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1.
Sci Rep ; 14(1): 12615, 2024 06 01.
Article in English | MEDLINE | ID: mdl-38824217

ABSTRACT

Standard clinical practice to assess fetal well-being during labour utilises monitoring of the fetal heart rate (FHR) using cardiotocography. However, visual evaluation of FHR signals can result in subjective interpretations leading to inter and intra-observer disagreement. Therefore, recent studies have proposed deep-learning-based methods to interpret FHR signals and detect fetal compromise. These methods have typically focused on evaluating fixed-length FHR segments at the conclusion of labour, leaving little time for clinicians to intervene. In this study, we propose a novel FHR evaluation method using an input length invariant deep learning model (FHR-LINet) to progressively evaluate FHR as labour progresses and achieve rapid detection of fetal compromise. Using our FHR-LINet model, we obtained approximately 25% reduction in the time taken to detect fetal compromise compared to the state-of-the-art multimodal convolutional neural network while achieving 27.5%, 45.0%, 56.5% and 65.0% mean true positive rate at 5%, 10%, 15% and 20% false positive rate respectively. A diagnostic system based on our approach could potentially enable earlier intervention for fetal compromise and improve clinical outcomes.


Subject(s)
Cardiotocography , Deep Learning , Heart Rate, Fetal , Heart Rate, Fetal/physiology , Humans , Pregnancy , Female , Cardiotocography/methods , Neural Networks, Computer , Fetal Monitoring/methods , Signal Processing, Computer-Assisted , Fetus
2.
PLoS One ; 19(5): e0303072, 2024.
Article in English | MEDLINE | ID: mdl-38722999

ABSTRACT

Qualitative research about women and birthing people's experiences of fetal monitoring during labour and birth is scant. Labour and birth is often impacted by wearable or invasive monitoring devices, however, most published research about fetal monitoring is focused on the wellbeing of the fetus. This manuscript is derived from a larger mixed methods study, 'WOmen's Experiences of Monitoring Baby (The WOMB Study)', aiming to increase understanding of the experiences of women and birthing people in Australia, of being monitored; and about the information they received about fetal monitoring devices during pregnancy. We constructed a national cross-sectional survey that was distributed via social media in May and June, 2022. Responses were received from 861 participants. As far as we are aware, this is the first survey of the experiences of women and birthing people of intrapartum fetal monitoring conducted in Australia. This paper comprises the analysis of the free text survey responses, using qualitative and inductive content analysis. Two categories were constructed, Tending to the machine, which explores participants' perceptions of the way in which clinicians interacted with fetal monitoring technologies; and Impressions of the machine, which explores the direct impact of fetal monitoring devices upon the labour and birth experience of women and birthing people. The findings suggest that some clinicians need to reflect upon the information they provide to women and birthing people about monitoring. For example, freedom of movement is an important aspect of supporting the physiology of labour and managing pain. If freedom of movement is important, the physical restriction created by a wired cardiotocograph is inappropriate. Many participants noticed that clinicians focused their attention primarily on the technology. Prioritising the individual needs of the woman or birthing person is key to providing high quality woman-centred intrapartum care. Women should be provided with adequate information regarding the risks and benefits of different forms of fetal monitoring including how the form of monitoring might impact her labour experience.


Subject(s)
Fetal Monitoring , Labor, Obstetric , Humans , Female , Pregnancy , Australia , Fetal Monitoring/methods , Adult , Cross-Sectional Studies , Surveys and Questionnaires , Parturition , Young Adult
3.
Sensors (Basel) ; 24(9)2024 May 06.
Article in English | MEDLINE | ID: mdl-38733053

