Pathophysiological interpretation of fetal heart rate tracings in clinical practice

The onset of regular, strong, and progressive uterine contractions may result in both mechanical (compression of the fetal head and/or umbilical cord) and hypoxic (repetitive and sustained compression of the umbilical cord or reduction in uteroplacental oxygenation) stresses to a human fetus. Most fetuses are able to mount effective compensatory responses to avoid hypoxic-ischemic encephalopathy and perinatal death secondary to the onset of anaerobic metabolism within the myocardium, culminating in myocardial lactic acidosis. In addition, the presence of fetal hemoglobin, which has a higher affinity for oxygen even at low partial pressures of oxygen than the adult hemoglobin, especially increased amounts of fetal hemoglobin (ie, 180-220 g/L in fetuses vs 110-140 g/L in adults), helps the fetus to withstand hypoxic stresses during labor. Different national and international guidelines are currently being used for intrapartum fetal heart rate interpretation. These traditional classification systems for fetal heart rate interpretation during labor are based on grouping certain features of fetal heart rate (ie, baseline fetal heart rate, baseline variability, accelerations, and decelerations) into different categories (eg, category I, II, and III tracings, "normal, suspicious, and pathologic" or "normal, intermediary, and abnormal"). These guidelines differ from each other because of the features included within different categories and because of their arbitrary time limits stipulated for each feature to warrant an obstetrical intervention. This approach fails to individualize care because the "ranges of normality" for stipulated parameters apply to the population of human fetuses and not to the individual fetus in question. Moreover, different fetuses have different reserves and compensatory responses and different intrauterine environments (presence of meconium staining of amniotic fluid, intrauterine inflammation, and the nature of uterine activity). Pathophysiological interpretation of fetal heart rate tracing is based on the application of the knowledge of fetal responses to intrapartum mechanical and/or hypoxic stress in clinical practice. Both experimental animal studies and observational human studies suggest that, just like adults undertaking a treadmill exercise, human fetuses show predictable compensatory responses to a progressively evolving intrapartum hypoxic stress. These responses include the onset of decelerations to reduce myocardial workload and preserve aerobic metabolism, loss of accelerations to abolish nonessential somatic body movements, and catecholamine-mediated increases in the baseline fetal heart rate and effective redistribution and centralization to protect the fetal central organs (ie, the heart, brain, and adrenal glands), which are essential for intrauterine survival. Moreover, it is essential to incorporate the clinical context (progress of labor, fetal size and reserves, presence of meconium staining of amniotic fluid and intrauterine inflammation, and fetal anemia) and understand the features suggestive of fetal compromise in nonhypoxic pathways (eg, chorioamnionitis and fetomaternal hemorrhage). It is important to appreciate that the timely recognition of the speed of onset of intrapartum hypoxia (ie, acute, subacute, and gradually evolving) and preexisting uteroplacental insufficiency (ie, chronic hypoxia) on fetal heart rate tracing is crucial to improve perinatal outcomes.

A Bibliometric Analysis of Research Articles on Midwifery Based on the Web of Science

Objective

This study aimed to bibliometrically analyse the main features of the 100 top-cited articles on the midwifery index on the Web of Science.

Methods

Academic articles on midwifery' research published from 1985 to 2020 were included. VOSviewer 1.6.15, SPSS 22.0 software and a homemade applet were used to identify, analyse and visualise the citation ranking, publication year, journal, country and organisation of origin, authorship, journal impact factor and keywords along with the total link strength of countries, organisations and keywords.

Results

Among the 100 top-cited articles, the highest number of citations of the retrieved articles was 484. The median number of citations per year was 5.16 (interquartile range: 3.74-8.38). Almost two-thirds of the included articles (n = 61) centred on nursing and obstetrics/gynaecology. The top-cited articles were published in 38 different journals, the highest number of which was published by Midwifery (15%). Australia was the most productive country (24%). According to the total link strength, the sequence ran from the United States (28) to England (28) to Australia (19). The University of Technology Sydney and La Trobe University in Australia topped the list with four papers each. Hunter B was the most productive author (n = 4), and the average citations were positively related to the number of authors (r = 0.336, p < 0.05).

Conclusion

This study identified the most influential articles on midwifery and documented the core journals and the most productive countries, organisations and authors along with future research hotspots for this field; the findings may be beneficial to researchers in their publication and scientific cooperation endeavours.

Shared decision-making and maternity care in the deep learning age: Acknowledging and overcoming inherited defeaters

In recent years there has been an explosion of interest in Artificial Intelligence (AI) both in health care and academic philosophy. This has been due mainly to the rise of effective machine learning and deep learning algorithms, together with increases in data collection and processing power, which have made rapid progress in many areas. However, use of this technology has brought with it philosophical issues and practical problems, in particular, epistemic and ethical. In this paper the authors, with backgrounds in philosophy, maternity care practice and clinical research, draw upon and extend a recent framework for shared decision-making (SDM) that identified a duty of care to the client's knowledge as a necessary condition for SDM. This duty entails the responsibility to acknowledge and overcome epistemic defeaters. This framework is applied to the use of AI in maternity care, in particular, the use of machine learning and deep learning technology to attempt to enhance electronic fetal monitoring (EFM). In doing so, various sub-kinds of epistemic defeater, namely, transparent, opaque, underdetermined, and inherited defeaters are taxonomized and discussed. The authors argue that, although effective current or future AI-enhanced EFM may impose an epistemic obligation on the part of clinicians to rely on such systems' predictions or diagnoses as input to SDM, such obligations may be overridden by inherited defeaters, caused by a form of algorithmic bias. The existence of inherited defeaters implies that the duty of care to the client's knowledge extends to any situation in which a clinician (or anyone else) is involved in producing training data for a system that will be used in SDM. Any future AI must be capable of assessing women individually, taking into account a wide range of factors including women's preferences, to provide a holistic range of evidence for clinical decision-making.

Training in the use of intrapartum electronic fetal monitoring with cardiotocography: systematic review and meta‐analysis

Background

Sub‐optimal classification, interpretation and response to intrapartum electronic fetal monitoring using cardiotocography are known problems. Training is often recommended as a solution, but there is lack of clarity about the effects of training and which type of training works best.

Objectives

Systematic review of the effects of training healthcare professionals in intrapartum cardiotocography (PROSPERO protocol: CRD42017064525).

Search strategy

CENTRAL, Cochrane Library, MEDLINE, EMBASE, PsycINFO, British Nursing Database, CINAHL, ERIC, Scopus, Web of Science, ProQuest, grey literature and ongoing clinical trials were searched.

Selection criteria

Primary studies that reported impact of training healthcare professionals in intrapartum cardiotocography. Title/abstract, full‐text screening and quality assessment were conducted in duplicate.

Data collection and analysis

Data were synthesised both narratively and using meta‐analysis. Risk of bias and overall quality were assessed with the Mixed Methods Appraisal Tool and GRADE.

Main results

Sixty‐four studies were included. Overall, training and reporting were heterogeneous, the outcomes evaluated varied widely and study quality was low. Five randomised controlled trials reported that training improved knowledge of maternity professionals compared with no training, but evidence was of low quality. Evidence for the impact of cardiotocography training on neonatal and maternal outcomes was limited, showed inconsistent effects, and was of low overall quality. Evidence for the optimal content and method of delivery of training was very limited.

