Fetal heart rate monitoring: is it salvageable?

Contribution of proactive management of healthcare risks to the reduction of adverse events in a maternity hospital

BACKGROUND

The risks of the childbirth assistance process are still very high, both for mothers and babies. According to the WHO, birth-related asphyxia accounts for 23% of all 3.3 million annual neonatal deaths and an even larger number of survivors with disabilities. On the other hand, maternal mortality is still a global challenge, affecting 17 mothers per 100 000 births in the USA. This is associated with the use of outdated technologies and a lack of well-defined processes in monitoring labour and early recognition of maternal clinical deterioration.

METHOD

This study used Lean methodology to map the care flow for pregnant women in a Brazilian maternity hospital (Hospital Israelita Albert Einstein) in order to identify the risks within this process and a set of actions to minimise them. The work team consisted of 29 individuals, including local medical and nursing leaders, as well as healthcare professionals. The What-if tool was used to categorise the levels of risks, and the proportion of severe and catastrophic adverse events was evaluated before and after the implementation of changes.

RESULTS

After the implementation of the actions, 100% of the extreme risks (28 risks) and 8% of the high risks (4 risks) were eliminated. This led to a reduction in the interval between severe/catastrophic events from 126 to 284 days, even with an increase in the average monthly number of visits from 367 to 449. Consequently, the weighted value of events decreased from 7.91 to 3.29 per 1000 patients treated, resulting in an annual cost savings of R$693 646.80 (US$139 000.00).

DISCUSSION

The construction of a process based on Lean methodology was essential for mapping the involved risks and implementing a set of actions to minimise them. The participation of the healthcare team and leadership seemed to be important in choosing the measures to be adopted and their applicability. The results found can be attributed to both the established changes and the safety culture brought about by this constructive process.

Does a physiology-based interpretation of cardiotocography allow to dispense with second-line methods? A cross-sectional online survey

CONTEXT

Second line methods are used to help obstetricians to identify abnormalities that reflect fetal acidosis. Since the use of a new technique of cardiotocography (CTG) interpretation based on the pathophysiology of the fetal period, the use of second-line tests has been questioned.

OBJECTIVE

To evaluate the impact of specific training in CTG physiology-based interpretation on professional attitudes towards the use of second-line methods.

METHODS

This cross-sectional study included 57 French obstetricians divided into two groups: the trained group (obstetricians who had already participated in a training course in physiology-based interpretation of CTG) and the control group. Ten medical records of patients who had abnormal CTG tracings and underwent fetal blood sampling pH measurement during labour were presented to the participants. They were given three choices: use a second-line method, continue labour without using second-line method, or perform a caesarean section. The main outcome measures was the median number of decisions to use second-line method.

RESULTS

Forty participants were included in the trained group and 17 in the control group. The median number of recourses to second-line method was significantly inferior for the trained group (4/10 second-line methods) than for the control group (6/10, p=0.040). Regarding the 4 records for which a caesarean section was the real outcome, the median number of decisions of continuing labour was significantly superior in the trained group than in the control group (p=0.032).

CONCLUSIONS

Participation in a training course in physiology-based interpretation of CTG could be associated with a less frequent use of second-line method at the cost of more frequently continuing labour with the risk compromising fetal and maternal well-being. Additional studies are required to determine whether this change in attitude is safe for the fetal well-being.

A second look at intrapartum fetal surveillance and future directions

Intrapartum fetal surveillance aims to predict significant fetal hypoxia and institute timely intervention to avoid fetal injury, and do so without unnecessary operative delivery of fetuses at no risk of intrapartum hypoxia. However, the configuration and application of current clinical guidelines inadvertently undermine these aims because of persistent failure to incorporate increased understanding of fetal cardiovascular physiology and adaptations to oxygen deprivation, advances in signal acquisition/processing, and related technologies. Consequently, the field on intrapartum fetal surveillance is stuck in rudimentary counts of the fetal R-R intervals and visual assessment of very common, but nonspecific fetal heart decelerations and fetal heart rate variability. The present authors argue that the time has come to move away from classifications of static morphological appearances of FHR decelerations, which do not assist the thinking clinician in understanding how the fetus defends itself and compensates for intrapartum hypoxic ischaemic insults or the patterns that suggest progressive loss of compensation. We also reappraise some of the controversial aspects of intrapartum fetal surveillance in modern obstetric practice, the current state of flux in training and certification, and contemplate the future of the field particularly in the context of the emerging role of artificial intelligence.

Fast electro-plasmonic detection of heart signal in Balb/C cells onto one-dimensional plasmonic grating

The heart is a vital and complex organ in the human body that forms with most organs between the second week of pregnancy, and fetal heart rate is an important indicator or biological index to know the condition of fetal well-being. In general, long-term measurement of fetal heart rate is the most widely used method of providing information about fetal health. In addition to fetal life, growth, and maturity, information such as congenital heart disease, often due to structural or functional defects in heart structure that often occur during the first trimester of pregnancy during fetal development, can be detected by continuous monitoring of fetal heart rate. The gold standard for monitoring the fetus's health is the use of non-invasive methods and portable devices so that while maintaining the health of the mother and fetus, it provides the possibility of continuous monitoring, especially for mothers who have a high-risk pregnancy. Therefore, the present study aimed to propose a low-cost, compact, and portable device for recording the heart rate of 18-day-old fetal mouse heart cells. Introduced device allows non-invasive heart rate monitoring instantly and without side effects for mouse fetal heart cells. One-dimensional gold-plated plasmonic specimens as a physiological signal recorder are mainly chips with nanoarray of resonant nanowire patterns perform in an integrated platform. Here the surface plasmon waves generated in a one-dimensional plasmonic sample are paired with an electrical wave from the heart pulse, and this two-wave pairing is used to record and detect the heart rate of fetal heart cells with high accuracy and good sensitivity. This measurement was performed in normal mode and two different stimulation modes. Stimulation of cells was performed once using adrenaline and again with electrical stimulation. Our results show that our sensor is sensitive enough to detect heart rate in both standard and excitatory states and is also well able to detect and distinguish between changes in heart rate caused by different excitatory conditions.