ABSTRACT

The fetal electrocardiogram (FECG) records changes in the graph of fetal cardiac action potential during conduction, reflecting the developmental status of the fetus in utero and its physiological cardiac activity. Morphological alterations in the FECG can indicate intrauterine hypoxia, fetal distress, and neonatal asphyxia early on, enhancing maternal and fetal safety through prompt clinical intervention, thereby reducing neonatal morbidity and mortality. To reconstruct FECG signals with clear morphological information, this paper proposes a novel deep learning model, CBLS-CycleGAN. The model's generator combines spatial features extracted by the CNN with temporal features extracted by the BiLSTM network, thus ensuring that the reconstructed signals possess combined features with spatial and temporal dependencies. The model's discriminator utilizes PatchGAN, employing small segments of the signal as discriminative inputs to concentrate the training process on capturing signal details. Evaluating the model using two real FECG signal databases, namely "Abdominal and Direct Fetal ECG Database" and "Fetal Electrocardiograms, Direct and Abdominal with Reference Heartbeat Annotations", resulted in a mean MSE and MAE of 0.019 and 0.006, respectively. It detects the FQRS compound wave with a sensitivity, positive predictive value, and F1 of 99.51%, 99.57%, and 99.54%, respectively. This paper's model effectively preserves the morphological information of FECG signals, capturing not only the FQRS compound wave but also the fetal P-wave, T-wave, P-R interval, and ST segment information, providing clinicians with crucial diagnostic insights and a scientific foundation for developing rational treatment protocols.


Subject(s)
Electrocardiography , Neural Networks, Computer , Signal Processing, Computer-Assisted , Humans , Electrocardiography/methods , Female , Pregnancy , Deep Learning , Fetal Monitoring/methods , Algorithms , Fetus
4.
Physiol Meas ; 45(5)2024 May 21.
Article in English | MEDLINE | ID: mdl-38722552

ABSTRACT

Objective.Perinatal asphyxia poses a significant risk to neonatal health, necessitating accurate fetal heart rate monitoring for effective detection and management. The current gold standard, cardiotocography, has inherent limitations, highlighting the need for alternative approaches. The emerging technology of non-invasive fetal electrocardiography shows promise as a new sensing technology for fetal cardiac activity, offering potential advancements in the detection and management of perinatal asphyxia. Although algorithms for fetal QRS detection have been developed in the past, only a few of them demonstrate accurate performance in the presence of noise and artifacts.Approach.In this work, we proposePower-MF, a new algorithm for fetal QRS detection combining power spectral density and matched filter techniques. We benchmarkPower-MFagainst three open-source algorithms on two recently published datasets (Abdominal and Direct Fetal ECG Database: ADFECG, subsets B1 Pregnancy and B2 Labour; Non-invasive Multimodal Foetal ECG-Doppler Dataset for Antenatal Cardiology Research: NInFEA).Main results.Our results show thatPower-MFoutperforms state-of-the-art algorithms on ADFECG (B1 Pregnancy: 99.5% ± 0.5% F1-score, B2 Labour: 98.0% ± 3.0% F1-score) and on NInFEA in three of six electrode configurations by being more robust against noise.Significance.Through this work, we contribute to improving the accuracy and reliability of fetal cardiac monitoring, an essential step toward early detection of perinatal asphyxia with the long-term goal of reducing costs and making prenatal care more accessible.


Subject(s)
Algorithms , Electrocardiography , Signal Processing, Computer-Assisted , Humans , Electrocardiography/methods , Female , Pregnancy , Fetal Monitoring/methods , Fetus/physiology
5.
Comput Methods Programs Biomed ; 249: 108145, 2024 Jun.
Article in English | MEDLINE | ID: mdl-38582038

