Comparison of Four Tests for Preterm Birth Prediction in Symptomatic Singleton Women: A Prospective Cohort Study

Background and Purpose: It is challenging to predict preterm births accurately. We sought to compare the diagnostic performance of cervical length in predicting preterm birth to those of contraction recording in cardiotocography (CTG), cervical funneling, and Bishop score. Methods: A total of 371 women with singleton pregnancies and threatened preterm labor admitted to tertiary hospitals of northwestern Iran were included in this prospective cohort study and followed up until childbirth. Transvaginal ultrasound was utilized to assess the cervical length and funneling. Also, a CTG test and digital vaginal examination were performed. The data of 218 women were analyzed in the STATA software. The sensitivity and other diagnostic performances, and 95% confidence intervals, were reported. Results: The CTG uterine contraction recording had the highest sensitivity for predicting birth within the next 2 days, whereas a Bishop score ≥6 revealed the highest specificity, positive predictive value, and positive likelihood ratio. Inadequate cervical length for gestational age exhibited a high negative predictive value and the lowest negative likelihood ratio. Conclusion: The cervical length test has good diagnostic and prognostic performance among the four tests for preterm birth. Cervical funneling and CTG tests have poor predictive value, whereas the Bishop score has a superior diagnostic performance to the other tests.

Antenatal cardiotocography in primary midwife-led care: a budget impact analysis

OBJECTIVES

In many countries, the healthcare sector is dealing with important challenges such as increased demand for healthcare services, capacity problems in hospitals and rising healthcare costs. Therefore, one of the aims of the Dutch government is to move care from in-hospital to out-of-hospital care settings. An example of an innovation where care is moved from a more specialised setting to a less specialised setting is the performance of an antenatal cardiotocography (aCTG) in primary midwife-led care. The aim of this study was to assess the budget impact of implementing aCTG for healthy pregnant women in midwife-led care compared with usual obstetrician-led care in the Netherlands.

METHODS

A budget impact analysis was conducted to estimate the actual costs and reimbursement of aCTG performed in midwife-led care and obstetrician-led care (ie, base-case analysis) from the Dutch healthcare perspective. Epidemiological and healthcare utilisation data describing both care pathways were obtained from a prospective cohort, survey and national databases. Different implementation rates of aCTG in midwife-led care were explored. A probabilistic sensitivity analysis was conducted to estimate the uncertainty surrounding the budget impact estimates.

RESULTS

Shifting aCTG from obstetrician-led care to midwife-led-care would increase actual costs with €311 763 (97.5% CI €188 574 to €426 072) and €1 247 052 (97.5% CI €754 296 to €1 704 290) for implementation rates of 25% and 100%, respectively, while it would decrease reimbursement with -€7 538 335 (97.5% CI -€10 302 306 to -€4 559 661) and -€30 153 342 (97.5% CI -€41 209 225 to -€18 238 645) for implementation rates of 25% and 100%, respectively. The sensitivity analysis results were consistent with those of the main analysis.

CONCLUSIONS

From the Dutch healthcare perspective, we estimated that implementing aCTG in midwife-led care may increase the associated actual costs. At the same time, it might lower the healthcare reimbursement.

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.

Fetal Heart Rate Auscultation, 4th Edition

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

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.