Methods for Monitoring Risk of Hypoxic Damage in Fetal and Neonatal Brains: A Review

Fetal, perinatal, and neonatal asphyxia are vital health issues for the most vulnerable groups in human beings, including fetuses, newborns, and infants. Severe reduction in oxygen and blood supply to the fetal brain can cause hypoxic-ischemic encephalopathy, leading to long-term neurological disorders, including mental impairment and cerebral palsy. Such neurological disorders are major healthcare concerns. Therefore, there has been a continuous effort to develop clinically useful diagnostic tools for accurately and quantitatively measuring and monitoring blood and oxygen supply to the fetal and neonatal brain to avoid severe consequences of asphyxia Hypoxic-Ischemic Encephalopathy (HIE) and Neonatal Encephalopathy (NE). Major diagnostic technologies used for this purpose include fetal heart rate monitoring (FHRM), fetus scalp blood sampling (FBS), ultrasound (US) imaging, magnetic resonance imaging (MRI), x-ray computed tomography (CT), and nuclear medicine. In addition, given the limitations and shortcomings of traditional diagnostic methods, emerging technologies such as near-infrared spectroscopy (NIRS) and photoacoustic (PA) imaging have also been introduced as stand-alone or complementary solutions to address this critical gap in fetal and neonatal care. This review provides a thorough overview of the traditional and emerging technologies for monitoring fetal and neonatal brain oxygenation status and describes their clinical utility, performance, advantages, and disadvantages.

Relationship Between Umbilical Cord Gas Values and Neonatal Outcomes: Implications for Electronic Fetal Heart Rate Monitoring

OBJECTIVE

To evaluate the relationship between umbilical artery cord gas values and fetal tolerance of labor, as reflected by Apgar score. We hypothesized the existence of wide biological variability in fetal tolerance of metabolic acidemia, which, if present, would weaken one fundamental assumption underlying the use of electronic fetal heart rate (FHR) monitoring.

METHODS

We conducted a retrospective cohort study of term, singleton, nonanomalous fetuses delivered in our institution between March 2012 and July 2020. Universally obtained umbilical cord gas values and Apgar scores were extracted. We calculated Spearman correlation coefficients and receiver operating characteristic curves for various levels of umbilical artery pH, base excess, and Apgar scores.

RESULTS

We analyzed data from 29,787 deliveries. The statistical correlation between umbilical artery pH and base excess and both 1- and 5-minute Apgar scores was weak or nonexistent in all pH range subgroups (range 0.064-0.213). Receiver operating characteristic curve analysis suggested umbilical artery pH value of 7.22 yields the best discrimination for prediction of a severely depressed newborn (5-minute Apgar score less than 4), but sensitivity and specificity for this predictive value remains poor to moderate.

CONCLUSION

The use of electronic FHR monitoring is predicated on a documented relationship between FHR patterns and umbilical artery pH, and an assumed correlation between pH and fetal outcomes, reflecting fetal tolerance of labor and delivery. Our data demonstrate a weak-to-absent correlation between metabolic acidemia and even short-term fetal condition, thus significantly weakening this latter assumption. No amount of future modification of FHR pattern interpretation to better predict newborn pH is likely to lead to improved newborn outcomes, given this weakness in a fundamental assumption on which FHR monitoring is based.

[Critical Outcome and Hypoxic Ischemic Encephalopathy - A quality Assurance Issue]

The study evaluates the predictive value of the critical status of a newborn as to the risk of developing hypoxic ischemic encephalopathy (HIE).

METHODS

On the basis of the data set from the perinatal survey in Hesse, Germany, in the year 2016, including 52,122 live births (singleton, 37+0 GA), cases of critical newborns were identified. A conjoined analysis with the data set of the neonatal survey from the identical period provided the basis to evaluate the relationship to cases compromised by HIE.

RESULTS

The incidence of cases with a critical outcome (n=11) and those with HIE (n=29) was low. The sensitivity of the status of the newborn for detecting a risk of HIE was 10.34%. The specificity was 99.98%. The positive predictive value was 27.35%. The negative predictive value was 99.95%. The detailed, confidential single-case analysis indicated the ability to avoid negative outcomes in about one third of cases with a critical status of the newborn (4/11) and HIE (9/29).

DISCUSSION AND CONCLUSION

The likelihood of developing encephalopathy (HIE) increases after a critical outcome after birth. Intensified monitoring of these newborns is justified. A single-case analysis identifies the potential ways to improve perinatal outcomes. Measures of external quality assurance should integrate the analysis of both perinatal and neonatal surveys as a basis for quality management (QM).

