RESUMO
Objective.Even though the electrocardiogram (ECG) has potential to be used as a monitoring or diagnostic tool for fetuses, the use of non-invasive fetal ECG is complicated by relatively high amounts of noise and fetal movement during the measurement. Moreover, machine learning-based solutions to this problem struggle with the lack of clean reference data, which is difficult to obtain. To solve these problems, this work aims to incorporate fetal rotation correction with ECG denoising into a single unsupervised end-to-end trainable method.Approach.This method uses the vectorcardiogram (VCG), a three-dimensional representation of the ECG, as an input and extends the previously introduced Kalman-LISTA method with a Kalman filter for the estimation of fetal rotation, applying denoising to the rotation-corrected VCG.Main results.The resulting method was shown to outperform denoising auto-encoders by more than 3 dB while achieving a rotation tracking error of less than 33∘. Furthermore, the method was shown to be robust to a difference in signal to noise ratio between electrocardiographic leads and different rotational velocities.Significance.This work presents a novel method for the denoising of non-invasive abdominal fetal ECG, which may be trained unsupervised and simultaneously incorporates fetal rotation correction. This method might prove clinically valuable due the denoised fetal ECG, but also due to the method's objective measure for fetal rotation, which in turn might have potential for early detection of fetal complications.
Assuntos
Eletrocardiografia , Processamento de Sinais Assistido por Computador , Razão Sinal-Ruído , Vetorcardiografia , Vetorcardiografia/métodos , Humanos , Eletrocardiografia/métodos , Monitorização Fetal/métodos , Gravidez , Feto/fisiologia , FemininoRESUMO
OBJECTIVE: The reconstruction of an input based on a sparse combination of signals, known as sparse coding, has found widespread use in signal processing. In this work, the combination of sparse coding with Kalman filtering is explored and its potential is shown on two use-cases. METHODS: This work extends the Iterative Shrinkage and Thresholding Algorithm with a Kalman filter in the sparse domain. The resulting method may be implemented as a deep unfolded neural network and may be applied to any signal which has a sparse representation and a known or assumed relation between consecutive measurements. This method is evaluated on the use cases of noise reduction in the electrocardiogram (ECG) and the estimation of object motility. RESULTS: For ECG denoising, the proposed method achieved an improvement in Signal-to-Noise ratio of 18.6 dB, which is comparable to state-of-the-art. In motility estimation, a correlation of 0.84 with ground truth simulations was found. CONCLUSION: The proposed method was shown to have advantages over sparse coding and Kalman filtering alone. Due to the low complexity and high generalizability of the proposed method, the implementation of context-specific knowledge or an extension to other applications can be readily made. SIGNIFICANCE: The presented Kalman-ISTA algorithm is a resource-efficient method combining the promise of both sparse coding and Kalman filtering, making it well-suited for various applications.
Assuntos
Algoritmos , Eletrocardiografia , Processamento de Sinais Assistido por Computador , Razão Sinal-Ruído , Eletrocardiografia/métodos , Humanos , Movimento/fisiologiaRESUMO
Due to the association between dysfunctional maternal autonomic regulation and pregnancy complications, tracking non-invasive features of autonomic regulation derived from wrist-worn photoplethysmography (PPG) measurements may allow for the early detection of deteriorations in maternal health. However, even though a plethora of these features-specifically, features describing heart rate variability (HRV) and the morphology of the PPG waveform (morphological features)-exist in the literature, it is unclear which of these may be valuable for tracking maternal health. As an initial step towards clarity, we compute comprehensive sets of HRV and morphological features from nighttime PPG measurements. From these, using logistic regression and stepwise forward feature elimination, we identify the features that best differentiate healthy pregnant women from non-pregnant women, since these likely capture physiological adaptations necessary for sustaining healthy pregnancy. Overall, morphological features were more valuable for discriminating between pregnant and non-pregnant women than HRV features (area under the receiver operating characteristics curve of 0.825 and 0.74, respectively), with the systolic pulse wave deterioration being the most valuable single feature, followed by mean heart rate (HR). Additionally, we stratified the analysis by sleep stages and found that using features calculated only from periods of deep sleep enhanced the differences between the two groups. In conclusion, we postulate that in addition to HRV features, morphological features may also be useful in tracking maternal health and suggest specific features to be included in future research concerning maternal health.
