Intrapartum electronic fetal heart rate monitoring to predict acidemia at birth with the use of deep learning.

BACKGROUND: Electronic fetal monitoring is used in most US hospital births but has significant limitations in achieving its intended goal of preventing intrapartum hypoxic-ischemic injury. Novel deep learning techniques can improve complex data processing and pattern recognition in medicine. OBJECTIVE: This study aimed to apply deep learning approaches to develop and validate a model to predict fetal acidemia from electronic fetal monitoring data. STUDY DESIGN: The database was created using intrapartum electronic fetal monitoring data from 2006 to 2020 from a large, multisite academic health system. Data were divided into training and testing sets with equal distribution of acidemic cases. Several different deep learning architectures were explored. The primary outcome was umbilical artery acidemia, which was investigated at 4 clinically meaningful thresholds: 7.20, 7.15, 7.10, and 7.05, along with base excess. The receiver operating characteristic curves were generated with the area under the receiver operating characteristic assessed to determine the performance of the models. External validation was performed using a publicly available Czech database of electronic fetal monitoring data. RESULTS: A total of 124,777 electronic fetal monitoring files were available, of which 77,132 had <30% missingness in the last 60 minutes of the electronic fetal monitoring tracing. Of these, 21,041 were matched to a corresponding umbilical cord gas result, of which 10,182 were time-stamped within 30 minutes of the last electronic fetal monitoring reading and composed the final dataset. The prevalence rates of the outcomes in the data were 20.9% with a pH of <7.2, 9.1% with a pH of <7.15, 3.3% with a pH of <7.10, and 1.3% with a pH of <7.05. The best performing model achieved an area under the receiver operating characteristic of 0.85 at a pH threshold of <7.05. When predicting the joint outcome of both pH of <7.05 and base excess of less than -10 meq/L, an area under the receiver operating characteristic of 0.89 was achieved. When predicting both pH of <7.20 and base excess of less than -10 meq/L, an area under the receiver operating characteristic of 0.87 was achieved. At a pH of <7.15 and a positive predictive value of 30%, the model achieved a sensitivity of 90% and a specificity of 48%. CONCLUSION: The application of deep learning methods to intrapartum electronic fetal monitoring analysis achieves promising performance in predicting fetal acidemia. This technology could help improve the accuracy and consistency of electronic fetal monitoring interpretation.

Intrapartum cardiotocography with simultaneous maternal heart rate registration improves neonatal outcome.

BACKGROUND: Intrapartum cardiotocographic monitoring of fetal heart rate by abdominal external ultrasound transducer without simultaneous maternal heart rate recording has been associated with increased risk of early neonatal death and other asphyxia-related neonatal outcomes. It is unclear, however, whether this increase in risk is independently associated with fetal surveillance method or is attributable to other factors. OBJECTIVE: This study aimed to compare different fetal surveillance methods and their association with adverse short- and long-term fetal and neonatal outcomes in a large retrospective cohort of spontaneous term deliveries. STUDY DESIGN: Fetal heart rate and maternal heart rate patterns were recorded by cardiotocography during labor in spontaneous term singleton cephalic vaginal deliveries in the Hospital District of Helsinki and Uusimaa, Finland between October 1, 2005, and September 30, 2023. According to the method of cardiotocography monitoring at birth, the cohort was divided into the following 3 groups: women with ultrasound transducer, women with both ultrasound transducer and maternal heart rate transducer, and women with internal fetal scalp electrode. Umbilical artery pH and base excess values, low 1- and 5-minute Apgar scores, need for intubation and resuscitation, neonatal intensive care unit admission for asphyxia, neonatal encephalopathy, and early neonatal death were used as outcome variables. RESULTS: Among the 213,798 deliveries that met the inclusion criteria, the monitoring type was external ultrasound transducer in 81,559 (38.1%), both external ultrasound transducer and maternal heart rate recording in 62,268 (29.1%), and fetal scalp electrode in 69,971 (32.7%) cases, respectively. The rates of both neonatal encephalopathy (odds ratio, 1.48; 95% confidence interval, 1.08-2.02) and severe acidemia (umbilical artery pH <7.00 and/or umbilical artery base excess ≤-12.0 mmol/L) (odds ratio, 2.03; 95% confidence interval, 1.65-2.50) were higher in fetuses of women with ultrasound transducer alone compared with those of women with concurrent external fetal and maternal heart rate recording. Monitoring with ultrasound transducer alone was also associated with increased risk of neonatal intubation for resuscitation (odds ratio, 1.22; 95% confidence interval, 1.03-1.44). A greater risk of severe neonatal acidemia was observed both in the ultrasound transducer (odds ratio, 2.78; 95% confidence interval, 2.23-3.48) and concurrent ultrasound transducer and maternal heart rate recording (odds ratio, 1.37; 95% confidence interval, 1.05-1.78) groups compared with those monitored with fetal scalp electrodes. No difference in risk of neonatal encephalopathy was found between newborns monitored with concurrent ultrasound transducer and maternal heart rate recording and those monitored with fetal scalp electrodes. CONCLUSION: The use of external ultrasound transducer monitoring of fetal heart rate without simultaneous maternal heart rate recording is associated with higher rates of neonatal encephalopathy and severe neonatal acidemia. We suggest that either external fetal heart rate monitoring with concurrent maternal heart rate recording or internal fetal scalp electrode be used routinely as a fetal surveillance tool in term deliveries.

