Continuous Electronic Fetal Heart Rate Research Articles

Category II Intrapartum Fetal Heart Rate Patterns Unassociated With Recognized Sentinel Events: Castles in the Air.

The evolution of continuous electronic fetal heart rate (FHR) monitoring has presented the obstetrician with a critical clinical conundrum: basic science observations suggest that such monitoring might be associated with improved long-term neurologic outcomes, yet, after a half century of use and millions of cesarean deliveries based on FHR monitoring, evidence for such improvement remains absent. This dichotomy appears to be related to widespread misconceptions regarding the physiology underlying various FHR patterns and the developmental origins of cerebral palsy. These misconceptions are strengthened by a reliance on anecdotal experience and tradition in lieu of evidence-based medicine, the confusing "category II" FHR designation, medical-legal considerations, and our tendency to view fetal monitoring, as originally conceptualized, as a single, indivisible entity whose concepts must be accepted or rejected en bloc. Ill-defined and largely imaginary conditions such as "depletion of fetal reserve" are particularly harmful and their use in clinical medicine uniquely not evidence based. A solution to this self-inflicted injury to our specialty will require a concerted effort involving teachers, authors, and researchers.

Continuous electronic fetal heart rate monitoring in labour is a screening test, not a diagnostic test

Continuous electronic fetal heart rate monitoring in labour is a screening test, not a diagnostic test

Computerised Interpretation of Fetal Heart Rate During Labour (INFANT): A Randomized Controlled Trial

(Lancet. 2017;389:1719–1729) Although continuous electronic fetal heart rate (FHR) monitoring in labor has been widely used for several years, its ability to significantly improve neonatal outcomes has not yet been realized. The difficulty of correctly interpreting FHR tracings has been suggested as a contributing factor to this lack of improved outcomes.

Cardiotocography alone is outdated and ST analysis is the way forward in fetal monitoring: AGAINST: An opportunity to avoid past mistakes in fetal monitoring

Continuous electronic fetal heart rate monitoring is standard care in many regions, despite a lack of evidence that it reduces adverse neurodevelopmental sequelae, including hypoxic-ischaemic neonatal encephalopathy and cerebral palsy. It has a high false-positive rate, poor inter- and intra-observer reliability, and increases the operative delivery rate: surprising characteristics for a test in widespread use. Current risk stratification systems for intrapartum fetal heart rate monitoring are limited by indeterminate categories, where fetal status and perinatal outcome cannot be reliably predicted. The use of an adjunctive test to adjudicate indeterminate heart rate tracings has therefore been highly sought, and the use of fetal electrocardiogram (ECG) ST-segment analysis (ST analysis) has been evaluated in six randomised trials and several meta-analyses for this purpose. Initial trials conducted in Europe suggested that ST analysis reduced operative delivery, acidaemia, and neonatal encephalopathy. Subsequent trials have had conflicting findings. In 2015, a US randomised trial was published demonstrating that ST analysis did not improve composite perinatal outcome, nor decrease the rate of operative vaginal delivery or caesarean delivery (Belfort et al. N Engl J Med 2015;373:632–41). The most recent meta-analysis demonstrated no differences in the most meaningful outcomes, including caesarean delivery, severe acidaemia at birth, or neonatal encephalopathy (Neilson Cochrane Database Syst Rev 2015;12:CD000116). Fewer scalp blood samples and marginally fewer operative vaginal deliveries have been demonstrated: outcomes of dubious importance when considering the overarching intent to prevent adverse neonatal outcomes and unnecessary caesarean deliveries. Indeed, these positive outcomes are even less relevant in settings where fetal scalp sampling is uncommon, like the US. The summative literature therefore suggests that adjunctive ST analysis does not meaningfully and consistently modify intrapartum and neonatal outcomes. The biological basis of fetal ST analysis is compelling; however, its success depends on correct interpretation and appropriate intervention (or non-intervention). It remains as susceptible to human fallibility as traditional fetal heart rate monitoring. There is a learning curve seen within published clinical trials, and intense education and training may improve test performance; however, if meaningful outcome differences cannot be demonstrated in large randomised trials, we have no hope of seeing a positive effect in daily practice, where education and oversight may be less than ideal. A promising technology and the hope of finally having an effective intrapartum monitoring tool should not blind us to the fact that our collective investment as a scientific community in ST analysis has not paid off, and is unlikely to do so in the future. The debate about fetal ST analysis and its potential usefulness has not ended. But, perhaps it should. Do we as a society, who must be conscientious of cost-effectiveness and value in health care, want to continue to invest in ST analysis for the minimal demonstrated benefit? We have a new opportunity to decline to use a technology that does not improve neonatal outcomes, nor reduce the rate of caesarean delivery, and in the process save considerable time and money that might be better spent developing effective prevention and intervention strategies for mothers and their babies. None declared. Completed disclosure of interests form available to view online as supporting information. Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.