Conclusions

Given the scale of harm and litigation claims associated with electronic fetal monitoring, the evidence‐base for training requires improvement. It should address intervention design, evaluation of clinical outcomes and system‐wide contexts of sub‐optimal practice.

Tweetable abstract

Training in fetal monitoring: systematic review finds little evidence of impact on neonatal outcomes.

Training in fetal monitoring: systematic review finds little evidence of impact on neonatal outcomes.

A review of fetal cardiac monitoring, with a focus on low- and middle-income countries

There is limited evidence regarding the utility of fetal monitoring during pregnancy, particularly during labor and delivery. Developed countries rely on consensus 'best practices' of obstetrics and gynecology professional societies to guide their protocols and policies. Protocols are often driven by the desire to be as safe as possible and avoid litigation, regardless of the cost of downstream treatment. In high-resource settings, there may be a justification for this approach. In low-resource settings, in particular, interventions can be costly and lead to adverse outcomes in subsequent pregnancies. Therefore, it is essential to consider the evidence and cost of different fetal monitoring approaches, particularly in the context of treatment and care in low-to-middle income countries. This article reviews the standard methods used for fetal monitoring, with particular emphasis on fetal cardiac assessment, which is a reliable indicator of fetal well-being. An overview of fetal monitoring practices in low-to-middle income counties, including perinatal care access challenges, is also presented. Finally, an overview of how mobile technology may help reduce barriers to perinatal care access in low-resource settings is provided.

Clinician Identification of Birth Asphyxia Using Intrapartum Cardiotocography Among Neonates With and Without Encephalopathy in New Zealand

IMPORTANCE

Despite improvements in antenatal care and increasing cesarean delivery rates, birth asphyxia leading to neonatal encephalopathy (NE) continues to contribute to neonatal death and long-term neurodevelopmental disability. Cardiotocography (CTG) has been used in labor for several decades to detect a stressed fetus so that delivery can be expedited and NE avoided.

OBJECTIVE

To investigate whether experienced clinicians can detect and respond to abnormal readings from CTGs during the penultimate hour before birth in infants with moderate to severe NE but no acute peripartum event.

DESIGN, SETTING, AND PARTICIPANTS

This case-control study included 10 practicing obstetricians and midwives at maternity hospitals in New Zealand. Participants, who were masked to the perinatal outcome, were asked to assess CTG tracings from 35 neonates with NE and evidence of birth hypoxia (ie, cases) and 105 neonates without NE or birth hypoxia (ie, controls), all of whom were born in 2010 to 2011. Data analysis was conducted from May to December 2017.

EXPOSURES

Brief clinical details and 1 hour of CTG tracings from the penultimate hour before birth were provided for each baby. Clinicians assessed the CTG tracings and recommended a plan.

MAIN OUTCOMES AND MEASURES

Intra-assessor and interassessor agreement on CTG findings and action plans as well as sensitivity (ie, detection of NE) and specificity (ie, ruling out those without NE) for the assessment of abnormal CTG readings leading to immediate action (ie, fetal blood sample or immediate delivery) were reported.

RESULTS

A total of 35 infants (mean [SD] gestational age, 40 [1.4] weeks; 16 [45.7%] cesarean deliveries) were designated cases, and 105 infants (mean [SD] gestational age, 39.4 [1.2] weeks; 22 [21.0%] cesarean deliveries) were designated controls. No infants had congenital anomalies. The mean (range) sensitivity for detection of abnormal CTG results and for recommending immediate action for all assessors was 75% (63%-91%) and 41% (23%-57%), respectively, with a mean (range) specificity of 67% (53%-77%) and 87% (65%-99%), respectively. A sensitivity analysis including only assessors with 80% or more interassessor agreement only differed from the main analysis by 6% or less (mean [range] sensitivity for detection, 76% [63%-91%]; sensitivity for action plan, 36% [25%-49%]; specificity for detection, 71% [53%-77%]; and specificity for action plan, 93% [88%-99%]).

CONCLUSIONS AND RELEVANCE

Experienced clinicians detected 3 of 4 infants who were subsequently diagnosed with NE. Action to expedite delivery was recommended for more than 40% of infants with NE. These results indicate that CTG does not identify all infants at risk of NE, and that there is a need for further investment in new approaches to fetal surveillance in labor.

Intermittent auscultation fetal monitoring during labour: A systematic scoping review to identify methods, effects, and accuracy

BACKGROUND

Intermittent auscultation (IA) is the technique of listening to and counting the fetal heart rate (FHR) for short periods during active labour and continuous cardiotocography (CTC) implies FHR monitoring for longer periods. Although the evidence suggests that IA is the best way to monitor healthy women at low risk of complications, there is no scientific evidence for the ideal device, timing, frequency and duration for IA. We aimed to give an overview of the field, identify and describe methods and practices for performing IA, map the evidence and accuracy for different methods of IA, and identify research gaps.

METHODS

We conducted a systematic scoping review following the Joanna Briggs methodology. Medline, EMBASE, Cinahl, Maternity & Infant Care, Cochrane Library, SveMed+, Web of Science, Scopus, Lilacs and African Journals Online were searched for publications up to January 2019. We did hand searches in relevant articles and databases. Studies from all countries, international guidelines and national guidelines from Denmark, United Kingdom, United States, New Zealand, Australia, The Netherlands, Sweden, Denmark, and Norway were included. We did quality assessment of the guidelines according to the AGREEMENT tool. We performed a meta-analysis assessing the effects of IA with a Doppler device vs. Pinard device using methods described in The Cochrane Handbook, and we performed an overall assessment of the summary of evidence using the GRADE approach.

RESULTS

The searches generated 6408 hits of which 26 studies and 11 guidelines were included in the review. The studies described slightly different techniques for performing IA, and some did not provide detailed descriptions. Few of the studies provided details of normal and abnormal IA findings. All 11 guidelines recommended IA for low risk women, although they had slightly different recommendations on the frequency, timing, and duration for IA, and the FHR characteristics that should be observed. Four of the included studies, comprising 8436 women and their babies, were randomised controlled trials that evaluated the effect of IA with a Doppler device vs. a Pinard device. Abnormal FHRs were detected more often using the Doppler device than in those using the Pinard device (risk ratio 1.77; 95% confidence interval 1.29-2.43). There were no significant differences in any of the other maternal or neonatal outcomes. Four studies assessed the accuracy of IA findings. Normal FHR was easiest to identify correctly, whereas identifying periodic FHR patterns such as decelerations and saltatory patterns were more difficult.

CONCLUSION

Although IA is the recommended method, no trials have been published that evaluate protocols on how to perform it. Nor has any study assessed interrater agreements regarding interpretations of IA findings, and few have assessed to what degree clinicians can describe FHR patterns detected by IA. We found no evidence to recommend Doppler device instead of the Pinard for IA, or vice versa.

IMproving the practice of intrapartum electronic fetal heart rate MOnitoring with cardiotocography for safer childbirth (the IMMO programme): protocol for a qualitative study

INTRODUCTION

Suboptimal electronic fetal heart rate monitoring (EFM) in labour using cardiotocography (CTG) has been identified as one of the most common causes of avoidable harm in maternity care. Training staff is a frequently proposed solution to reduce harm. However, current approaches to training are heterogeneous in content and format, making it difficult to assess effectiveness. Technological solutions, such as digital decision support, have not yet demonstrated improved outcomes. Effective improvement strategies require in-depth understanding of the technical and social mechanisms underpinning the EFM process. The aim of this study is to advance current knowledge of the types of errors, hazards and failure modes in the process of classifying, interpreting and responding to CTG traces. This study is part of a broader research programme aimed at developing and testing an intervention to improve intrapartum EFM.