Correlation between total deceleration area in CTG records and cord blood pH in pregnancies with IUGR.

PURPOSE: Fetal cardiotocography is the most common method to assess fetal well-being during labor. Nevertheless, its predictive ability for acidemia is limited, both in low-risk and high-risk pregnancies (Nelson et al. in N Engl J Med 334: 613-9, 1996; Rinciples P et al. in Health and Human Development Workshop Report on Electronic Fetal Monitoring : Update on Definitions. no. 2007, 510-515, 2008), especially in high-risk pregnancies, such as those complicated by growth restriction. In this study we aim examine the association between deceleration and acceleration areas and other measure of fetal heart rate in intrapartum fetal monitoring and neonatal arterial cord blood pH in pregnancies complicated by growth restriction. MATERIALS AND METHODS: A retrospective cohort study of 100 deliveries complicated by growth restriction, delivered during 2018, was conducted. Known major fetal anomalies, non-vertex presentation and elective cesarean deliveries were excluded. Total deceleration and acceleration areas were calculated as the sum of the areas within the deceleration and acceleration, respectively. RESULTS: In deliveries complicated by growth restriction, cord blood pH is significantly associated with total deceleration area (p = 0.05) and correlates with cumulative duration of the decelerations (Spearman's rank -0.363, p < 0.05), and total acceleration area (-0.358, p < 0.05). By comparing the cord blood pH in deliveries with a total deceleration area that was above and below the median total deceleration area, we demonstrated a significant difference between the categories. CONCLUSIONS: Cord blood pH significantly correlates with total deceleration area and other fetal monitoring characteristics in neonates with growth restriction. Future studies using real-time, machine-learning based techniques of fetal heart rate monitoring, may provide population specific threshold values that will support bedside clinical decision making and perhaps achieve better outcomes.

Improving the interpretation of electronic fetal monitoring: the fetal reserve index.

Electronic fetal monitoring, particularly in the form of cardiotocography, forms the centerpiece of labor management. Initially successfully designed for stillbirth prevention, there was hope to also include prediction and prevention of fetal acidosis and its sequelae. With the routine use of electronic fetal monitoring, the cesarean delivery rate increased from <5% in the 1970s to >30% at present. Most at-risk cases produced healthy babies, resulting in part from considerable confusion as to the differences between diagnostic and screening tests. Electronic fetal monitoring is clearly a screening test. Multiple attempts have aimed at enhancing its ability to accurately distinguish babies at risk of in utero injury from those who are not and to do this in a timely manner so that appropriate intervention can be performed. Even key electronic fetal monitoring opinion leaders admit that this goal has yet to be achieved. Our group has developed a modified approach called the "Fetal Reserve Index" that contextualizes the findings of electronic fetal monitoring by formally including the presence of maternal, fetal, and obstetrical risk factors and increased uterine contraction frequencies and breaking up the tracing into 4 quantifiable components (heart rate, variability, decelerations, and accelerations). The result is a quantitative 8-point metric, with each variable being weighted equally in version 1.0. In multiple previously published refereed papers, we have shown that in head-to-head studies comparing the fetal reserve index with the American College of Obstetricians and Gynecologists' fetal heart rate categories, the fetal reserve index more accurately identifies babies born with cerebral palsy and could also reduce the rates of emergency cesarean delivery and vaginal operative deliveries. We found that the fetal reserve index scores and fetal pH and base excess actually begin to fall earlier in the first stage of labor than was commonly appreciated, and the fetal reserve index provides a good surrogate for pH and base excess values. Finally, the last fetal reserve index score before delivery combined with early analysis of neonatal heart rate and acid/base balance shows that the period of risk for neonatal neurologic impairment can continue for the first 30 minutes of life and requires much closer neonatal observation than is currently being done.

The relationship between maternal anemia and electronic fetal monitoring patterns.