A study of an intelligent system to support decision making in the management of labour using the cardiotocograph - the INFANT study protocol.

BackgroundContinuous electronic fetal heart rate monitoring in labour is widely used but its potential for improving fetal and neonatal outcomes has not been realised. The most likely reason is the difficulty of interpreting the fetal heart rate trace correctly during labour. Computerised interpretation of the fetal heart rate and intelligent decision-support has the potential to deliver this improvement in care.This trial will test whether the addition of decision support software to aid the interpretation of the cardiotocogram (CTG) during labour will reduce the number of ‘poor neonatal outcomes’ in those women judged to require continuous electronic fetal heart rate monitoring.Methods and designAn individually randomised controlled trial of 46,000 women who are judged to require continuous electronic fetal monitoring in labour.Eligibility criteria: Women admitted to a participating labour ward who are judged to require continuous electronic fetal monitoring, have a singleton or twin pregnancy, are ≥ 35 weeks’ gestation, have no known gross fetal abnormality and are ≥ 16 years of age.Exclusion criteria: Triplets or higher order pregnancy, elective caesarean section prior to the onset of labour, planned admission to NICU.Trial interventions: Computerised interpretation of the CTG with decision-support.Primary outcomes: Short term: A composite of ‘poor neonatal outcome’ including stillbirth after trial entry, early neonatal death except deaths due to congenital anomalies, significant morbidity: neonatal encephalopathy, admissions to the neonatal unit with 48 h for > 48 h with evidence of feeding difficulties, respiratory illness or encephalopathy where there is evidence of compromise at birth. Long term: Developmental assessment at the age of 2 years in a subset of 7000 surviving babies.Data Collection: For all participating women and babies, labour variables and outcomes will be stored automatically and contemporaneously onto the Guardian® system.DiscussionThe results of this trial will have importance for pregnant women and for health professionals who provide care for them.Trial registrationCurrent Controlled Trials ISRCTN98680152 assigned 30.09.2008

Fetal electrocardiogram (ECG) for fetal monitoring during labour.