ABSTRACT

BACKGROUND AND OBJECTIVE: Obstetricians use Cardiotocography (CTG), which is the continuous recording of fetal heart rate and uterine contraction, to assess fetal health status. Deep learning models for intelligent fetal monitoring trained on extensively labeled and identically distributed CTG records have achieved excellent performance. However, creation of these training sets requires excessive time and specialist labor for the collection and annotation of CTG signals. Previous research has demonstrated that multicenter studies can improve model performance. However, models trained on cross-domain data may not generalize well to target domains due to variance in distribution among datasets. Hence, this paper conducted a multicenter study with Deep Semi-Supervised Domain Adaptation (DSSDA) for intelligent interpretation of antenatal CTG signals. This approach helps to align cross-domain distribution and transfer knowledge from a label-rich source domain to a label-scarce target domain. METHODS: We proposed a DSSDA framework that integrated Minimax Entropy and Domain Invariance (DSSDA-MMEDI) to reduce inter-domain gaps and thus achieve domain invariance. The networks were developed using GoogLeNet to extract features from CTG signals, with fully connected, softmax layers for classification. We designed a Dynamic Gradient-driven strategy based on Mutual Information (DGMI) to unify the losses from Minimax Entropy (MME), Domain Invariance (DI), and supervised cross-entropy during iterative learning. RESULTS: We validated our DSSDA model on two datasets collected from collaborating healthcare institutions and mobile terminals as the source and target domains, which contained 16,355 and 3,351 CTG signals, respectively. Compared to the results achieved with deep learning networks without DSSDA, DSSDA-MMEDI significantly improved sensitivity and F1-score by over 6%. DSSDA-MMEDI also outperformed other state-of-the-art DSSDA approaches for CTG signal interpretation. Ablation studies were performed to determine the unique contribution of each component in our DSSDA mechanism. CONCLUSIONS: The proposed DSSDA-MMEDI is feasible and effective for alignment of cross-domain data and automated interpretation of multicentric antenatal CTG signals with minimal annotation cost.


Subject(s)
Cardiotocography , Fetal Monitoring , Pregnancy , Female , Humans , Cardiotocography/methods , Entropy , Fetal Monitoring/methods , Uterine Contraction , Heart Rate, Fetal/physiology
8.
Nurs Womens Health ; 28(2): e1-e39, 2024 Apr.
Article in English | MEDLINE | ID: mdl-38363259

ABSTRACT

Intermittent auscultation (IA) is an evidence-based method of fetal surveillance during labor for birthing people with low-risk pregnancies. It is a central component of efforts to reduce the primary cesarean rate and promote vaginal birth (American College of Obstetricians and Gynecologists, 2019; Association of Women's Health, Obstetric and Neonatal Nurses, 2022a). The use of intermittent IA decreased with the introduction of electronic fetal monitoring, while the increased use of electronic fetal monitoring has been associated with an increase of cesarean births. This practice monograph includes information on IA techniques; interpretation and documentation; clinical decision-making and interventions; communication; education, staffing, legal issues; and strategies to implement IA.


Subject(s)
Fetal Monitoring , Labor, Obstetric , Pregnancy , Infant, Newborn , Female , Humans , Fetal Monitoring/methods , Heart Rate, Fetal , Auscultation/methods , Cardiotocography/methods
9.
J Obstet Gynecol Neonatal Nurs ; 53(3): e10-e48, 2024 May.
Article in English | MEDLINE | ID: mdl-38363241

ABSTRACT

Intermittent auscultation (IA) is an evidence-based method of fetal surveillance during labor for birthing people with low-risk pregnancies. It is a central component of efforts to reduce the primary cesarean rate and promote vaginal birth (American College of Obstetricians and Gynecologists, 2019; Association of Women's Health, Obstetric and Neonatal Nurses, 2022a). The use of intermittent IA decreased with the introduction of electronic fetal monitoring, while the increased use of electronic fetal monitoring has been associated with an increase of cesarean births. This practice monograph includes information on IA techniques; interpretation and documentation; clinical decision-making and interventions; communication; education, staffing, legal issues; and strategies to implement IA.


