Electronic fetal heart rate monitoring: applying principles of patient safety

Labor management and neonatal outcomes in cardiotocography categories II and III (Review)

The safe care of both mothers and fetuses during labor is a primary goal of all health professionals. The assessment of fetal oxygenation and well-being is a key aspect of perinatal care provided. Fetal heart rate (FHR) auscultation became part of daily obstetric practice in a number of countries during the 20th century and remains a key method of fetal monitoring, particularly in low-risk pregnancies. Cardiotocography (CTG) is the continuous monitoring and recording of the FHR and uterine myometrial activity, making it possible to assess the fetal condition. It therefore plays a critical role in the detection of fetal hypoxia during labor, a condition directly related to short- and long-term complications in the newborn. Herein, particular reference is made to the management of CTG category II and III standards, as well as to the handling of childbirth. In addition, specific FHR patterns are associated with immediate neonatal outcomes based on updated studies conducted worldwide. Finally, the prognostic significance of CTG and its potential as a prospective avenue for further investigation are also highlighted herein. Given that the misinterpretation of CTG findings is the most common cause of medical-legal responsibility, this knowledge field requires more emphasis and attention. The aim of the present review was to further deepen the knowledge on issues that mainly concern the safety and monitoring of pregnant women and fetuses during childbirth.

Acquisition Devices for Fetal Phonocardiography: A Scoping Review

Timely and reliable fetal monitoring is crucial to prevent adverse events during pregnancy and delivery. Fetal phonocardiography, i.e., the recording of fetal heart sounds, is emerging as a novel possibility to monitor fetal health status. Indeed, due to its passive nature and its noninvasiveness, the technique is suitable for long-term monitoring and for telemonitoring applications. Despite the high share of literature focusing on signal processing, no previous work has reviewed the technological hardware solutions devoted to the recording of fetal heart sounds. Thus, the aim of this scoping review is to collect information regarding the acquisition devices for fetal phonocardiography (FPCG), focusing on technical specifications and clinical use. Overall, PRISMA-guidelines-based analysis selected 57 studies that described 26 research prototypes and eight commercial devices for FPCG acquisition. Results of our review study reveal that no commercial devices were designed for fetal-specific purposes, that the latest advances involve the use of multiple microphones and sensors, and that no quantitative validation was usually performed. By highlighting the past and future trends and the most relevant innovations from both a technical and clinical perspective, this review will represent a useful reference for the evaluation of different acquisition devices and for the development of new FPCG-based systems for fetal monitoring.

Maternal, obstetric, and fetal Doppler characteristics in a high-risk population: prediction of adverse perinatal outcomes and of cesarean section due to intrapartum fetal compromise

Objective

To evaluate the capacity of fetal Doppler, maternal, and obstetric characteristics for the prediction of cesarean section due to intrapartum fetal compromise (IFC), a 5-min Apgar score < 7, and an adverse perinatal outcome (APO), in a high-risk population.

Materials and Methods

This was a prospective cohort study involving 613 singleton pregnant women, admitted for labor induction or at the beginning of spontaneous labor, who underwent Doppler ultrasound within the last 72 h before delivery. The outcome measures were cesarean section due to IFC, a 5-min Apgar score < 7, and any APO.

Results

We found that maternal characteristics were neither associated with nor predictors of an APO. Abnormal umbilical artery (UA) resistance index (RI) and the need for intrauterine resuscitation were found to be significant risk factors for cesarean section due to IFC (p = 0.03 and p < 0.0001, respectively). A UA RI > the 95th percentile and a cerebroplacental ratio (CPR) < 0.98 were also found to be predictors of cesarean section due to IFC. Gestational age and a UA RI > 0.84 were found to be predictors of a 5-min Apgar score < 7 for newborns at < 29 and ≥ 29 weeks, respectively. The UA RI and CPR presented moderate accuracy in predicting an APO, with areas under the ROC curve of 0.76 and 0.72, respectively.

Conclusion

A high UA RI appears to be a significant predictor of an APO. The CPR seems to be predictive of cesarean section due to IFC and of an APO in late preterm and term newborns.

Comparison of Four Intrapartum Cardiotocography Classifications for Predicting Neonatal Acidemia at Birth

Objective

To compare diagnostic values of four intrapartum cardiotocography (CTG) classifications in predicting neonatal acidemia at birth.