BACKGROUND: Anemia is a commonly diagnosed comorbidity in pregnancy that is associated with increased risk of maternal and neonatal complications. Recent data demonstrate that maternal anemia is associated with higher umbilical artery and umbilical vein O2 content at the time of delivery. OBJECTIVE: This study aimed to examine the relationship between maternal anemia and electronic fetal monitoring patterns associated with fetal hypoxia. STUDY DESIGN: This is a secondary analysis of a prospective cohort study of singleton term deliveries with cord gases and universal complete blood count collected on admission between 2010 and 2014. Maternal anemia was defined as hemoglobin ≤11.0 g/dL on admission. The primary outcome was a composite of high-risk category 2 electronic fetal monitoring features in the last 60 minutes before delivery (recurrent late and/or variable decelerations, minimal variability, tachycardia, or >1 prolonged deceleration); secondary outcomes were total deceleration area and total deceleration area >90th percentile. Of the 8580 patients in the original study, 8196 were included in the analysis. Outcomes were compared between patients with and without anemia. Multivariable logistic regression was used to adjust for potentially confounding factors, including hypertensive disorders of pregnancy and induction of labor. RESULTS: Of the 8196 patients with complete blood count on admission and fetal monitoring data, 2672 (32.6%; 2672/8196) were anemic and 5524 (67.4%; 5524/8196) were not. Patients with anemia were significantly less likely to have composite high-risk category 2 features on electronic fetal monitoring (34.2% vs 32.0%; adjusted risk ratio, 0.93; 95% confidence interval, 0.86-0.99). Women with anemia also had decreased total deceleration area and were less likely to have total deceleration area >90th percentile (18.7% vs 16.2%; adjusted risk ratio, 0.85; 95% confidence interval, 0.77-0.94). CONCLUSION: Patients with anemia are less likely to have high-risk category 2 electronic fetal monitoring features associated with fetal hypoxia. This finding is consistent with the association between maternal anemia and increased umbilical cord O2 content, and suggests that maternal anemia may be protective against intrapartum fetal hypoxia.

Clinical practice guidelines for intrapartum cardiotocography interpretation: A systematic review.

BACKGROUND: Clinical practice guidelines on intrapartum cardiotocography (CTG) interpretation provide structured tools to detect fetal hypoxia. Despite frequent use of different guidelines, little is known about their comparable consistency. We sought to appraise guidelines relevant to intrapartum CTG interpretation and summarise consensus and non-consensus recommendations. AIMS: To compare existing intrapartum CTG interpretation guidelines. MATERIALS AND METHODS: We searched PubMed, CINAHL, Cochrane, Embase, guideline databases and websites of guideline development institutions using terms 'cardiotocography', 'electronic fetal/foetal monitoring', and 'guideline' or equivalent term. The search was restricted to English-language articles published between January 1980 and January 2023 and excluded animal studies. The initial search yielded 2128 articles with 1253 unique citations. Guidelines were included if they: used English as the reporting language; included CTG interpretation criteria or guidelines as a primary objective; were published or updated since 1980; and were the most recently updated publications when multiple versions were identified. RESULTS: Nineteen studies were considered for full review, and 13 met inclusion criteria. Two reviewers independently assessed guideline quality using the AGREE II instrument, and synthesised consensus and non-consensus recommendations using the content analysis approach. Most guidelines employed a three-tier interpretation framework. There were significant differences between the guidelines for relative importance of key CTG features such as accelerations, decelerations and variability, with respect to the outcome of fetal hypoxia. CONCLUSIONS: There are significant differences between key intrapartum CTG interpretation guidelines currently being used. Greater consistency is needed across CTG interpretation guidelines to improve the quality of data, clinical governance, monitoring of outcomes, and to support future developments.

Increased variability of fetal heart rate during labour: a review of preclinical and clinical studies.

Increased fetal heart rate variability (FHRV) in intrapartum cardiotocographic recording has been variably defined and poorly understood, limiting its clinical utility. Both preclinical (animal) and clinical (human) evidence support that increased FHRV is observed in the early stage of intrapartum fetal hypoxaemia but can also be observed in a subset of fetuses during the preterminal stage of repeated hypoxaemia. This review of available evidence provides data and expert opinion on the pathophysiology of increased FHRV, its clinical significance and a stepwise approach regarding the management of this pattern, and propose recommendations for standardisation of related terminology.

The evolution of prenatal care delivery guidelines in the United States.