METHODS AND ANALYSIS

The study is organised into two workstreams. First, we will conduct observations and interviews in three UK maternity units to gain an in-depth understanding of how intrapartum EFM is performed in routine clinical practice. Data analysis will combine the insights of an ethnographic approach (focused on the social norms and interactions, values and meanings that appear to be linked with the process of EFM) with a systems thinking approach (focused on modelling processes, actors and their interactions). Second, we will use risk analysis techniques to develop a framework of the errors, hazards and failure modes that affect intrapartum EFM.

ETHICS AND DISSEMINATION

This study has been approved by the West Midlands-South Birmingham Research Ethics Committee, reference number: 18/WM/0292. Dissemination will take the form of academic articles in peer-reviewed journals and conferences, along with tailored communication with various stakeholders in maternity care.

Admission cardiotocography: A hospital based validation study

OBJECTIVE

Admission CTG is a short fetal heart rate (FHR) tracing recorded immediately at hospital admission to avoid unnecessary delay in action among pregnancies complicated by pre-existent fetal distress. There are different opinions regarding the value of the admission CTG, especially in low risk pregnancies.

STUDY DESIGN

A retrospective validation study from Karolinska University Hospital, Jan 2011 to June 2015 (total number of deliveries = 40,061). All women who underwent emergency cesarean section within one hour of admittance due to suspected fetal distress were identified. We assessed whether an admission CTG was performed, if it was beneficial for the decision to perform emergent cesarean delivery and if there were objective signs of fetal compromise or if it was performed unnecessarily. The main outcome was the benefit of the admission CTG in the decision to perform emergency cesarean delivery.

RESULTS

Eighty-eight cases (0.22%) fulfilled our inclusion criteria. Over 90% of these women (80/88) had objective evidence of compromised fetal well-being, i.e., indicating that emergent delivery was necessary. In 74% (54/73) of all cases was admission CTG determined to have been beneficial in the decision to perform cesarean delivery, equally effective of those classified as low- and high risk pregnancies before admission. In 28% (15/54) the CTG pathology was deemed difficult to identify by auscultation.

CONCLUSION

Admission CTG was deemed beneficial in 74% of both low- and high-risk pregnancies that were delivered by emergent cesarean section within one hour of admittance due to suspected fetal distress.

Comparative Effectiveness of ICA and PCA in Extraction of Fetal ECG From Abdominal Signals: Toward Non-invasive Fetal Monitoring

Non-adaptive signal processing methods have been successfully applied to extract fetal electrocardiograms (fECGs) from maternal abdominal electrocardiograms (aECGs); and initial tests to evaluate the efficacy of these methods have been carried out by using synthetic data. Nevertheless, performance evaluation of such methods using real data is a much more challenging task and has neither been fully undertaken nor reported in the literature. Therefore, in this investigation, we aimed to compare the effectiveness of two popular non-adaptive methods (the ICA and PCA) to explore the non-invasive (NI) extraction (separation) of fECGs, also known as NI-fECGs from aECGs. The performance of these well-known methods was enhanced by an adaptive algorithm, compensating amplitude difference and time shift between the estimated components. We used real signals compiled in 12 recordings (real01-real12). Five of the recordings were from the publicly available database (PhysioNet-Abdominal and Direct Fetal Electrocardiogram Database), which included data recorded by multiple abdominal electrodes. Seven more recordings were acquired by measurements performed at the Institute of Medical Technology and Equipment, Zabrze, Poland. Therefore, in total we used 60 min of data (i.e., around 88,000 R waves) for our experiments. This dataset covers different gestational ages, fetal positions, fetal positions, maternal body mass indices (BMI), etc. Such a unique heterogeneous dataset of sufficient length combining continuous Fetal Scalp Electrode (FSE) acquired and abdominal ECG recordings allows for robust testing of the applied ICA and PCA methods. The performance of these signal separation methods was then comprehensively evaluated by comparing the fetal Heart Rate (fHR) values determined from the extracted fECGs with those calculated from the fECG signals recorded directly by means of a reference FSE. Additionally, we tested the possibility of non-invasive ST analysis (NI-STAN) by determining the T/QRS ratio. Our results demonstrated that even though these advanced signal processing methods are suitable for the non-invasive estimation and monitoring of the fHR information from maternal aECG signals, their utility for further morphological analysis of the extracted fECG signals remains questionable and warrants further work.

Detection rate of fetal distress using contraction-dependent fetal heart rate variability analysis

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.

Cardiotocography interpretation skills and the association with size of maternity unit, years of obstetric work experience and healthcare professional background: a national cross-sectional study

INTRODUCTION

We aimed to examine whether cardiotocography (CTG) knowledge, interpretation skills and decision-making measured by a written assessment were associated with size of maternity unit, years of obstetric work experience and healthcare professional background.

MATERIAL AND METHODS

A national cross-sectional study in the setting of a CTG teaching intervention involving all 24 maternity units in Denmark. Participants were midwives (n = 1260) and specialists (n = 269) and residents (n = 142) in obstetrics and gynecology who attended a 1-day CTG course and answered a 30-item multiple-choice question test. Associations between mean test score and work conditions were analyzed using multivariable robust regression, in which the three variables were mutually adjusted.

RESULTS

Participants from units with > 3000 deliveries/year scored higher on the test than participants from units with < 1000 deliveries/year (3000-3999 deliveries/year: mean difference 0.8, p < 0.0001; > 4000 deliveries/year: mean difference 0.5, p = 0.006). Participants with < 15 years of work experience scored higher than participants with > 15 years of experience (15-20 years of experience: mean difference - 0.6, p = 0.007; > 20 years experience: mean difference - 0.9, p < 0.0001). No differences were detected concerning professional background.

CONCLUSIONS

CTG knowledge, interpretation skills and decision-making measured by a written assessment were positively associated with working in large maternity units and having < 15 years of obstetric work experience. This might indicate a challenge in maintaining CTG skills in small units and among experienced staff but could also reflect different levels of motivation, test familiarity and learning culture. Whether the findings are transferable to the clinical setting was not examined.

Reliability in cardiotocography interpretation - impact of extended on-site education in addition to web-based learning: an observational study

INTRODUCTION

Previous studies have shown poor reproducibility in cardiotocography (CTG) interpretation. Studies evaluating the Swedish web-based CTG-education program have not proven to increase accurate CTG assessments. The aim of this study was to evaluate whether an extended education can improve inter- and intra-observer reliability in CTG interpretation.

MATERIAL AND METHODS

Six obstetricians from two different departments interpreted 106 CTG tracings on two occasions. Both departments used a Swedish national web-based CTG education and test for training. One department had, in addition, an extended education program consisting of on-site lectures and oral examinations. Inter- and intra-observer agreements were calculated by simple or weighted kappa (κ) values for the five parameters assessed on CTG.