Subject(s)
Fetal Monitoring , Heart Rate, Fetal , Humans , Female , Pregnancy , Heart Rate, Fetal/physiology , Fetal Monitoring/methods , Heart Auscultation/methods , Auscultation/methods , Cardiotocography/methods , Cardiotocography/standards
10.
Curr Opin Anaesthesiol ; 37(3): 285-291, 2024 Jun 01.
Article in English | MEDLINE | ID: mdl-38390901

ABSTRACT

PURPOSE OF REVIEW: Nonobstetric surgery during pregnancy is associated with maternal and fetal risks. Several physiologic changes create unique challenges for anesthesiologists. This review highlights physiologic changes of pregnancy and presents clinical recommendations based on recent literature to guide anesthetic management for the pregnant patient undergoing nonobstetric surgery. RECENT FINDINGS: Nearly every anesthetic technique has been safely used in pregnant patients. Although it is difficult to eliminate confounding factors, exposure to anesthetics could endanger fetal brain development. Perioperative fetal monitoring decisions require an obstetric consult based on anticipated maternal and fetal concerns. Given the limitations of fasting guidelines, bedside gastric ultrasound is useful in assessing aspiration risk in pregnant patients. Although there is concern about appropriateness of sugammadex for neuromuscular blockade reversal due its binding to progesterone, preliminary literature supports its safety. SUMMARY: These recommendations will equip anesthesiologists to provide safe care for the pregnant patient and fetus undergoing nonobstetric surgery.


Subject(s)
Anesthesia , Fetus , Humans , Pregnancy , Female , Anesthesia/methods , Anesthesia/adverse effects , Anesthesia/standards , Fetus/drug effects , Fetus/surgery , Anesthetics/adverse effects , Anesthetics/administration & dosage , Fetal Monitoring/methods , Fetal Monitoring/standards , Pregnancy Complications/prevention & control , Practice Guidelines as Topic , Surgical Procedures, Operative/adverse effects , Anesthesia, Obstetrical/methods , Anesthesia, Obstetrical/adverse effects , Anesthesia, Obstetrical/standards
11.
Crit Rev Biomed Eng ; 52(2): 1-14, 2024.
Article in English | MEDLINE | ID: mdl-38305274

ABSTRACT

Combined the improved fast independent component analysis (FastICA) algorithm with the singular value decomposition algorithm, a single-channel fetal electrocardiogram (fECG) extraction method is proposed. First, the improved FastICA algorithm is used to estimate the maternal ECG component from a single-channel abdominal signal of pregnant women using an overrelaxation factor. Then, a preliminary estimate of the fECG signal is obtained by subtracting from the single-channel abdominal signal. Subsequently, the singular value decomposition algorithm is used to denoise the preliminarily estimated fECG signal to obtain a high signal-to-noise ratio. In addition, in the singular value decomposition algorithm for fetal arrhythmia, an improved method for constructing the ECG signal reconstruction matrix is proposed. Finally, the fECG extraction experiments on synthetic abdominal signals and actual abdominal signals (data from 49 abdominal channels sourced from DAISY database and the non-invasive fECG database in PhysioNet) are carried out. The experimental results show that the method in this paper can effectively improve the signal-to-noise ratio and the accuracy of fECG signal extraction, and is suitable for maternal or fetal arrhythmias. Compared with the FastICA algorithm, the signal-to-noise ratio of the fECG signal extracted by the method in this paper is improved by about 5 dB, and the accuracy of fECG extraction in the PhysioNet database can reach 96.54%.


Subject(s)
Fetal Monitoring , Signal Processing, Computer-Assisted , Female , Pregnancy , Humans , Fetal Monitoring/methods , Electrocardiography/methods , Algorithms , Signal-To-Noise Ratio
12.
Acta Obstet Gynecol Scand ; 103(5): 980-991, 2024 May.
Article in English | MEDLINE | ID: mdl-38229258