The coronavirus disease 2019 pandemic led to some of the most drastic changes in clinical care delivery ever seen in the United States. Almost overnight, providers of prenatal care adopted virtual visits and reduced visit schedules. These changes stood in stark contrast to the 12 to 14 in-person prenatal visit schedule that had been previously recommended for almost a century. As maternity care providers consider what prenatal care delivery changes we should maintain following the acute pandemic, we may gain insight from understanding the evolution of prenatal care delivery guidelines. In this paper, we start by sketching out the relatively unstructured beginnings of prenatal care in the 19th century. Most medical care fell within the domain of laypeople, and childbirth was a central feature of female domestic culture. We explore how early discoveries about "toxemia" created the groundwork for future prenatal care interventions, including screening of urine and blood pressure-which in turn created a need for routine prenatal care visits. We then discuss the organization of the medical profession, including the field of obstetrics and gynecology. In the early 20th century, new data increasingly revealed high rates of both infant and maternal mortalities, leading to a greater emphasis on prenatal care. These discoveries culminated in the first codification of a prenatal visit schedule in 1930 by the Children's Bureau. Surprisingly, this schedule remained essentially unchanged for almost a century. Through the founding of the American College of Obstetricians and Gynecologists, significant technological advancements in laboratory testing and ultrasonography, and calls of the National Institutes of Health Task Force for changes in prenatal care delivery in 1989, prenatal care recommendations continued to be the same as they had been in 1930-monthly visits until 28 weeks' gestation, bimonthly visits until 36 weeks' gestation, and weekly visits until delivery. However, coronavirus disease 2019 forced us to change, to reconsider both the need for in-person visits and frequency of visits. Currently, as we transition from the acute pandemic, we should consider how to use what we have learned in this unprecedented time to shape future prenatal care. Lessons from a century of prenatal care provide valuable insights to inform the next generation of prenatal care delivery.

iPREFACE score: Integrated score index to predict fetal acidemia by intrapartum fetal heart rate monitoring.

AIM: Cardiotocography is used worldwide to evaluate fetal well-being during pregnancy and labor. In past guidelines, the management plan was determined based on the assessment of the most severe waveform. There are no guidelines for evaluating the integrated recurrent decelerations; however, we believe their assessment to be essential for predicting the status of the fetus. The objective of this study was to propose an indicator for performing medical interventions during labor by creating a scoring system that reflects integrated recurrent decelerations. METHODS: In this retrospective cohort study, we included data for only full-term single fetus births from vaginal deliveries. The score named the iPREFACE score (integrated score index to predict fetal acidemia by intrapartum fetal heart rate monitoring) was calculated using cardiotocography findings from continuing 30 min before delivery. We examined the iPREFACE score and fetal acidemia association and calculated the cut-off iPREFACE scores for acidemia using receiver operating characteristic curves. RESULTS: The study included 469 delivery cases. Their iPREFACE scores exhibited a significant negative correlation with the umbilical artery blood pH (correlation coefficient; -0.43). The cut-off iPREFACE scores for the umbilical artery blood with pH <7.20, <7.10 and <7.0 were 44, 46 and 67, respectively (the areas under the curve were 0.776, 0.962 and 0.996, respectively). CONCLUSION: The iPREFACE score may predict fetal acidemia and could be used as an indicator for timely medical interventions during labor. Because assessments using a cardiotocography are quick and easy to perform, the iPREFACE score could be a valuable tool in clinical practice.

Machine Learning Algorithm to Predict Acidemia Using Electronic Fetal Monitoring Recording Parameters.

BACKGROUND: Electronic fetal monitoring (EFM) is the universal method for the surveillance of fetal well-being in intrapartum. Our objective was to predict acidemia from fetal heart signal features using machine learning algorithms. METHODS: A case-control 1:2 study was carried out compromising 378 infants, born in the Miguel Servet University Hospital, Spain. Neonatal acidemia was defined as pH < 7.10. Using EFM recording logistic regression, random forest and neural networks models were built to predict acidemia. Validation of models was performed by means of discrimination, calibration, and clinical utility. RESULTS: Best performance was attained using a random forest model built with 100 trees. The discrimination ability was good, with an area under the Receiver Operating Characteristic curve (AUC) of 0.865. The calibration showed a slight overestimation of acidemia occurrence for probabilities above 0.4. The clinical utility showed that for 33% cutoff point, missing 5% of acidotic cases, 46% of unnecessary cesarean sections could be prevented. Logistic regression and neural networks showed similar discrimination ability but with worse calibration and clinical utility. CONCLUSIONS: The combination of the variables extracted from EFM recording provided a predictive model of acidemia that showed good accuracy and provides a practical tool to prevent unnecessary cesarean sections.

Characteristics of Heart Rate Tracings in Preterm Fetus.