Hypoxaemia during labour can alter the shape of the fetal electrocardiogram (ECG) waveform, notably the relation of the PR to RR intervals, and elevation or depression of the ST segment. Technical systems have therefore been developed to monitor the fetal ECG during labour as an adjunct to continuous electronic fetal heart rate monitoring with the aim of improving fetal outcome and minimising unnecessary obstetric interference. To compare the effects of analysis of fetal ECG waveforms during labour with alternative methods of fetal monitoring. The Cochrane Pregnancy and Childbirth Group's Trials Register (latest search 23 September 2015) and reference lists of retrieved studies. Randomised trials comparing fetal ECG waveform analysis with alternative methods of fetal monitoring during labour. One review author independently assessed trials for inclusion and risk of bias, extracted data and checked them for accuracy. One review author assessed the quality of the evidence using the GRADE approach. Seven trials (27,403 women) were included: six trials of ST waveform analysis (26,446 women) and one trial of PR interval analysis (957 women). The trials were generally at low risk of bias for most domains and the quality of evidence for ST waveform analysis trials was graded moderate to high. In comparison to continuous electronic fetal heart rate monitoring alone, the use of adjunctive ST waveform analysis made no obvious difference to primary outcomes: births by caesarean section (risk ratio (RR) 1.02, 95% confidence interval (CI) 0.96 to 1.08; six trials, 26,446 women; high quality evidence); the number of babies with severe metabolic acidosis at birth (cord arterial pH less than 7.05 and base deficit greater than 12 mmol/L) (average RR 0.72, 95% CI 0.43 to 1.20; six trials, 25,682 babies; moderate quality evidence); or babies with neonatal encephalopathy (RR 0.61, 95% CI 0.30 to 1.22; six trials, 26,410 babies; high quality evidence). There were, however, on average fewer fetal scalp samples taken during labour (average RR 0.61, 95% CI 0.41 to 0.91; four trials, 9671 babies; high quality evidence) although the findings were heterogeneous and there were no data from the largest trial (from the USA). There were marginally fewer operative vaginal births (RR 0.92, 95% CI 0.86 to 0.99; six trials, 26,446 women); but no obvious difference in the number of babies with low Apgar scores at five minutes or babies requiring neonatal intubation, or babies requiring admission to the special care unit (RR 0.96, 95% CI 0.89 to 1.04, six trials, 26,410 babies; high quality evidence). There was little evidence that monitoring by PR interval analysis conveyed any benefit of any sort. The modest benefits of fewer fetal scalp samplings during labour (in settings in which this procedure is performed) and fewer instrumental vaginal births have to be considered against the disadvantages of needing to use an internal scalp electrode, after membrane rupture, for ECG waveform recordings. We found little strong evidence that ST waveform analysis had an effect on the primary outcome measures in this systematic review.There was a lack of evidence showing that PR interval analysis improved any outcomes; and a larger future trial may possibly demonstrate beneficial effects.There is little information about the value of fetal ECG waveform monitoring in preterm fetuses in labour. Information about long-term development of the babies included in the trials would be valuable.

Planned caesarean section for women with a twin pregnancy.

Twin pregnancies are associated with increased perinatal mortality, mainly related to prematurity, but complications during birth may contribute to perinatal loss or morbidity. The option of planned caesarean section to avoid such complications must therefore be considered. On the other hand, randomised trials of other clinical interventions in the birth process to avoid problems related to labour and birth (planned caesarean section for breech, and continuous electronic fetal heart rate monitoring), have shown an unexpected discordance between short-term perinatal morbidity and long-term neurological outcome. The risks of caesarean section for the mother in the current and subsequent pregnancies must also be taken into account. To determine the short- and long-term effects on mothers and their babies, of planned caesarean section for twin pregnancy. We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (18 November 2015) and reference lists of retrieved studies. Randomised trials comparing a policy of caesarean section with planned vaginal birth for women with twin pregnancy. Two review authors independently assessed eligibility, quality and extracted data. Data were checked for accuracy. For important outcomes the quality of the evidence was assessed using the GRADE approach. We included two trials comparing planned caesarean section versus planned vaginal birth for twin pregnancies.Most of the data included in the review were from a multicentre trial where 2804 women were randomised in 106 centres in 25 countries. All centres had facilities to perform emergency caesarean section and had anaesthetic, obstetrical, and nursing staff available in the hospital at the time of planned vaginal delivery. In the second trial carried out in Israel, 60 women were randomised. We judged the risk of bias to be low for all categories except performance (high) and outcome assessment bias (unclear).There was no clear evidence of differences between women randomised to planned caesarean section or planned vaginal birth for maternal death or serious morbidity (risk ratio (RR) 0.86, 95% confidence interval (CI) 0.67 to 1.11; 2844 women; two studies; moderate quality evidence). There was no significant difference between groups for perinatal or neonatal death or serious neonatal morbidity (RR 1.15, 95% CI 0.80 to 1.67; data for 5565 babies, one study, moderate quality evidence). No studies reported childhood disability.For secondary outcomes there was no clear evidence of differences between groups for perinatal or neonatal mortality (RR 1.41, 95% CI 0.76 to 2.62; 5685 babies; two studies, moderate quality evidence), serious neonatal morbidity (RR 1.03, 95% CI 0.65 to 1.64; 5644 babies; two studies, moderate quality evidence) or any of the other neonatal outcomes reported.The number of women undergoing caesarean section was reported in both trials. Most women in the planned caesarean group had treatment as planned (90.9% underwent caesarean section), whereas in the planned vaginal birth group 42.9% had caesarean section for at least one twin. For maternal mortality; no events were reported in one trial and two deaths (one in each group) in the other. There were no significant differences between groups for serious maternal morbidity overall (RR 0.86, 95% CI 0.67 to 1.11; 2844 women; two studies) or for different types of short-term morbidity. There were no significant differences between groups for failure to breastfeed (RR 1.14, 95% CI 0.95 to 1.38; 2570 women, one study; moderate quality evidence) or the number of women with scores greater than 12 on the Edinbugh postnatal depression scale (RR 0.95, 95% CI 0.78 to 1.14; 2570 women, one study; moderate quality evidence). Data mainly from one large, multicentre study found no clear evidence of benefit from planned caesarean section for term twin pregnancies with leading cephalic presentation. Data on long-term infant outcomes are awaited. Women should be informed of possible risks and benefits of labour and vaginal birth pertinent to their specific clinical presentation and the current and long-term effects of caesarean section for both mother and babies. There is insufficient evidence to support the routine use of planned caesarean section for term twin pregnancy with leading cephalic presentation, except in the context of further randomised trials.

