Midwives' attitudes toward the use of cardiotocograph (CTG) machines in labor units: A study in Jordan

BACKGROUND

The purpose of cardiotocograph (CTG) usage is to detect any alterations in fetal heart rate (FHR) early before they are prolonged and profound. However, the use of CTG machines on a routine basis is not an evidence-supported practice. There is no Jordanian study that assesses the midwives' attitudes toward this machine. This study aimed to identify Jordanian midwives' attitudes towards the use of cardiotocograph (CTG) machines in labor units, alongside examining the relationships between midwives' personal sociodemographic characteristics and such attitudes.

METHODS

A descriptive research design was used to identify Jordanian midwives' attitudes towards the use of CTG machines in both public and private labor units in Jordan. Data were collected using the valid and reliable tool designed by Sinclair (2001), and these were used to identify midwives' attitudes towards CTG usage. A total of 329 midwives working in the labor units of governmental and private hospitals in the center and north of Jordan participated in the study from May to July 2022.

RESULTS

The total mean score for the attitude scale was M = 3.14 (SD = 0.83). More than half of the sample (N = 187, 58.4 %) demonstrated a mean score greater than 3.14, however, which indicates generally positive attitudes toward CTG usage in labor units. Midwives working in private hospitals and those holding Bachelor's degrees had more positive attitudes toward the use of CTG machines.

CONCLUSION

This study provides new insights into the attitudes of Jordanian midwives towards CTG use in labor units. These suggest that it is critical to conduct training courses for registered midwives to help them develop and/or regain confidence and competence with respect to various key aspects of intrapartum care, including intermittent auscultation and the appropriate use of CTG.

Intrapartum Fetal Monitoring

Continuous electronic fetal monitoring was developed to screen for signs of hypoxic-ischemic encephalopathy, cerebral palsy, and impending fetal death during labor. Because these events have a low prevalence, continuous electronic fetal monitoring has a false-positive rate of 99%. The widespread use of continuous electronic fetal monitoring has increased operative and cesarean delivery rates without improved neonatal outcomes, but its use is appropriate in high-risk labor. Structured intermittent auscultation is an underused form of fetal monitoring; when employed during low-risk labor, it can lower rates of operative and cesarean deliveries with neonatal outcomes similar to those of continuous electronic fetal monitoring. However, structured intermittent auscultation remains difficult to implement because of barriers in nurse staffing and physician oversight. The National Institute of Child Health and Human Development terminology is used when reviewing continuous electronic fetal monitoring and delineates fetal risk by three categories. Category I tracings reflect a lack of fetal acidosis and do not require intervention. Category II tracings are indeterminate, are present in the majority of laboring patients, and can encompass monitoring predictive of clinically normal to rapidly developing acidosis. Presence of moderate fetal heart rate variability and accelerations with absence of recurrent pathologic decelerations provides reassurance that acidosis is not present. Category II tracing abnormalities can be addressed by treating reversible causes and providing intrauterine resuscitation, which includes stopping uterine-stimulating agents, fetal scalp stimulation and/or maternal repositioning, intravenous fluids, or oxygen. Recurrent deep variable decelerations can be corrected with amnioinfusion. Category III tracings are highly concerning for fetal acidosis, and delivery should be expedited if immediate interventions do not improve the tracing.

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.

Functionality and acceptability of a wireless fetal heart rate monitoring device in term pregnant women in rural Southwestern Uganda

BACKGROUND

Over 3 million stillbirths occur annually in sub Saharan Africa; most occur intrapartum and are largely preventable. The standard of care for fetal heart rate (FHR) assessment in most sub-Saharan African settings is a Pinard Stethoscope, limiting observation to one person, at one point in time. We aimed to test the functionality and acceptability of a wireless FHR monitor that could allow for expanded monitoring capacity in rural Southwestern Uganda.

METHODS

In a mixed method prospective study, we enrolled 1) non-laboring healthy term pregnant women to wear the device for 30 min and 2) non-study clinicians to observe its use. The battery-powered prototype uses Doppler technology to measure fetal cardiotocographs (CTG), which are displayed via an android device and wirelessly transmit to cloud storage where they are accessible via a password protected website. Prototype functionality was assessed by the ability to obtain and transmit a 30-min CTG. Three obstetricians independently rated CTGs for readability and agreement between raters was calculated. All participants completed interviews on acceptability.

