ABSTRACT
BACKGROUND: Delivery is a critical moment for pregnant women and babies, and careful monitoring is essential throughout the delivery process. The partograph is a useful tool for monitoring and assessing labour progress as well as maternal and foetal conditions; however, it is often used inaccurately or inappropriately. A gap between practices and evidence-based guidelines has been reported in Cambodia, perhaps due to a lack of evidence-based knowledge in maternity care. This study aims to address to what extent skilled birth attendants in the first-line health services in Cambodia have knowledge on the management of normal delivery, and what factors are associated with their level of knowledge. METHODS: Midwives and nurses were recruited working in maternity in first-line public health facilities in Phnom Penh municipality, Kampong Cham and Svay Rieng provinces. Two self-administered questionnaires were applied. The first consisted of three sections with questions on monitoring aspects of the partograph: progress of labour, foetal, and maternal conditions. The second consisted of questions on diagnostic criteria, normal ranges, and standard intervals of monitoring during labour. A multiple linear regression analysis was performed to identify relationships between characteristics of the participants and the questionnaire scores. RESULTS: Of 542 eligible midwives and nurses, 523 (96%) participated. The overall mean score was 58%. Only 3% got scores of more than 90%. Multivariate analysis revealed that 'Kampong Cham province', 'younger age', and 'higher qualification' were significantly associated with higher scores. Previous training experience was not associated with the score. Substantial proportions of misclassification of monitoring items during labour were found; for example, 61% answered uterine contraction as a foetal condition, and 44% answered foetal head descent and 26% answered foetal heart rate as a maternal condition. CONCLUSION: This study found that knowledge was low on delivery management among skilled birth attendants. Previous training experience did not influence the knowledge level. A lack of understanding of physiology and anatomy was implied. Further experimental approaches should be attempted to improve the knowledge and quality of maternity services in Cambodia.
Pregnancy and childbirth are natural phenomena, but sometimes have risk for mothers and babies. Therefore, childbirth should be carefully and continuously monitored by the health care professional. The 'partograph' is a useful tool that defines three monitoring aspects of the delivery progress, and conditions of the mother and intrauterine baby. However, it is often used inaccurately or inappropriately in low- and middle-income countries. We hypothesised that health professionals who assist childbirth cannot effectively monitor delivery conditions because their knowledge is insufficient. Therefore, we evaluated the knowledge on monitoring the process of childbirth and explored factors which affect the level of knowledge among health care providers in Cambodia.Midwives and nurses were targeted in this study who deal with normal deliveries in the capital city and two provinces. The questionnaire was designed to evaluate if their knowledge on three monitoring aspects is accurate.Of 542 eligible personnel, 523 (96%) participated. The mean score was 58%. Only 3% got scores of more than 90%. According to the statistical analysis, 'working in Kampong Cham province', 'younger age', and 'higher qualification' were significantly associated with higher scores. Previous training experience was not associated with the score.This study found that basic knowledge was low on delivery management among health care providers. We suspect that a deficiency of basic medical knowledge, such as physiology and anatomy, causes the lack of knowledge on the childbirth process. Further intervention should be attempted to improve the knowledge and quality of maternity services in Cambodia.
Subject(s)
Delivery, Obstetric/standards , Fetal Monitoring/instrumentation , Midwifery/standards , Parturition , Postnatal Care , Uterine Monitoring/instrumentation , Adult , Cambodia/epidemiology , Cross-Sectional Studies , Female , Health Knowledge, Attitudes, Practice , Humans , Maternal Health Services , Middle Aged , Practice Guidelines as Topic , PregnancyABSTRACT
Contractions are produced through a complex interplay of hormonal, mechanical, and electrical factors. In labor, contractions are measured using the Montevideo unit. Clinical considerations in labor wherein contraction assessment becomes paramount include the care of women whose labor is complicated by abnormal progress or tachysystole. In an era of obstetrics in which the high cesarean rate is a major issue of concern, there remain many questions as to how to best incorporate contraction monitoring into practice in order to optimize care. Technological advancement has led to the development on new modalities that can be used to study contraction physiology, and there may be an opportunity in the future to apply these methods for use in the clinical setting. This article also makes a case for the need to reevaluate the current measures of uterine contractile activity and the definition of contraction adequacy using updated definitions of normal labor progress.