Continuous cardiotocography during labour: Analysis, classification and management

The use of continuous intrapartum electronic fetal heart rate monitoring (EFM) using a cardiotocograph (CTG) was developed to enable obstetricians and midwives to analyse the changes of fetal heart rateduring labour so as to institute timely intervention to avoid intrapartum hypoxic-ischaemic injury. Although CTG was initially developed as a screening tool to predict fetal hypoxia, its positive predictive value for intrapartum fetal hypoxia is approximately only 30%. Even though different international classifications have been developed with the aim of defining combinations of features that help predict intrapartum fetal hypoxia, the false-positive rate of the CTG is high (60%). Moreover, there has not been a demonstrable improvement in the rate of cerebral palsy or perinatal deaths since the introduction of CTG into clinical practice approximately 45 years ago. However, there has been a significant increase in intrapartum caesarean section and operative vaginal delivery rates. Unfortunately, existing guidelines employ the visual interpretation of CTG based on 'pattern recognition', which is fraught with inter- and intra-observer variability. Therefore, clinicians need to understand the physiology behind fetal heart rate changes and to respond to them accordingly, instead of purely relying on guidelines for management. It is very likely that such a 'physiology-based' approach would reduce unnecessary operative interventions and improve perinatal outcomes whilst reducing the need for 'additional tests' of fetal well-being.

To compare intrapartum cardiotocographic (CTG) recording with conventional intermittent fetal heart auscultation during labor

Standard evaluation of fetal well-being during labor includes the periodic assessment of the fetal heart rate (FHR), its pattern and response to intrapartum stimuli and events. Effective methods of evaluation and meaningful interpretation of FHR data range from non-invasive techniques like Intermittent Auscultation, continuous electronic fetal heart rate (FHR) monitoring to invasive techniques of fetal blood gas analysis and fetal ECG.

Electronic Fetal Heart Rate Monitoring: The Future

Continuous electronic fetal heart rate monitoring (EFM) using a cardiotocograph (CTG) is associated with a high false positive rate of approximately 60%. Current scientific evidence does not support a significant reduction in perinatal mortality or cerebral palsy, except for a 50% reduction in neonatal convulsions. Recent scientific evidence has questioned the role of ‘peripheral’ tests of fetal wellbeing such as fetal scalp blood sampling (FBS), fetal scalp lactate and fetal pulse oximetry in reducing the false positive rate of CTG. Fetal ECG (ST-Analyzer or STAN) shows promise in reducing neonatal admissions and operative vaginal births. Computerized CTG analysis and Fetal Physiological Score (FPS) may help reduce errors associated with CTG interpretation. Keywords: Fetal scalp blood sampling, fetal scalp lactate, ST-Analyzer (STAN), Fetal Physiological Score (FPS), computerised analysis.