RESULTS

Fifty pregnant women and 7 clinicians were enrolled. 46 (92.0%) CTGs were successfully recorded and stored. Mean scores for readability were 4.71, 4.71 and 4.83 (out of 5) with high agreement (intra class correlation 0.84; 95% CI 0.74 to 0.91). All pregnant women reported liking or really liking the device, as well as high levels of comfort, flexibility and usefulness of the prototype; all would recommend it to others. Clinicians described the prototype as portable, flexible, easy-to-use and a time saver. Adequate education for clinicians and women also seemed to improve correct usage and minimise concerns on safety of the device.

CONCLUSIONS

This prototype wireless FHR monitor functioned well in a low-resource setting and was found to be acceptable and useful to both pregnant women and clinicians. The device also seemed to have potential to improve the experience of the users compared with standard of care and expand monitoring capacity in settings where bulky, wired or traditional equipment are unreliable. Further research needs to investigate the potential impact and cost of such innovations to improve perinatal outcomes.

Evaluation of standardized, computerized Dawes/Redman heart-rate analysis based on different recording methods and in relation to fetal beat-to-beat heart rate variability

Dawes and Redman (DR) based their definition of short-term variation (STV) on the successive differences of mean inter-beat intervals dividing 1 min of cardiotocography recordings in 16 epochs of 3.75 s each. In contrast, heart rate variability (HRV) is based on the inter-beat intervals of discrete R peaks, also referred to as normal-to-normal (NN) intervals. Despite the historical achievements of DR in providing a robust method with the equipment available at the time to encourage the widespread use and creation of large databases, one must ask whether the STV (DR) parameter is reproducible using a different method of recording, and how much temporal information is actually lost by applying the averaging algorithm sketched above. We simultaneously performed both standard Oxford cardiotocography and transabdominal fetal electrocardiography recordings in 26 patients with low-risk singletons. In addition, we revisited our database of 418 standard fetal magnetocardiographic recordings, applying the DR algorithm to the fetal NN data and compared them to standard HRV parameters. The correlation between STV (DR) from cardiotocography and fetal electrocardiography was stronger that of either with short term fHRV from NN intervals. The methodological trade-off to gain STV as a robust parameter from heart rate traces of limited temporal resolution is accompanied by a loss of temporal information that, at the moment, only fetal magnetocardiography and, to a lesser extent, fetal electrocardiography may provide.

[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.

In a heartbeat. Our review of two intrapartum fetal monitors

Intrapartum fetal monitors help clinicians determine the well-being of the fetus during labor. However, with at least two heart rates involved (the mother's and the fetus's), the possibility exists that the measurements will be misrepresented. We evaluate two intrapartum monitors, basing our ratings primarily on their capability to alert the user to possible misrepresentation of fetal heart rates.

[Intrapartum foetal monitoring: from stethoscope to ST analysis of the ECG]

Since the 1970s, intrapartum monitoring of the distressed foetus has been managed by continuous registration of the foetal heart rate, together with uterine activity (cardiotocogram; CTG). Use of CTG without additional foetal information leads to unnecessary interventions because of the high number of false-positive signals. Foetal blood sampling (FBS) is a solution to this problem, but is not always consistently carried out. Automated ST analysis of the foetal electrocardiogram (STAN method), combined with the CTG, may lead to reduction of metabolic acidosis, fewer interventions and fewer foetal blood samples. A disadvantage of application of the STAN method is that it is based on visual interpretation of the CTG, with large inter- and intraobserver variability. In spite of this shortcoming the method may be promising.

A framework for standardized management of intrapartum fetal heart rate patterns

OBJECTIVE

The purpose of this study was to classify fetal heart rate (FHR) monitor patterns according to risk of fetal acidemia and risk of evolution to a more serious pattern and to use this information to construct a standardized process for FHR pattern management, with the ultimate aim of minimizing newborn infant acidemia without excessive obstetric intervention.

STUDY DESIGN

We have identified 134 FHR patterns that have been classified by baseline rate, baseline variability, and type of deceleration. Based on the best available evidence, we have assigned a risk of newborn infant acidemia or low 5-minute Apgar score to these patterns. We have also evaluated each pattern for the risk that the pattern would evolve further into a pattern with a higher risk of acidemia.

