Proposed cutoff for fetal scalp blood lactate in intrapartum fetal surveillance based on neonatal outcomes: a large prospective observational study.

OBJECTIVE: Determination of lactate in fetal scalp blood (FBS) during labour has been recognised since the 1970s. The internationally accepted cutoff of >4.8 mmol/l indicating fetal acidosis is exclusive for the point-of-care device (POC) LactatePro™, which is no longer in production. The aim of this study was to establish a new cutoff for scalp lactate based on neonatal outcomes with the use of the StatstripLactate® /StatstripXpress® Lactate system, the only POC designed for hospital use. DESIGN: Observational study. SETTING: January 2016 to March 2020 labouring women with indication for FBS were prospectively included from seven Swedish and one Australian delivery unit. POPULATION: Inclusion criteria: singleton pregnancy, vertex presentation, ≥35+0 weeks of gestation. METHOD: Based on the optimal correlation between FBS lactate and cord pH/lactate, only cases with ≤25 minutes from FBS to delivery were included in the final calculations. MAIN OUTCOME MEASURES: Metabolic acidosis in cord blood defined as pH <7.05 plus BDecf >10 mmol/l and/or lactate >10 mmol/l. RESULTS: A total of 3334 women were enrolled of whom 799 were delivered within 25 minutes. The areas under the receiver operating characteristics curves (AUC) and corresponding optimal cutoff values were as follows; metabolic acidosis AUC 0.87 (95% CI 0.77-0.97), cutoff 5.7 mmol/l; pH <7.0 AUC 0.83 (95% CI 0.68-0.97), cutoff 4.6 mmol/l; pH <7.05 plus BDecf ≥12 mmol/l AUC 0.97 (95% CI 0.92-1), cutoff 5.8 mmol/l; Apgar score <7 at 5 minutes AUC 0.74 (95% CI 0.63-0.86), cutoff 5.2 mmol/l; and pH <7.10 plus composite neonatal outcome AUC 0.76 (95% CI 0.67-0.85), cutoff 4.8 mmol/l. CONCLUSION: A scalp lactate level <5.2 mmol/l using the StatstripLactate® /StatstripXpress® system will safely rule out fetal metabolic acidosis. TWEETABLE ABSTRACT: Scalp blood lactate <5.2 mmol/l using the StatstripLactate® /StatstripXpress system has an excellent ability to rule out fetal acidosis.

Intrapartum non-invasive electrophysiological monitoring: A prospective observational study.

INTRODUCTION: Doppler ultrasound cardiotocography is a non-invasive alternative that, despite its poor specificity, is often first choice for intrapartum monitoring. Doppler ultrasound suffers from signal loss due to fetal movements and is negatively correlated with maternal body mass index (BMI). Reported accuracy of fetal heart rate monitoring by Doppler ultrasound varies between 10.6 and 14.3 bpm and reliability between 62.4% and 73%. The fetal scalp electrode (FSE) is considered the reference standard for fetal monitoring but can only be applied after membranes have ruptured with sufficient cervical dilatation and is sometimes contra-indicated. A non-invasive alternative that overcomes the shortcomings of Doppler ultrasound, providing reliable information on fetal heart rate, could be the answer. Non-invasive fetal electrocardiography (NI-fECG) uses a wireless electrode patch on the maternal abdomen to obtain both fetal and maternal heart rate signals as well as an electrohysterogram. We aimed to validate a wireless NI-fECG device for intrapartum monitoring in term singleton pregnancies, by comparison with the FSE. MATERIAL AND METHODS: We performed a multicenter cross-sectional observational study at labor wards of 6 hospitals located in the Netherlands, Belgium, and Spain. Laboring women with a healthy singleton fetus in cephalic presentation and gestational age between 36 and 42 weeks were included. Participants received an abdominal electrode patch and FSE after written informed consent. Accuracy, reliability, and success rate of fetal heart rate readings were determined, using FSE as reference standard. Analysis was performed for the total population and measurement period as well as separated by labor stage and BMI class (≤30 and >30 kg/m2 ). RESULTS: We included a total of 125 women. Simultaneous registrations with NI-fECG and FSE were available in 103 women. Overall accuracy is -1.46 bpm and overall reliability 86.84%. Overall success rate of the NI-fECG is around 90% for the total population as well as for both BMI subgroups. Success rate dropped to 63% during second stage of labor, similar results are found when looking at the separate BMI groups. CONCLUSIONS: Performance measures of the NI-fECG device are good in the overall group and the separate BMI groups. Compared with Doppler ultrasound performance measures from the literature, NI-fECG is a more accurate alternative. Especially, when women have a higher BMI, NI-fECG performs well, resembling FSE performance measures.