Background and Objectives: Prematurity is currently a serious public health issue worldwide, because of its high associated morbidity and mortality. Optimizing the management of these pregnancies is of high priority to improve perinatal outcomes. One tool frequently used to determine the degree of fetal wellbeing is cardiotocography (CTG). A review of the available literature on fetal heart rate (FHR) monitoring in preterm fetuses shows that studies are scarce, and the evidence thus far is unclear. The lack of reference standards for CTG patterns in preterm fetuses can lead to misinterpretation of the changes observed in electronic fetal monitoring (EFM). The aims of this narrative review were to summarize the most relevant concepts in the field of CTG interpretation in preterm fetuses, and to provide a practical approach that can be useful in clinical practice. Materials and Methods: A MEDLINE search was carried out, and the published articles thus identified were reviewed. Results: Compared to term fetuses, preterm fetuses have a slightly higher baseline FHR. Heart rate is faster in more immature fetuses, and variability is lower and increases in more mature fetuses. Transitory, low-amplitude decelerations are more frequent during the second trimester. Transitory increases in FHR are less frequent and become more frequent and increase in amplitude as gestational age increases. Conclusions: The main characteristics of FHR tracings changes as gestation proceeds, and it is of fundamental importance to be aware of these changes in order to correctly interpret CTG patterns in preterm fetuses.

Relative accuracy of computerized intrapartum fetal heart rate pattern recognition by ultrasound and abdominal electrocardiogram detection.

INTRODUCTION: Noninvasive fetal heart rate monitoring using transabdominal fetal electrocardiographic detection is now commercially available and has been demonstrated to be an effective alternative to traditional Doppler ultrasonographic techniques. Our objective in this study was to compare the results of computerized identification of fetal heart rate patterns generated by ultrasound-based and transabdominal fetal electrocardiogram-based techniques with simultaneously obtained fetal scalp electrode-derived heart rate information. MATERIAL AND METHODS: We applied an objective computer-based analysis for recognition of fetal heart rate patterns (Monica Decision Support) to data obtained simultaneously from a direct fetal scalp electrode, Doppler ultrasound, and the abdominal-fetal electrocardiogram techniques. This allowed us to compare over 145 hours of fetal heart rate patterns generated by the external devices with those derived from the scalp electrode in 30 term singleton uncomplicated pregnancies during labor. The direct fetal scalp electrode is considered to be the most accurate and reliable technique used in current clinical practice, and was, therefore, used as the standard for comparison. The program quantified the baseline heart rate, long- and short-term variability. It indicated when an acceleration or deceleration was present and whether it was large or small. RESULTS: Ultrasound was associated with significantly greater deviations from the fetal scalp electrode results than the abdominal fetal electrocardiogram technique in recognizing the correct baseline heart rate, its variability, and the presence of small and large accelerations and small decelerations. For large decelerations the two external methods were each not significantly different from the scalp electrode results. CONCLUSIONS: Noninvasive fetal heart rate monitoring using maternal abdominal wall electrodes to detect fetal cardiac activity more reliably reproduced the computerized analysis of heart rate patterns derived from a direct fetal scalp electrode than did traditional ultrasound-based monitoring. Abdominal-fetal electrocardiogram should, therefore, be considered a primary option for externally monitored patients.

No. 396-Fetal Health Surveillance: Intrapartum Consensus Guideline.

OBJECTIVE: To present evidence and recommendations regarding use, classification, interpretation, response, and documentation of fetal surveillance in the intrapartum period and to provide information to help minimize the risk of birth asphyxia while maintaining the lowest possible rate of obstetrical intervention. INTENDED USERS: Members of intrapartum care teams, including but not limited to obstetricians, family physicians, midwives and nurses, and their learners TARGET POPULATION: Intrapartum women OPTIONS: All methods of uterine activity assessment and fetal heart rate surveillance were considered in developing this document. OUTCOMES: The impact, benefits, and risks of different methods of surveillance on the diverse maternal-fetal health conditions have been reviewed based on current evidence and expert opinion. No fetal surveillance method will provide 100% detection of fetal compromise; thus, all FHS methods are viewed as screening tests. As the evidence continues to evolve, caregivers from all disciplines are encouraged to attend evidence-based Canadian educational programs every 2 years. EVIDENCE: Literature published between January 1976 and February 2019 was reviewed. Medline, the Cochrane Database, and international guidelines were used to search the literature for all studies on intrapartum fetal surveillance. VALIDATION METHODS: The principal and contributing authors agreed to the content and recommendations. The Board of the Society of Obstetricians and Gynaecologists of Canada approved the final draft for publication. The level of evidence has been determined using the criteria and classifications of the Canadian Task Force on Preventive Health Care. BENEFITS, HARM, AND COSTS: Consistent interdisciplinary use of the guideline, appropriate equipment, and trained professional staff enhances safe intrapartum care. Women and their support person(s) should be informed of the benefits and harms of different methods of fetal health surveillance. RECOMMENDATIONS: CommunicationSupport During Active LabourPrinciples of Intrapartum Fetal SurveillanceSelecting the Method of Fetal Heart Rate Monitoring: Intermittent Auscultation or Electronic Fetal MonitoringPaper SpeedAdmission AssessmentsEpidural AnalgesiaIntermittent Auscultation in LabourElectronic Fetal Monitoring in LabourClassification of Intrapartum Fetal SurveillanceMaternal Heart RateFetal Health Surveillance Assessment in the Active Second Stage of LabourIntrauterine ResuscitationDigital Fetal Scalp StimulationFetal Scalp Blood SamplingUmbilical Cord Blood GasesDocumentationFetal Surveillance Technology Not RecommendedFetal Health Surveillance Education.