RESULTS

Each FHR pattern has been color-coded, from no threat of fetal acidemia (green, no intervention required) to severe threat of acidemia (red, rapid delivery recommended). Three intermediate categories (blue, yellow, and orange) require escalated informing of appropriate individuals for intervention and resuscitation (obstetrician, anesthesiologist, and neonatal resuscitator) and preparation for urgent delivery (eg, staff and surgical suite availability and conservative techniques to ameliorate the FHR patterns).

CONCLUSION

This framework is applicable potentially to the institutions where it was developed and will need to be modified for other situations, depending on the logistics, facilities, and personnel available. This may provide a framework for developing algorithms for the standardized management of FHR patterns during labor, which can be tested for validity.

Limitations of ST analysis in clinical practice: three cases of intrapartum metabolic acidosis

OBJECTIVE

To examine detailed intrapartum events in cases of neonatal metabolic acidosis despite monitoring using STAN (cardiotocography [CTG] plus ST waveform analysis of fetal electrocardiogram [ECG]).

DESIGN

Retrospective case review.

SETTING

High-risk pregnancies monitored by STAN.

METHODS

Case note review was performed in newborns with metabolic acidosis where no significant ST changes in the fetal ECG occurred prior to birth.

MAIN OUTCOME MEASURES

Metabolic acidosis.

RESULTS

Detailed review of three cases identified poor signal quality, difficulties in CTG interpretation, failure to comply with STAN clinical guidelines and deterioration of the CTG without ECG alert as the leading causes of these adverse outcomes.

CONCLUSIONS

The cases illustrate some of the pitfalls associated with the clinical application of the STAN technology which prevent severe metabolic acidosis being eradicated completely. It may be useful to expand the STAN guidelines protocol towards the identification of exceptional clinical situations, such as in our cases, and towards appropriate additional interventions, as this may lead to a further reduction in adverse neonatal outcomes.

Four years' experience with antepartum cardiotocography using telemedicine

We reviewed the first four years of experience with telemonitoring of patients with high-risk pregnancies. Nine peripheral units (eight in Campania, a region of south Italy, and one in Hungary) recorded cardiotocographic traces and transmitted them via modem to an operations centre at the University 'Federico II' in Naples, where the computerized analysis was performed. The medical report was returned to the peripheral unit via fax or email. Four thousand and twenty one traces were recorded: 2674 (67%) from 764 high-risk patients and 1347 (34%) from 499 patients at apparent low risk. The neonatal outcome was good overall. Questionnaires were sent to the operators working at the peripheral units to evaluate the acquisition of specific skills and their level of satisfaction. Sixty-six questionnaires about cardiotocographic trace interpretation were collected. The number of correct answers increased during the study. A total of 33 questionnaires about job satisfaction were collected. The answers showed that the operators gradually overcame their scepticism during the study. A total of 1098 questionnaires were answered by the patients. Their answers showed a moderate level of satisfaction. Telecardiotocography allowed the decentralization of prenatal surveillance.

How long does a fetal scalp blood sample take?

The study aim was to identify the time from a decision to perform a fetal blood sample to the result of the test being available. A total of 100 consecutive fetal scalp blood samples taken on women in labour were identified from the blood gas analysers on the delivery suite. Eighty-nine percent of attempts yielded a result. The median time taken was 18 minutes (interquartile range 12-25 minutes). In 9% of women, the result took longer than 30 minutes. This is important clinically when repeated testing is required or in the second stage when operative vaginal delivery is achievable. Furthermore, when retrospectively analysing cases with a poor outcome, the time to obtain a result needs to be taken into account when determining the time at which a baby could have been delivered.

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.

Marked fetal acidosis and specific changes in power spectrum analysis of fetal heart rate variability recorded during the last hour of labour

OBJECTIVE

To assess whether intrapartum acidosis affects specific components of fetal heart rate variability.

DESIGN

Prospective clinical study.

SETTING

Twelve Nordic delivery units.

SUBJECTS

Fetal heart rate variability was studied in 334 fetuses divided into two groups according to cord pH value: the acidotic group (cord arterial pH < 7.05 at birth, n= 15) and the control group (cord arterial pH > or =7.05 at birth, n= 319).

METHODS

In spectral analysis of fetal heart rate variability, frequencies were integrated over the total frequency band (0.04-1.0 Hz), low-frequency band (0.04-0.15 Hz) and high-frequency band (0.15-1.0 Hz). We also calculated the low-to-high frequency ratio.

MAIN OUTCOME MEASURES

The spectral bands of fetal heart rate variability were compared between the acidotic and control fetuses.