Methods

Retrospective case-control study. Forty-three CTG traces with an umbilical artery pH < 7.00 (study group) and 43 traces with a pH ≥ 7.00 (control group) were analyzed. Inclusion criteria were singleton pregnancy, cephalic presentation, admission to labour ward during active phase of first stage of labour, and gestational age 37⁺⁰ to 41⁺⁶ weeks. Exclusion criteria were suspected intrauterine growth restriction, oligohydramnios, polyhydramnios, pregestational or gestational insulin-dependent diabetes mellitus, and preeclampsia. Last 30-60 minutes before delivery of CTG traces was classified retrospectively according to four classification systems-International Federation of Gynecology and Obstetrics (FIGO), Royal College of Obstetricians and Gynaecologists (RCOG), National Institute of Child Health and Human Development (NICHD), and the 5-tier system by Parer and Ikeda. Predictive value of each classification for neonatal acidemia was assessed using receiver operating characteristics (ROC) analysis.

Results

FIGO, RCOG, and NICHD classifications predicted neonatal acidemia with areas under the ROC curves (AUC) of 0.73, 95% confidence interval (CI) 0.63-0.84; 0.72, 95% CI 0.60-0.83; and 0.69, 95% CI 0.57-0.80, respectively. The five-tier system by Parer and Ikeda had significantly better predictive value with an AUC of 0.96, 95% CI 0.91-1.00.

Conclusions

The 5-tier classification system proposed by Parer and Ikeda for assessing CTG in labour was superior to FIGO, RCOG, and NICHD intrapartum CTG classifications in predicting severe neonatal acidemia at birth.

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.

Identification of the Fetus at Risk for Metabolic Acidemia Using Continuous Fetal Heart Rate Monitoring

The fetal heart rate can be used to assess the current metabolic state of the fetus and predict the risk of the evolution of metabolic acidemia through the course of labor. In this chapter, we will present the pathophysiology of the development of fetal acidemia and provide an organized approach to identifying the risk of worsening acidemia using changes noted in the fetal heart rate pattern to allow for interventions that might alter this course.

Effects of Obstetric Interventions During Labor on Birth Process and Newborn Health

AIM

This study aimed to investigate the effects of the interventions in the delivery room on the delivery process and the newborn health.

METHOD

The analytical-cross-sectional study was carried out with 354 puerperal women who gave birth in hospital between December 2016 and June 2017 in a public hospital. The data were collected by the data collection form developed by the researchers. Data analysis was done by using descriptive statistics and chi-square test in SPSS 21.00 program.

RESULTS

The interventions were determined in continuous electro fetal monitoring (80.5%), oxytocin induction (79.9%), restriction of free movement (56.8%), amniotomy (49.7%), enema (44.1%), and movement restriction (56.8%). The intervention period of the second phase of delivery was longer and the rate of cesarean section was higher, and the need for NICU, suction difficulty, 5th APGAR score less than 7, trauma development, difficulty in suction, and higher trauma rates were found in infants. It was determined that the rate of oxygen need in puerperals admitted to the delivery room with cervical dilatation below five cm, vacuum and episiotomy applications in those who underwent amniotomy, and vacuum application rates in those undergoing oxytocin inductions were found to be high. In addition, the rate of fundal compression and episiotomy was significantly higher in patients who used continuous electro fetal monitoring, fundal compression and vacuum rate in patients who were administered analgesic drugs, and episiotomy rates in patients using analgesic drugs.

CONCLUSION

It has been concluded that interventions in the first phase of labor negatively affect the delivery process and neonatal health and increase the need for intervention in the second phase.

Heart rate variability in Dorper sheep in the fetal and neonatal periods until 120 days of age: Use of the technique in the field

The evaluation of the autonomic cardiac functions may be performed through the analysis of the heart rate variability. Heart rate variability is defined as the fluctuations in the heart rhythm or rate, and represents a useful tool in the evaluation of the autonomic nervous system through the sympathetic and parasympathetic components, as well as its balance and its reflexes on the cardiorespiratory control system. Fetal electrocardiography provides important information regarding the well-being of the fetus since, in human fetuses, there are changes in the behavior of the fetal heart rate during the second and third trimesters of pregnancy due to an increase in parasympathetic activity. Therefore, considering the importance of evaluating fetal viability, this study aims at evaluating the behavior of fetal heart rate and heart rate variability in Dorper sheep, as well as the activity of the autonomic nervous system during fetal life and in newborn lambs. The species is often used in experimental studies and autonomic nervous system activity is a prognostic index, therefore, the diagnosis of modifications in the sympathovagal balance may represent an early index for fetal viability and well-being in lambs. The analyses were performed in 10 Dorper sheep during pregnancy and in 10 lambs after birth until 120 days of age. There was a decrease in the fetal heart rate and heart rate variability indexes during the fifth month of pregnancy, but without statistical significance for the period evaluated. The heart rate of the lambs decreased gradually until they were 21 days old. The indexes SDNN (standard deviation of RR intervals) and RMSSD (square root of the mean of successive differences between adjacent RR intervals) diverged according to age, being high at day 60. Fetal viability is relevant in sheep fetuses to avoid losses during pregnancy and risks to the health of the mother. In the species, there seems to be a predominance of parasympathetic activity starting from the 21st day of age. Heart rate variability may be employed as a tool in the evaluation of the fetus and development of lambs, since changes in its behavior may represent an adverse effect to fetal and neonatal health.