Subject(s)
Labor, Obstetric/physiology , Obstetrics/methods , Uterine Contraction/physiology , Uterine Monitoring/methods , Cesarean Section , Female , Humans , Obesity/complications , Obesity/physiopathology , Obstetrics/trends , Pregnancy , Pregnancy Complications/physiopathology , Uterine Monitoring/instrumentationABSTRACT
BACKGROUND: Uterine activity monitoring is an essential part of managing the progress of pregnancy and labor. Although intrauterine pressure (IUP) is the only reliable method of estimating uterine mechanical activity, it is highly invasive. Since there is a direct relationship between the electrical and mechanical activity of uterine cells, surface electrohysterography (EHG) has become a noninvasive monitoring alternative. The Teager energy (TE) operator of the EHG signal has been used for IUP continuous pressure estimation, although its accuracy could be improved. We aimed to develop new optimized IUP estimation models for clinical application. APPROACH: We first considered enhancing the optimal estimation of IUP clinical features (maximum pressure and tonus) rather than optimizing the signal only (continuous pressure). An adaptive algorithm was also developed to deal with inter-patient variability. For each optimizing signal feature (continuous pressure, maximum pressure and tonus), individual (single patient), global (full database) and adaptive models were built to estimate the recorded IUP signal. The results were evaluated by computing the root mean square errors (RMSe): continuous pressure error (CPe), maximum pressure error (MPe) and tonus error (TOe). MAIN RESULTS: The continuous pressure global model yielded IUP estimates with Cpe = 14.61 mm Hg, MPe = 29.17 mm Hg and Toe = 7.8 mm Hg. The adaptive models significantly reduced errors to CPe = 11.88, MPe = 16.02 and Toe = 5.61 mm Hg. The EHG-based IUP estimates outperformed those from traditional tocographic recordings, which had significantly higher errors (CPe = 21.93, MPe = 26.97, and TOe = 13.96). SIGNIFICANCE: Our results show that adaptive models yield better IUP estimates than the traditional approaches and provide the best balance of the different errors computed for a better assessment of the labor progress and maternal and fetal well-being.
Subject(s)
Electromyography , Labor, Obstetric/physiology , Signal Processing, Computer-Assisted , Uterine Contraction , Uterine Monitoring/methods , Uterus/physiology , Adult , Female , Humans , Pregnancy , Uterine Monitoring/instrumentationABSTRACT
BACKGROUND: There are questions about the use of the 'one-centimetre per hour rule' as a valid benchmark for assessing the adequacy of labour progress. OBJECTIVES: To determine the accuracy of the alert (1-cm/hour) and action lines of the cervicograph in the partograph to predict adverse birth outcomes among women in first stage of labour. SEARCH STRATEGY: PubMed, EMBASE, CINAHL, POPLINE, Global Health Library, and reference lists of eligible studies. SELECTION CRITERIA: Observational studies and other study designs reporting data on the correlation between the alert line status of women in labour and the occurrence of adverse birth outcomes. DATA COLLECTION AND ANALYSIS: Two reviewers at a time independently identified eligible studies and independently abstracted data including population characteristics and maternal and perinatal outcomes. MAIN RESULTS: Thirteen studies in which 20 471 women participated were included in the review. The percentage of women crossing the alert line varied from 8 to 76% for all maternal or perinatal outcomes. No study showed a robust diagnostic test accuracy profile for any of the selected outcomes. CONCLUSIONS: This systematic review does not support the use of the cervical dilatation over time (at a threshold of 1 cm/h during active first stage) to identify women at risk of adverse birth outcomes. TWEETABLE ABSTRACT: Alert line of partograph does not identify women at risk of adverse birth outcomes.
Subject(s)
Cesarean Section/statistics & numerical data , Pregnancy Complications/prevention & control , Uterine Monitoring , Adult , Delivery, Obstetric , Female , Humans , Infant, Newborn , Labor, Obstetric , Predictive Value of Tests , Pregnancy , Pregnancy Complications/diagnosis , Pregnancy Outcome , Reproducibility of Results , Term Birth , Uterine Inertia/diagnosis , Uterine Monitoring/instrumentationABSTRACT
Uterine contraction (UC) is an important clinical indictor for monitoring uterine activity. The purpose of this study is to develop a portable electrohysterogram (EHG) recording system (called PregCare) for monitoring UCs with EHG signals. The PregCare consisted of sensors, a signal acquisition device, and a computer with application software. Eight-channel EHG signals, the tocodynamometry (TOCO) signal, and maternal perception were recorded simultaneously by the signal acquisition device controlled by the computer via Bluetooth. PregCare was firstly evaluated by a signal simulator. Its relative error (RE) and coefficient of variation (CV) were calculated, and its agreement with the commercial instrument PowerLab was assessed by Bland-Altman plots. After that, PregCare was applied to 20 pregnant women in a hospital to record their EHG signals. These EHG signals were preprocessed and segmented into UCs and non-UCs. Then, the EHG features corresponding to UCs and non-UCs were extracted, respectively, including power spectral density (PSD), root mean square (RMS), peak frequency (PF), median frequency (MDF), and sample entropy (SamEn). One-way ANOVA was employed to assess the difference between UCs and non-UCs. The results show that RE and CV were less than 8% and 0.03%, respectively, which indicated the high accuracy and repeatability of PregCare. The small differences of mean and standard deviation indicated the high agreement between PregCare and PowerLab. Besides, the PSD of UCs was much larger than non-UCs between 0 and 0.7 Hz. RMS of UCs was significantly larger than non-UCs (p < 0.05). PF and SamEn of UCs were significantly smaller than non-UCs (p < 0.05). In conclusion, the developed EHG recording system was able to record EHG signals reliably. It has the advantages of portability, low power consumption, and wireless transmission, which can be used for long-term monitoring of UCs and prediction of the preterm delivery.