Near-infrared spectroscopy of the placenta for monitoring fetal oxygenation during labour

Although being the golden standard for intrapartum fetal surveillance, cardiotocography (CTG) has been shown to have poor specificity for detecting fetal acidosis. Non-invasive near-infrared-spectroscopy (NIRS) monitoring of placental oxygenation during labour has not been studied yet. The objective of the study was to determine whether changes in placental NIRS values during labour could identify intrapartum fetal hypoxia and resulting acidosis. We included 43 healthy women in active stage of labour at term. CTG and NIRS parameters in groups with vs. without neonatal umbilical artery pH ≤ 7.20 were compared using Mann-Whitney-U. Receiver-operating-characteristics (ROC) curves were used to estimate predictive value of CTG and NIRS parameters for neonatal pH ≤ 7.20. A computer-based statistical classification was also performed to further evaluate predictive values of CTG and NIRS for neonatal acidosis. Ten (23%) neonates were born with umbilical artery pH ≤ 7.20. Compared to group with pH > 7.20, fetal acidosis was associated with more episodes of placental NIRS deoxygenation (9 (range 2-37) vs. 2 (range 0-65); p<0.001), higher velocity of placental NIRS deoxygenation (2.31 (range 0-22) vs. 1 (range 0-49) %/s; p = 0.03), more decelerations on CTG (25 (range 3-91) vs. 10 (range 10-60); p = 0.02), and more prolonged decelerations on CTG (2 (range 0-4) vs. 1 (range 0-3); p = 0.04). Number of placental deoxygenations had the highest prognostic value for fetal/neonatal acidosis (area under the ROC curve 0.85 (95% confidence interval 0.70-0.99). Computer-based classification also identified number of placental deoxygenations as the most accurate classifier, with 25% false positive and 93% true positive rate in the training dataset, with 100% accuracy when applied to the testing dataset. Placental deoxygenations during labour measured by NIRS are associated with fetal/neonatal acidosis. Predictive value of placental NIRS for neonatal acidosis was superior to that of CTG.

Monitoring Fetal Electroencephalogram Intrapartum: A Systematic Literature Review

Background: Studies about the feasibility of monitoring fetal electroencephalogram (fEEG) during labor began in the early 1940s. By the 1970s, clear diagnostic and prognostic benefits from intrapartum fEEG monitoring were reported, but until today, this monitoring technology has remained a curiosity. Objectives: Our goal was to review the studies reporting the use of fEEG including the insights from interpreting fEEG patterns in response to uterine contractions during labor. We also used the most relevant information gathered from clinical studies to provide recommendations for enrollment in the unique environment of a labor and delivery unit. Data Sources: PubMed. Eligibility Criteria: The search strategy was: ("fetus"[MeSH Terms] OR "fetus"[All Fields] OR "fetal"[All Fields]) AND ("electroencephalography"[MeSH Terms] OR "electroencephalography"[All Fields] OR "eeg"[All Fields]) AND (Clinical Trial[ptyp] AND "humans"[MeSH Terms]). Because the landscape of fEEG research has been international, we included studies in English, French, German, and Russian. Results: From 256 screened studies, 40 studies were ultimately included in the qualitative analysis. We summarize and report features of fEEG which clearly show its potential to act as a direct biomarker of fetal brain health during delivery, ancillary to fetal heart rate monitoring. However, clinical prospective studies are needed to further establish the utility of fEEG monitoring intrapartum. We identified clinical study designs likely to succeed in bringing this intrapartum monitoring modality to the bedside. Limitations: Despite 80 years of studies in clinical cohorts and animal models, the field of research on intrapartum fEEG is still nascent and shows great promise to augment the currently practiced electronic fetal monitoring. Prospero Number: CRD42020147474.

Wearable Fetal Monitoring Solution for Improved Mobility During Labor & Delivery

Electronic fetal monitoring (EFM) is used widely during labor & delivery, but existing solutions limit patient mobility, are uncomfortable, and do not consistently capture fetal heart rate (FHR) and uterine activity (UA) signals. A wireless EFM system was developed that features wearable US and tocodynamometer devices that conform to the body and do not require cables or belts. Benchtop testing demonstrated that the devices can accurately and consistently measure simulated FHRs and UAs over clinically meaningful ranges and body curvatures. The wearable EFM devices are expected to provide more reliable signal capture independent of maternal movement and repositioning, while also significantly improving patient comfort and mobility.

Does the Use of Diagnostic Technology Reduce Fetal Mortality?

OBJECTIVE

To examine the effect that the introduction of new diagnostic technology in obstetric care has had on fetal death.

DATA SOURCE

The Medical Birth Registry of Norway provided detailed medical information for approximately 1.2 million deliveries from 1967 to 1995. Information about diagnostic technology was collected directly from the maternity units, using a questionnaire.

STUDY DESIGN

The data were analyzed using a hospital fixed-effects regression with fetal mortality as the outcome measure. The key independent variables were the introduction of ultrasound and electronic fetal monitoring at each maternity ward. Hospital-specific trends and risk factors of the mother were included as control variables. The richness of the data allowed us to perform several robustness tests.

PRINCIPAL FINDING

The introduction of ultrasound caused a significant drop in fetal mortality rate, while the introduction of electronic fetal monitoring had no effect on the rate. In the population as a whole, ultrasound contributed to a reduction in fetal deaths of nearly 20 percent. For post-term deliveries, the reduction was well over 50 percent.

CONCLUSION

The introduction of ultrasound made a major contribution to the decline in fetal mortality at the end of the last century.

The effect of cigarette smoking on fetal heart rate tracing during pregnancy

OBJECTIVE

The objective of this study is to investigate the alterations caused by smoking on the features of fetal heart rate (FHR) tracings as well as to make a comparison between pregnant smokers and pregnant women with intrauterine growth restriction (IUGR).