ABSTRACT

INTRODUCTION: In clinical practice, fetal heart rate monitoring is performed intermittently using Doppler ultrasound, typically for 30 minutes. In case of a non-reassuring heart rate pattern, monitoring is usually prolonged. Noninvasive fetal electrocardiography may be more suitable for prolonged monitoring due to improved patient comfort and signal quality. This study evaluates the performance and patient experience of four noninvasive electrocardiography devices to assess candidate devices for prolonged noninvasive fetal heart rate monitoring. MATERIAL AND METHODS: Non-critically sick women with a singleton pregnancy from 24 weeks of gestation were eligible for inclusion. Fetal heart rate monitoring was performed during standard care with a Doppler ultrasound device (Philips Avalon-FM30) alone or with this Doppler ultrasound device simultaneously with one of four noninvasive electrocardiography devices (Nemo Fetal Monitoring System, Philips Avalon-Beltless, Demcon Dipha-16 and Dräger Infinity-M300). Performance was evaluated by: success rate, positive percent agreement, bias, 95% limits of agreement, regression line, root mean square error and visual agreement using FIGO guidelines. Patient experience was captured using a self-made questionnaire. RESULTS: A total of 10 women were included per device. For fetal heart rate, Nemo performed best (success rate: 99.4%, positive percent agreement: 94.2%, root mean square error 5.1 BPM, bias: 0.5 BPM, 95% limits of agreement: -9.7 - 10.7 BPM, regression line: y = -0.1x + 11.1) and the cardiotocography tracings obtained simultaneously by Nemo and Avalon-FM30 received the same FIGO classification. Comparable results were found with the Avalon-Beltless from 36 weeks of gestation, whereas the Dipha-16 and Infinity-M300 performed significantly worse. The Avalon-Beltless, Nemo and Infinity-M300 closely matched the performance of the Avalon-FM30 for maternal heart rate, whereas the performance of the Dipha-16 deviated more. Patient experience scores were higher for the noninvasive electrocardiography devices. CONCLUSIONS: Both Nemo and Avalon-Beltless are suitable devices for (prolonged) noninvasive fetal heart rate monitoring, taking their intended use into account. But outside its intended use limit of 36 weeks' gestation, the Avalon-Beltless performs less well, comparable to the Dipha-16 and Infinity-M300, making them currently unsuitable for (prolonged) noninvasive fetal heart rate monitoring. Noninvasive electrocardiography devices appear to be preferred due to greater comfort and mobility.


Subject(s)
Cardiotocography , Heart Rate Determination , Pregnancy , Female , Humans , Cardiotocography/methods , Fetal Monitoring/methods , Electrocardiography , Heart Rate, Fetal/physiology , Patient Outcome Assessment
13.
Enferm. glob ; 23(73): 68-94, ene. 2024. ilus, graf, tab
Article in Spanish | IBECS | ID: ibc-228888

ABSTRACT

Introducción: El vínculo madre-feto juega un papel importante en la atención del embarazo, impactando los resultados del nacimiento. El monitoreo del movimiento fetal es una competencia fundamental para que las mujeres embarazadas lo hagan de manera independiente. Objetivo: Producir monitoreo audiovisual del movimiento fetal independiente y probar su efectividad en el apego materno-fetal y los resultados del parto. Métodos: La etapa I, desarrollo de Monitoreo de Bienestar Fetal Audiovisual, con estudio de literatura, etapas, desarrollo de escenarios, creación de audiovisuales, prueba de validez de expertos. La etapa 2 probó la efectividad de los medios audiovisuales sobre el apego materno-fetal con el instrumento Inventario de Apego Prenatal y los resultados del nacimiento a partir del peso del bebé al nacer. Diseño de un verdadero enfoque experimental de grupo de control pretest-postest. Muestras de mujeres embarazadas con antecedentes de atención prenatal en el Centro de Salud Kasihan II, Bantul, Yogyakarta, Indonesia con los siguientes criterios: embarazo único, normal, edad gestacional de 28 a 36 semanas. Los encuestados de 60 sujetos se dividieron en grupos experimentales y de control. Los datos normales se probaron mediante la prueba t pareada, la prueba t independiente y MANOVA. Resultados: Puntaje de prueba de validez de experto en contenido 81% muy válido, puntaje de validez de experto en medios 80.33%, válido. La aplicación audiovisual mostró los resultados de la prueba t pareada, tanto en el grupo experimental como en el control hubo diferencias en el pretest y postest, P<0.05. La prueba t de muestra independiente P < 0,05 y los resultados MANOVA simultáneos mostraron una puntuación de apego materno-fetal y un resultado del nacimiento P < 0,05 (AU)