RESULTS

We found that during the last hour of monitoring, baseline fetal heart rate gradually decreased, whereas total, low-frequency and high-frequency fetal heart rate variability initially increased but then, near the delivery, decreased in the acidotic fetuses when compared with the controls. Low-to-high frequency ratio was greater in the acidotic group during the whole study period (P= 0.002). Cord artery pH was inversely associated with total fetal heart rate variability (P < 0.001), low-frequency fetal heart rate variability (P < 0.001) and low-to-high frequency ratio (P= 0.004).

CONCLUSIONS

Marked fetal acidosis was associated with frequency-specific changes in fetal heart rate variability as reflecting the compensation ability of autonomic nervous activation during the last hour of labour.

The quality of intrapartum fetal heart rate monitoring

OBJECTIVE

To determine the quality of fetal heart rate (FHR) recordings during the first and second stage of labor by quantifying the amount of fetal signal loss in relation to the method of monitoring: external ultrasound or directly via a scalp electrode.

STUDY DESIGN

Analysis of 239 intrapartum recordings stored between 1 January 2001 and 1 July 2001 from consecutive deliveries at the Vrije Universiteit Medical Center in Amsterdam. Singletons delivered via the vaginal route were included in the study. FHR recordings had duration of at least 1h prior to birth of the infant. Subdivision in three groups took place on the basis of the recording technique which had been used; i.e. ultrasound, scalp electrode or a combination of both methods. FHR data was obtained using HP-M1350 cardiotocographs. The status (pen on, pen off, maternal signal) and the mode of the signals were acquired. The duration of pen lifts and maternal signals was divided by the total duration of the recording. Statistical analyses were performed with the Mann-Whitney U-test and the Wilcoxon signed ranks test.

RESULTS

Recordings obtained via ultrasound demonstrated significantly more fetal signal loss than those obtained via the direct mode, particularly in the second stage. The FIGO criteria for fetal signal loss with external ultrasound were not fulfilled during this stage for about half the cases.

CONCLUSION

Intrapartum FHR monitoring via a scalp electrode provides far better quality FHR signals than external ultrasound and deserves a more prominent position in fetal surveillance than it currently has.

Cardiotocography and medicolegal issues

Obstetric litigation is on the increase. A review of litigation cases reveals that the majority of claims relating to the intrapartum period arise because the cardiotocograph- (CTG) was misinterpreted or because inappropriate action was taken in the presence of fetal heart rate abnormalities. Compulsory education and training in the interpretation of CTGs and in best practice are key factors in minimizing the threat of litigation. Newer methods, such as pulse oximetry or fetal electrocardiogram waveform analysis, can act as adjuncts to CTG and help to avoid birth asphyxia and hence litigation.

Multi-channel magnetocardiography for detecting beat morphology variations in fetal arrhythmias

OBJECTIVE

Over the last few years, a number of studies have shown that fetal magnetocardiography (fMCG) is useful in describing fetal cardiac activity. A 55-channel MCG system in Ulm was used to record fetal cardiac activity in 12 pregnant women (with normal fetal heart activity in echocardiography) and in 5 pregnant women in whom the echocardiography showed fetal arrhythmias.

METHOD

The recorded MCG data were treated in order to eliminate the maternal signal and three MCG channels with the best signals were used to emulate a standard electrocardiogram (ECG) recording so that standard MCG analysis could be performed.

RESULTS

The results in assessing fetal electrophysiology, demonstrating its potential, are presented here for two fetuses with recorded supraventricular extrasystoles (SVES) and for one with ventricular extrasystoles (VES). Concerning the SVES, the analysis software OMEGA was able to separate three different beat morphologies. The VES could be detected exactly and have been confirmed by postnatal ECG.

CONCLUSION

The beat morphology and the beat-to-beat variations allow new insights into the electrophysiology of the fetal heart.

Reproducibility and reliability of fetal cardiac time intervals using magnetocardiography

We investigated several factors which may affect the accuracy of fetal cardiac time intervals (CTI) determined in magnetocardiographic (MCG) recordings: observer differences, the number of available recording sites and the type of sensor used in acquisition. In 253 fetal MCG recordings, acquired using different biomagnetometer devices between the 15th and 42nd weeks of gestation, P-wave, QRS complex and T-wave onsets and ends were identified in signal averaged data sets independently by different observers. Using a defined procedure for setting signal events, interobserver reliability was high. Increasing the number of registration sites led to more accurate identification of the events. The differences in wave morphology between magnetometer and gradiometer configurations led to deviations in timing whereas the differences between low and high temperature devices seemed to be primarily due to noise. Signal-to-noise ratio played an important overall role in the accurate determination of CTI and changes in signal amplitude associated with fetal maturation may largely explain the effects of gestational age on reproducibility. As fetal CTI may be of value in the identification of pathologies such as intrauterine growth retardation or fetal cardiac hypertrophy, their reliable estimation will be enhanced by strategies which take these factors into account.