RESULTS

In both departments inter-observer and intra-observer κ showed moderate to excellent agreement (ranges for κ 0.41-0.76 and 0.65-0.93, respectively). Obstetricians at the department with extended CTG education had better inter-observer reliability for variability and accelerations. This was also the case for intra-observer reliability with the addition of baseline frequency. Both inter- and intra-observer agreement increased from moderate to substantial in both departments when decelerations were dichotomized into harmless (including early and simple variable decelerations) or hypoxic (including late, severe variable, prolonged and combined decelerations) (κ 0.63-0.78) compared with the current sub-classification of decelerations (κ 0.42-0.65).

CONCLUSIONS

Agreement in CTG interpretation was better than expected in both departments, especially when divided into harmless/hypoxic changes. Combination of different learning methods (web-based, on-site lectures and case discussion) might result in a better CTG interpretation agreement compared with web-based learning solely.

Agreement and accuracy using the FIGO, ACOG and NICE cardiotocography interpretation guidelines

INTRODUCTION

One of the limitations reported with cardiotocography is the modest interobserver agreement observed in tracing interpretation. This study compared agreement, reliability and accuracy of cardiotocography interpretation using the International Federation of Gynecology and Obstetrics, American College of Obstetrics and Gynecology and National Institute for Health and Care Excellence guidelines.

MATERIAL AND METHODS

A total of 151 tracings were evaluated by 27 clinicians from three centers where International Federation of Gynecology and Obstetrics, American College of Obstetrics and Gynecology and National Institute for Health and Care Excellence guidelines were routinely used. Interobserver agreement was evaluated using the proportions of agreement and reliability with the κ statistic. The accuracy of tracings classified as "pathological/category III" was assessed for prediction of newborn acidemia. For all measures, 95% confidence interval were calculated.

RESULTS

Cardiotocography classifications were more distributed with International Federation of Gynecology and Obstetrics (9, 52, 39%) and National Institute for Health and Care Excellence (30, 33, 37%) than with American College of Obstetrics and Gynecology (13, 81, 6%). The category with the highest agreement was American College of Obstetrics and Gynecology category II (proportions of agreement = 0.73, 95% confidence interval 0.70-76), and the ones with the lowest agreement were American College of Obstetrics and Gynecology categories I and III. Reliability was significantly higher with International Federation of Gynecology and Obstetrics (κ = 0.37, 95% confidence interval 0.31-0.43), and National Institute for Health and Care Excellence (κ = 0.33, 95% confidence interval 0.28-0.39) than with American College of Obstetrics and Gynecology (κ = 0.15, 95% confidence interval 0.10-0.21); however, all represent only slight/fair reliability. International Federation of Gynecology and Obstetrics and National Institute for Health and Care Excellence showed a trend towards higher sensitivities in prediction of newborn acidemia (89 and 97%, respectively) than American College of Obstetrics and Gynecology (32%), but the latter achieved a significantly higher specificity (95%).

CONCLUSIONS

With American College of Obstetrics and Gynecology guidelines there is high agreement in category II, low reliability, low sensitivity and high specificity in prediction of acidemia. With International Federation of Gynecology and Obstetrics and National Institute for Health and Care Excellence guidelines there is higher reliability, a trend towards higher sensitivity, and lower specificity in prediction of acidemia.

[Does the paper speed in fetal heart monitoring during labour influence the variability in the interpretation by professionals?]

OBJECTIVE

Assessing inter- and intra- observer agreement in the reading of fetal heart rate (FHR) between two different paper speeds (1 and 2cm/min) using FIGO classification.

MATERIAL AND METHODS

Single-centre experimental study consisting in reading 60minutes FHR tracings by six readers (3 midwives and 3 obstetricians) during 1cm and 2cm/min sessions within a period of three weeks. The reading guideline was based on FIGO classification. Inter- and intra-observer agreement was assessed thanks to Kappa coefficient (K) and percentage of agreement (PA) using the classification of FHR tracings drawn up by readers.

RESULTS

Intra-observer agreement reached 60% between the two paper speeds, and PA ranged from 48 to 67%. Inter-observer agreement was poor to moderate (K=0.42 for 1cm/min sessions and K=0.38 for 2cm/min sessions). Inter-observer agreement was significantly higher for normal tracings (PA ranged from 55.2% for 2cm/min sessions to 57.4% for 1cm/min sessions). The preterminal category had the lowest concordance rates (PA=19% for 1cm/min sessions and 20, 7% for 2cm/min sessions).

CONCLUSION

This study did not highlight significant differences in intra- and inter-observer variability between the two FHR paper speeds. The 1cm/min paper speed, which is commonly used in France, is more economical and gives a better bedside overview of FHR. Therefore, it should be recommended.

Using uterine activity to improve fetal heart rate variability analysis for detection of asphyxia during labor

During labor, uterine contractions can cause temporary oxygen deficiency for the fetus. In case of severe and prolonged oxygen deficiency this can lead to asphyxia. The currently used technique for detection of asphyxia, cardiotocography (CTG), suffers from a low specificity. Recent studies suggest that analysis of fetal heart rate variability (HRV) in addition to CTG can provide information on fetal distress. However, interpretation of fetal HRV during labor is difficult due to the influence of uterine contractions on fetal HRV. The aim of this study is therefore to investigate whether HRV features differ during contraction and rest periods, and whether these differences can improve the detection of asphyxia. To this end, a case-control study was performed, using 14 cases with asphyxia that were matched with 14 healthy fetuses. We did not find significant differences for individual HRV features when calculated over the fetal heart rate without separating contractions and rest periods (p  >  0.30 for all HRV features). Separating contractions from rest periods did result in a significant difference. In particular the ratio between HRV features calculated during and outside contractions can improve discrimination between fetuses with and without asphyxia (p  <  0.04 for three out of four ratio HRV features that were studied in this paper).

Intra- and interobserver agreement among obstetric experts in court regarding the review of abnormal fetal heart rate tracings and obstetrical management

OBJECTIVE

The objective of the study was to evaluate the intra- and interobserver agreement among obstetric experts in court regarding the retrospective review of abnormal fetal heart rate tracings and obstetrical management of patients with abnormal fetal heart rate during labor.

STUDY DESIGN

A total of 22 French obstetric experts in court reviewed 30 cases of term deliveries of singleton pregnancies diagnosed with at least 1 hour of abnormal fetal heart rate, including 10 cases with adverse neonatal outcome. The experts reviewed all cases twice within a 3-month interval, with the first review being blinded to neonatal outcome. For each case reviewed, the experts were provided with the obstetric data and copies of the complete fetal heart rate recording and the partogram. The experts were asked to classify the abnormal fetal heart rate tracing and to express whether they agreed with the obstetrical management performed. When they disagreed, the experts were asked whether they concluded that an error had been made and whether they considered the obstetrical management as the cause of cerebral palsy in children if any.

RESULTS

Compared with blinded review, the experts were significantly more likely to agree with the obstetric management performed (P < .001) and with the mode of delivery (P < .001) when informed about the neonatal outcome and were less likely to conclude that an error had been made (P < .001) or to establish a link with potential cerebral palsy (P = .003). The experts' intraobserver agreement for the review of abnormal fetal heart rate tracing and obstetrical management were both mediocre (kappa = 0.46-0.51 and kappa = 0.48-0.53, respectively). The interobserver agreement for the review of abnormal fetal heart rate tracing was low and was not improved by knowledge of the neonatal outcome (kappa = 0.11-0.18). The interobserver agreement for the interpretation of obstetrical management was also low (kappa = 0.08-0.19) but appeared to be improved by knowledge of the neonatal outcome (kappa = 0.15-0.32).