Introduction: The mother-fetus bond plays an important role in pregnancy care, impacting birth outcomes. Monitoring fetal movement is a fundamental competence for pregnant women to do independently. Objective: to produce audiovisual monitoring of independent fetal movement and prove its effectiveness on maternal-fetal attachment and birth outcomes. Methods: Phase I, developing Audiovisual Fetal Well-being Monitoring, with literature study steps, developing scenarios, creating audiovisuals, testing the validity of experts. Stage 2 tested the effectiveness of audiovisual media on maternal-fetal attachment with the Prenatal Attachment Inventory instrument and birth outcomes from infant birth weight. Design of true experimental pretest-posttest control group approach. Samples of pregnant women with a history of antenatal care at the Kasihan II Health Center, Bantul, Yogyakarta, Indonesia with the following criteria: single pregnancy, normal, gestational age 28-36 weeks. Respondents of 60 subjects were divided into experimental and control groups. Normal data were tested by paired t test, independent t-test and MANOVA. Results: Content expert validity test score 81% very valid, media expert validity score 80.33%, valid. The audiovisual application showed the results of the paired t-test, both in the experimental and control groups there were differences in pretest and posttest, P <0.05. Independent sample t-test P < 0.05 and simultaneous MANOVA results showed maternal-fetal attachment score and birth outcome P < 0.05. Conclusion: Independent monitoring of fetal well-being using audiovisual media simultaneously affects the increase in maternal-fetal attachment scores and birth outcomes so it is recommended that second trimester pregnant women be taught techniques for counting fetal movements and practicing them routinely (AU)


Subject(s)
Humans , Female , Pregnancy , Infant, Newborn , Fetal Monitoring/methods , Maternal-Fetal Relations , Pregnancy Outcome , Multivariate Analysis
14.
Reprod Sci ; 31(5): 1401-1407, 2024 May.
Article in English | MEDLINE | ID: mdl-38253982

ABSTRACT

Fetal acidosis among low-risk pregnancies is not common; however, identifying those at risk for this complication antenatally is of great interest. We aimed to assess the correlation between the total decelerations area during the last 120 min of fetal monitoring prior to delivery and neonatal acidemia in low-risk pregnancies and whether the total acceleration area has a protective effect in the presence of decelerations. A retrospective cohort study was conducted among women with term low-risk pregnancies. A researcher blinded to fetal outcomes interpreted electronic fetal monitor patterns during the 120 min prior to delivery. The primary outcome was fetal acidemia, defined as umbilical artery pH below 7.10. The correlation between the total decelerations and accelerations areas and cord blood pH was tested using the Spearman correlation coefficient. A total of 109 women were included and of these, six (5.5%) delivered infants with cord blood pH < 7.10. A significant correlation was demonstrated between the total decelerations area and cord blood pH (p = 0.01). No correlation was found between the total accelerations area and cord blood pH. Among low-risk pregnancies, a correlation was found between the total decelerations area but not the total accelerations area during the final 120 min of labor and cord blood pH.


Subject(s)
Acidosis , Fetal Blood , Humans , Female , Fetal Blood/chemistry , Fetal Blood/metabolism , Pregnancy , Hydrogen-Ion Concentration , Retrospective Studies , Adult , Acidosis/blood , Acidosis/physiopathology , Infant, Newborn , Heart Rate, Fetal/physiology , Cardiotocography , Fetal Monitoring/methods
15.
Sci Rep ; 14(1): 630, 2024 01 05.
Article in English | MEDLINE | ID: mdl-38182757