Subject(s)
Electromyography , Signal Processing, Computer-Assisted , Uterine Contraction/physiology , Uterine Monitoring , Adult , Electromyography/instrumentation , Electromyography/methods , Equipment Design , Female , Humans , Pregnancy , Reproducibility of Results , Uterine Monitoring/instrumentation , Uterine Monitoring/methodsABSTRACT
Every intrauterine procedure begins with dilation of the cervix to enable insertion of surgical tools into the uterus. The 2 most common methods for this procedure (mechanical dilators and hygroscopic materials) are time-consuming or require anesthesia for the painful process of inserting metal or plastic rods of increasing diameter. Both methods expose the patient to increased risk of infection. Aqueduct-100 combines the advantages of both methods and provides safe and painless radial dilation of the cervix within minutes. The results of the study suggest that the Aqueduct-100 device should be used as an alternative to mechanical dilators to prevent injuries to the cervix and uterus during cervical dilations
Cada procedimiento intrauterino comienza con la dilatación del cuello del útero para la inserción de los instrumentos quirúrgicos en el útero. Los dos métodos más comunes para este procedimiento (dilatadores mecánicos y materiales higroscópicos) o bien toman mucho tiempo o requieren anestesia para un proceso doloroso que implica la inserción de varillas de metal o de plástico de diámetro creciente. Ambos métodos exponen al paciente a un mayor riesgo de infección. Aqueduct-100 combina las ventajas de los dos métodos y proporciona dilatación radial segura y sin dolor del cuello uterino, en cuestión de minutos. Los resultados del estudio sugieren que el dispositivo Aqueduct-100 se debe utilizar como una alternativa de los dilatadores mecánicos para prevenir lesiones uterinas y cervicales durante dilataciones cervicales
Subject(s)
Humans , Female , Uterine Monitoring/methods , Catheterization/methods , Dilatation/methods , Uterine Monitoring/instrumentation , Treatment OutcomeABSTRACT
The assessment of uterine contractions is important in clinical decision-making, but the precise role for appraising contractions remains controversial. Four clinical approaches to assessing contractions are available: manual palpation; intrauterine pressure determination; external tocodynamometry; and electrohysterography. Palpation is inexpensive and harmless but requires the constant bedside presence of a trained observer. Intrauterine pressure measurement is considered the most sensitive and specific technique, and has become the standard by which other methods are judged; however, its quantitative measurements are not always precise or reproducible. Moreover, the availability of intrauterine pressure measurements does not seem to improve maternal or neonatal outcomes in most situations. External tocodynamometry is the most widely used technique. It is easy to apply and provides reasonably accurate information about the frequency and duration of contractions, but not their amplitude. It can require frequent adjustment during labor and might not work well in patients who are obese. Electrohysterography is a recently available noninvasive technology that detects uterine electrical activity using electrodes placed on the mother's abdominal wall. This approach is at least as reliable and accurate as tocodynamometry.
Subject(s)
Electromyography/methods , Labor, Obstetric , Uterine Contraction , Uterine Monitoring/methods , Electromyography/instrumentation , Female , Humans , Pregnancy , Prenatal Care , Uterine Monitoring/instrumentationABSTRACT
OBJECTIVE: Tocodynamometry is the most common method of labor evaluation but most clinicians would agree it has limited utility before 26 weeks of gestation. The obesity epidemic has further reduced our ability to accurately detect uterine contractions using the tocodynamometer at any gestational age. We sought to design and test a novel contraction monitor that bypasses the maternal abdomen. METHODS: An optimized version of an intravaginal electrohysterographic ring device was tested in an ovine model. The device and its methodology as well as the tocodynamometer were validated against the current gold standard uterine activity monitor, the intrauterine pressure catheter in six sheep at varying gestational ages. RESULTS: Both the intravaginal ring device and the tocodynamometer correlated well with IUPC, r = 0.69 and 0.73, respectively (p < 0.001). The number of contractions detected by each monitor remained similar even after accounting for confounders. CONCLUSIONS: These results suggest that uterine activity can be monitored from the vaginal interface in an ovine model and offers an alternative clinical tool for the detection of contractions in situations, in which tocodynamometry would be ineffective or intrauterine monitoring inappropriate.