STUDY DESIGN

A number of established features derived from linear and nonlinear fields were employed to study the possible influence of maternal smoking on FHR tracings. Moreover, correlation and measures of complexity of the FHR were explored, in order to get closer to the core of information that the signal of FHR tracings conveys. Data included FHR tracings from 61 uncomplicated singleton pregnancies, 16 pregnant smoker cases, and 15 pregnancies of women with IUGR.

RESULTS

The analysis of FHR indicated that some parameters, such as mutual information (P=0.0025), multiscale entropy (P=0.01), and algorithmic complexity (P=0.024) appeared decreased in the group of pregnant smokers, while kurtosis (P=0.0011) increased. The comparison between pregnant smokers and pregnant women with IUGR indicated a reduction in Hjorth complexity (P=0.039) for the former.

CONCLUSION

Smoking during pregnancy seems to induce differences in several linear and nonlinear indices in recordings of FHR tracings. This may be the consequence of an altered neurodevelopmental maturation possibly resulting from chronic fetal hypoxemia in cigarette-exposed fetuses.

Acute fetal heart rate tracing changes secondary to cigarette smoking in third trimester pregnancies

OBJECTIVE

In this study, we aimed to assess the acute alterations on some features of fetal heart rate (FHR) tracings in third trimester pregnancies.

METHODS

Data of FHR tracing records were obtained from 79 otherwise healthy pregnant women aged between 18 and 41. Among 79 women, 39 were nonsmokers while the remaining were chronic smokers (six or more cigarettes per day, with an average of 10 cigarettes per day). The baseline of tracings, the number of accelerations and decelerations of FHR, as well as the FHR mean, standard deviation, short-term variability of FHR were all calculated for each participant. The results of smokers and nonsmokers, then the results of smokers before and after smoking were compared.

RESULTS

Comparison of some demographic and FHR tracing characteristics between smoker and nonsmoker groups indicated significantly decreased variability in smoker group. All FHR tracing characteristics were compared before and, immediately after cigarette smoking and revealed significantly higher mean baseline, lower variability and acceleration after smoking a cigarette.

CONCLUSION

Even in a short time period, smoking is associated with some changes in FHR monitorization characteristics, detailed analyses of these changes may clarify the pathophysiology of smoking associated perinatal outcome.

Effects of 3-h hypothermia after neonatal hyperthermic hypoxic-ischemic encephalopathy in rat models on behavioral prognosis and anatomical and histological features after growth

OBJECTIVE

To clarify the effects of 3-h hypothermia on learning ability and motor function after growth, employing neonatal rat models with hyperthermic hypoxic-ischemic encephalopathy (HIE).

METHODS

We divided all rats into three groups: N (adult rats after neonatal hyperthermic HIE without subsequent 3-h hypothermia), H (adult rats after neonatal hyperthermic HIE with subsequent 3-h hypothermia) and Sham (S) groups. We evaluated their malfunctions with the rota-rod test and the step-down passive avoidance test. We also analyzed the cerebrum width and the hippocampal CA1 area of the insulted hemisphere.

RESULTS

In the rota-rod test, the result of the N group was significantly worse than that of the S group. In the step-down passive avoidance test, the result of the N group was significantly worse than those of the S and H groups. The longest cerebrum width and the hippocampal CA1 area of the insulted hemisphere of the N group were significantly smaller than those of the S and H groups.

CONCLUSION

Neonatal hyperthermic hypoxic-ischemic insult restricts motor function and learning ability after growth, and such neuronal malfunctions can be relieved by hypothermia for 3 h soon after neonatal HIE.

Recognition and response to electronic fetal heart rate patterns: impact on newborn outcomes and primary cesarean delivery rate in women undergoing induction of labor

OBJECTIVE

The objective of the study was to examine the clinical impact of specific fetal monitoring-related practices during induced labor.

STUDY DESIGN

This was a prospective, nonrandomized study.

RESULTS

We studied 14,398 women undergoing oxytocin induction of labor. A decrease in the infusion rate of oxytocin in the face of specified category II fetal heart rate tracings was associated with a significantly reduced rate of neonatal intensive care unit admission (3.8% vs 5.2%, P = .01) and Apgar score less than 7 at 1 and 5 minutes (4.9% vs 6.4%, P = .01, 0.6% vs 1.1%, P = .04). Compliance with an in-use checklist was associated with both a reduction in the rate of neonatal intensive care unit admission (2.9 vs 4.4, P = .00) and a reduction in the cesarean delivery rate (15.8% vs 18.8%, P = .00).

CONCLUSION

Electronic fetal heart rate monitoring improves neonatal outcomes when unambiguous definitions of abnormal fetal heart rate and tachysystole are coupled with specific interventions. Utilization of a checklist for oxytocin monitoring is associated with improved neonatal outcomes and a reduction in the cesarean delivery rate.

Are we (mis)guided by current guidelines on intrapartum fetal heart rate monitoring? Case for a more physiological approach to interpretation

Original interpretations of fetal heart rate (FHR) patterns equated FHR decelerations with 'fetal distress', requiring expeditious delivery. This simplistic interpretation is still implied in our clinical guidelines despite 40 years of increasing understanding of the behaviour and regulation of the fetal cardiovascular system during labour. The physiological basis of FHR responses and adaptations to oxygen deprivation is de-emphasised, whilst generations of obstetricians and midwives are trained to focus on, and classify, the morphological appearances of decelerations into descriptive categories, with no attempt to understand how the fetus defends itself and compensates for intrapartum hypoxic ischaemic insults, or the patterns that suggest progressive loss of compensation. Consequently, there is a lack of confidence, marked variation in FHR interpretation, defensive practices, unnecessary operative interventions, and a failure to recognise abnormal FHR patterns, resulting in adverse outcomes and expensive litigation.