ABSTRACT

Assessment of fetal heart rate (fHR) through non-invasive fetal electrocardiogram (fECG) is challenging task. This study compares the performance of five template subtraction (TS) methods on Labor (12 5-min recordings) and Pregnancy datasets (10 20-min recordings). The methods include TS without adaptation, TS using singular value decomposition (TS[Formula: see text]), TS using linear prediction (TS[Formula: see text]), TS using scaling factor (TS[Formula: see text]), and sequential analysis (SA). The influence of the chosen maternal wavelet for the continuous wavelet transform (CWT) detector is also compared. The F1 score was used to measure performance. Each recording in both datasets consisted of four signals, resulting in a total comparison of 88 signals for the TS-based methods. The study reported the following results: F1 = 95.71% with TS, F1 = 95.93% with TS[Formula: see text], F1 = 95.30% with TS[Formula: see text], F1 = 95.82% with TS[Formula: see text], and F1 = 95.99% with SA. The study identified gaus3 as the suitable maternal wavelet for fetal R-peak detection using the CWT detector. Furthermore, the study classified signals from the tested datasets into categories of high, medium, and low quality, providing valuable insights for subsequent fECG signal extraction. This research contributes to advancing the understanding of non-invasive fECG signal processing and lays the groundwork for improving fetal monitoring in clinical settings.


Subject(s)
Fetus , Prenatal Care , Female , Pregnancy , Humans , Electrocardiography , Fetal Monitoring , Heart Rate, Fetal
16.
Placenta ; 146: 110-119, 2024 Feb.
Article in English | MEDLINE | ID: mdl-38241840

ABSTRACT

INTRODUCTION: Ensuring adequate fetal oxygenation is an essential aim of fetal monitoring. The purpose of this study was to establish a basic technique for real-time measurement of blood oxygen saturation of the placenta by photoacoustic (PA) technique as a new fetal monitoring method. METHODS: The hypoxia model established in our previous study was applied to 7 pregnant rabbits. Three phases were induced: normal phase, hypoxia phase, and recovery phase. Three methods were simultaneously used for real-time fetal monitoring: fetal heat rate (FHR) monitoring, oxygen saturation (SO2) measurement by near-infrared spectroscopy (SNO2), and placenta SO2 measured by PA technique (SplO2). The maternal hypoxia was assessed by skin SO2 measured by PA technique (SsO2), and arterial blood SO2 by blood gas analysis (SaO2). RESULTS: The average of SplO2 in normal phase was 52.6 ± 13.9 %. The averages of SNO2, SSO2, and SplO2 in the seven rabbits changed in parallel from the normal phase to hypoxia phase. In the recovery phase, the SplO2 rose in parallel with recovery of SaO2. There was lag in increase of the FHR compared to the change in the other values. In the detailed analysis of PA signals from the labyrinth and decidua, a unique change in oxygen saturation was seen in one case. DISCUSSION: Results of this study showed that sensitivity of our novel PA technique in detecting tissue hypoxia was similar to near-infrared spectroscopy (NIRS). As an advantage, unlike NIRS, monitoring with PA technique was unaffected by ischemia and surface changes in oxygen saturation because of its higher spatial resolution. We conclude that PA technique provides more accurate information about fetal blood placenta than NIRS. Ultrasound imaging, combined with oxygen saturation monitoring by PA technique, would improve fetal monitoring and fetal diagnosis in the future.


Subject(s)
Oxygen , Placenta , Animals , Rabbits , Female , Pregnancy , Oxygen/metabolism , Placenta/diagnostic imaging , Placenta/metabolism , Oxygen Saturation , Hypoxia/diagnostic imaging , Hypoxia/metabolism , Fetal Monitoring
17.
Ultraschall Med ; 45(2): 147-167, 2024 Apr.
Article in English, German | MEDLINE | ID: mdl-37582399