Subject(s)
Uterine Monitoring/instrumentation , Animals , Female , Models, Animal , Pregnancy , Sheep , Uterine ContractionABSTRACT
INTRODUCTION: The goal was to test a newly developed pneumatic tocodynamometer (pTOCO) that is disposable and lightweight, and evaluate its equivalence to the standard strain gauge-based tocodynamometer (TOCO). MATERIAL AND METHODS: The equivalence between the devices was determined by both mechanical testing and recording of contractile events on women. The data were recorded simultaneously from a pTOCO prototype and standard TOCO that were in place on women who were undergoing routine contraction monitoring in the Labor and Delivery unit at the University of Arkansas for Medical Sciences. In this prospective equivalence study, the output from 31 recordings on 28 pregnant women that had 171 measureable contractions simultaneously in both types of TOCO were analyzed. The traces were scored for contraction start, peak and end times, and the duration of the event was computed from these times. RESULTS: The response curve to loaded weights and applied pressure were similar for both devices, indicating their mechanical equivalence. The paired differences in times and duration between devices were subjected to mixed-models analysis to test the pTOCO for equivalence with standard TOCOs using the two-one-sided tests procedure. The event times and duration analyzed simultaneously from both TOCO types were all found to be significantly equivalent to within ±10 s (all p-values ≤0.0001). CONCLUSION: pTOCO is equivalent to the standard TOCO in the detection of the timing and duration of uterine contractions. pTOCO would provide a lightweight, disposable alternative to commercially available standard TOCOs.
Subject(s)
Disposable Equipment , Uterine Contraction/physiology , Uterine Monitoring/instrumentation , Adolescent , Adult , Female , Humans , Pregnancy , Prospective Studies , Time Factors , Young AdultABSTRACT
Cardiotocographic (CTG) monitors are complex electronic devices developed to acquire, process and display foetal heart rate (FHR) and uterine contraction (UC) signals. This chapter describes the main characteristics of current CTG monitors, in order to allow a better understanding of the technology. An ultrasound transducer is used for the external monitoring of FHR signals, whereas a tocodynamometer is used for the external monitoring of UCs. These technologies are recommended for routine clinical use in both the antepartum and intrapartum periods. Foetal electrode and intrauterine pressure sensors provide internal monitoring of FHR and UC signals, respectively, which are more precise than external signals. They are only applicable during labour, after cervical dilatation and ruptured membranes, and they have established contraindications. The registration of foetal movements, simultaneous monitoring of twins and triplets, continuous maternal heart rate monitoring, monitoring of other maternal parameters, alarms, digital outputs and telemetry are other available characteristics in some CTG monitors.
Subject(s)
Cardiotocography/instrumentation , Electrodes , Heart Rate, Fetal , Ultrasonography/instrumentation , Uterine Monitoring/instrumentation , Cardiotocography/methods , Female , Fetal Monitoring , Humans , Labor, Obstetric , Pregnancy , Scalp , Uterine Contraction , Uterine Monitoring/methodsABSTRACT
The recent past years have seen a noticeable increase of interest in the correlation analysis of electrohysterographic (EHG) signals in the perspective of improving the pregnancy monitoring. Here we propose a new approach based on the functional connectivity between multichannel (4×4 matrix) EHG signals recorded from the women's abdomen. The proposed pipeline includes i) the computation of the statistical couplings between the multichannel EHG signals, ii) the characterization of the connectivity matrices, computed by using the imaginary part of the coherence, based on the graph-theory analysis and iii) the use of these measures for pregnancy monitoring. The method was evaluated on a dataset of EHGs, in order to track the correlation between EHGs collected by each electrode of the matrix (called `node-wise' analysis) and follow their evolution along weeks before labor. Results showed that the strength of each node significantly increases from pregnancy to labor. Electrodes located on the median vertical axis of the uterus seemed to be the more discriminant. We speculate that the network-based analysis can be a very promising tool to improve pregnancy monitoring.