English

Monitoring of health of fetus during labor is critical component of obstetric care. Present study was done to determine the clinical usefulness of continuous electronic fetal heart rate monitoring for identification of distressed fetus. The present study was conducted on 120 cases who were admitted in labor room during labor in SVBP hospital MRT. Continuous EFHRM was done by Hewlett Packard Cardio- tocograph and findings were correlated with neonatal outcome. Cases with high risk factors(70), who had reassuring patterns (i.e. 44 cases) ,all were delivered vaginally but with non reassuring patterns only 8(30.8%)were delivered normally .84(70%) cases with reassuring patterns had zero neonatal mortality .But 36(30%) with non- reassuring patterns 3 neonates expired in spite of all resuscitative measures . But out of 84 reassuring FHR patterns, 10 neonates were diseased i.e they required NICU admission. Continuous EFHRM detected hypoxia even before asphyxia developed and had sensitivity of 84.1% and specificity of 68.75%.False negatives were 15.9%,false positives were 31.25%.Predictive values of reassuring and non-reassuring patterns were 88% & 61% respectively.

Planned caesarean section for women with a twin pregnancy.

Twin pregnancies are associated with increased perinatal mortality, mainly related to prematurity, but complications during birth may contribute to perinatal loss or morbidity. The option of planned caesarean section to avoid such complications must therefore be considered. On the other hand, randomised trials of other clinical interventions in the birth process to avoid problems related to labour and birth (planned caesarean section for breech, and continuous electronic fetal heart rate monitoring), have shown an unexpected discordance between short-term perinatal morbidity and long-term neurological outcome. The risks of caesarean section for the mother in the current and subsequent pregnancies must also be taken into account. To determine the short- and long-term effects on mothers and their babies, of planned caesarean section for twin pregnancy. We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (30 September 2011). Randomised trials comparing a policy of caesarean section with planned vaginal birth for women with twin pregnancy. Two researchers independently assessed eligibility, quality and extracted data. Data were checked for accuracy. One small trial with unconfirmed allocation concealment compared caesarean section with planned vaginal birth in 60 women with vertex/non-vertex twin pregnancies. There were no differences in perinatal outcome. The trial was too small to exclude the possibility of clinically meaningful benefits of either approach. There is one additional trial currently ongoing. There is a lack of robust evidence to guide clinical advice regarding the method of birth for twin pregnancies. Women should be informed of possible benefits and risks of either approach, including short-term and long-term consequences for both mother and babies. Future research should aim to provide unbiased evidence, including long-term outcomes.

Hypoxémie, chémorécepteurs périphériques et rythme cardiaque fœtal

The perinatal results of the widespread adoption of the continuous electronic fetal heart rate monitoring during labor remain rather disappointing. This is due in part to a lack of consistent interpretation of the fetal heart tracings. Despite efforts by referral agencies over the past decade the situation has not improved. In defense of practitioners the heterogeneity and complexity of definitions and classifications patterns especially morphological currently proposed should be noted. Whereas with the recent advances in the field of neuroscience, it is now possible to visualize the chain of pathophysiological events that lead from the hypoxemic stimulus of the glomus cell to changes in the morphology of the fetal heart rate tracing. Thus by taking some examples of real situations, we propose a method of analysis that dissects the fetal heart tracing and take into account the functional specifications of the chemoreceptor when exposed to a hypoxic environment. Furthermore we can identify tracings with a "threshold effect" and also "sensitization and desensitization effects" according to the intensity, duration and recurrence of hypoxaemic episodes. This new approach based upon specific research into the mechanism behind the fetal heart rate abnormalities may be useful to complement the morphological study of the fetal heart tracing, to provide a better idea of the fetal status and to better define the indications of fetal blood sampling procedures.