Assuntos
Fotopletismografia , Punho , Humanos , Feminino , Gravidez , Frequência Cardíaca/fisiologia , Articulação do Punho , Nível de Saúde , EletrocardiografiaRESUMO
OBJECTIVE(S): Accidental rupture of membranes (acROM), an insertion-related complication of the balloon catheter for labor induction, may prolong the duration of ruptured membranes. Prolonged rupture of membranes is associated with an increased risk of intra-uterine infection with possibly neonatal infection as result. Little is known about safety profiles of different catheters regarding the occurrence of these complications. This study compares the incidence of neonatal early-onset sepsis (EOS) and acROM in women receiving either silicone or latex balloon catheters. STUDY DESIGN: A retrospective cohort study was performed including 2200 women (silicone balloon catheter, n = 1100 vs. latex balloon catheter, n = 1100). The primary outcomes were the incidence of acROM, and suspected and proven neonatal EOS. Secondary outcomes were: prolonged rupture of membranes, intrapartum fever, pre- or postnatal neonatal exposure to antibiotics, and perinatal outcomes. A subgroup analysis was performed between women with and without acROM. RESULTS: No statistically significant difference with regard to suspected or proven EOS was seen between the silicone and latex groups. The acROM rate was significantly higher in the silicone group compared to the latex group (2.9 % and 0.3 %, p < 0.01). Prolonged rupture of membranes was significantly more common in the silicone group compared to the latex group (5.0 % and 2.4 %, p < 0.01), as was the use of intrapartum antibiotics (12.7 % and 9.6 %, p = 0.02). Neonates were significantly more often exposed to pre- or postnatal antibiotics in the silicone group compared to the latex group (17.6 % and 13.6 %, p = 0.01). Subgroup analysis showed significantly more suspected and proven neonatal EOS when catheter-insertion was complicated with acROM (11.4 % and 20.0 %), compared to cases without acROM (3.8 % and 2.5 %), irrespective of the type of catheter used. CONCLUSION(S): The use of silicone balloon catheters for labor induction results in higher rates of acROM, prolonged rupture of membranes and use of intrapartum antibiotics, compared to latex balloon catheters. No statistically significant differences were found in the occurrence of suspected or proven neonatal EOS, however neonates from the silicone group were more often exposed to pre- or postnatal antibiotics. When acROM occurs, irrespective of type of catheter used, suspected and proven neonatal EOS was seen more often.
Assuntos
Ruptura Prematura de Membranas Fetais , Sepse Neonatal , Recém-Nascido , Gravidez , Feminino , Humanos , Látex/efeitos adversos , Estudos Retrospectivos , Silicones/efeitos adversos , Trabalho de Parto Induzido/métodos , Cateteres Urinários , Catéteres/efeitos adversos , Ruptura Prematura de Membranas Fetais/epidemiologia , Ruptura Prematura de Membranas Fetais/etiologia , Antibacterianos/uso terapêutico , Maturidade CervicalRESUMO
Pregnancy complications are associated with insufficient adaptation of the maternal autonomic nervous system to the physiological demands of pregnancy. Consequently, assessing maternal heart rate variability (mHRV)-which reflects autonomic regulation-is a promising tool for detecting early deterioration in maternal health. However, before mHRV can be used to screen for complications, an understanding of the factors influencing mHRV during healthy pregnancy is needed. In this retrospective observational study, we develop regression models to unravel the effects of maternal demographics (age, body mass index (BMI), gestational age (GA), and parity), cardiorespiratory factors (heart rate and breathing rate), and inter-subject variation on mHRV. We develop these models using two datasets which are comprised of, respectively, single measurements in 290 healthy pregnant women and repeated measurements (median = 8) in 29 women with healthy pregnancies. Our most consequential finding is that between one-third and two-thirds of the variation in mHRV can be attributed to inter-subject variability. Additionally, median heart rate dominantly affects mHRV (p < 0.001), while BMI and parity have no effect. Moreover, we found that median breathing rate, age, and GA all impact mHRV (p < 0.05). These results suggest that personalized, long-term monitoring would be necessary for using mHRV for obstetric screening.