Subject(s)
Labor, Obstetric/physiology , Myometrium/physiology , Uterine Monitoring/methods , Electrodes , Electrodiagnosis/instrumentation , Electrodiagnosis/methods , Female , Humans , Pregnancy , Signal Processing, Computer-Assisted , Uterine Contraction/physiology , Uterine Monitoring/instrumentation , Uterus/physiologyABSTRACT
Monitoring contractions during labour using the external tocodynamometer can be difficult or even impossible, and using the invasive intrauterine pressure catheter is associated with rare but serious complications. A new non-invasive technique is currently available: electrohysterography (EHG). This technique converts the electrical activity of the uterine muscle into a legible tocogram. The EHG signal has a high correlation with the intra-uterine pressure and provides a more accurate assessment of uterine activity compared to external tocodynamometry. EHG is suitable for women in labour with failure of the external tocodynamometer. In clinical practice EHG also appeared to report a more detailed tocographic waveform, like hypertonia or unorganized electrical uterine activity. However, its signal quality depends on adequate skin preparation and correct positioning of the electrodes on the maternal abdomen. Hence, with electrohysterography as non-invasive alternative for uterine monitoring, choosing between safety and accuracy is no longer necessary.
Subject(s)
Electromyography/methods , Uterine Contraction/physiology , Uterine Monitoring/methods , Female , Humans , Labor, Obstetric , Pregnancy , Uterine Monitoring/instrumentationABSTRACT
BACKGROUND: To reduce the morbidity and mortality associated with preterm birth, home uterine activity monitoring aims for early detection of increased contraction frequency, and early intervention with tocolytic drugs to inhibit labour and prolong pregnancy. However, the effectiveness of such monitoring is disputed. OBJECTIVES: To determine whether home uterine activity monitoring is effective in improving the outcomes for women and their infants considered to be at high risk of preterm birth, when compared with conventional or other care packages that do not include home uterine monitoring. SEARCH METHODS: We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (31 October 2014), CENTRAL (The Cochrane Library 2014, Issue 8), MEDLINE (1966 to 31 August 2014), EMBASE (1974 to 31 August 2014), CINAHL (1982 to 31 August 2014) and scanned reference lists of retrieved studies. SELECTION CRITERIA: Randomised control trials of home uterine activity monitoring, with or without patient education programmes, for women at risk for preterm birth, in comparison to the same care package without home uterine activity monitoring. DATA COLLECTION AND ANALYSIS: Two review authors independently assessed trials for inclusion and risk of bias, extracted data and checked them for accuracy. We did not attempt to contact authors to resolve queries. MAIN RESULTS: There were 15 included studies (total number of enrolled participants 6008); 13 studies contributed data. Women using home uterine monitoring were less likely to experience preterm birth at less than 34 weeks (risk ratio (RR) 0.78; 95% confidence interval (CI) 0.62 to 0.99; three studies, n = 1596; fixed-effect analysis) (GRADE high). The significant difference was not evident when we carried out a sensitivity analysis, restricting the analysis to studies at low risk of bias based on study quality (RR 0.75; 95% CI 0.57 to 1.00, one study, 1292 women). There was no significant difference in the rate of perinatal mortality (RR 1.22; 95% CI 0.86 to 1.72; two studies, n = 2589) (GRADE low)There was no significant difference in the number of preterm births at less than 37 weeks (average RR 0.85; CI 0.72 to 1.01; eight studies, n = 4834; random-effects, T² = 0.03, I² = 68%) (GRADE very low). Infants born to women using home uterine monitoring were less likely to be admitted to neonatal intensive care unit (average RR 0.77; 95% CI 0.62 to 0.96; five studies, n = 2367; random-effects, T² = 0.02, I² = 32%) (GRADE moderate). The difference was not statistically significant when only high quality studies were included (RR 0.86; 95% CI 0.74 to 1.01; one study, n = 1292). Women using home uterine monitoring made more unscheduled antenatal visits (mean difference (MD) 0.49; 95% CI 0.39 to 0.62; two studies, n = 3707) (GRADE moderate). Women using home uterine monitoring were also more likely to have prophylactic tocolytic drug therapy (average RR 1.21; 95% CI 1.01 to 1.45; seven studies, n = 4316; random-effects. T² = 0.03, I² = 62%) but this difference was no longer significant when the analysis was restricted to higher quality studies (average RR 1.22; 95% CI 0.90 to 1.65, three studies, n = 3749,random-effects, T² = 0.05, I² = 76%) (GRADE low). One small study reported that the home uterine monitoring group spent fewer days in hospital antenatally. No data on maternal anxiety or acceptability were found. AUTHORS' CONCLUSIONS: Home uterine monitoring may result in fewer admissions to a neonatal intensive care unit but more unscheduled antenatal visits and tocolytic treatment, but the level of evidence is generally low to moderate. Important group differences were not evident when sensitivity analysis was undertaken using only high quality trials. There is no impact on maternal and perinatal outcomes such as perinatal mortality or incidence of preterm birth.