Inter-observer variation in assessment of 845 labour admission tests: comparison between midwives and obstetricians in the clinical setting and two experts

OBJECTIVE

To assess the inter-observer agreement in assessment of the labour admission test between midwives and obstetricians in the clinical setting and two experts in the non-clinical setting, the inter-observer agreement between two experts in the non-clinical setting and to what degree fetal distress in labour could be predicted by the two experts.

DESIGN

Observational study.

SETTING

The maternity unit of Hammerfest Hospital, Norway.

POPULATION

Eight hundred and forty-five high and low risk women.

METHOD

The labour admission test was first assessed by the midwife or obstetrician in the clinical setting, and was later assessed by two experts. The traces were assessed as normal, equivocal or ominous. Weighted kappa (kappaw), proportion of agreement (Pa) and predictive values were calculated.

MAIN OUTCOME MEASURES

Weighted kappa, proportion of agreement, sensitivity, positive predictive value and likelihood ratios.

RESULTS

Inter-observer agreement between Expert 1 and Expert 2: kappaw 0.38 (CI 0.31-0.46), Pa for reactive labour admission test 0.86 (CI 0.83-0.88) and Pa for equivocal/ominous test 0.33 (CI 0.26-0.40). Agreement between Expert 1 and midwives/obstetricians: kappaw 0.25 (CI 0.15-0.36), Pa for reactive labour admission test 0.89 (CI 0.87-0.91) and Pa for equivocal/ominous labour admission test 0.18 (CI 0.11-0.25). Agreement between Expert 2 and midwives/obstetricians: kappaw 0.28 (CI 0.20-0.37), Pa for reactive labour admission test 0.85 (CI 0.82-0.88) and Pa for equivocal/ominous test 0.20 (CI 0.14-0.26). Totally 5.9% of the newborns had fetal distress. At cutoff equivocal test, sensitivity was 0.22 and 0.31 in the two observers. Positive predictive values were 0.13 and 0.11. Likelihood ratio for a positive test was 2.30 and 1.92 and likelihood ratio for a negative test 0.86 and 0.83.

CONCLUSION

A labour admission test is still routine practice in most obstetric units in the Western world when there is little evidence on its benefits. The results from this study may provide some reconsideration for such practice, and for more research.

The combination of computerized cardiotocography and amniotic fluid index for the prediction of neonatal acidemia at birth: a modified biophysical profile

OBJECTIVE

To study the combination of computerized cardiotocography (cCTG) and the amniotic fluid index (AFI) in the prediction of neonatal acidemia at birth.

METHODS

A total of 89 singleton third-trimester high-risk pregnancies delivered by Cesarean section, with an AFI evaluated within 24 h from birth, and an antepartum cCTG performed within 6 h from delivery, were studied. The score was the sum of values for AFI (oligo/anhydramnios = 1, normal = 0) and cCTG (Dawes-Redman criteria, not met = 1, met = 0). The endpoint was to predict an abnormal neonatal outcome as defined by an umbilical artery pH of < or = 7.2.

RESULTS

Fifteen neonates had an umbilical artery pH of < 7.2. The combination of cCTG + AFI score was able to predict pH values (< or = 7.20) with an OR = 2.83 (p < 0.02). The diagnostic accuracy of the combination of cCTG + AFI was as follows: sensitivity 80%, specificity 58%, positive predictive value 28%, negative predictive value 83%.

COMMENT

We suggest that the cCTG + AFI score may be of value in the prediction of neonatal acidemia and help in the management of third-trimester high-risk pregnancies.

Fetal heart rate patterns in normal and ritodrine-treated pregnancies, detected by magnetocardiography

OBJECTIVE

The aim of the present study was to test the validity of magnetocardiography in the diagnosis of fetal heart rate arrhythmias in normal pregnancies, as compared to the number of arrhythmias reported in other series, which were detected by use of other diagnostic techniques. We also evaluated the influence of ritodrine on the fetal heart rhythm in pregnancies treated for the risk of preterm labor by means of magnetocardiography, in order to provide preliminary results that could be utilized in the future establishment of magnetocardiography as a screening procedure in the diagnosis and management of fetal arrhythmias.