ABSTRACT

PURPOSE: The aim of this guideline was to find evidence on whether carrying out Doppler examinations and CTGs in low-risk cohorts of pregnant women improves outcomes. METHODS: First, a systematic search for guidelines was carried out. Identified guidelines were evaluated using the DELPHI instrument of the AWMF. Three guidelines were found to be suitable to evaluate CTG. Two DEGUM best practice guidelines were judged suitable to describe the methods. All studies on this issue were additionally analyzed using 8 PICO questions. A structured consensus of the participating professional societies was achieved using a nominal group process and a structured consensus conference moderated by an independent moderator. RECOMMENDATIONS: No antepartum Doppler sonography examinations should be carried out in low-risk cohorts in the context of antenatal care. No antepartum CTG should be carried out in low-risk cohorts. NOTE: The guideline will be published simultaneously in the official journals of both professional societies (i. e., Geburtshilfe und Frauenheilkunde for the DGGG and Ultraschall in der Medizin/European Journal of Ultrasound for the DEGUM).


Subject(s)
Cardiotocography , Fetal Monitoring , Pregnancy , Female , Humans , Risk Factors , Ultrasonography , Registries
18.
Acta Obstet Gynecol Scand ; 103(3): 437-448, 2024 Mar.
Article in English | MEDLINE | ID: mdl-38093630

ABSTRACT

INTRODUCTION: ST waveform analysis (STAN) was introduced as an adjunct to cardiotocography (CTG) to improve neonatal and maternal outcomes. The aim of the present study was to quantify the efficacy of STAN vs CTG and assess the quality of the evidence using GRADE. MATERIAL AND METHODS: We performed systematic literature searches to identify randomized controlled trials and assessed included studies for risk of bias. We performed meta-analyses, calculating pooled risk ratio (RR) or Peto odds ratio (OR). We also performed post hoc trial sequential analyses for selected outcomes to assess the risk of false-positive results and the need for additional studies. RESULTS: Nine randomized controlled trials including 28 729 women were included in the meta-analysis. There were no differences between the groups in operative deliveries for fetal distress (10.9 vs 11.1%; RR 0.96; 95% confidence interval [CI] 0.82-1.11). STAN was associated with a significantly lower rate of metabolic acidosis (0.45% vs 0.68%; Peto OR 0.66; 95% CI 0.48-0.90). Accordingly, 441 women need to be monitored with STAN instead of CTG alone to prevent one case of metabolic acidosis. Women allocated to STAN had a reduced risk of fetal blood sampling compared with women allocated to conventional CTG monitoring (12.5% vs 19.6%; RR 0.62; 95% CI 0.49-0.80). The quality of the evidence was high to moderate. CONCLUSIONS: Absolute effects of STAN were minor and the clinical significance of the observed reduction in metabolic acidosis is questioned. There is insufficient evidence to state that STAN as an adjunct to CTG leads to important clinical benefits compared with CTG alone.


Subject(s)
Acidosis , Cardiotocography , Pregnancy , Infant, Newborn , Female , Humans , Cardiotocography/methods , Randomized Controlled Trials as Topic , Fetal Distress/diagnosis , Electrocardiography/methods , Acidosis/diagnosis , Acidosis/prevention & control , Fetal Monitoring/methods , Heart Rate, Fetal
19.
Aust N Z J Obstet Gynaecol ; 64(1): 77-79, 2024 Feb.
Article in English | MEDLINE | ID: mdl-37702257

ABSTRACT

Monitoring the fetal heartbeat underpins assessment of fetal wellbeing in labour. Although commonly employed in clinical practice, shortcomings remain. A recent review of clinical practice guidelines highlights the variation in definitions of the fetal heart rate that will lead to differences in interpretation. Will intrapartum care be improved by greater consensus around clinical practice guidelines through rationalisation or refinement of guidelines, or will the future see this technique replaced by more accurate forms of fetal monitoring?


Subject(s)
Cardiotocography , Labor, Obstetric , Pregnancy , Female , Humans , Cardiotocography/methods , Heart Rate Determination , Fetal Monitoring/methods , Forecasting , Heart Rate, Fetal
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