Subject(s)
Obstetric Labor, Premature/diagnosis , Uterine Monitoring/methods , Early Diagnosis , Female , Humans , Infant, Newborn , Perinatal Mortality , Pregnancy , Premature Birth/prevention & control , Randomized Controlled Trials as Topic , Sensitivity and Specificity , Uterine Monitoring/instrumentationABSTRACT
The conduction velocity and propagation patterns of the electrohysterogram (EHG) provide fundamental information on the electrophysiological condition of the uterus. However, the accuracy of these measurements can be impaired by both the poor spatial selectivity and sensitivity to the relative direction of the contraction propagation associated with conventional disc electrodes. Concentric ring electrodes could overcome these limitations. The aim of this study was to examine the feasibility of picking up surface EHG signals using a new flexible tripolar concentric ring electrode (TCRE), and to compare these signals with conventional bipolar recordings. Simultaneous recording of conventional bipolar signals and bipolar concentric EHG (BC-EHG) were carried out on 22 pregnant women. Signal bursts were characterized and compared. No significant differences were found between the channels in either duration or dominant frequency in the Fast Wave High frequency range. Nonetheless, the high pass filtering effect of the BC-EHG recordings gave lower frequency content between 0.1 and 0.2 Hz. Although the BC-EHG signal amplitude was about 5-7 times smaller than that of bipolar recordings, a similar signal-to-noise ratio was obtained. These results suggest that the flexible TCRE is able to pick up uterine electrical activity and could provide additional information for deducing the uterine electrophysiological condition.
Subject(s)
Electrodiagnosis , Electrophysiological Phenomena , Pregnancy/physiology , Uterine Monitoring , Uterus/physiology , Adult , Electrodes , Electrodiagnosis/instrumentation , Electrodiagnosis/methods , Female , Humans , Uterine Monitoring/instrumentation , Uterine Monitoring/methodsABSTRACT
Electrohysterography (EHG) is a noninvasive technique for monitoring uterine electrical activity. However, the presence of artifacts in the EHG signal may give rise to erroneous interpretations and make it difficult to extract useful information from these recordings. The aim of this work was to develop an automatic system of segmenting EHG recordings that distinguishes between uterine contractions and artifacts. Firstly, the segmentation is performed using an algorithm that generates the TOCO-like signal derived from the EHG and detects windows with significant changes in amplitude. After that, these segments are classified in two groups: artifacted and nonartifacted signals. To develop a classifier, a total of eleven spectral, temporal, and nonlinear features were calculated from EHG signal windows from 12 women in the first stage of labor that had previously been classified by experts. The combination of characteristics that led to the highest degree of accuracy in detecting artifacts was then determined. The results showed that it is possible to obtain automatic detection of motion artifacts in segmented EHG recordings with a precision of 92.2% using only seven features. The proposed algorithm and classifier together compose a useful tool for analyzing EHG signals and would help to promote clinical applications of this technique.
Subject(s)
Electromyography/methods , Uterine Contraction , Uterine Monitoring/methods , Uterus/diagnostic imaging , Algorithms , Artifacts , Female , Humans , Image Processing, Computer-Assisted , Labor, Obstetric , Models, Statistical , Motion , Pattern Recognition, Automated , Pregnancy , Reproducibility of Results , Signal Processing, Computer-Assisted , Software , Time Factors , Ultrasonography , Uterine Monitoring/instrumentationABSTRACT
AIM: To obtain and study new data on the dynamics of the labor process and to develop a contraction-based index of labor progress. METHODS: This study was carried out at the Delivery Room, Department of Obstetrics and Gynecology, Western Galilee Hospital, Nahariya, Israel, using a new device (Birth Track). We continuously monitored cervical dilatation (CD) and head descent (HD) in 30 nulliparaous women during active labor with (augmented group) and without (study group) oxytocin augmentation. This led to the development and validation of progress indices based on features extracted from continuous monitoring. RESULTS: There were no significant differences between the average of each parameter in the study and augmented groups, except for HD velocity. Average HD velocity was faster in the study group. Linear regression analyses demonstrated that head station (HS) amplitude and Toco amplitude were the best parameters for predicting HD velocity in both groups. In the study group, average HD velocity was also significantly related to Toco rate and contraction efficiency. In the augmented group, only a weak correlation with Toco rate was seen, and no correlation with contraction efficiency. CONCLUSION: With the assistance of the Birth Track device, we can obtain continuous data on the labor process and indices to estimate the labor progress process without the use of vaginal (manual) examination.