METHODS

We performed a prospective study on two subgroups of pregnant women: one of 84 women with normal healthy singleton pregnancies and one of 68 pregnant women treated with ritodrine for the risk of preterm labor.

RESULTS

The prevalence of fetal arrhythmias in the first subgroup was 3.5% (3/84), while in the second subgroup the prevalence was 16% (11/68).

CONCLUSIONS

The incidence of fetal arrhythmias detected in our population of normal pregnancies was comparable to that reported in previous studies by use of other techniques. Results gained from the second subgroup, although not comparable to others, owing to lack of similar reports, led us to believe that magnetocardiography's advantages over conventional methods of fetal cardiac surveillance could highlight the technique as a useful screening procedure for the detection of preterm fetuses, which should be submitted to closer investigation, because of the arrhythmias caused by ritodrine infusion.

Computerised antenatal fetal heart rate recordings between 24 and 28 weeks of gestation

OBJECTIVE

To assess computerised fetal heart rate recordings between 24 and 28 weeks of gestation for gestation related differences.

DESIGN

Prospective, cross sectional observational study.

SETTING

Liverpool Women's Hospital.

POPULATION

112 women: 28 at 27 weeks, 30 at 26 weeks, 27 at 25 weeks and 27 at 24 weeks of gestation, respectively.

METHODS

Fetal heart recordings of 60 minutes duration were performed once in each pregnancy using the System 8000 fetal heart rate programme (System 8000, Oxford Sonicaid Ltd, Chichester, UK). For each gestational age, records were analysed for short term variation, basal heart rate, accelerations and time spent in high episodes.

RESULTS

The mean short term variation increased with gestation (P = 0.05). No record had a short term variation <4 msecs. There was no relationship between heart rate and increasing gestation. The mean number of accelerations per record increased with increasing gestation (P < 0.01). 20% of recordings showed no accelerations > 15 bpm. The mean duration spent in episodes of high variation increased with gestation (P = 0.05). 13% of recordings showed no time spent in high episodes. All fetuses had normal outcomes at delivery.

CONCLUSIONS

Absence of episodes of high variation or absence of accelerations is not an abnormal finding at lower gestations. The standard threshold of 4 msecs for short term variation appears to remain valid at lower gestations. These differences should be considered when using computerised CTG analysis at early gestations.

Evaluation of fetal heart monitoring in the first stage of labor

OBJECTIVE

To evaluate the usefulness of continuous electronic fetal heart rate (FHR) monitoring in the first stage of labor.

METHODS

A total of 814 pregnant women in labor without identifiable risk factors was divided into two groups. In group A (468 cases), continuous FHR monitoring began in the earliest phase of the first stage of labor (cervical dilatation < or = 4 cm), while in group B (346 cases) it began when the cervical dilatation was > 4 cm. Initial FHR tracings were normal in all 814 cases. The fetal monitoring findings were analyzed at 10-min intervals, and comparisons were made between the two groups concerning FHR findings and their correlation with the state of the newborns.

RESULTS

No significant difference was found between the two groups in the incidence of repetitive variable decelerations (1.9% and 1.7%, respectively); sporadic variable decelerations (9.2% and 8.7%, respectively); persistent repetitive late decelerations that resulted in Cesarean section (1.1% and 1.4%, respectively); or sporadic late decelerations (8.3% and 8.1%, respectively). One newborn from each group required intensive neonatal care.

CONCLUSIONS

The same tracing sufficiency of fetal stress was observed in the two groups. However, the manner of labor supervision in group B seemed to be more beneficial, because of greater maternal comfort, a lower necessity for personnel, lower consumption of cardiotocographic materials and the possibility of labor induction for more women. Since fetal monitoring is widely used, it is preferable to start continuous FHR monitoring when the dilatation of the cervix approximates 4-5 cm (second phase of the first stage of labor) without risk of fetal loss.

Managing nonreassuring fetal heart rate patterns before cesarean delivery. Compliance with ACOG recommendations

OBJECTIVE

To determine the rate of compliance with current American College of Obstetricians and Gynecologists (ACOG) recommendations for management of parturients undergoing cesarean delivery for persistent nonreassuring fetal heart rate (FHR) tracings.