CONCLUSION

The intra- and interobserver agreement among obstetric experts in court for the review of abnormal fetal heart rate tracing and the appropriateness of obstetrical care is poor, suggesting a lack of objectivity of obstetrical expertise as currently performed in court.

Agreement on intrapartum cardiotocogram recordings between expert obstetricians

RATIONALE, AIMS AND OBJECTIVES

To evaluate obstetricians' inter- and intra-observer agreement on intrapartum cardiotocogram (CTG) recordings and to examine obstetricians' evaluations with respect to umbilical artery pH and base deficit.

METHODS

Nine experienced obstetricians annotated 634 intrapartum CTG recordings. The evaluation of each recording was divided into four steps: evaluation of two 30-minute windows in the first stage of labour, evaluation of one window in the second stage of labour and labour outcome prediction. The complete set of evaluations used for this experiment is available online. The inter- and intra-observer agreement was evaluated using proportion of agreement and kappa coefficient. Clinicians' sensitivity and specificity was computed with respect to umbilical artery pH, base deficit and to Apgar score at the fifth minute.

RESULTS

The overall proportion of agreement between clinicians reached 48% with 95% confidence intervals (CI) (CI: 47-50). Regarding the different classes, proportion of agreement ranged from 57% (CI: 54-60) for normal to 41% (CI: 36-46) for pathological class. The sensitivity of clinicians' majority vote to objective outcome was 39% (CI: 16-63) for the umbilical artery base deficit and 27% (CI: 16-42) for pH. The specificity was 89% (CI: 86-92) for both types of objective outcome.

CONCLUSIONS

The reported inter-/intra-observer variability is large and this holds irrespective of clinicians' experience or work place. The results support the need of modernized guidelines for CTG evaluation and/or objectivization and repeatability by introduction of a computerized approach that could standardize the process of CTG evaluation within the delivery ward.

Single versus pairwise interpretation of cardiotochography, a comparative study from six Swedish delivery units

OBJECTIVE

The aim of the study was to evaluate whether interpreting CTG pairwise brings about a higher level of correctly classified CTG recordings in a non-selected population of midwives and physicians.

STUDY DESIGN

A comparative study.

SETTING

Five delivery units in Stockholm and one delivery unit in Uppsala, with 1589, 3740, 3908, 4539, 6438, and 7331 deliveries in 2011, respectively.

SUBJECTS

536 midwives and physicians classified one randomly selected CTG recording individually followed by a pairwise classification. The pairs consisted of two midwives (119 pairs) or one midwife and one physician (149 pairs), a total of 268 pairs.

MAIN OUTCOME MEASURE

The proportion of individually correctly classified CTG recordings versus the proportion of pairwise correctly classified CTG recordings.

RESULTS

The proportion of individually correctly classified CTG's was 75% and the proportion of pairwise correctly classified CTG's was 80% (difference 5%, p = 0.12).

CONCLUSIONS

There was no statistically significant difference when CTG's were classified pairwise compared to individual classifications. The proportion of individually correctly classified CTG's was high (75%). There were differences in the proportion of correctly classified CTG recordings between the delivery units, indicating potential areas of improvement.

Analysis of obstetricians' decision making on CTG recordings

Interpretation of cardiotocogram (CTG) is a difficult task since its evaluation is complicated by a great inter- and intra-individual variability. Previous studies have predominantly analyzed clinicians' agreement on CTG evaluation based on quantitative measures (e.g. kappa coefficient) that do not offer any insight into clinical decision making. In this paper we aim to examine the agreement on evaluation in detail and provide data-driven analysis of clinical evaluation. For this study, nine obstetricians provided clinical evaluation of 634 CTG recordings (each ca. 60min long). We studied the agreement on evaluation and its dependence on the increasing number of clinicians involved in the final decision. We showed that despite of large number of clinicians the agreement on CTG evaluations is difficult to reach. The main reason is inherent inter- and intra-observer variability of CTG evaluation. Latent class model provides better and more natural way to aggregate the CTG evaluation than the majority voting especially for larger number of clinicians. Significant improvement was reached in particular for the pathological evaluation - giving a new insight into the process of CTG evaluation. Further, the analysis of latent class model revealed that clinicians unconsciously use four classes when evaluating CTG recordings, despite the fact that the clinical evaluation was based on FIGO guidelines where three classes are defined.

Open access intrapartum CTG database

Background

Cardiotocography (CTG) is a monitoring of fetal heart rate and uterine contractions. Since 1960 it is routinely used by obstetricians to assess fetal well-being. Many attempts to introduce methods of automatic signal processing and evaluation have appeared during the last 20 years, however still no significant progress similar to that in the domain of adult heart rate variability, where open access databases are available (e.g. MIT-BIH), is visible. Based on a thorough review of the relevant publications, presented in this paper, the shortcomings of the current state are obvious. A lack of common ground for clinicians and technicians in the field hinders clinically usable progress. Our open access database of digital intrapartum cardiotocographic recordings aims to change that.

Description

The intrapartum CTG database consists in total of 552 intrapartum recordings, which were acquired between April 2010 and August 2012 at the obstetrics ward of the University Hospital in Brno, Czech Republic. All recordings were stored in electronic form in the OB TraceVue®;system. The recordings were selected from 9164 intrapartum recordings with clinical as well as technical considerations in mind. All recordings are at most 90 minutes long and start a maximum of 90 minutes before delivery. The time relation of CTG to delivery is known as well as the length of the second stage of labor which does not exceed 30 minutes. The majority of recordings (all but 46 cesarean sections) is – on purpose – from vaginal deliveries. All recordings have available biochemical markers as well as some more general clinical features. Full description of the database and reasoning behind selection of the parameters is presented in the paper.

Conclusion

A new open-access CTG database is introduced which should give the research community common ground for comparison of results on reasonably large database. We anticipate that after reading the paper, the reader will understand the context of the field from clinical and technical perspectives which will enable him/her to use the database and also understand its limitations.

Learning dependencies among fetal heart rate features using Bayesian networks

We present preliminary results on the use of Bayesian-network (BN) structure learning algorithms for deciphering dependencies from amongst different fetal heart rate (FHR) features collected from a real database. We used a greedy search-and-score procedure known as the K2 algorithm for the estimation of the BN structure. The database consists of a collection of discrete-valued features quantifying presence of morphological changes as prescribed by expert guidelines (updated by the National Institute of Child Health and Human Development (NICHD)) and implemented as rule-based programs. We compare the results of structure learning to the expert-guided structure and use decision functions for classification using posterior probabilities. It was found that the BN estimated from structure learning algorithms had comparable classification performance, but fewer edges, leading to more efficient characterization of conditional probability tables (CPD's). Moreover, structure learning algorithms offer a method of learning novel correlations between FHR features that may be exploited for automatic categorization.