Computerized analysis of cardiotocograms and ST signals is associated with significant reductions in hypoxic-ischemic encephalopathy and cesarean delivery: an observational study in 38,466 deliveries.

BACKGROUND: Intrapartum cardiotocography is widely used in high-resource countries and remains at the center of fetal monitoring and the decision to intervene, but there is ample evidence of poor reliability in visual interpretation as well as limited accuracy in identifying fetal hypoxia. Combined monitoring of intrapartum cardiotocography and ST segment signals was developed to increase specificity, but analysis relies heavily on intrapartum cardiotocography interpretation and is therefore also affected by the previously referred problems. Computerized analysis was developed to overcome these limitations, aiding in the quantification of parameters that are difficult to evaluate visually, such as variability, integrating the complex guidelines of combined intrapartum cardiotocography and ST analysis, and using visual and sound alerts to prompt health care professionals to reevaluate features associated with fetal hypoxia. OBJECTIVE: The objective of the study was to evaluate the effect of introducing a central fetal monitoring system with computerized analysis of intrapartum cardiotocography and ST signals into the labor ward of a tertiary care university hospital in which all women are continuously monitored with intrapartum cardiotocography. The incidence of adverse perinatal outcomes and intervention rates was evaluated over time. STUDY DESIGN: In this retrospective cohort study, yearly rates of hypoxic-ischemic encephalopathy, instrumental vaginal delivery, overall cesarean delivery, and urgent cesarean delivery were obtained from the hospital's clinical databases. The rates occurring in the period from January 2001 to December 2003, before the introduction of the central monitoring system with computerized analysis of intrapartum cardiotocography and ST signals (Omniview-SisPorto), were compared with those occurring from January 2004 to December 2014, after the introduction of the system. All rates were calculated with 95% confidence intervals. RESULTS: A total of 38,466 deliveries occurred during this period. After introduction of the system, there was a significant decrease in the number of hypoxic-ischemic encephalopathy cases per 1000 births (5.3%, 95% confidence interval [4.0-7.0] vs 2.2%, 95% confidence interval [1.7-2.8]; relative risk, 0.42, 95% confidence interval [0.29-0.61]), overall cesarean delivery rates (29.9%, 95% confidence interval [28.9-30.8] vs 28.3%, 95% confidence interval [27.8-28.8]; relative risk, 0.96, 95% confidence interval [0.92-0.99]), and urgent cesarean deliveries (21.6%, 95% confidence interval [20.7-22.4] vs 19.2%, 95% confidence interval [18.8-19.7]; relative risk, 0.91, 95% confidence interval [0.87-0.95]). The instrumental vaginal delivery rate increased (19.5%, 95% confidence interval [18.7-20.3] vs 21.4%, 95% confidence interval [21.0-21.9; relative risk, 1.07, 95% confidence interval 1.02-1.13]. CONCLUSION: Introduction of computerized analysis of intrapartum cardiotocography and ST signals in a tertiary care hospital was associated with a significant reduction in the incidence of hypoxic-ischemic encephalopathy and a modest reduction in cesarean deliveries.

The impact of a national cardiotocography education program on neonatal and maternal outcomes: A historical cohort study.