Assuntos
Frequência Cardíaca , Gravidez , Feminino , Humanos , Estudos Retrospectivos , Idade Gestacional , Paridade , DemografiaRESUMO
OBJECTIVES: To determine if the electrical heart axis in different types of congenital heart defects (CHD) differs from that of a healthy cohort at mid-gestation. METHODS: Non-invasive fetal electrocardiography (NI-fECG) was performed in singleton pregnancies with suspected CHD between 16 and 30 weeks of gestation. The mean electrical heart axis (MEHA) was determined from the fetal vectorcardiogram after correction for fetal orientation. Descriptive statistics were used to determine the MEHA with corresponding 95% confidence intervals (CI) in the frontal plane of all fetuses with CHD and the following subgroups: conotruncal anomalies (CTA), atrioventricular septal defects (AVSD) and hypoplastic right heart syndrome (HRHS). The MEHA of the CHD fetuses as well as the subgroups was compared to the healthy control group using a spherically projected multivariate linear regression analysis. Discriminant analysis was applied to calculate the sensitivity and specificity of the electrical heart axis for CHD detection. RESULTS: The MEHA was determined in 127 fetuses. The MEHA was 83.0° (95% CI: 6.7°; 159.3°) in the total CHD group, and not significantly different from the control group (122.7° (95% CI: 101.7°; 143.6°). The MEHA was 105.6° (95% CI: 46.8°; 164.4°) in the CTA group (n = 54), -27.4° (95% CI: -118.6°; 63.9°) in the AVSD group (n = 9) and 26.0° (95% CI: -34.1°; 86.1°) in the HRHS group (n = 5). The MEHA of the AVSD and the HRHS subgroups were significantly different from the control group (resp. p = 0.04 and p = 0.02). The sensitivity and specificity of the MEHA for the diagnosis of CHD was 50.6% (95% CI 47.5% - 53.7%) and 60.1% (95% CI 57.1% - 63.1%) respectively. CONCLUSION: The MEHA alone does not discriminate between healthy fetuses and fetuses with CHD. However, the left-oriented electrical heart axis in fetuses with AVSD and HRHS was significantly different from the control group suggesting altered cardiac conduction along with the structural defect. TRIAL REGISTRATION: Clinical trial registration number: NL48535.015.14.
Assuntos
Cardiopatias Congênitas , Defeitos dos Septos Cardíacos , Humanos , Gravidez , Feminino , Cardiopatias Congênitas/diagnóstico por imagem , Feto , Eletrocardiografia , Ultrassonografia Pré-Natal , Coração Fetal/diagnóstico por imagemRESUMO
OBJECTIVE: Current guidelines provide little supporting literature for the definition of uterine tachysystole during labour and no distinction is made for optimal contraction frequency depending on the clinical situation. We hypothesize that fetal hypoxia is frequently caused by uterine tachysystole and that high uterine contraction frequencies are especially harmful when fetal heart rate (FHR) abnormalities are present. We studied the association between contraction frequency and fetal scalp pH values in women with an indication for fetal blood sampling (FBS) based on FHR abnormalities. STUDY DESIGN: A retrospective study including 762 women was performed in a tertiary teaching hospital in the Netherlands from January 2015 until January 2020. Women with a singleton pregnancy with a gestational age ≥ 34+0 weeks were included when FBS was performed because of suspicious or pathological FHR tracings. Exclusion criteria were maternal age < 18 years, failed fetal scalp pH values, lack of thirty minute registration by tocodynamometry prior to FBS, poor quality of uterine monitoring, intrauterine resuscitation in the thirty minutes prior to FBS, maternal body mass index ≥ 30 kg/m2 and neonatal birth weight < 10th percentile. Uterine contractions in the thirty minutes prior to FBS were manually annotated by a researcher who was blinded to FBS values, FHR and other obstetrical data. Linear and logistic analysis were used to explore the association between uterine contraction frequency and FBS results. RESULTS: Low fetal scalp pH values were significantly associated with contraction frequency prior to FBS. Fetuses of women with four to five contractions per ten minutes prior to FBS were 2.4 times more likely to have hypoxia as compared to fetuses of women with two to three contractions per ten minutes (aOR 2.4, 95% CI 1.1-5.4). With increasing contraction frequency, the risk of fetal hypoxia further increased. CONCLUSIONS: Contraction frequency above four per ten minutes prior to FBS is significantly associated with fetal hypoxia in women with FHR abnormalities. We suggest to aim for a maximum contraction frequency of four per ten minutes in these women.