STUDY DESIGN

We performed a retrospective chart review (July 1995-June 1998) of all parturients who underwent cesarean delivery for nonreassuring FHR tracings. Outcome measures included maneuvers for fetal assessment (scalp stimulation or scalp blood pH) and therapeutic interventions (tocolytic agents for reducing uterine activity or amnioinfusion). Patients with multiple gestations and cesarean delivery for other indications were excluded. Student's t test, chi 2 and Fisher's exact tests were used; odds ratio and 95% confidence interval were calculated. P < .05 was considered significant.

RESULTS

Cesarean delivery for persistent nonreassuring FHR patterns included 134 (3.6%) of the 3,671 deliveries during three years. Thirty patients produced intrapartum FHR tracings containing persistent variable decelerations; 12 (40%) of these patients received amnioinfusion. In only 37% (50/134) of cases was there a documented attempt at scalp or acoustic stimulation prior to delivery. Scalp pH was obtained in 15% (15/98) of patients whose cervix was at least 3 cm dilated. Tocolytic agents were used for intrauterine resuscitation in 25% (34/134) of cases; their use varied significantly (P = .006) with the type of FHR abnormality.

CONCLUSION

At our tertiary center, ACOG recommendations for management of nonreassuring intrapartum FHR tracings were used in a limited number of cases.

The development and validation of an algorithm for real-time computerised fetal heart rate monitoring in labour

OBJECTIVE

To develop and validate a computerised algorithm for the interpretation of the characteristics of fetal heart rate monitoring in labour.

DESIGN

Prospective observational study.

SETTING

Labour ward in a tertiary hospital.

SAMPLE

Intrapartum cardiotocograms from 24 pregnancies.

METHODS

A computerised algorithm was developed to assess the fetal heart baseline rate, variability, the number of accelerations and the number of decelerations. Twenty five minute segments of cardiotocograms were interpreted by the algorithm and also by seven expert reviewers independently. The reviewers were unaware of the outcome of labour. The reliability of the characteristics of cardiotocography and the validity of the computerised algorithm were assessed using the intraclass correlation coefficient and weighted kappa statistic for continuous and ordinal variables respectively.

RESULTS

The inter rater reliability of the baseline fetal heart rate and the number and type of decelerations was good (intraclass correlation coefficient 0.93, 0.93 and 0.79, respectively). The reliability of baseline variability (kappa = 0.27) and accelerations (intraclass correlation coefficient = 0.27) was poor. The computerised algorithm had good agreement with the reviewers for the baseline fetal heart rate (intraclass correlation coefficient 0.91 to 0.98) and the number of decelerations (intraclass correlation coefficient 0.82 to 0.91), but was less valid as regards the number of late decelerations (intraclass correlation coefficient 0.68 to 0.85) and the number of accelerations (intraclass correlation coefficient 0.06 to 0.80), and was invalid as regards baseline variability (kappa 0.00 to 0.34).

CONCLUSIONS

The high level of validity of the computerised algorithm for the estimation of the baseline fetal heart rate and the number of decelerations justifies its further technical development.

A comparison of performance by medical and midwifery students in multiprofessional teaching

AIM

At Dundee University, midwifery and medical students are taught obstetrics together in a 2-week intensive course. We set out to test the hypothesis that staff time and effort could be saved by using shared resources in teaching a multidisciplinary group of students to an acceptable level.

METHOD

In order to measure the knowledge gain by two different groups of students, we tested the students before and after a timetabled computer-assisted learning (CAL) session focusing on how to interpret a cardiotocograph (CTG). Also, half of each student group was given extra CTG teaching before the CAL session.

RESULTS

The medical students (n=38) increased their median score from 9 to 17 after the CAL (P<0.001) but the midwifery students (n=13) only increased their median score from 12 to 14 after the CAL (n.s.). However, when given a tutorial and CAL, the post-test scores for both medical and midwifery students were similar and significantly higher than pre-test scores (median score increase from 8.5 to 18 for medical students, P<0.001, n=34, and from 9 to 16 for midwifery students, P<0.01 n=11). There was no significant knowledge gain by the medical students who undertook the additional tutorial.

CONCLUSION

We conclude that shared resources could be used by medical and midwifery students to reach equivalent levels of skill in CTG interpretation. However, in order to achieve equivalence, staff time and effort was wasted as medical students were given unnecessary tuition.