Maternal and fetal heart rate confusion during labour

Continuous electronic fetal heart rate monitoring is commonly used by clinicians during labour and delivery to assess fetal wellbeing. The Doppler ultrasound cardiotocograph (CTG) detects the fetal heart rate (FHR) and the uterine activity (toco) simultaneously and displays it in the form of graph. There have been reports of the FHR being substituted by the maternal heart rate (MHR) with this method of monitoring. FHR/MHR confusion left undetected can lead to adverse outcomes. This article gives an overview of the pattern of the MHR during labour in continuous maternal and fetal heart rate monitoring using an abdominal maternal and fetal electrocardiograph monitor (abfECG) in contrast with more traditional Doppler methods. The exploration of the pattern of the MHR during labour and delivery demonstrates how an incorrect assessment of fetal wellbeing could be made if the monitor was used in isolation and the MHR was being reported rather than the FHR. This article also explores how midwives can minimize the risk of such incidents occurring.

Guidelines for the Management of Vasa Previa

ObjectivesTo describe the etiology of vasa previa and the risk factors and associated condition, to identify the various clinical presentations of vasa previa, to describe the ultrasound tools used in its diagnosis, and to describe the management of vasa previa. OutcomesReduction of perinatal mortality, short-term neonatal morbidity, long-term infant morbidity, and short-term and long-term maternal morbidity and mortality. EvidencePublished literature on randomized trials, prospective cohort studies, and selected retrospective cohort studies was retrieved through searches of PubMed or Medline, CINAHL, and the Cochrane Library, using appropriate controlled vocabulary (e.g., selected epidemiological studies comparing delivery by Caesarean section with vaginal delivery; studies comparing outcomes when vasa previa is diagnosed antenatally vs. intrapartum) and key words (e.g., vasa previa). Results were restricted to systematic reviews, randomized control trials/controlled clinical trials, and observational studies. Searches were updated on a regular basis and incorporated into the guideline to October 1, 2008. Grey (unpublished) literature was identified through searching the websites of health technology assessment and health technology assessment-related agencies, clinical practice guideline collections, clinical trial registries, and from national and international medical specialty societies. ValuesThe evidence collected was reviewed by the Diagnostic Imaging Committee and the Maternal Fetal Medicine Committee of the Society of Obstetricians and Gynaecologists of Canada (SOGC) and quantified using the evaluation of evidence guidelines developed by the Canadian Task Force on Preventive Health Care. Benefits, Harms, and CostsThe benefit expected from this guideline is facilitation of optimal and uniform care for pregnancies complicated by vasa previa. SponsorsThe Society of Obstetricians and Gynaecologists of Canada. Summary StatementA comparison of women who were diagnosed antenatally and those who were not shows respective neonatal survival rates of 97% and 44%, and neonatal blood transfusion rates of 3.4% and 58.5%, respectively. Vasa previa can be diagnosed antenatally, using combined abdominal and transvaginal ultrasound and colour flow mapping; however, many cases are not diagnosed, and not making such a diagnosis is still acceptable. Even under the best circumstances the false positive rate is extremely low. (II-2) Recommendations1.If the placenta is found to be low lying at the routine second trimester ultrasound examination, further evaluation for placental cord insertion should be performed. (II-2B)2.Transvaginal ultrasound may be considered for all women at high risk for vasa previa, including those with low or velamentous insertion of the cord, bilobate or succenturiate placenta, or for those having vaginal bleeding, in order to evaluate the internal cervical os. (II-2B)3.If vasa previa is suspected, transvaginal ultrasound colour Doppler may be used to facilitate the diagnosis. Even with the use of transvaginal ultrasound colour Doppler, vasa previa may be missed. (II-2B)4.When vasa previa is diagnosed antenatally, an elective Caesarean section should be offered prior to the onset of labour. (II-1A)5.In cases of vasa previa, premature delivery is most likely; therefore, consideration should be given to administration of corticosteroids at 28 to 32 weeks to promote fetal lung maturation and to hospitalization at about 30 to 32 weeks. (II-2B)6.In a woman with an antenatal diagnosis of vasa previa, when there has been bleeding or premature rupture of membranes, the woman should be offered delivery in a birthing unit with continuous electronic fetal heart rate monitoring and, if time permits, a rapid biochemical test for fetal hemoglobin, to be done as soon as possible; if any of the above tests are abnormal, an urgent Caesarean section should be performed. (III-B)7.Women admitted with diagnosed vasa previa should ideally be transferred for delivery in a tertiary facility where a pediatrician and blood for neonatal transfusion are immediately available in case aggressive resuscitation of the neonate is necessary. (II-3B)8.Women admitted to a tertiary care unit with a diagnosis of vasa previa should have this diagnosis clearly identified on the chart, and all health care providers should be made aware of the potential need for immediate delivery by Caesarean section if vaginal bleeding occurs. (III-B)