Fetal heart rate classification proposed by the perinatology committee of the Japan Society of Obstetrics and Gynecology: reproducibility and clinical usefulness

AIM

Intrapartum management guidelines based on fetal heart rate classification comprising a 5-tier system (Levels 1-5) was proposed by the Perinatology Committee of the Japan Society of Obstetrics and Gynecology (JSOG). This study aimed to assess the reproducibility and clinical usefulness of this classification.

METHODS

For assessing intraobserver and interobserver reproducibility in the interpretation of fetal heart rate tracing, 2 obstetricians reviewed 247 fetal heart rate tracings using the JSOG classification (Level 1, normal; Level 2, benign variant; Level 3, mild variant; Level 4, moderate variant; and Level 5, severe variant) and a subjective 3-tier classification (normal, equivocal, and ominous). In a separate series, we investigated whether the JSOG classification is related to early neonatal outcome and the delivery mode in 96 deliveries.

RESULTS

Weighted kappa coefficients of intraobserver and interobserver reproducibility in the interpretation of fetal heart rate tracings based on the JSOG classification were 0.73 to 0.77 and 0.70, respectively. In the subjective classification, these values were 0.69 to 0.72 and 0.59. There was a progressive increase in the rate of instrumental or cesarean deliveries across the 5 levels of the JSOG classification (P<0.001). Although, level 5 of the JSOG classification had a lower Apgar score and umbilical artery pH than did the other 4 levels (p<0.05), there were no significant differences among the other levels in regard to early neonatal outcome.

CONCLUSIONS

This study demonstrated that both intraobserver reproducibility and interobserver reproducibility of the JSOG classification for interpreting FHR tracings were clinically acceptable. The results also suggest that the intervention according to the JSOG classification is useful for avoiding worsening early neonatal outcomes.

Intrapartum heart rate ambiguity: a comparison of cardiotocogram and abdominal fetal electrocardiogram with maternal electrocardiogram

OBJECTIVE/AIMS

To investigate the presence of signal ambiguity of intrapartum fetal heart rate (FHR) monitoring during delivery by comparing simultaneous cardiotocogram (CTG), abdominal fetal electrocardiogram (ECG) with continuous maternal ECG.

METHODS

A total of 144 simultaneous CTG (Corometrics 250 series), abdominal fetal ECG (Monica -AN24™) and maternal ECG (Monica AN24™) recordings were evaluated.

MAIN OUTCOME MEASURES

When the FHR is within 5 bpm of the maternal heart rate (MHR) acquired from the ECG, it is classified as 'MHR/FHR ambiguity'. Statistical analyses were performed with Fisher's exact test and the Wilcoxon signed-rank test.

RESULTS

Comparison of abdominal fetal ECG against CTG demonstrates significantly less 'MHR/FHR ambiguity' in both the first stage (mean 0.70 vs. 1.22%, p < 0.001) and second stage of labour (mean 3.30 vs. 6.20%, p < 0.001).

CONCLUSION

Intrapartum FHR monitoring in daily practice via the CTG modality provides significantly more 'MHR/FHR ambiguity' than abdominal fetal ECG, which also provides additional information on the MHR.

Maternal and umbilical cord ischemia-modified albumin levels in nonreassuring fetal heart rate tracings regarding the mode of delivery

OBJECTIVE

To evaluate umbilical cord blood ischemia-modified albumin (IMA) levels in cases of fetal distress (FD) and to explore fetal blood IMA levels regarding the route of delivery.

METHODS

Umbilical cord and maternal serum IMA concentrations were assessed in term 40 cases with cesarean section (CS) due to FD, 76 cases with elective repeat CS and 85 cases with noncomplicated vaginal delivery.

RESULTS

The maternal and umbilical cord IMA levels were significantly lower in vaginal deliveries when compared with CS cases either in FD or previous CS groups (p = 0.02). Although no statistically significant difference was found in IMA levels of CS groups (previous CS vs. FD), cord blood IMA levels tend to be higher in FD group. Neither demographic characteristics nor fetal outcome parameters were found to have any correlation with maternal IMA levels. However, umbilical cord IMA levels were found to be negatively correlated with 1th min Apgar scores (r = -0.143, p = 0.043).

CONCLUSIONS

IMA seems to be responsive to hypoxic FD showing the highest levels in cases with severe fetal hypoxia. Higher levels of IMA in cases with elective repeat CS might indicate acute transient hypoxia and possible myocardial ischemia in these cases.

Preventing primary cesarean sections: intrapartum care

Some intrapartum care practices promote vaginal birth, whereas others may increase the risk for cesarean section. Electronic fetal monitoring and use of the Friedman graph to plot and monitor labor progress are associated with increasing the cesarean section rate. Continuous one-to-one support and midwifery management are associated with lower cesarean section rates. This article reviews the evidence that links specific intrapartum care practices to cesarean section. Strategies that can be implemented in the current social and cultural setting of obstetrics today are recommended.

Prenatal Foetal Non-invasive ECG instead of Doppler CTG - A Better Alternative?