Assuntos
Frequência Cardíaca Fetal , Contração Uterina , Adolescente , Feminino , Feto , Frequência Cardíaca Fetal/fisiologia , Humanos , Concentração de Íons de Hidrogênio , Lactente , Recém-Nascido , Gravidez , Estudos Retrospectivos , Couro CabeludoRESUMO
BACKGROUND: The diagnostic value of ST analysis of the fetal electrocardiogram (fECG) during labor is uncertain. False alarms (ST events) may be explained by physiological variation of the fetal electrical heart axis. Adjusted ST events, based on a relative rather than an absolute rise from baseline, correct for this variation and may improve the diagnostic accuracy of ST analysis. AIMS: Determine the optimal cut-off for relative ST events in fECG to detect fetal metabolic acidosis. STUDY DESIGN: Post-hoc analysis on fECG tracings from the Dutch STAN trial (STAN+CTG branch). SUBJECTS: 1328 term singleton fetuses with scalp ECG tracing during labor, including 10 cases of metabolic acidosis. OUTCOME MEASURES: Cut-off value for relative ST events at the point closest to (0,1) in the receiver operating characteristic (ROC) curve with corresponding sensitivity and specificity. RESULTS: Relative baseline ST events had an optimal cut-off at an increment of 85% from baseline. Relative ST events had a sensitivity of 90% and specificity of 80%. CONCLUSIONS: Adjusting the current definition of ST events may improve ST analysis, making it independent of CTG interpretation.
Assuntos
Acidose , Trabalho de Parto , Acidose/diagnóstico , Cardiotocografia , Eletrocardiografia , Feminino , Coração Fetal , Monitorização Fetal , Frequência Cardíaca Fetal , Humanos , GravidezRESUMO
OBJECTIVES: Two-dimensional speckle-tracking echocardiography (2D-STE) is a promising technique which allows assessment of fetal cardiac function, and can be used in the evaluation of cardiac and non-cardiac diseases in pregnancy. However, reliable fetal reference values for deformation parameters measured using 2D-STE are needed before it can be introduced into clinical practice. This study aimed to obtain reference values for fetal global longitudinal strain (GLS) and GLS rate (GLSR) measured using 2D-STE and compare right and left ventricular values. METHODS: This was a prospective longitudinal cohort study of uncomplicated pregnancies that underwent echocardiography every 4 weeks from inclusion at 18-21 weeks until delivery to obtain four-chamber loops of the fetal heart. Left and right ventricular GLS and GLSR were measured using 2D-STE at each examination. Using Bayesian mixed-effects models, reference values with lower and upper 5% prediction limits were calculated according to gestational age. Right and left ventricular GLS values according to gestational age were compared using the Wilcoxon signed-rank test. RESULTS: A total of 592 left ventricular and 566 right ventricular GLS and GLSR measurements were obtained from 124 women with uncomplicated pregnancy and non-anomalous, appropriately grown fetuses. Reference values were obtained for both fetal ventricles according to gestational week. GLS and GLSR values of both ventricles increased (i.e. became less negative) significantly during pregnancy. Right ventricular GLS values were significantly higher (i.e. less negative) than the respective left ventricular values at every gestational week. CONCLUSIONS: Reference values were obtained for fetal GLS and GLSR measured using 2D-STE. GLS and GLSR values increased significantly for both ventricles from the second trimester until delivery. GLS values were significantly higher for the right ventricle compared with the left ventricle. Future studies are needed to assess whether the obtained reference values are helpful in clinical practice in the assessment of pregnancy complications, such as fetal growth restriction or cardiac anomaly. © 2022 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.