The development and evaluation of a computer-assisted teaching programme for intrapartum fetal monitoring

OBJECTIVE

The development and evaluation of a computer-assisted teaching programme of cardiotocography and acid-base balance.

DESIGN

Randomised controlled trial.

PARTICIPANTS

One hundred and seventeen midwifery and obstetric staff at Derriford Hospital, Plymouth.

METHODS

The obstetricians and midwives were randomly allocated to use the teaching programme, either early or late. The late group (control) used the teaching programme three months after the early group. To assess the effect of the teaching programme, participants were tested on four occasions over eight months by a multiple choice questionnaire. Two questionnaires on ease of use were also completed.

MAIN OUTCOME MEASURES

Multiple choice questionnaire scores and opinion questionnaire results.

RESULTS

The mean score in the early group improved from 50-8% (test 1, pre-teaching programme) to 70.2% (test 2, post-teaching programme). The mean score in the control group was 50.3% (test 1) and 54.8% (test 2). Knowledge was retained up to seven months.

CONCLUSIONS

The teaching programme was effective in improving knowledge of acid-base balance and cardiotocography and can be used by all staff whilst on duty on the labour ward.

Using telemedicine to facilitate training in cardiotocography (CTG) interpretation

Electronic fetal monitoring is a controversial practice in modern obstetric care and is frequently an aspect of medicolegal cases involving the management of labour and delivery. The interpretation of the cardiotocograph (CTG) produced by such monitors is a skill required by those caring for the pregnant woman. Studies have shown that most 'experts' do not interpret CTGs in a consistent manner, when compared with either other experts or themselves. However, it has also been shown that consistency can be improved with training. Telemedicine has been used to advantage in the training of obstetrics and gynaecology registrars in CTG interpretation.

Inconsistencies in classification by experts of cardiotocograms and subsequent clinical decision

Inter-observer agreement in the interpretation according to the FIGO guidelines of 33 cardiotocographic tracings by experts and subsequent clinical decision was evaluated, using the kappa statistic (K) and the proportions of agreement (Pa). Overall agreement in the classification of tracings was fair (K = 0.48) and was better for normal (Pa = 0.62), than for suspicious (Pa = 0.42) or pathologic tracings (Pa = 0.25). Overall agreement on clinical decision was slightly higher (K = 0.59), but mostly was centred on the decision to take 'no action' (Pa = 0.79). Experts especially disagreed over the decisions to 'monitor closely' (Pa = 0.14) or to 'intervene immediately' (Pa = 0.38). These limitations should be taken into account in clinical audits and in medical jurisprudence.

Computerised evaluation of fetal heart rate in post-term fetuses: long term variation

Computerised fetal heart rate records were obtained between 1987 and 1993 using the Sonicaid System 8000 for a cross-sectional study of postdates fetal heart rate variation; 567 singleton pregnancies at 41 and 43 weeks provided 1502 records. In all cases gestational age had been verified by ultrasound examination in early pregnancy. The mean minute range of the long term pulse interval variation, which is known to be correlated with fetal oxygenation was found to decrease progressively from an average value of 48.5 ms at 41 weeks to 46.4 ms and 42.4 ms at 42 and 43 or more weeks, respectively. When conservative management of postdate pregnancies is chosen, accurate measurements are needed to follow the evolution of fetal condition. Reference values for calculated pulse interval variation at later gestational ages are now provided.

[The medico-legal value of monitoring of the fetal heart rate during labor]

We show that most litigations against obstetricians have to do with fetal cardiotocography. The experts called upon in this matter are faced with great difficulties mainly because of the variability in the interpretation of the cardiotocogram. The following questions are addressed: can one do without the fetal heart rate recording during labor? What is the relevance of such recording? The issue of the quality and of the storage of the recordings is addressed. So as to avoid the litigations, we suggest to respect "the right practice" which is developed.

Electronic fetal heart rate monitoring: research guidelines for interpretation. The National Institute of Child Health and Human Development Research Planning Workshop

The purpose of the National Institutes of Health (NIH) research planning workshops are to assess the research status of clinically important areas. This article reports on a workshop, whose meetings were held between May 1995 and November 1996, in Bethesda, MD, and Chicago, IL. Its specific purpose was to develop standardized and unambiguous definitions for fetal heart rate (FHR) tracings. Their recommendations for interpreting FHR patterns are being published here, in JOGNN, and simultaneously by the American Journal of Obstetrics and Gynecology.