Introduction: This study aimed to evaluate foetal signal quality obtained using an antenatal foetal ECG system (Monica 24™) and compare it with Doppler ultrasound CTG monitoring (Corometrics® 250 series). Material and Methods: Seventy pregnant women (gestational age: between 20 + 0 weeks and 40 + 0 weeks) were examined using the Monica AN24™ system and also underwent Doppler CTG. The signal quality of both methods was compared and correlated with gestational age and pre-pregnancy body mass index (BMI). Results: Overall, ECG had a signal quality of 77.4 % and CTG had a signal quality of 73.1 % (p > 0.05). In gestational weeks (GW) 20-26, the signal quality of ECG was significantly better compared to that obtained with CTG (75.5 vs. 45.3 %; p = 0.003), while in GW 27-36, the signal quality was better with CTG (72.3 vs. 83.0 %, p = 0.001). No difference in signal quality was found between the two methods after the 37th GW (87.7 vs. 86.1 %; p > 0.05). CTG showed a statistically significant correlation with BMI (rho 0.25, p < 0.05) while ECG showed no such correlation. Conclusion: The use of non-invasive ECG is particularly indicated in the early weeks of pregnancy, while CTG offers superior results during the vernix period. There was no difference in signal quality after the vernix period. The signal quality with ECG was found to be independent of BMI, while the signal quality of CTG deteriorated with increasing BMI.

Non-invasive Foetal ECG - a Comparable Alternative to the Doppler CTG?

This review discusses the alternative of using the non-invasive foetal ECG compared with the conventionally used Doppler CTG. Non-invasive abdominal electrocardiograms (ECG) have been approved for clinical routine since 2008; subsequently they were also approved for antepartum and subpartum procedures. The first study results have been published. Non-invasive foetal ECG is especially indicated during early pregnancy, while the Doppler CTG is recommended for the vernix period. Beyond the vernix period no difference has been recorded in the success rate of either approach. The foetal ECG signal quality is independent of the BMI, whereas the success rate of the Doppler CTG is diminished with an increased BMI. During the first stage of labour, non-invasive foetal ECG demonstrates better signal quality; however during the second stage of labour no difference has been identified between the methods.

Electronic fetal heart rate monitoring and its relationship to neonatal and infant mortality in the United States

OBJECTIVE

To examine the association between electronic fetal heart rate monitoring and neonatal and infant mortality, as well as neonatal morbidity.

STUDY DESIGN

We used the United States 2004 linked birth and infant death data. Multivariable log-binomial regression models were fitted to estimate risk ratio for association between electronic fetal heart rate monitoring and mortality, while adjusting for potential confounders.

RESULTS

In 2004, 89% of singleton pregnancies had electronic fetal heart rate monitoring. Electronic fetal heart rate monitoring was associated with significantly lower infant mortality (adjusted relative risk, 0.75); this was mainly driven by the lower risk of early neonatal mortality (adjusted relative risk, 0.50). In low-risk pregnancies, electronic fetal heart rate monitoring was associated with decreased risk for Apgar scores <4 at 5 minutes (relative risk, 0.54); in high-risk pregnancies, with decreased risk of neonatal seizures (relative risk, 0.65).

CONCLUSION

In the United States, the use of electronic fetal heart rate monitoring was associated with a substantial decrease in early neonatal mortality and morbidity that lowered infant mortality.

English Midwives' Views and Experiences of Intrapartum Fetal Heart Rate Monitoring in Women at Low Obstetric Risk: Conflicts and Compromises

Over the last 20 years in the United Kingdom, midwives have implemented the routine use of intrapartum fetal monitoring regardless of the risk status of laboring women. This practice is at odds with the published research. The discrepancy between practice and best evidence merits further investigation. A qualitative study was conducted to evaluate midwives' attitudes and experiences about the use of fetal monitoring for women at low obstetric risk. Fifty-eight midwives working in two hospitals in the north of England were interviewed by using a semistructured approach. The taped interviews were transcribed and analyzed by using a general thematic approach. Issues included midwives' perceptions of low-risk status, the socialization of midwives, and the loss of woman-centered care. Midwives subscribed to the notion of woman-centered care, but because of a complexity of factors experienced in their daily working lives, they felt vulnerable when attempting to implement evidence-based fetal monitoring practices. Midwives regretted the loss of a woman-centered approach to care when technologic methods of intrapartum fetal heart rate monitoring were used indiscriminately. An appreciation of the complex factors affecting the ability of midwives to implement evidence-based practice is important when attempting to facilitate the development of appropriate fetal monitoring practices for women at low obstetric risk.

Foetal monitoring: a woman-centred decision-making pathway

PROBLEM

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

PARTICIPANTS

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

METHODS

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

FINDINGS

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

CONCLUSIONS

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

STAN® S21 fetal heart monitor for fetal surveillance during labor: an observational study in 637 patients

OBJECTIVE

To assess the value of the STAN fetal heart monitor for intrapartum fetal monitoring using cardiotocography (CTG) and fetal electrocardiography (ECG).

DESIGN

Prospective observational study.

MATERIAL AND METHODS

Between August 2000 and November 2002, 637 high-risk labors were monitored using a STAN S21 fetal heart monitor, providing CTG plus automatic ST analysis of the fetal ECG. Guidelines with recommendations about when to intervene were available. During the study period labor-ward personnel were systematically instructed about the (patho)-physiology of asphyxia and CTG and ST changes during labor.