Assuntos
Ecocardiografia , Ultrassonografia Pré-Natal , Teorema de Bayes , Ecocardiografia/métodos , Feminino , Coração Fetal/diagnóstico por imagem , Ventrículos do Coração/diagnóstico por imagem , Humanos , Estudos Longitudinais , Masculino , Gravidez , Estudos Prospectivos , Reprodutibilidade dos Testes , Função Ventricular EsquerdaRESUMO
BACKGROUND: Worldwide, hypertensive disorders of pregnancy (HDP), fetal growth restriction (FGR) and preterm birth remain the leading causes of maternal and fetal pregnancy-related mortality and (long-term) morbidity. Fetal cardiac deformation changes can be the first sign of placental dysfunction, which is associated with HDP, FGR and preterm birth. In addition, preterm birth is likely associated with changes in electrical activity across the uterine muscle. Therefore, fetal cardiac function and uterine activity can be used for the early detection of these complications in pregnancy. Fetal cardiac function and uterine activity can be assessed by two-dimensional speckle-tracking echocardiography (2D-STE), non-invasive fetal electrocardiography (NI-fECG), and electrohysterography (EHG). This study aims to generate reference values for 2D-STE, NI-fECG and EHG parameters during the second trimester of pregnancy and to investigate the diagnostic potential of these parameters in the early detection of HDP, FGR and preterm birth. METHODS: In this longitudinal prospective cohort study, eligible women will be recruited from a tertiary care hospital and a primary midwifery practice. In total, 594 initially healthy pregnant women with an uncomplicated singleton pregnancy will be included. Recordings of NI-fECG and EHG will be made weekly from 22 until 28 weeks of gestation and 2D-STE measurements will be performed 4-weekly at 16, 20, 24 and 28 weeks gestational age. Retrospectively, pregnancies complicated with pregnancy-related diseases will be excluded from the cohort. Reference values for 2D-STE, NI-fECG and EHG parameters will be assessed in uncomplicated pregnancies. After, 2D-STE, NI-fCG and EHG parameters measured during gestation in complicated pregnancies will be compared with these reference values. DISCUSSION: This will be the a large prospective study investigating new technologies that could potentially have a high impact on antepartum fetal monitoring. TRIAL REGISTRATION: Registered on 26 March 2020 in the Dutch Trial Register (NL8769) via https://www.trialregister.nl/trials and registered on 21 October 2020 to the Central Committee on Research Involving Human Subjects (NL73607.015.20) via https://www.toetsingonline.nl/to/ccmo_search.nsf/Searchform?OpenForm .
Assuntos
Ecocardiografia/métodos , Eletrocardiografia/métodos , Diagnóstico Pré-Natal/métodos , Adulto , Feminino , Retardo do Crescimento Fetal/diagnóstico , Frequência Cardíaca Fetal/fisiologia , Humanos , Hipertensão Induzida pela Gravidez/diagnóstico , Estudos Longitudinais , Países Baixos , Gravidez , Segundo Trimestre da Gravidez , Nascimento Prematuro/diagnóstico , Estudos Prospectivos , Monitorização Uterina , Útero/fisiologiaRESUMO
Objective. Fetal heart rate (HR) monitoring is routinely used during pregnancy and labor to assess fetal well-being. The noninvasive fetal electrocardiogram (ECG), obtained by electrodes on the maternal abdomen, is a promising alternative to standard fetal monitoring. Subtraction of the maternal ECG from the abdominal measurements results in fetal ECG signals, in which the fetal HR can be determined typically through R-peak detection. However, the low signal-to-noise ratio and the nonstationary nature of the fetal ECG make R-peak detection a challenging task.Approach. We propose an alternative approach that instead of performing R-peak detection employs deep learning to directly determine the fetal HR from the extracted fetal ECG signals. We introduce a combination of dilated inception convolutional neural networks (CNN) with long short-term memory networks to capture both short-term and long-term temporal dynamics of the fetal HR. The robustness of the method is reinforced by a separate CNN-based classifier that estimates the reliability of the outcome.Main results. Our method achieved a positive percent agreement (within 10% of the actual fetal HR value) of 97.3% on a dataset recorded during labor and 99.6% on set-A of the 2013 Physionet/Computing in Cardiology Challenge exceeding top-performing state-of-the-art algorithms from the literature.Significance. The proposed method can potentially improve the accuracy and robustness of fetal HR extraction in clinical practice.