Conséquences fœtales des techniques d’anesthésie au cours du travail

Continuous electronic fetal heart rate (FHR) monitoring is part of routine care for laboring patients under either systemic or locoregional analgesia. Opioid systemic analgesia (mainly meperidine in early labor), yet less frequently used in our country, is associated with a decrease in FHR-variability and worse acid-base and neonatal status compared to epidural or combined spinal epidural analgesia. Although epidural analgesia may cause maternal hypotension and fever, longer second stage of labour and more instrumental vaginal deliveries, these potentially adverse factors appear to be outweighed by benefits on clinical and neonatal acid-base status when compared with maternal opioid systemic analgesia. The mechanisms by which epidural or spinal analgesia may affect fetal well-being include maternal hypotension and/or uterine hyperactivity. All these undesirable side effects which may induce severe intrapartum fetal distress must be adequately detected and treated with intrauterine resuscitation techniques, including correction of maternal hypotension and/or the use of tocolytics agents. Reinstallation of electronic fetal monitoring at arrival in the operating room before cesarean section for suspected fetal hypoxia may be helpful to choose better anesthetic technique and try to avoid general anesthesia associated with increased maternal morbidity and mortality.

Modern intrapartum fetal monitoring: room for improvement?

Electronic fetal heart monitoring is the standard of care for intrapartum surveillance of the fetus. Despite its widespread use and general acceptance, data regarding the clinical beneWt in terms of fetal morbidity and mortality are controversial. While early trials could not demonstrate a beneWt from intrapartum monitoring [1, 2], a recent systematic review and meta analysis published by the Cochrane Collaboration clariWes that electronic fetal heart rate monitoring by cardiotocography does not reduce fetal mortality, but reduces neonatal seizures by 50%. Based on 22 randomized trials, continuous cardiotocography showed no signiWcant diVerence in the overall perinatal death rate compared to intermittent auscultation [relative risk (RR) 0.85, 95% conWdence interval (CI) 0.59–1.23, n = 33,513, 11 trials], but was associated with a halving of neonatal seizures (RR 0.50, 95% CI 0.31–0.80, n = 32,386, 9 trials). Cardiotocography had no signiWcant impact on the rates of cerebral palsy (RR 1.74, 95% CI 0.97–3.11, n = 13,252, 2 trials) [3]. Therefore, it is clear that electronic fetal heart rate monitoring is a valuable instrument for improving fetal morbidity. It comes, however, at a high price for the mother, because it signiWcantly increases the risk of cesarean section (RR 1.66, 95% CI 1.30–2.13, n = 18,761, 10 trials) as well as vaginal operative delivery (RR 1.16, 95% CI 1.01–1.32, n = 18,151, 9 trials) [3]. After the widespread acceptance of continuous electronic fetal heart rate monitoring, numerous interventions have been tested in an attempt to reduce the increased rate of operative deliveries while at the same time maintaining or improving fetal safety, among them fetal scalp blood sampling, fetal ST waveform analysis and fetal pulse oxymetry. Only fetal scalp blood sampling, however, has been implicated into clinical practice so far. Fetal scalp blood sampling and the subsequent assessment of fetal pH or lactate values is a promising method using equipment readily available in the labor ward. Despite its common use and interesting experimental data and correlations with perinatal fetal outcome, fetal scalp blood sampling has not been tested in randomized trials. Thus, there are no data allowing for an evidence-based recommendation of this method as an adjunct to non-reassuring fetal heart rate patterns on cardiotocography. Based on what we know today, fetal pulse oxymetry is not helpful in improving maternal or fetal outcomes. Bloom et al. [4] clearly demonstrated in a recent large randomized trial of 5,341 nulliparous women that fetal pulse oxymetry is not associated with a reduced rate of cesarean delivery or with an improvement in perinatal morbidity and mortality. This is in accordance with a previous Cochrane Collaboration review [5], making further trials of this diagnostic method seem unpromising. On the other hand, fetal ST waveform analysis has been shown to reduce the rate of cesarean section in two properly designed randomised trials [6, 7]. This technique uses electrocardiogram analysis of the ST C. Tempfer · L. HeXer · P. Husslein Department of Obstetrics and Gynecology, Medical University of Vienna, Vienna, Austria