Medical-Grade ECG Sensor for Long-Term Monitoring.

The recent trend in electrocardiogram (ECG) device development is towards wireless body sensors applied for patient monitoring. The ultimate goal is to develop a multi-functional body sensor that will provide synchronized vital bio-signs of the monitored user. In this paper, we present an ECG sensor for long-term monitoring, which measures the surface potential difference between proximal electrodes near the heart, called differential ECG lead or differential lead, in short. The sensor has been certified as a class IIa medical device and is available on the market under the trademark Savvy ECG. An improvement from the user's perspective-immediate access to the measured data-is also implemented into the design. With appropriate placement of the device on the chest, a very clear distinction of all electrocardiographic waves can be achieved, allowing for ECG recording of high quality, sufficient for medical analysis. Experimental results that elucidate the measurements from a differential lead regarding sensors' position, the impact of artifacts, and potential diagnostic value, are shown. We demonstrate the sensors' potential by presenting results from its various areas of application: medicine, sports, veterinary, and some new fields of investigation, like hearth rate variability biofeedback assessment and biometric authentication.

Evaluation of an external fetal electrocardiogram monitoring system: a randomized controlled trial.

OBJECTIVE: The objective of the study was to compare interpretability of 2 intrapartum abdominal fetal heart rate-monitoring strategies. We hypothesized that an external fetal electrocardiography monitoring system, a newer technology using wireless abdominal pads, would generate more interpretable fetal heart rate data compared with standard external Doppler fetal heart rate monitoring (standard external monitoring). STUDY DESIGN: We conducted a randomized controlled trial at 4 Utah hospitals. Patients were enrolled at labor admission and randomized in blocks based on body mass index to fetal electrocardiography or standard external monitoring. Two reviewers, blinded to study allocation, reviewed each fetal heart rate tracing. The primary outcome was the percentage of interpretable minutes of fetal heart rate tracing. An interpretable minute was defined as >25% fetal heart rate data present and no more than 25% continuous missing fetal heart rate data or artifact present. Secondary outcomes included the percentage of interpretable minutes of fetal heart rate tracing obtained while on study device only, the number of device adjustments required intrapartum, clinical outcomes, and patient/provider device satisfaction. We determined that 100 patients per arm (200 total) would be needed to detect a 5% difference in interpretability with 95% power. RESULTS: A total of 218 women were randomized, 108 to fetal electrocardiography and 110 to standard external monitoring. Device setup failure occurred more often in the fetal electrocardiography group (7.5% [8 of 107] vs 0% [0 of 109] for standard external monitoring). There were no differences in the percentage of interpretable tracing between the 2 groups. However, fetal electrocardiography produced more interpretable fetal heart rate tracing in subjects with a body mass index ≥30 kg/m2. When considering the percentage of interpretable minutes of fetal heart rate tracing while on study device only, fetal electrocardiography outperformed standard external monitoring for all subjects, regardless of maternal body mass index. Maternal demographics and clinical outcomes were similar between arms. In the fetal electrocardiography group, more device changes occurred compared with standard external monitoring (51% vs 39%), but there were fewer nursing device adjustments (2.9 vs 6.2 mean adjustments intrapartum, P < .01). There were no differences in physician device satisfaction scores between groups, but fetal electrocardiography generated higher patient satisfaction scores. CONCLUSION: Fetal electrocardiography performed similarly to standard external monitoring when considering percentage of interpretable tracing generated in labor. Furthermore, patients reported overall greater satisfaction with fetal electrocardiography in labor. Fetal electrocardiography may be particularly useful in patients with a body mass index ≥30 kg/m2.

Use and experiences with external fetal monitoring devices among obstetrical providers.

Introduction: Fetal heart rate monitoring presents one of the few available methods for evaluating the fetus prior to birth. However, current devices on the market have significant shortcomings. We sought to describe the use and experiences with external fetal monitoring (EFM) devices among obstetrical providers.Materials and methods: We performed a cross-sectional survey in an academic medical center between April and July 2017 including nurse, midwife, and physician obstetrical providers (n = 217) who were invited to participate in this study regarding their experiences with the external fetal monitoring (EFM) device utilized by their hospital system in the outpatient, inpatient, and labor and delivery (L&D) settings. Associations between provider characteristics, device use, perception of challenging patients, and potential usefulness of an improved system were assessed by Fisher's exact test.Results: The 137 respondents (63.1%) reported difficulties monitoring obese women (98.5%), multiple gestation pregnancies (90.5%), and early gestational ages (71.5%). Over half (59.5%) of L&D nurses reported interacting with EFM devices for greater than 1-hour during a typical 12-hour shift and fewer than half (42.3%) reported being satisfied with current EFM devices. There were no statistically significant associations between provider age, experience, or time spent utilizing the devices with perception of challenging patient types.Conclusions: In conclusion, obstetrical providers perceive shortcomings of current EFM devices across all levels of provider experience and time utilizing these devices. Nurses reported significant time operating the devices, representing an opportunity to reduce time and costs with an improved device.

