 weeks of 60-90%, outcomes in early-onset TTTS were at the lower bound of this range. Gestational age at intervention is similar to that of later onset TTTS, indicating a lack of therapeutic options when a diagnosis is made before 18 weeks.
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High-intensity focused ultrasound (HIFU) is a non-invasive method of selective placental vascular occlusion, providing a potential therapy for conditions such as twin-twin transfusion syndrome. In order to translate this technique into human studies, evidence of prolonged fetal recovery and maintenance of a healthy fetal physiology following exposure to HIFU is essential. At 116 ± 2 days gestation, 12 pregnant ewes were assigned to control ( n = 6) or HIFU vascular occlusion ( n = 6) groups and anaesthetized. Placental blood vessels were identified using colour Doppler ultrasound; HIFU-mediated vascular occlusion was performed through intact maternal skin (1.66 MHz, 5 s duration, in situ ISPTA 1.8-3.9 kW cm-2). Unidentifiable colour Doppler signals in targeted vessels following HIFU exposure denoted successful occlusion. Ewes and fetuses were then surgically instrumented with vascular catheters and transonic flow probes and recovered from anaesthesia. A custom-made wireless data acquisition system, which records continuous maternal and fetal cardiovascular data, and daily blood sampling were used to assess wellbeing for 20 days, followed by post-mortem examination. Based on a comparison of pre- and post-treatment colour Doppler imaging, 100% (36/36) of placental vessels were occluded following HIFU, and occlusion persisted for 20 days. All fetuses survived. No differences in maternal or fetal blood pressure, heart rate, heart rate variability, metabolic status or oxygenation were observed between treatment groups. There was evidence of normal fetal maturation and no evidence of chronic fetal stress. There were no maternal injuries and no placental vascular haemorrhage. There was both a uterine and fetal burn, which did not result in any obstetric or fetal complications. This study demonstrates normal long-term recovery of fetal sheep from exposure to HIFU-mediated placental vascular occlusion and underlines the potential of HIFU as a potential non-invasive therapy in human pregnancy.
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Transfusão Feto-Fetal , Feto , Ablação por Ultrassom Focalizado de Alta Intensidade , Placenta , Ultrassonografia Doppler , Doenças Vasculares , Animais , Feminino , Transfusão Feto-Fetal/diagnóstico por imagem , Transfusão Feto-Fetal/fisiopatologia , Transfusão Feto-Fetal/terapia , Feto/diagnóstico por imagem , Feto/fisiopatologia , Humanos , Placenta/diagnóstico por imagem , Placenta/fisiopatologia , Gravidez , Ovinos , Doenças Vasculares/diagnóstico por imagem , Doenças Vasculares/embriologia , Doenças Vasculares/fisiopatologia , Doenças Vasculares/terapiaRESUMO
Pre-clinically, High Intensity Focused Ultrasound (HIFU) has been shown to safely and effectively occlude placental blood vessels in the acute setting, when applied through the uterus. However, further development of the technique to overcome the technical challenges of targeting and occluding blood vessels through intact skin remains essential to translation into human studies. So too does the assessment of fetal wellbeing following this procedure, and demonstration of the persistence of vascular occlusion. At 115 ± 10 d gestational age (term~147 days) 12 pregnant sheep were exposed to HIFU (n = 6), or to a sham (n = 6) therapy through intact abdominal skin (1.66 MHz, 5 s duration, in situ ISPTA 1.3-4.4 kW.cm-2). Treatment success was defined as undetectable colour Doppler signal in the target placental vessel following HIFU exposures. Pregnancies were monitored for 21 days using diagnostic ultrasound from one day before HIFU exposure until term, when post-mortem examination was performed. Placental vessels were examined histologically for evidence of persistent vascular occlusion. HIFU occluded 31/34 (91%) of placental vessels targeted, with persistent vascular occlusion evident on histological examination 20 days after treatment. The mean diameter of occluded vessels was 1.4 mm (range 0.3-3.3 mm). All pregnancies survived until post mortem without evidence of significant maternal or fetal iatrogenic harm, preterm labour, maternal or fetal haemorrhage or infection. Three of six ewes exposed to HIFU experienced abdominal skin burns, which healed without intervention within 21 days. Mean fetal weight, fetal growth velocity and other measures of fetal biometry were not affected by exposure to HIFU. Fetal Doppler studies indicated a transient increase in the umbilical artery pulsatility index (PI) and a decrease in middle cerebral artery PI as a result of general anaesthesia, which was not different between sham and treatment groups. We report the first successful application of fully non-invasive HIFU for occlusion of placental blood flow in a pregnant sheep model, with a low risk of significant complications. This proof of concept study demonstrates the potential of this technique for clinical translation.