Assuntos
Frequência Cardíaca Fetal , Processamento de Sinais Assistido por Computador , Algoritmos , Eletrocardiografia , Feminino , Monitorização Fetal , Frequência Cardíaca , Humanos , Redes Neurais de Computação , Gravidez , Reprodutibilidade dos TestesRESUMO
OBJECTIVE: To assess the association between ketonuria and hyperemesis gravidarum (HG) disease severity. STUDY DESIGN: We included pregnant women hospitalised for HG who participated in the Maternal and Offspring outcomes after Treatment of HyperEmesis by Refeeding (MOTHER) trial and women who were eligible, chose not to be randomised and agreed to participate in the observational cohort. Between October 2013 and March 2016, in 19 hospitals in the Netherlands, women hospitalised for HG were approached for study participation. The presence of ketonuria was not required for study entry. Ketonuria was measured at hospital admission with a dipstick, which distinguishes 5 categories: negative and 1+ through 4 + . The outcome measures were multiple measures of HG disease severity at different time points: 1) At hospital admission (study entry): severity of nausea and vomiting, quality of life and weight change compared to pre-pregnancy weight, 2) One week after hospital admission: severity of nausea and vomiting, quality of life and weight change compared to admission, 3) Duration of index hospital admission and readmission for HG at any time point RESULTS: 215 women where included. Ketonuria was not associated with severity of nausea and vomiting, quality of life or weight loss at hospital admission, nor was the degree of ketonuria at admission associated with any of the outcomes 1 week after hospital admission. The degree of ketonuria was also not associated with the number of readmissions. However, women with a higher degree of ketonuria had a statistically significant longer duration of hospital stay (per 1+ ketonuria, difference: 0.27 days, 95 % CI: 0.05 to 0.48). CONCLUSIONS: There was no association between the degree of ketonuria at admission and severity of symptoms, quality of life, maternal weight loss, or number of readmissions, suggesting that ketonuria provides no information about disease severity or disease course. Despite this, women with a higher degree of ketonuria at admission were hospitalised for longer. This could suggest that health care professionals base length of hospital stay on the degree of ketonuria. Based on the lack of association between ketonuria and disease severity, we suggest it has no additional value in the clinical management of HG.
Assuntos
Hiperêmese Gravídica , Cetose , Feminino , Humanos , Hiperêmese Gravídica/terapia , Países Baixos , Gravidez , Qualidade de Vida , Índice de Gravidade de DoençaRESUMO
OBJECTIVE: To investigate the effect of maternal hyperoxygenation on fetal heart rate (FHR) when applied for suspected fetal distress during the second stage of term labor. APPROACH: A single-center randomized controlled trial was conducted in a tertiary care hospital in The Netherlands. Participants were included during the second stage of labor in case of an intermediary or abnormal FHR pattern. Patients were randomized to receive either 100% oxygen at 10 l/min until delivery, or conventional care without additional oxygen. The primary outcome was the change in FHR pattern before and after the onset of the study, measured as the change in depth and duration of FHR decelerations. Secondary outcome measures were features based on phase-rectified signal averaging (PRSA), baseline assignability, and deceleration characteristics of the FHR pattern. MAIN RESULTS: Between March 2016 and April 2018, 117 women were included. The FHR pattern could be analyzed for 71 participants, the other 46 women delivered before the end of the post time-frame. A 2.3% reduction in depth and duration of FHR decelerations was found after maternal hyperoxygenation, compared to a 10% increase in the control group (p = 0.24). Maternal hyperoxygenation had a significantly positive effect on PRSA metrics, with a decrease in PRSA-acceleration capacity (p = 0.03) and PRSA-deceleration capacity (p = 0.02) in the intervention group compared to the control group. SIGNIFICANCE: The difference in depth and duration of decelerations after the start of the study was not significantly different between both study groups. A statistically significant positive effect on PRSA-deceleration capacity and PRSA-acceleration capacity was found after maternal hyperoxygenation, which might be associated with a positive effect on neonatal outcome.
Assuntos
Sofrimento Fetal , Frequência Cardíaca Fetal , Trabalho de Parto , Oxigênio/administração & dosagem , Aceleração , Feminino , Humanos , Recém-Nascido , Países Baixos , Gravidez , Centros de Atenção TerciáriaRESUMO
BACKGROUND: Hypertensive pregnancy disorders (HPD) are associated with dysfunction of the autonomic nervous system. Cardiac autonomic functions can be assessed by heart rate variability (HRV) measurements. OBJECTIVE: To study whether HRV detects differences in the function of the autonomic nervous system between pregnant women with HPD compared to normotensive pregnant women and between women with a history of a pregnancy complicated by HPD compared to women with a history of an uncomplicated pregnancy. METHODS: A systematic search was performed in Medline, EMBASE, and CENTRAL to identify studies comparing HRV between pregnant women with HPD or women with a history of HPD to women with (a history of) normotensive pregnancies. RESULTS: The search identified 523 articles of which 24 were included in this review, including 850 women with (a history of) HPD and 1205 normotensive controls. The included studies showed a large heterogenicity. A decrease in overall HRV was found in preeclampsia (PE), compared to normotensive pregnant controls. A trend is seen towards increased low frequency/high frequency-ratio in women with PE compared to normotensive pregnant controls. CONCLUSION: Our systematic review supports the hypothesis a sympathetic overdrive is found in HPD which is associated with a parasympathetic withdrawal. However, the included studies in our review showed a large diversity in the methods applied and their results.