Comparison of High-Fidelity Simulation and Lecture to Improve the Management of Fetal Heart Rate Monitoring

BACKGROUND

We developed a training course of fetal monitoring using high-fidelity simulation for obstetric nurses.

METHOD

All participants were assessed by two standardized written tests for knowledge and interpretation of fetal heart rate tracing before and after the training. In addition, a self-estimated questionnaire survey was performed twice-after the training and 6 months later.

RESULTS

The knowledge and interpretation of fetal heart rate tracing significantly improved in the simulation group. Compared with the lecture group, the perceived improvements of knowledge and interpretation of fetal heart rate tracing in the simulation group were significantly better following the training and 6 months later.

CONCLUSION

High-fidelity simulation courses are useful in improving the knowledge and interpretation of fetal heart rate tracings for obstetric nurses. They are more effective to improve both short- and long-term management in fetal heart rate monitoring. [J Contin Educ Nurs. 2019;50(12):557-562.].

Response to category II tracings: Does anything help?

Electronic fetal monitoring (EFM) is the most commonly used tool to screen for intrapartum fetal hypoxia. Category II EFM is present in over 80% of laboring patients and poses a unique challenge to management given the breadth of EFM features that fall within this category. Certain Category II patterns, such as recurrent late or recurrent variable decelerations, are more predictive of neonatal acidemia than others. A key feature among many published algorithms for Category II management is the use of intrauterine fetal resuscitation techniques including maternal oxygen administration, amnioinfusion, intravenous fluid bolus, discontinuation of oxytocin, and tocolytic administration. The goal of intrauterine resuscitation is to prevent or reverse fetal hypoxia. This is most likely to be successful if the etiology of the Category II EFM pattern is identified and targeted resuscitative measures are performed.

The importance of the learning process in ST analysis interpretation and its impact in improving clinical and neonatal outcomes

BACKGROUND

Intrapartum fetal heart rate monitoring was introduced with the goal to reduce fetal hypoxia and deaths. However, continuous fetal heart rate monitoring has been shown to have a high sensitivity but also a high false-positive rate. To improve specificity, adjunctive technologies have been developed to identify fetuses at risk for intrapartum asphyxia. Intensive research on the value of ST-segment analysis of the fetal electrocardiogram as an adjunct to standard electronic fetal monitoring in lowering the rates of fetal metabolic acidosis and operative deliveries has been ongoing. The conflicting results in randomized and observational studies may partly be due to differences in study design.

OBJECTIVE

This study aims to determine the significance of the learning process for the introduction of ST analysis into clinical practice and its impact on initial and subsequent obstetric outcomes.

STUDY DESIGN

This was a prospective observational study with the primary objective to evaluate the importance of the learning period on the rates of metabolic acidosis and operative deliveries after the implementation of ST analysis. The study was conducted at the Turku University Hospital, Turku, Finland, with 3400-4200 annual deliveries. The whole study population consisted of all 42,146 deliveries during the study period 2001 through 2011. The ST analysis usage rate was 18%. The data were collected prospectively from labors monitored with ST analysis as an adjunct to conventional intrapartum fetal heart rate monitoring. Primary endpoints were the rates of metabolic acidosis (cord artery pH <7.05 and an extracellular fluid compartment base deficit >12.0 mmol/L), fetal scalp blood sampling, and operative deliveries. Comparisons of these outcomes were made between the initiation period (the first 2 years) and the subsequent usage period (the next 9 years).

RESULTS

In the whole study population the prevalence of cord pH <7.05 decreased from 1.5-0.81% (relative risk, 0.54; 95% confidence interval, 0.43-0.67), the rate of cesarean deliveries from 17.2-14.1% (relative risk, 0.82; 95% confidence interval, 0.89-0.97), and the rate of fetal scalp blood sampling from 1.75-0.82% (relative risk, 0.47; 95% confidence interval, 0.38-0.58) when the 2 study periods were compared. In the ST analysis group, the frequency of cord metabolic acidosis rate was reduced from 1.0-0.25% (relative risk, 0.33; 95% confidence interval, 0.15-0.72).

CONCLUSION

We provide evidence that the results improve over time and there is a learning curve in the introduction of the ST analysis method. This was demonstrated by the lower rates of metabolic acidosis and operative deliveries after the initial implementation period.