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Hemorragia/terapia , Ablação por Ultrassom Focalizado de Alta Intensidade , Placenta/diagnóstico por imagem , Ultrassonografia Pré-Natal/métodos , Útero/diagnóstico por imagem , Animais , Velocidade do Fluxo Sanguíneo , Vasos Sanguíneos/diagnóstico por imagem , Vasos Sanguíneos/fisiopatologia , Modelos Animais de Doenças , Feminino , Feto , Hemorragia/diagnóstico por imagem , Hemorragia/fisiopatologia , Humanos , Artéria Cerebral Média/diagnóstico por imagem , Artéria Cerebral Média/fisiopatologia , Placenta/irrigação sanguínea , Placenta/fisiopatologia , Gravidez , Ovinos , Artérias Umbilicais/irrigação sanguínea , Artérias Umbilicais/diagnóstico por imagem , Artérias Umbilicais/fisiopatologia , Útero/irrigação sanguínea , Útero/fisiopatologiaRESUMO
We investigated the efficacy, maternofetal responses, and safety of using high-intensity focused ultrasound (HIFU) for noninvasive occlusion of placental vasculature compared to sham treatment in anesthetized pregnant sheep. This technique for noninvasive occlusion of placental vasculature may be translatable to the treatment of conditions arising from abnormal placental vasculature, such as twin-twin transfusion syndrome (TTTS). Eleven pregnant sheep were instrumented with maternal and fetal arterial catheters and time-transit flow probes to monitor cardiovascular, acid-base, and metabolic status, and then exposed to HIFU (n = 5) or sham (n = 6) ablation of placental vasculature through the exposed uterine surface. Placental vascular flow was occluded in 28 of 30 targets, and histological examination confirmed occlusion in 24 of 30 targets. In both HIFU and sham exposures, uterine contact reduced maternal uterine artery flow, but delivery of oxygen and glucose to the fetal brain remained normal. HIFU can consistently occlude in vivo placental vessels and ablate blood flow in a pregnant sheep model. Cardiovascular and metabolic fetal responses suggest that the technique is safe in the short term and potentially translatable to human pregnancy.
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Transfusão Feto-Fetal/cirurgia , Feto/cirurgia , Ablação por Ultrassom Focalizado de Alta Intensidade/métodos , Animais , Encéfalo/metabolismo , Feminino , Feto/metabolismo , Glucose/metabolismo , Oxigênio/metabolismo , Gravidez , OvinosRESUMO
Impetigo herpetiformis or gestational pustular psoriasis can account for 4.25% of all pregnancy dermatoses seen. Unlike other pregnancy dermatoses, it can be associated with constitutional symptoms including fever, rigors, arthralgia and complications of secondary infection and sepsis. There is an increased risk of fetal anomalies and stillbirths. A 25-year-old para 1 presented to primary care at 7 weeks gestation with a peri-umbilical rash non-responsive to topical steroids and underwent hospital admission at 31 weeks gestation with fever and a widespread painful erythematous rash. Her condition worsened despite high-dose oral steroids. With the use of cyclosporine and regular opioid analgesia over 2 weeks, her symptoms were adequately controlled. She went into spontaneous labour at 41(+2) weeks and delivered a healthy male infant. Impetigo herpetiformis can be treated first line with topical and oral steroids and supportive measures, but immunomodulatory therapies such as cyclosporine have shown success in treating resistant cases.