RESULTS

Four hundred and forty-nine recordings were available for analysis of outcome in relation to ST changes. In 61 cases, ST changes requiring intervention occurred > 10 min before birth. In 35 (57%) of these cases, umbilical artery blood pH at delivery was < 7.15. Eighteen (4.0%) neonates were born with metabolic acidosis (umbilical artery pH < 7.05 and extracellular base deficit > 12 mmol/l). Significant ST changes (18-31 min before birth) were present in all five cases with pH < 7.00 and in six of the 13 cases with pH of 7.00-7.04 (false-negative rate 1.6%). Neonatal follow-up showed no adverse outcome. One hundred and ninety-two fetal blood samples (121 in the first stage and 71 in the second stage of labor) were taken from 142 women. Fetal scalp blood pH was < 7.15 in ten samples, 7.15-7.19 in 11 samples, 7.20-7.24 in 30 samples and > or =7.25 in 141 samples. ST changes occurred in eight (80%), six (55%), nine (30%) and 15 (11%) of these cases, respectively. In 188 (29.5%) women, outcome could not be analyzed in relation to ST changes because of inadequate recording (time between end of recording and delivery > 20 min or poor signal quality) or the absence of umbilical cord gases. In this group, four (2.1%) neonates with metabolic acidosis were born. In three of these cases the fetal ECG signal was of was poor quality and in one case the recording had ended 60 min before birth.

CONCLUSION

ST changes were present in all five cases with severe metabolic acidosis (umbilical artery pH < 7.00). ST changes occurred in 46% of cases with mild metabolic acidosis. CTG plus ST analysis was more specific in detecting fetal acidemia than CTG alone.

ST-segment analysis of the fetal electrocardiogram improves fetal heart rate tracing interpretation and clinical decision making

INTRODUCTION

Since its introduction into clinical use, the efficacy of electronic fetal heart rate (FHR) monitoring (EFM) has been questionable. This has been due partly to the marked variation in interpretation of the FHR pattern and subsequent decisions for obstetric intervention, (e.g., the need for prompt delivery). Current application of EFM is limited to the assessment of FHR patterns and uterine contractions. Recent development of higher-order FHR analysis has yielded monitoring systems that can add automated fetal electrocardiographic ST segment analysis to the standard FHR and uterine contraction information. Our goal was to evaluate the effect of adding ST segment analysis to standard FHR information on observer agreement for clinical decision making.

METHODS

Seven practitioners who were trained and experienced in combined FHR and ST monitoring reviewed 51 fetal monitor tracings, ranging from 2 to 4 h in length. Reviews were conducted in two sessions and at different times. The first session presented only the FHR and uterine contraction information, following which the participants determined the time at which intervention (decision for operative vaginal or Cesarean section delivery) was indicated. In the second session, the participants were provided with a randomized sequence of the same tracings with the addition of ST segment information, as produced by the STAN monitor system (Neoventa Medical, Gothenburg, Sweden). Observer agreement was based on the proportion of participants who agreed on the need for an intervention, and the per cent agreement on the timing of the intervention within 20 min before or after the median time of intervention.

RESULTS

Of the 51 cases included in this study there were ten fetuses with umbilical artery (UA) pH between 7.05 and 7.14, and nine with UA pH of < 7.05. Observer agreement increased significantly for required intervention when the ST segment information was available for tracing analysis as compared with review of the standard tracing alone (0.96 vs. 0.80, p < 0.05) and the timing of intervention (0.92 vs. 0.66, respectively, p < 0.05). Similarly, correct identification for needed interventions on fetuses with abnormal outcomes increased from 86 to 93% while unneeded interventions on normal fetuses decreased from 43 to 6%.

CONCLUSION

The addition of ST analysis to standard FHR monitoring improves observer consistency in both the decision for and timing of obstetric interventions. The incorporation of ST segment data with the standard FHR tracing may reduce the number of unneeded obstetric interventions when fetal compromise is absent.

Development and significance of a fetal electrocardiogram recorded by signal-averaged high-amplification electrocardiography

Although ultrasonic diagnostic imaging and fetal heart monitors have undergone great technological improvements, the development and use of fetal electrocardiograms to evaluate fetal arrhythmias and autonomic nervous activity have not been fully established. We verified the clinical significance of the novel signal-averaged vector-projected high amplification ECG (SAVP-ECG) method in fetuses from 48 gravidas at 32-41 weeks of gestation and in 34 neonates. SAVP-ECGs from fetuses and newborns were recorded using a modified XYZ-leads system. Once noise and maternal QRS waves were removed, the P, QRS, and T wave intervals were measured from the signal-averaged fetal ECGs. We also compared fetal and neonatal heart rates (HRs), coefficients of variation of heart rate variability (CV) as a parasympathetic nervous activity, and the ratio of low to high frequency (LF/HF ratio) as a sympathetic nervous activity. The rate of detection of a fetal ECG by SAVP-ECG was 72.9%, and the fetal and neonatal QRS and QTc intervals were not significantly different. The neonatal CVs and LF/HF ratios were significantly increased compared with those in the fetus. In conclusion, we have developed a fetal ECG recording method using the SAVP-ECG system, which we used to evaluate autonomic nervous system development.

Inter- and intra-observer agreement of intrapartum ST analysis of the fetal electrocardiogram in women monitored by STAN

OBJECTIVE

The objective of this study was to quantify inter- and intra-observer agreement on classification of the intrapartum cardiotocogram (CTG) and decision to intervene following STAN guidelines.

DESIGN

A prospective, observational study.

SETTING

Obstetrics Department of a tertiary referral hospital.

POPULATION

STAN recordings of 73 women after 36 weeks of gestation with a high-risk pregnancy, induced or oxytocin-augmented labour, meconium-stained amniotic fluid or epidural analgesia.

METHODS

Six observers classified 73 STAN recordings and decided if and when they would suggest an intervention. Proportions of specific agreement (Ps) and kappa values (Kappa) were calculated.