Assuntos
Sistema Nervoso Autônomo/fisiopatologia , Pressão Sanguínea , Sistema Cardiovascular/inervação , Frequência Cardíaca , Hipertensão Induzida pela Gravidez/fisiopatologia , Adolescente , Adulto , Feminino , Idade Gestacional , Humanos , Hipertensão Induzida pela Gravidez/diagnóstico , Gravidez , Adulto JovemRESUMO
BACKGROUND: Double-layer compared to single-layer closure of the uterus after a caesarean section (CS) leads to a thicker myometrial layer at the site of the CS scar, also called residual myometrium thickness (RMT). It possibly decreases the development of a niche, which is an interruption of the myometrium at the site of the uterine scar. Thin RMT and a niche are associated with gynaecological symptoms, obstetric complications in a subsequent pregnancy and delivery and possibly with subfertility. METHODS: Women undergoing a first CS regardless of the gestational age will be asked to participate in this multicentre, double blinded randomised controlled trial (RCT). They will be randomised to single-layer closure or double-layer closure of the uterine incision. Single-layer closure (control group) is performed with a continuous running, unlocked suture, with or without endometrial saving technique. Double-layer closure (intervention group) is performed with the first layer in a continuous unlocked suture including the endometrial layer and the second layer is also continuous unlocked and imbricates the first. The primary outcome is the reported number of days with postmenstrual spotting during one menstrual cycle nine months after CS. Secondary outcomes include surgical data, ultrasound evaluation at three months, menstrual pattern, dysmenorrhea, quality of life, and sexual function at nine months. Structured transvaginal ultrasound (TVUS) evaluation is performed to assess the uterine scar and if necessary saline infusion sonohysterography (SIS) or gel instillation sonohysterography (GIS) will be added to the examination. Women and ultrasound examiners will be blinded for allocation. Reproductive outcomes at three years follow-up including fertility, mode of delivery and complications in subsequent deliveries will be studied as well. Analyses will be performed by intention to treat. 2290 women have to be randomised to show a reduction of 15% in the mean number of spotting days. Additionally, a cost-effectiveness analysis will be performed from a societal perspective. DISCUSSION: This RCT will provide insight in the outcomes of single- compared to double-layer closure technique after CS, including postmenstrual spotting and subfertility in relation to niche development measured by ultrasound. TRIAL REGISTRATION: Dutch Trial Register ( NTR5480 ). Registered 29 October 2015.
Assuntos
Cesárea/métodos , Metrorragia/etiologia , Técnicas de Sutura/efeitos adversos , Útero/cirurgia , Cicatriz/diagnóstico por imagem , Cicatriz/etiologia , Método Duplo-Cego , Dismenorreia/etiologia , Endossonografia , Feminino , Fertilidade , Humanos , Menstruação , Complicações do Trabalho de Parto/etiologia , Gravidez , Qualidade de Vida , Ensaios Clínicos Controlados Aleatórios como Assunto , Sexualidade , Útero/diagnóstico por imagemRESUMO
BACKGROUND: Betamethasone is widely used to enhance fetal lung maturation in case of threatened preterm birth. Antenatal corticosteroids are known to reduce fetal heart rate variability (fHRV) in the days following administration. Since decreased fHRV is a marker for fetal distress, this transient decrease of fHRV can cause unnecessary medical intervention. AIM: To describe the effect of betamethasone on fHRV, by applying spectral analysis on non-invasive fetal electrocardiogram (fECG) recordings. STUDY DESIGN: Secondary analysis of a prospective cohort study. SUBJECTS: Women with a singleton pregnancy, at risk for preterm delivery and receiving betamethasone, admitted to the obstetric high care unit in the period from March 2013 until July 2016. OUTCOME MEASURES: The primary outcome measure was fHRV in both time- and frequency-domain. Secondary outcome measures included basal fetal heart rate (fHR) and fHR variance. FHRV parameters were then calculated separately for the quiet and active state. RESULTS: Following 68 inclusions, 22 patients remained with complete series of measurements and sufficient data quality. FHRV parameters and fHR showed a decrease on day 2 compared to day 1, significant for short-term variability and high-frequency power. Similar results were found when analyzing for separate behavioral states. The number of segments in quiet state increased during days 1 and 2. Normalized values showed no difference for all behavioral states. CONCLUSION: FHRV decreases on day 2 after betamethasone administration, while periods of fetal quiescence increase. No changes were found in the normalized values, indicating that the influence of autonomic modulation is minor. Clinical trial registration number NL43294.015.13.