Antepartum evaluation of the fetus and fetal well being

Despite widespread use of many methods of antenatal testing, limited evidence exists to demonstrate effectiveness at improving perinatal outcomes. An exception is the use of Doppler ultrasound in monitoring high-risk pregnancies thought to be at risk of placental insufficiency. Otherwise, obstetricians should proceed with caution and approach the initiation of a testing protocol by obtaining an informed consent. When confronted with an abnormal test, clinicians should evaluate with a second antenatal test and consider administering betamethasone, performing amniocentesis to assess lung maturity, and/or repeating testing to minimize the chance of iatrogenic prematurity in case of a healthy fetus.

Assessment of features for automatic CTG analysis based on expert annotation

Cardiotocography (CTG) is the monitoring of fetal heart rate (FHR) and uterine contractions (TOCO) since 1960's used routinely by obstetricians to detect fetal hypoxia. The evaluation of the FHR in clinical settings is based on an evaluation of macroscopic morphological features and so far has managed to avoid adopting any achievements from the HRV research field. In this work, most of the ever-used features utilized for FHR characterization, including FIGO, HRV, nonlinear, wavelet, and time and frequency domain features, are investigated and the features are assessed based on their statistical significance in the task of distinguishing the FHR into three FIGO classes. Annotation derived from the panel of experts instead of the commonly utilized pH values was used for evaluation of the features on a large data set (552 records). We conclude the paper by presenting the best uncorrelated features and their individual rank of importance according to the meta-analysis of three different ranking methods. Number of acceleration and deceleration, interval index, as well as Lempel-Ziv complexity and Higuchi's fractal dimension are among the top five features.

"Every case of asphyxia can be used as a learning example". Conclusions from an analysis of substandard obstetrical care

AIM

To propose suggestions for improvements in care based on conclusions from studies on low Apgar scores and substandard care during labor.

SETTING AND PATIENTS

Studies on infants with low Apgar scores in a general obstetric population 2004-2006 and claims for financial compensation on the behalf of infants, based on the suspicion that substandard care in conjunction with childbirth has caused severe asphyxia or neonatal death in Sweden 1990-2005.

RESULTS

The most common flaws were related to insufficient fetal surveillance, defective interpretation of cardiotocography (CTG) tracings, not acting in a timely fashion on abnormal CTG, and the incautious use of oxytocin. Besides, in half of the infants a suboptimal mode of delivery added further trauma to the already asphyxiated infant. Additionally, resuscitation was unsatisfactory in many of these infants. The most critical flaw was defective compliance with the guidelines concerning ventilation and the early paging of skilled personnel in cases of imminent asphyxia or known complications during labor. In many case reports, the documentation of the neonatal resuscitation was insufficient to enable accurate and reliable evaluation.

CONCLUSIONS

Examples of proposed improvements in care during labor are the introduction of a permanent educational atmosphere with aside time for daily educational rounds and discussion, cooperation around the use of standardized terminology in CTG interpretation, the cautious use of oxytocin, and the routine paging of a pediatrician before birth in cases of complicated delivery or imminent asphyxia. The proposed interventions need to be evaluated in clinical trials in the future.

Observation on validity of the five-tier system for fetal heart rate pattern interpretation proposed by Japan Society of Obstetricians and Gynecologists

OBJECTIVE

To evaluate the five-tier classification of fetal heart rate (FHR) tracings recently proposed by Japan Society of Obstetricians and Gynecologists (JSOG).

METHODS

The database between January and June 2009 was reviewed for women in active labor at ?36 + 0 gestational weeks, with singleton fetuses in cephalic presentation and with umbilical artery blood gas analyses. Continuous FHR tracings were assessed according to the five-tier classification proposed by JSOG, where level 1 is normal, level 2 is subnormal and levels 3?5 are abnormal patterns.

RESULTS

A total of 341 parturient women were eligible for this study protocol. The median (range) of the levels in the first and the second stage of labor were 1 (1-4) and 2 (1-4), respectively (p < 0.001). Both pH and base excess of umbilical artery decreased with higher levels of FHR tracings interpretation (p < 0.01). Interventions resulting in delivery were more necessary in the first stage of labor than in the second stage of labor in cases of levels 3 and more.

CONCLUSIONS

Five-tier system for FHR tracing interpretation proposed by JSOG intercorrelates with the fetal acid-base balance well. Categorization of FHR tracings by uniform diagnostic criteria will be useful to standardize therapeutic strategy by sharing common perception among obstetrical staff.

Interobserver and intraobserver reliability of the NICHD 3-Tier Fetal Heart Rate Interpretation System

OBJECTIVE

Our purpose was to test the reliability of the Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD) 3-Tier Fetal Heart Rate (FHR) classification system.

STUDY DESIGN

Individual 15- to 20-minute FHR segments (n = 154) were independently reviewed without clinical data by 3 maternal-fetal medicine examiners and classified by NICHD category (I, II, III).

RESULTS

Interobserver reliability was moderate (kappa 0.45) and varied by NICHD category (category I moderate [kappa 0.48], category II moderate [kappa 0.44], and category III poor [kappa 0.0]). The intraobserver agreement ranged from substantial to perfect (kappa 0.74-1.0).

CONCLUSION

Interobserver agreement of 3-Tier FHR classification System was moderate for NICHD categories I and II. Agreement for category III tracings was poor mainly due to lack of agreement regarding absent vs minimal variability.

Automatic evaluation of intrapartum fetal heart rate recordings: a comprehensive analysis of useful features

Cardiotocography is the monitoring of fetal heart rate (FHR) and uterine contractions (TOCO), used routinely since the 1960s by obstetricians to detect fetal hypoxia. The evaluation of the FHR in clinical settings is based on an evaluation of macroscopic morphological features and so far has managed to avoid adopting any achievements from the HRV research field. In this work, most of the features utilized for FHR characterization, including FIGO, HRV, nonlinear, wavelet, and time and frequency domain features, are investigated and assessed based on their statistical significance in the task of distinguishing the FHR into three FIGO classes. We assess the features on a large data set (552 records) and unlike in other published papers we use three-class expert evaluation of the records instead of the pH values. We conclude the paper by presenting the best uncorrelated features and their individual rank of importance according to the meta-analysis of three different ranking methods. The number of accelerations and decelerations, interval index, as well as Lempel-Ziv complexity and Higuchi's fractal dimension are among the top five features.

ST analysis of fetal electrocardiography in labor

Since its introduction more than 40 years ago, electronic fetal monitoring has become widely used for intrapartum surveillance to determine fetal wellbeing in labor. Although fetal hypoxia and acidosis are reflected in changes in fetal heart rate, there is no evidence that cardiotocography has been effective in reducing neonatal morbidity related to fetal distress occurring during labor. Indeed the specificity of this tool is poor and in many instances the incorporation of electronic fetal monitoring into intrapartum care has merely led to an increase in medical intervention rather than an improvement in neonatal outcome. Fetal electrocardiography (ECG) analysis provides an additional method for assessing the response of the fetus to hypoxia and in particular to the development of metabolic acidosis. ST changes in the fetal ECG can be quantified with computational analysis, reducing subjective interpretation that has been problematic with traditional electronic fetal monitoring. Formal algorithms indicating appropriate points for intervention in labor have been designed. The fetal ECG has been shown to be a useful adjunct to traditional electronic fetal monitoring in several randomized controlled trials with evidence of reduced rates of neonatal encephalopathy and reduced rates of obstetric intervention.