MAIN OUTCOME MEASURES

Agreement upon classification of the intrapartum CTG and decision to perform an intervention.

RESULTS

Agreement for classification of a normal and a (pre)terminal CTG was good (Ps range 0.50-0.84), but poor for the intermediary and abnormal CTG (Ps range 0.34-0.56). Agreement on the decision to intervene was higher, especially on the decision to perform 'no intervention' (Ps range 0.76-0.94). Overall inter-observer agreement on the decision to intervene was considered moderate in five of six observer combinations according to the kappa (Kappa range 0.42-0.73). Intra-observer agreement for CTG classification and decision to intervene was moderate (Kappa range 0.52-0.67 and 0.61-0.75).

CONCLUSIONS

Inter-observer agreement on classification of the intrapartum CTG is poor, but addition of information regarding fetal electrocardiogram, especially in case of intermediary or abnormal CTG traces, results in a more standardised decision to intervene.

Fetal monitoring in the prehospital setting

BACKGROUND

Prehospital emergency care providers have very little information regarding fetal perfusion adequacy in the field.

OBJECTIVE

This study was conducted to evaluate the feasibility of the use of fetal monitoring in the prehospital setting.

METHODS

A mobile cardiotocometer was used for all consecutive pregnant women managed by our physician-staffed Emergency Medical Services unit. The visualization of interpretable tracings (both fetal heart rate and tocography) at the different stages of prehospital management was evaluated. Any change in a patient's management was also recorded.

RESULTS

There were 145 patients enrolled during 119 inter-hospital transfers and 26 primary prehospital interventions. Interpretable tracings were obtained for 81% of the patients during the initial examination. This rate decreased to 66% during handling and transfer procedures. For 17 patients (12%), the monitoring led to a change in the patient's management.

CONCLUSION

This study shows that cardiotocography can be easily performed in the prehospital setting, and is usually feasible. Moreover, the study demonstrates a positive impact of fetal heart rate monitoring on prehospital management.

The quality of intrapartum uterine activity monitoring

AIMS

To determine the quality of intrapartum uterine activity (UA) monitoring in daily practice during the first and second stage of labor. The total duration of inadequate UA monitoring is quantified in relation to the technique applied: external or internal.

METHODS

One hundred and ninety-two UA recordings, collected from 1 April 2006 untill 1 October 2006 from consecutive deliveries at the Vrije Universiteit Medical Center in Amsterdam, were analyzed. Included recordings were from singleton, spontaneous, vaginal deliveries. The last two hours of the first stage and the complete second stage had to be monitored. Internal and external UA recordings were judged by their quality: adequate, a recognizable and reliable UA pattern during the complete registration, or inadequate. Recordings labeled as inadequate were divided into two groups: absence of UA recording (non recognizable) or inadequate calibration (unreliable). Statistical analyses were performed with the Mann-Whitney U-test and the Wilcoxon signed ranks test.

RESULTS

The percentages of adequate UA recordings in the first stage of labor were much higher for the internal than the external mode. Only 2% of the external recordings were of good quality vs. 40% of the internal recordings. In the second stage, percentages of adequate UA recordings were nearly equal, approximately 30%. Inadequate external registrations were characterized by almost 30% of the time absent UA monitoring, whereas with inadequate internal registrations the primary problem was correct calibration.

CONCLUSION

Intrapartum UA monitoring in daily practice via the direct mode provides a more recognizable UA trace.

Minimizing perinatal neurologic injury at term: is cesarean section the answer?

Despite advances in obstetric and neonatal care, the last several decades have not witnessed an improvement in the prediction or prevention of term cerebral palsy. Obstetric interventions such as electronic fetal heart rate monitoring and cesarean delivery, although biologically plausible as intervention strategies, do not improve perinatal outcomes in clinical practice. In reaction to mounting medicolegal pressure, obstetricians continue to increase the number of cesarean deliveries they perform as a form of defensive medicine, despite evidence that this practice is not associated with improved perinatal outcomes. The current standard for expeditious delivery in a case of potential fetal compromise is described by the "30-minute rule." However, obstetricians' determinations of the need for expedited delivery may be a preferable guide for appropriate delivery timing.

Uterine activity: implications for the condition of the fetus

AIM

The aim of this review is to provide more insight in the fetal mechanisms as a response to uterine contractions and to emphasize the importance of correct assessment of uterine activity (UA) patterns during labor.

STUDY RESULTS

UA causes a decreased flow through the uterine artery. In the healthy uncompromised fetus, this will not cause fetal acidemia. The fetus has developed certain protection mechanisms to survive labor; (1) During a contraction, fetal preload increases and enables the fetus to maintain a constant blood flow through the umbilical artery and (2) UA increases the blood flow in the fetal middle cerebral artery, i.e., a brain sparing effect. The shortcoming of those protection mechanisms in the compromised fetus and in case of excessive UA increases the risk of adverse fetal outcome. The brain sparing effect will become more pronounced to compensate for the decreased umbilical artery blood flow and fetal oxygen saturation. Maintenance of normal UA, especially a sufficiently long relaxation time, is essential so that the supply of well oxygenated maternal blood to the intervillous space will be restored and the fetal cerebral oxygen saturation can remain stable.

CONCLUSION

Adequate UA monitoring is a prerequisite for proper reading and interpretation of cardiotocograms. It alarms in cases of excessive UA and can help to prevent fetal acidemia. Uterine contraction monitoring deserves full attention in daily obstetric practice.