Assuntos
Betametasona/efeitos adversos , Glucocorticoides/efeitos adversos , Frequência Cardíaca Fetal/efeitos dos fármacos , Adulto , Betametasona/administração & dosagem , Betametasona/uso terapêutico , Eletrocardiografia/métodos , Feminino , Glucocorticoides/administração & dosagem , Glucocorticoides/uso terapêutico , Humanos , Trabalho de Parto Prematuro/tratamento farmacológico , Trabalho de Parto Prematuro/prevenção & controle , GravidezRESUMO
Extraction of a clean fetal electrocardiogram (ECG) from non-invasive abdominal recordings is one of the biggest challenges in fetal monitoring. An ECG allows for the interpretation of the electrical heart activity beyond the heart rate and heart rate variability. However, the low signal quality of the fetal ECG hinders the morphological analysis of its waveform in clinical practice. The time-sequenced adaptive filter has been proposed for performing optimal time-varying filtering of non-stationary signals having a recurring statistical character. In our study, the time-sequenced adaptive filter is applied to enhance the quality of multichannel fetal ECG after the maternal ECG is removed. To improve the performance of the filter in cases of low signal-to-noise ratio (SNR), we enhance the ECG reference signals by averaging consecutive ECG complexes. The performance of the proposed augmented time-sequenced adaptive filter is evaluated in both synthetic and real data from PhysioNet. This evaluation shows that the suggested algorithm clearly outperforms other ECG enhancement methods, in terms of uncovering the ECG waveform, even in cases with very low SNR. With the presented method, quality of the fetal ECG morphology can be enhanced to the extent that the ECG might be fit for use in clinical diagnostics. Graphical abstract The extracted fetal ECG signals from non-invasive abdominal recordings still contain a substantial amount of noise. The time-sequenced adaptive filter provides a relatively accurate estimate of the underlying fetal ECG signal when the quality of the reference channels is enhanced prior to filtering.
Assuntos
Eletrocardiografia/métodos , Diagnóstico Pré-Natal/métodos , Processamento de Sinais Assistido por Computador , Algoritmos , Feminino , Humanos , Gravidez , Razão Sinal-RuídoRESUMO
OBJECTIVE: Monitoring of the fetal condition during labor is currently performed by cardiotocograpy (CTG). Despite the use of CTG in clinical practice, CTG interpretation suffers from a high inter- and intra-observer variability and a low specificity. In addition to CTG, analysis of fetal heart rate variability (HRV) has been shown to provide information on fetal distress. However, fetal HRV can be strongly influenced by uterine contractions, particularly during the second stage of labor. Therefore, the aim of this study is to examine if distinguishing contractions from rest periods can improve the detection rate of HRV features for fetal distress during the second stage of labor. APPROACH: We used a dataset of 100 recordings, containing 20 cases of fetuses with adverse outcome. The most informative HRV features were selected by a genetic algorithm and classification performance was evaluated using support vector machines. MAIN RESULTS: Classification performance of fetal heart rate segments closest to birth improved from a geometric mean of 70% to 79%. If the classifier was used to indicate fetal distress over time, the geometric mean at 15 minutes before birth improved from 60% to 72%. SIGNIFICANCE: Our results show that combining contraction-dependent HRV features with HRV features calculated over the entire fetal heart rate signal improves the detection rate of fetal distress.