Toward Quantitative Fetal Heart Rate Monitoring

Continuous electronic fetal heart rate (FHR) monitoring during labor is motivated by the clinical experience that fetal distress causes loss of FHR variation and the occurrence of decelerations late during uterine contraction. This practice is of uncertain clinical benefit, perhaps because the interpretation is qualitative. We have developed new quantitative measures and analyzed cardiotocograph records from 148 consecutive patients, 44 of whom had at least one "nonreassuring" epoch. In multivariate regression models, measures of deceleration and variability were significantly associated with the obstetrician's diagnosis (receiver operating characteristic area 0.84, p < 0.05). This approach may be useful clinically.

Vaginal Birth After Cesarean Section: A Survey of Practice in Australia and New Zealand

Obstetrical & Gynecological Survey: January 2004 - Volume 59 - Issue 1 - p 19-21 doi: 10.1097/01.OGX.0000102783.03796.8F

Vaginal birth after Caesarean section: a survey of practice in Australia and New Zealand.

Women with a single prior Caesarean section (CS) in a subsequent pregnancy will be offered either a planned elective repeat CS or vaginal birth after Caesarean (VBAC). Recent reports of VBAC have highlighted risks of increased morbidity, including uterine rupture, and adverse infant outcome. A survey of practice was sent to fellows and members of the Royal Australian and New Zealand College of Obstetricians and Gynaecologists to determine current care for women in a subsequent pregnancy with a single prior CS, and to assess variations by length and type of obstetric practice. Questions asked about the safety of VBAC, induction of labour with a uterine scar, and requirements to conduct VBAC and elective repeat CS. A total of 1641 surveys were distributed, with 1091 (67%) returned, 844 from practicing obstetricians (51% of college membership). Almost all respondents (96%) agreed or strongly agreed that VBAC should be presented as an option to the woman, varying from 90% where the indication for primary CS was breech, 88% for fetal distress, and 55% for failure to progress. Forty percent of respondents agreed or strongly agreed that VBAC was the safest option for the woman, and associated with fewer risks than CS. In contrast, 44% of respondents disagreed or strongly disagreed that VBAC was the safest option for the infant, and opinions varied as to whether risks of VBAC outweighed those of CS for the infant. Almost two-thirds of practitioners would offer induction of labour to a woman with a prior CS in a subsequent pregnancy, one-third indicating a willingness to use vaginal prostaglandins, and 77% syntocinon. Most respondents preferred to conduct VBAC in a level two or three hospital (86%); required the availability within 30 min of an anaesthetist (81%), a neonatologist (84%), and operating theatre (97%); recommended continuous electronic fetal heart rate monitoring (86%); intravenous access (90%); and routine group and hold (79%) during labour. For an elective repeat CS, most practitioners request routine blood for group and hold (78%), a neonatologist in theatre (77%), the use of an in-dwelling urinary catheter (96%), and the use of intraoperative antibiotics (82%). Most obstetricians indicated VBAC to be the safest option for the woman, but were less certain about benefits and risks for the infant. The consensus of practice is to present VBAC as an option and induce labour if needed. Vaginal birth after Caesarean is preferred in a level two or three hospital, with an anaesthetist, neonatologist and operating theatre available within 30 min. The use of continuous electronic fetal heart rate monitoring and intravenous access are recommended. In planned CS, a neonatologist in theatre is preferred, and an in-dwelling urinary catheter an;! intraoperative antibiotics will be used.