INTRODUCTION: Studies indicate an association between errors in cardiotocography (CTG) management and hypoxic brain injuries among newborns. Continuing professional education is recommended. We aimed to examine whether the implementation of a national interprofessional CTG education program in Denmark was associated with a decrease in risk of fetal hypoxia measured by umbilical cord pH < 7.00, 5-minute Apgar score <7 or neonatal therapeutic hypothermia. As a secondary aim, we assessed whether the educational intervention was associated with an increase in operative deliveries. MATERIAL AND METHODS: We conducted a historical cohort study from 2009 to 2015 including all intended vaginal deliveries with liveborn singletons in cephalic presentation and gestational age ≥37 weeks. Data were retrieved from the Medical Birth Register and the National Patient Register. The study period was divided in three: pre-implementation (2009-2012), implementation (2013) and post-implementation (2014-2015). Using logistic regression we estimated odds ratios (OR) of fetal hypoxia outcomes using the pre-implementation period as reference. Analyses were adjusted for potential maternal, neonatal and delivery-associated confounders. Missing data were accounted for by multiple imputation. RESULTS: In all, 331 282 deliveries were included. Overall risks of pH < 7.00, Apgar score <7 and therapeutic hypothermia were respectively 0.45%, 0.58% and 0.06%. Adjusted OR in the post-implementation period were 1.12 (95% confidence interval [CI] 1.00-1.26), 0.99 (95% CI 0.90-1.10) and 1.34 (95% CI 0.99-1.82) for the three outcomes, respectively. The pH missingness equaled 12.4%. Odds of emergency cesarean section was unaltered, whereas the odds of assisted vaginal delivery decreased by 14% (0.86, 95% CI 0.84-0.89). CONCLUSIONS: Healthcare professionals are considered the weakest link of CTG technology. We did not find that increasing healthcare professionals' CTG interpretation skills affected the risk of fetal hypoxia. Missing data for pH values were substantial and represent a limitation of the study. We cannot with certainty rule out that missingness masked a true effect of the intervention. Our study indicates that assisted vaginal deliveries can be decreased without an increased risk of fetal hypoxia. Dilution of effect in a complex clinical setting, rare outcomes, insufficient intervention and a possible overestimation of the impact of errors in CTG management might explain the lack of effect.

Computer-based intrapartum fetal monitoring and beyond: A review of the 2nd Workshop on Signal Processing and Monitoring in Labor (October 2017, Oxford, UK).

The second Signal Processing and Monitoring in Labor workshop gathered researchers who utilize promising new research strategies and initiatives to tackle the challenges of intrapartum fetal monitoring. The workshop included a series of lectures and discussions focusing on: new algorithms and techniques for cardiotocogoraphy (CTG) and electrocardiogram acquisition and analyses; the results of a CTG evaluation challenge comparing state-of-the-art computerized methods and visual interpretation for the detection of arterial cord pH <7.05 at birth; the lack of consensus about the role of intrapartum acidemia in the etiology of fetal brain injury; the differences between methods for CTG analysis "mimicking" expert clinicians and those derived from "data-driven" analyses; a critical review of the results from two randomized controlled trials testing the former in clinical practice; and relevant insights from modern physiology-based studies. We concluded that the automated algorithms performed comparably to each other and to clinical assessment of the CTG. However, the sensitivity and specificity urgently need to be improved (both computerized and visual assessment). Data-driven CTG evaluation requires further work with large multicenter datasets based on well-defined labor outcomes. And before first tests in the clinic, there are important lessons to be learnt from clinical trials that tested automated algorithms mimicking expert CTG interpretation. In addition, transabdominal fetal electrocardiogram monitoring provides reliable CTG traces and variability estimates; and fetal electrocardiogram waveform analysis is subject to promising new research. There is a clear need for close collaboration between computing and clinical experts. We believe that progress will be possible with multidisciplinary collaborative research.

Impact of continuous electronic fetal monitoring on birth outcomes in low-risk pregnancies.

BACKGROUND: Continuous electronic fetal monitoring (CEFM) is a standard of hospital care during the intrapartum period. We investigated its use on childbirth outcomes in low-risk pregnancies, and examined whether outcomes differed by gestational age within a term pregnancy. METHODS: A retrospective secondary data analysis using birth registry data from two diverse northeastern US states from 1992 to 2014. Chi-square test and the Fisher exact tests were used to examine associations between CEFM and childbirth outcomes. Multivariable Poisson regression models were used to estimate risk ratios of childbirth outcomes related to CEFM use, adjusting for potential confounders. RESULTS: Use of CEFM was independently associated with a 10% (State 1) and 40% (State 2) increased risk for primary cesarean delivery and an increased risk for assisted vaginal births (14% and 24%, respectively) after adjustment for confounders. CEFM use was not associated with reduced risk for infant mortality (neonatal mortality, 0-27 days, and post-neonatal mortality, 28-364 days) in term births (37-41 weeks' gestation). After stratifying term pregnancies into early term, full term, and late term, use of CEFM was associated with reduced risk for neonatal mortality in early-term births (37 0/7 weeks' to 38 6/7 weeks' gestation) in State 2 (RR 0.44 [95% CI 0.21-0.92]), but not in State 1. There was no association between CEFM use and infant mortality (neonatal and post-neonatal) in full-term or late-term births. CONCLUSIONS: The study results do not support universal use of CEFM in pregnancies that are low-risk and at term.