Subject(s)
Fetal Monitoring/methods , Labor Stage, First , Labor Stage, Second , Uterine Contraction , Uterine Monitoring/methods , Adult , Analgesia, Epidural , Analgesia, Obstetrical , Female , Fetal Monitoring/instrumentation , Humans , Israel , Labor Stage, First/drug effects , Labor Stage, Second/drug effects , Obstetrics and Gynecology Department, Hospital , Oxytocics , Oxytocin , Practice Guidelines as Topic , Pregnancy , Uterine Contraction/drug effects , Uterine Monitoring/instrumentation , Young AdultABSTRACT
BACKGROUND: Uterine contractions can be registered by external tocodynamometry (ET) or, after rupture of the membranes, by internal tocodynamometry (IT). Monitoring of the frequency of contractions is important especially when intravenous oxytocin is used as excessive uterine activity (hyperstimulation or tachysystole) can cause fetal distress. During induction of labour as well as during augmentation with intravenous oxytocin, some clinicians choose to monitor frequency and strength of contractions with IT rather than with ET as an intrauterine pressure catheter measures intrauterine activity more accurately than an extra-abdominal tocodynamometry device. However, insertion of an intrauterine catheter has higher costs and also potential risks for mother and child. OBJECTIVES: To assess the effectiveness of IT compared with using ET when intravenous oxytocin is used for induction or augmentation of labour. SEARCH METHODS: We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (31 March 2013) and PubMed (1966 to 6 April 2013). SELECTION CRITERIA: We included all published randomised controlled trials with data from women in whom IT was compared with ET in induced or augmented labour with oxytocin. We excluded trials that employed quasi-randomised methods of treatment allocation. We found no unpublished or ongoing studies on this subject. DATA COLLECTION AND ANALYSIS: Two review authors independently assessed trial eligibility and risk of bias, and independently extracted data. Data were checked for accuracy. Where necessary, we contacted study authors for additional information. MAIN RESULTS: Three studies involving a total of 1945 women were included. Overall, risk of bias across the three trials was mixed. No serious complications were reported in the trials and no neonatal or maternal deaths occurred. The neonatal outcome was not statistically different between groups: Apgar score less than seven at five minutes (RR 1.78, 95% CI 0.83 to 3.83; three studies, n = 1945); umbilical artery pH less than 7.15 (RR 1.31, 95% CI 0.95 to 1.79; one study, n = 1456); umbilical artery pH less than 7.16 (RR 1.23, 95% CI 0.39 to 3.92; one study, n = 239); admission to the neonatal intensive care unit (RR 0.34, 95% CI 0.07 to 1.67; two studies, n = 489); and more than 48 hours hospitalisation (RR 0.92, 95% CI 0.71 to 1.20; one study, n = 1456). The pooled risk for instrumental delivery (including caesarean section, ventouse and forceps extraction) was not statistically significantly different (RR 1.05, 95% CI 0.91 to 1.21; three studies, n = 1945). Hyperstimulation was reported in two studies (n = 489), but there was no statistically significant difference between groups (RR 1.21, 95% CI 0.78 to 1.88). AUTHORS' CONCLUSIONS: This review found no differences between the two types of monitoring (internal or external tocodynamometry) for any of the maternal or neonatal outcomes. Given that this review is based on three studies (N = 1945 women) of moderate quality, there is insufficient evidence to recommend the use of one form of tocodynamometry over another for women where intravenous oxytocin was administered for induction or augmentation of labour.