A Standardized Approach to Electronic Fetal Monitoring in Critical Care Obstetrics

From the periphery, pregnancy is a common event in women of childbearing age. Normal anatomic and physiologic adaptations occur and, in most cases, will result in ideal maternal-fetal outcomes. Yet, every day, obstetric clinicians are facing complex pregnancies with complicated life-threatening conditions or coexisting medical and surgical problems that not only alter maternal physiology but also impact fetal survival. A challenge in this population is individualizing maternal-fetal care in critical care women while integrating medical-surgical specialties in creating an interdisciplinary team with similar management goals. Questions frequently arise concerning admission criteria, location of care, as well as type and mix of personnel. Furthermore, how to simultaneously manage a critically ill parturient while monitoring a viable fetus is often obscured. This article focuses on crucial fetal monitoring concepts using a standardized approach to interpretation and management in pregnancies managed in an intensive care environment. Application of fetal monitoring during surgical procedures, during perimortem cesarean birth, and in women who have irreversible loss of brain function is included.

Utah obstetricians' opinions of planned home birth and conflicting NICE/ACOG guidelines: A qualitative study

BACKGROUND

The United Kingdom's National Institute for Health and Care Excellence (NICE) recently published recommendations that support planned home birth for low-risk women. The American College of Obstetricians and Gynecologists (ACOG) remains wary of planned home birth, asserting that hospitals and birthing centers are the safest birth settings. Our objective was to examine opinions of obstetricians in Salt Lake City, Utah about home birth in the context of rising home birth rates and conflicting guidelines.

METHODS

Participants were recruited through online searches of Salt Lake City obstetricians and through snowball sampling. We conducted individual interviews exploring experiences with and attitudes toward planned home birth and the ACOG/NICE guidelines.

RESULTS

Fifteen obstetricians who varied according to years of experience, location of medical training, sex, and subspecialty (resident, OB/GYN, maternal-fetal medicine specialist) were interviewed. Participants did not recommend home birth but supported a woman's right to choose her birth setting. Obstetrician opinions about planned home birth were shaped by misconceptions of home birth benefits, confusion surrounding the scope of care at home and among home birth providers, and negative transfer experiences. Participants were unfamiliar with the literature on planned home birth and/or viewed the evidence as unreliable. Support for ACOG guidelines was high, particularly in the context of the United States health care setting.

CONCLUSION

Physician objectivity may be limited by biases against home birth, which stem from limited familiarity with published evidence, negative experiences with home-to-hospital transfers, and distrust of home birth providers in a health care system not designed to support home birth.

How to Approach Intrapartum Category II Tracings

Since its inception, many have questioned the utility of electronic fetal heart rate (FHR) monitoring. However, it arrived without the benefit of clear, standard nomenclature, leading to difficulty interpreting studies regarding its benefit. In 2008, the National Institute of Child Health and Human Development (NICHD) developed standard nomenclature for interpreting eFHR tracings. Understanding what drives the tracings is key to managing them. Category II FHR patterns are by far the most common and most diverse patterns, leading to broad variation in care. Presented here is an algorithm for standardization of management of category II FHR tracings, based on the pathophysiology of decelerations, that can be followed in any labor unit.

A collaborative interdisciplinary approach to electronic fetal monitoring: report of a statewide initiative

Intrapartum electronic fetal monitoring (EFM) is one of the most common procedures in obstetrics. Current consensus statements provide clinicians with a common language for EFM as well as provide a basis for a simplified approach to interpretation and management. This article presents a summary of the content and implementation of a statewide initiative in interdisciplinary EFM education and training designed to give clinicians of all backgrounds a shared mental model in EFM. Challenges to implementation at individual institutions may include physician and nursing engagement as well as time and cost constraints.

Fetal monitoring: creating a culture of safety with informed choice

The dominant culture in labor and birth is the medical model, not the midwifery model of woman-centered care. Consensus among professional and governmental groups is that, based on the evidence, intermittent auscultation is safer to use in healthy women with uncomplicated pregnancies than electronic fetal monitoring (EFM). Barriers impact the laboring woman's ability to give informed choice regarding fetal monitoring. Lack of informed choice denies a woman her right to be in control of her birth experience, and is in opposition to a woman's right to autonomy and self-determination.

When is primary cesarean appropriate: fetal indications

The objective of this review was to assess the evidence that supports cesarean delivery for fetal indications. The main fetal reasons for abdominal delivery include abnormal fetal heart rate patterns in labor, malpresentation, fetal macrosomia, multiple gestation, and both functional and structural fetal abnormalities. Although the level of evidence is not as strong as anticipated, there is sufficient support for cesarean delivery when these fetal conditions complicate pregnancy. Efforts to decrease cesarean delivery for fetal indications in the current medicolegal environment will not be easy; however, the development of more sensitive tools to assess fetal well-being in labor and practices to deliver or reduce fetuses in breech presentation at term have the potential for greatest impact on the overall primary cesarean delivery rate.