Foetal monitoring: a woman-centred decision-making pathway

PROBLEM

Many midwives continue to use continuous foetal monitoring on low risk women in labour, despite evidence based clinical guidelines to the contrary. Continuous foetal monitoring has been linked to increased rates of medical intervention during labour and birth with no improvement in long term neonatal outcomes.

PARTICIPANTS

Midwives who used continuous foetal monitoring on low risk women in labour at two regional Queensland hospitals.

METHODS

This Grounded Theory study explored midwives' decision-making processes related to the use of continuous electronic foetal monitoring on low risk labouring women. Primary data were gathered in semi-structured interviews with five purposively selected midwives and concurrently analysed using Grounded Theory techniques of theoretical sampling and constant comparison.

FINDINGS

The midwives made the decision that led to continuous electronic foetal monitoring on low risk women at two key decision points during labour care; the first during the midwives' initial assessment of the woman and foetus, and the second when the midwives categorised the women as high or low risk. However, various factors impacted on these decisions including trust and staff workloads within a context of risk management and medical dominance. There was limited opportunity for women to be involved in the decision-making process about foetal monitoring and only partial information was provided prior to cardiotocography.

CONCLUSIONS

Consistent with current clinical guidelines which recommend open, consultative discussion with the woman about foetal monitoring and a partnership approach towards decision-making following informed choice, a woman-centred foetal monitoring decision-making pathway is proposed. This pathway is applicable in midwifery education, research and clinical practice to promote both evidence based practice and woman-centred decision-making.

The development and initiation of the NSW Department of Health interprofessional Fetal welfare Obstetric emergency Neonatal resuscitation Training project

BACKGROUND

The Fetal Welfare Obstetric emergency Neonatal resuscitation Training (FONT) project was initiated on a background of rising notifications of adverse events in NSW maternity units, the significant proportion of which were related to fetal welfare assessment.

AIMS

The aim of the study is to describe the development and introduction of the NSW state-wide interprofessional FONT project.

METHODS

Following development and risk assessment, FONT was launched in February 2008. The project consists of an online component and two face-to-face training days to be completed each 3 years; the first day for fetal welfare assessment and the second for obstetric and newborn emergencies. Eight, 2-day training sessions were conducted throughout NSW for FONT trainers. Each trainer underwent pre- and post-testing for changes in knowledge of fetal welfare assessment. The 2005-2008 NSW adverse event report numbers were assessed.

RESULTS

From 20 February to 17 April 2008, 240 trainers had been trained in fetal welfare assessment, and by the end of 2008 these trainers had trained 954 clinicians. There were significant improvements in the interpretation and management planning of electronic fetal heart rate patterns following training. Analysis of Severity Assessment Codes 1 and 2 showed no significant trend in the number of notifications for adverse events related to fetal welfare assessment.

CONCLUSIONS

In the first 11 months, 25% of the state's maternity practitioners had received training in the first stage of the FONT project. The FONT project has shown short-term improvements in learning and communication skills and in the participants of the project.

How often is a low Apgar score the result of substandard care during labour?

Please cite this paper as: Berglund S, Pettersson H, Cnattingius S, Grunewald C. How often is a low Apgar score the result of substandard care during labour? BJOG 2010;117:968-978. Objective To increase our knowledge of the occurrence of substandard care during labour. Design A population-based case-control study. Setting Stockholm County. Population Infants born in the period 2004-2006 in Stockholm County. Methods Cases and controls were identified from the Swedish Medical Birth Register, had a gestational age of >/=33 complete weeks, had planned for a vaginal delivery, and had a normal cardiotocographic (CTG) recording on admission. We compared 313 infants with an Apgar score of <7 at 5 minutes of age with 313 randomly selected controls with a full Apgar score, matched for year of birth. Main outcome measure Substandard care during labour. Results We found that 62% of cases and 36% of controls were subject to some form of substandard care during labour. In half of the cases and in 12% of the controls, CTG was abnormal for >/=45 minutes before birth. Fetal blood sampling was not performed in 79% of both cases and controls, when indicated. Oxytocin was provided without signs of uterine inertia in 20% of both cases and controls. Uterine contractions were hyperstimulated by oxytocin in 29% of cases and in 9% of controls, and the dose of oxytocin was increased despite abnormal CTG in 19% and 6% of cases and controls, respectively. Assuming that substandard care is a risk factor for low Apgar score, we estimate that up to 42% of the cases could be prevented by avoiding substandard care. Conclusions There was substandard care during labour of two-thirds of infants with a low Apgar score. The main reasons for substandard care were related to misinterpretation of CTG, not acting on an abnormal CTG in a timely fashion and incautious use of oxytocin.

Analysis of fetal heart rate in healthy and pathological pregnancies using wavelet-based features

In this paper, a new approach for feature extraction from the Fetal Heart Rate (FHR) signal is introduced. It considers the use of Continuous Wavelet Transform to extract wavelet-based features of FHR signal in order to discriminate the normal from the abnormal cases. The proposed methodology is tested on real data acquired before the beginning or during labor. The results proved the viability of the approach and its potential for further application.

[Fetal assessment of the labor admission in low risk pregnancies]

The assessment of fetal well-being at the beginning of labor must lead to an appropriate monitoring, adapted to the present risks. Even if some medical events are unforeseeable, three ways of reflexions get clear: abnormal maternofetal signs at the admission indicate the need for an increased monitoring (NP5); the reading of the medical file could reveal a high-risk pregnancy; at least, the realization of electronic fetal heart rate monitoring for any woman at the beginning of the labor is recommended: in case of normality, it remains a good criterion of a fetal good health. In this context of admission, there is no evidence supporting that other techniques (amnioscopy, acoustic test, echography, Doppler, etc.) could be beneficial in low-risk women and be recommended (NP5). Research is to be continued in this field.

Norwegian midwives’ perception of the labour admission test

OBJECTIVE

To explore what information and knowledge the labour admission test is perceived to provide and what meaning the test carries in the daily work of practising midwives.

DESIGN

In-depth interviews transcribed verbatim and analysed using the grounded theory technique.

SETTING

Four different labour wards in Norway.

PARTICIPANTS

A theoretical sample of 12 practising midwives.

FINDINGS

The core category "experiencing contradictions" was identified during the analyses, indicating that the midwives found conflicting interests within themselves, or between themselves and others when using the labour admission test. They experienced contradictions between professional identity and the increasing use of technology, between feeling safe and feeling unsafe and between having power and being powerless.

KEY CONCLUSIONS

The labour admission traces could be difficult to interpret, especially for newly qualified midwives. Some midwives thought that a labour admission trace could protect them in case of litigation. The hierarchy of power in the labour ward influences the use and interpretation of the labour admission test. Some midwives felt their professional identity threatened and that midwives in general are losing their traditional skills because of the increasing use of obstetric technology.

IMPLICATIONS FOR PRACTICE

The findings of the present study should be taken into consideration when changing practice to not routinely perform the labour admission test. There is also a need for further research on what effect the increasing use of obstetric technology has on traditional midwifery skills.

Intrapartum cardiotocography -- the dilemma of interpretational variation

OBJECTIVE

To evaluate and compare interobserver variation in interpretation of intrapartum cardiotocograms.

SUBJECTS

Fifteen senior (experience >4 years) and 16 junior (experience < or =4 years) obstetricians from 10 delivery units.

DESIGN

Thirty-one obstetricians interpreted intrapartum cardiotocographic (CTG) readings from 22 parturients.