Subject(s)
Labor, Induced/methods , Oxytocics/administration & dosage , Oxytocin/administration & dosage , Uterine Contraction/physiology , Uterine Monitoring/methods , Female , Humans , Injections, Intravenous , Pregnancy , Pregnancy Outcome , Randomized Controlled Trials as Topic , Uterine Monitoring/instrumentationABSTRACT
OBJECTIVE: maternal mortality represents the single greatest health disparity between high and low income countries. This inequity is especially felt in low income countries in sub Saharan Africa and Southeast Asia where 99% of the global burden of maternal death is borne. A goal of MDG 5 is to reduce maternal mortality and have a skilled attendant at every birth by 2015. A critical skill is ongoing intrapartum monitoring of labour progress and maternal/fetal well-being. The WHO partograph was designed to assess these parameters. DESIGN AND SETTING: a retrospective review of charts (n=1,845) retrieved consecutively over a 2 month period in a tertiary teaching hospital in Ghana was conducted to assess the adequacy of partograph use by skilled birth attendants and the timeliness of action taken if the action line was crossed. WHO guidelines were implemented to assess the adequacy of partograph use and how this affected maternal neonatal outcomes. Further, the timeliness and type of action taken if action line was crossed was assessed. FINDINGS: partographs were adequately completed in accordance with WHO guidelines only 25.6% (472) of the time and some data appeared to be entered retrospectively. Partograph use was associated with less maternal blood loss and neonatal injuries. When the action line was crossed (464), timely action was taken only 48.7% of the time and was associated with less assisted delivery and a fewer low Apgar scores and NICU admissions. CONCLUSION: when adequately used and timely interventions taken, the partograph was an effective tool. Feasibility of partograph use requires more scrutiny; particularly identification of minimum frequency for safe monitoring and key variables as well as a better understanding of why skilled attendants have not consistently 'bought in' to partograph use. Frontline workers need access to ongoing and current education and strategically placed algorhythims.
Subject(s)
Diagnostic Equipment , Fetal Monitoring , Obstetric Labor Complications/diagnosis , Uterine Monitoring , Adolescent , Adult , Apgar Score , Cross-Sectional Studies , Diagnostic Equipment/statistics & numerical data , Female , Fetal Monitoring/instrumentation , Fetal Monitoring/methods , Ghana/epidemiology , Hospitals, Teaching/statistics & numerical data , Humans , Infant, Newborn , Labor, Obstetric , Maternal Mortality , Obstetric Labor Complications/epidemiology , Obstetric Labor Complications/prevention & control , Pregnancy , Pregnancy Outcome/epidemiology , Retrospective Studies , Uterine Monitoring/instrumentation , Uterine Monitoring/methodsABSTRACT
OBJECTIVE: Tocodynamometry (Toco; strain gauge technology) provides contraction frequency and approximate duration of labor contractions but suffers frequent signal dropout, necessitating repositioning by a nurse, and may fail in obese patients. The alternative invasive intrauterine pressure catheter (IUPC) is more reliable and adds contraction pressure information but requires ruptured membranes and introduces small risks of infection and abruption. Electrohysterography (EHG) reports the electrical activity of the uterus through electrodes placed on the maternal abdomen. This study compared all 3 methods of contraction detection simultaneously in laboring women. STUDY DESIGN: Upon consent, laboring women were monitored simultaneously with Toco, EHG, and IUPC. Contraction curves were generated in real-time for the EHG, and all 3 curves were stored electronically. A contraction detection algorithm was used to compare frequency and timing between methods. Seventy-three subjects were enrolled in the study; 14 were excluded due to hardware failure of 1 or more of the devices (n = 12) or inadequate data collection duration (n = 2). RESULTS: In comparison with the gold-standard IUPC, EHG performed significantly better than Toco with regard to the Contractions Consistency Index (CCI). The mean CCI for EHG was 0.88 ± 0.17 compared with 0.69 ± 0.27 for Toco (P < .0001). In contrast to Toco, EHG was not significantly affected by obesity. CONCLUSION: Toco does not correlate well with the gold-standard IUPC and fails more frequently in obese patients. EHG provides a reliable noninvasive alternative, regardless of body habitus.
Subject(s)
Electromyography/methods , Fetal Monitoring/methods , Labor, Obstetric/physiology , Uterine Contraction/physiology , Uterine Monitoring/methods , Uterus/physiology , Adult , Female , Humans , Pregnancy , Uterine Monitoring/instrumentationABSTRACT
The objective of this paper is to evaluate the novel method for analyzing the nonlinear correlation of the uterine electromyography (EMG). The application of this method may improve monitoring in pregnancy, labor detection, and preterm labor detection. Uterine EMG signals recorded from a 4 × 4 matrix of electrodes on the subjects' abdomen are used here. The propagation was analyzed using the nonlinear correlation coefficient h(2). Signals from 49 women (36 during pregnancy and 13 in labor) at different gestational age were used. ROC curves were computed to evaluate the potential of three methods to differentiate between 174 contractions recorded during pregnancy and 115 contractions recorded during labor. The results indicate considerably better performance of the nonlinear correlation analysis (area under curve = 0.85) when compared to classical frequency parameters (area under curve = 0.76 and 0.66) in distinguishing labor contractions from normal pregnancy contractions. We conclude that the analysis of the propagation of the uterine electrical activity using the nonlinear correlation coefficient h(2) is a promising way of improving the usefulness of uterine EMG signals for clinical purposes, such as monitoring in pregnancy, labor detection, and prediction of preterm labor.