Simplifying the language of fetal monitoring.

BACKGROUND: Health professionals in Australia and New Zealand have used various intrapartum fetal surveillance (IFS) guidelines, with clear differences in how these guidelines present information. Based on clinician feedback, the 2015 Queensland Clinical Guideline on IFS structured the prose-based Royal Australian and New Zealand College of Obstetricians and Gynaecologists (RANZCOG) IFS Guidelines as a traffic-light matrix and represented the categorical terms of unlikely, maybe, possible and likely fetal compromise, as the colours GREEN, BLUE, AMBER, and RED, respectively. AIMS: To determine whether the interpretation of the RANZCOG IFS Guidelines in Table Format is more accurate and quicker compared to the current presentation of the RANZCOG Guideline in prose format. MATERIALS AND METHOD: Twenty-nine clinicians, naïve to the use of the RANZCOG IFS Guidelines, interpreted ten cardiotocographs (CTGs) using one format and then the alternative format (totalling 580 CTG interpretations). Accuracy and time to decision were recorded as well as a participant questionnaire. A repeated measures analysis of variance was used to compare differences. RESULTS: Compared to prose format, clinicians interpreted CTGs quicker using the table format (P < 0.01), especially CTGs representative of unlikely and maybe fetal compromise. There was a trend toward more accurate interpretation for table format for all clinicians, with significance among medical officers (P = 0.02). Participants responded more favourably to the table format regarding questions about ease of use, determining actions required, and desire to use the system in the future (P < 0.01). CONCLUSIONS: Presenting the RANZCOG IFS Guideline in table format as opposed to prose format improved the speed and accuracy of CTG interpretation and is preferred by clinicians.

Refining the Prediction and Prevention of Emergency Operative Deliveries with the Fetal Reserve Index.

Electronic fetal monitoring (EFM) is a poor predictor of outcomes attributable to delivery problems. Contextualizing EFM by adding maternal, obstetrical, and fetal risk-related information to create an index called the Fetal Reserve Index (FRI) improves the predictive capacity and facilitates the timing of interventions. Here, we test critical assumptions of FRI as a clinical tool. Our conceptualization implies that the earlier one reaches the red zone (FRI ≤25) and the longer one spends in the red zone, the greater the likelihood of emergency operative deliveries (EOD). METHODS: We analyzed 1,402 patients using logistic regression predicting the probability of EOD and employed qualitative methodology techniques to refine predictive capabilities. RESULTS: Reaching the red zone early and staying there > 1 h increases the probability of EOD. When these risk factors are paired with intrauterine resuscitation (IR) in Stage 1, the reduction of EOD is substantial. CONCLUSION: FRI is a capable predictor of EOD because it accurately identifies the level of malleable risk. FRI analysis increases the risk of using IR in Stage 1. Matching risk and resources dramatically reduces the chances of EOD. Earlier IR improves the outcomes if the calculated risk is high.

The Placenta in Neonatal Encephalopathy: A Case-Control Study.

OBJECTIVE: We assessed whether specific histologic placental lesions were associated with risk for neonatal encephalopathy, a strong predictor of death or cerebral palsy. STUDY DESIGN: Case-control study of singletons with gestational ages ≥35 weeks. Data were abstracted from a prospectively collected database of consecutive births at a hospital in which placental samples from specified sites are collected and stored for all inborn infants. Placentas of infants with neonatal encephalopathy were compared with randomly selected control infants (ratio of 1:3). Placental histologic slides were read by a single experienced perinatal pathologist unaware of case status, using internationally recommended definitions and terminology. Findings were grouped into inflammatory, maternal, or fetal vascular malperfusion (FVM) and other lesions. RESULTS: Placental samples were available for 73 of 87 (84%) cases and 253 of 261 (97%) controls. Delivery complications and gross placental abnormalities were more common in cases, of whom 4 died. Inflammation and maternal vascular malperfusion did not differ, and findings consistent with global FVM were more frequent in case (20%) than control (7%) placentas (P = .001). There was a trend toward more segmental FVM and high-grade FVM (fetal thrombotic vasculopathy) among cases. Some type of FVM was observed in 24% of placentas with neonatal encephalopathy. In infants with both neonatal encephalopathy and placental FVM, more often than in infants with neonatal encephalopathy without FVM, electronic fetal monitoring tracings were considered possibly or definitely abnormal (P = .028). CONCLUSIONS: Vascular malperfusion of subacute or chronic origin on the fetal side of the placenta was associated with increased risk of neonatal encephalopathy.