METHODS

Inter-observer agreement in CTG interpretation and decision-making was assessed via proportions of agreement (Pa), with 95% confidence intervals (CI).

MAIN OUTCOME MEASURES

The level of inter-observer agreement was analyzed by calculating Pa values for CTG baseline, variability, early, variable and late decelerations, uterine tonus, power of contractions, hypertonus and clinical decision.

RESULTS

In assessments of normal cases the Pa were acceptable or good (0.63-0.82) as regards all CTG interpretation elements except for the power of contractions (0.24), but in assessments of abnormal cases the Pa values were lower (0.18-0.60). As regards clinical decisions, a higher Pa was found in cases without recommendation for intervention (0.63, 95% CI 0.62-0.64) than in cases with such recommendation (0.55, 95% CI 0.54-0.56). The Pa in the abnormal cases was better among senior than among junior obstetricians.

CONCLUSIONS

Inter-observer variation in interpretation of abnormal CTG readings and recommendations for intervention is relatively wide. To improve reliability, uniform classification and standardized training in CTG interpretation are needed, as well as increased use of computerized CTG.

Risk and security in childbirth

Risk and security are often defined as being complementary. Security is based on risk calculations, which undergo constant change. An increasing number of abnormalities can be uncovered in the human body, and more and more people are defined as being at risk for various diseases or at risk as child bearers. The aim of this paper is to examine the notion of risk, and to understand it in different ways as it is applied to childbirth. General and professional perspectives on risk are different; views vary as to what constitutes acceptable risk, and the association between normalcy and complications is socially and culturally determined. Figures for risk and reliability are not objective values. The safe and the risky are anchored in certain symbol systems. Alternative and dialogic notions have been introduced in conversations and thinking about risk, and medicalism and paternalism have been questioned. This questioning has thus far had little influence on clinical practice. The two opposite perspectives of risk and security in the area of pregnancy and birth should be taken into consideration. The childbearing woman has preferences of her own. Dialog with the health professional and information about professional facts and professional uncertainty should be offered.

Midwives' visual interpretation of intrapartum cardiotocographs: intra- and inter-observer agreement

AIM

This paper reports an examination of intra- and inter-observer agreement in midwives' visual interpretation of intrapartum cardiotocographs (CTGs).

BACKGROUND

The issue of intra- and inter-observer agreement in the interpretation of CTG interpretation has serious implications for the validity of electronic fetal heart rate monitoring and subsequent decisions on intrapartum management. However, no studies were found that assessed intra- and inter-observer agreement in midwives' interpretations of CTG tracings.

METHODS

Twenty-eight midwives independently interpreted three intrapartum CTG tracings on two separate occasions using a self-administered Cardiotocograph Interpretation Skills Test. Inter-rater agreement in interpretation was assessed by cross-tabulating the two sets of raw data obtained at time 1 and time 2 and computing Cohen's Kappa (kappa). Intra-rater agreement was assessed by computing kappa for each rater with the two sets of raw data (time 1 and time 2) obtained from each individual. The data were collected in 2000.

RESULTS

Overall intra-rater agreement ranged from 'fair to good' (kappa = 0.48) to 'excellent' (kappa = 0.92). Raters' classifications altered in 18% (n = 5) of cases for the normal tracing, in 29% (n = 8) for the suspicious tracing and in 11% (n = 3) for the pathological tracing. Inter-rater agreement was fair to good, with kappa statistics ranging from 0.65 to 0.74, respectively. Agreement was highest in the classification of decelerations (kappa = 0.79) and lowest in the assessment of baseline variability (kappa = 0.50). Overall inter-rater agreement was highest in the suspicious tracing (kappa = 0.77, excellent) and lowest in the normal tracing (kappa = 0.54, fair to good).

CONCLUSION

Inter- and intra-observer variability are intrinsic characteristics of the interpretation of intrapartum CTGs. Levels of agreement revealed degrees of variation that expose room for improvement. Efforts are needed to reduce inter- and intra-observer variation in interpretation of intrapartum CTG tracings. In addition, research should focus on the development and evaluation of non-invasive, low observer variability methods of intrapartum assessment of fetal well-being. The subjectivity of CTG interpretation and inconsistencies in interpretation should also be considered in intrapartum management, clinical audit and in medico-legal settings.

Foetal heart rate power spectrum response to uterine contraction

Cardiotocography is the most diffused prenatal diagnostic technique in clinical routine. The simultaneous recording of foetal heart rate (FHR) and uterine contractions (UC) provides useful information about foetal well-being during pregnancy and labour. However, foetal electronic monitoring interpretation still lacks reproducibility and objectivity. New methods of interpretation and new parameters can further support physicians' decisions. Besides common time-domain analysis, study of the variability of FHR can potentially reveal autonomic nervous system activity of the foetus. In particular, it is clinically relevant to investigate foetal reactions to UC to diagnose foetal distress early. Uterine contraction being a strong stimulus for the foetus and its autonomic nervous system, it is worth exploring the FHR variability response. This study aims to analyse modifications of the power spectrum of FHR variability corresponding to UC. Cardiotocographic signal tracts corresponding to 127 UC relative to 30 healthy foetuses were analysed. Results mainly show a general, statistically significant (t test, p<0.01) power increase of the FHR variability in the LF 0.03-0.2 Hz and HF 0.2-1 in correspondence of the contraction with respect to a reference tract set before contraction onset. Time evolution of the power within these bands was computed by means of time-varying spectral estimation to concisely show the FHR response along a uterine contraction. A synchronised grand average of these responses was also computed to verify repeatability, using the contraction apex as time reference. Such modifications of the foetal HRV that follow a contraction can be a sign of ANS reaction and, therefore, additional, objective information about foetal reactivity during labour.

Interobserver agreements in assessing 549 labor admission tests after a standardized training program

BACKGROUND

The labor admission test is a short cardiotocography (CTG) performed upon admission to the maternity ward. The aim of the present study is to examine interobserver agreements when the labor admission tests were assessed by midwives and obstetricians who had received training in interpreting CTG.

METHODS

Five hundred forty-nine high- and low-risk women who delivered at Hammer-fest Hospital were included. The tests were assessed by three midwives and three obstetricians who had completed a standardized training program. The traces were assessed as normal, intermediary, or abnormal. Weighted kappa (kappaw), proportion of agreement (Pa), and predictive values were calculated.

RESULTS

Between the pairs of observers, kappaw varied between 0.57 and 0.75; Pa for a normal test between 0.78 and 0.88, and Pa for an intermediary/abnormal test between 0.56 and 0.69. At a cutoff intermediary test, mean sensitivity was 0.43 (range=0.39 -- 0.48), specificity 0.75 (range=0.69 - 0.81, positive predictive value 0.13 (range=0.12 -- 0.15), negative predictive value 0.94 (range=0.94 -- 0.94), likelihood ratio (LR) for a positive test result 1.73 (range=1.53--1.99), and LR for a negative test result 0.76 (range=0.75--0.77).

CONCLUSIONS

Midwives and obstetricians who had completed the training program achieved good levels of agreements in assessing labor admission tests. The agreements in normal tests were better than those in intermediary/abnormal tests. Obstetric staff should be aware that there are disagreements in assessing labor admission tests; especially in tests assessed as intermediary/abnormal.