Clinical Implications of Fetal Heart Rate Interpretation Based on Underlying Physiology.

Understanding the physiology of fetal oxygenation and various influences on fetal heart rate control supports nurses, midwives, and physicians in interpreting and managing electronic fetal heart rate tracings during labor and birth. Maternal oxygenation, placental circulation and exchange, umbilical blood flow and fetal circulation affect fetal oxygenation, which is reflected in observed fetal heart rate patterns. Fetal heart control is further influenced by the central and autonomic nervous systems, baroreceptors, chemoreceptors, humoral factors, sleep-wake patterns, breathing movements, medications, painful stimuli, sound and vibrations, and temperature. Knowledge of the physiologic basis for fetal heart rate pattern characteristics guides interventions to improve fetal oxygenation when indicated. A review and update on clinical implications of fetal heart rate pattern interpretation based on underlying physiology is presented.

HOspital care versus TELemonitoring in high-risk pregnancy (HOTEL): study protocol for a multicentre non-inferiority randomised controlled trial.

INTRODUCTION: Pregnant women faced with complications of pregnancy often require long-term hospital admission for maternal and/or fetal monitoring. Antenatal admissions cause a burden to patients as well as hospital resources and costs. A telemonitoring platform connected to wireless cardiotocography (CTG) and automated blood pressure (BP) devices can be used for telemonitoring in pregnancy. Home telemonitoring might improve autonomy and reduce admissions and thus costs. The aim of this study is to compare the effects on patient safety, satisfaction and cost-effectiveness of hospital care versus telemonitoring (HOTEL) as an obstetric care strategy in high-risk pregnancies requiring daily monitoring. METHODS AND ANALYSIS: The HOTEL trial is an ongoing multicentre randomised controlled clinical trial with a non-inferiority design. Eligible pregnant women are >26+0 weeks of singleton gestation requiring monitoring because of pre-eclampsia (hypertension with proteinuria), fetal growth restriction, preterm rupture of membranes without contractions, recurrent reduced fetal movements or an intrauterine fetal death in a previous pregnancy.Randomisation takes place between traditional hospitalisation (planned n=208) versus telemonitoring (planned n=208) until delivery. Telemonitoring at home is facilitated with Sense4Baby CTG devices, Microlife BP monitor and daily telephone calls with an obstetric healthcare professional as well as weekly hospital visits.Primary outcome is a composite of adverse perinatal outcome, defined as perinatal mortality, 5 min Apgar <7 or arterial cord blood pH <7.05, maternal morbidity (eclampsia, HELLP (hemolysis, elevated liver enzymes, and low platelets) syndrome, thromboembolic event), neonatal intensive care admission and caesarean section rate. Patient satisfaction and preference of care will be assessed using validated questionnaires. We will perform an economic analysis. Outcomes will be analysed according to the intention to treat principle. ETHICS AND DISSEMINATION: The study protocol was approved by the Ethics Committee of the Utrecht University Medical Center and the boards of all six participating centres. Trial results will be submitted to peer-reviewed journals. TRIAL REGISTRATION NUMBER: NTR6076.

Affordable and low-maintenance obstetric devices.

OBJECTIVE: Adequate obstetric care requires the availability of essential diagnostic and management equipment; however, for centers with budget restrictions, the acquisition and maintenance of these devices can pose major challenges. The purpose of the present paper is to disseminate knowledge about the availability of affordable and low-maintenance obstetric devices, which might help to save lives in low- and medium-resource countries. METHOD: Over the course of 2015-2018, the International Federation of Gynecology and Obstetrics (FIGO) Safe Motherhood and Newborn Health Committee acquired information from different clinical and commercial sources regarding the availability of affordable and low-maintenance essential obstetric devices. RESULTS: The Committee identified several devices that met the criteria of low cost and ease of maintenance: a winding handheld Doppler device for intermittent auscultation; a portable continuous fetal heart rate monitor; a validated semi-automated blood pressure monitor; the Foley catheter balloon for labor induction in women with an unfavorable cervix; reusable metal and plastic vacuum cups and manual pumps; an intrauterine tamponade balloon; and the non-pneumatic anti-shock garment. CONCLUSION: Several affordable and low-maintenance obstetric devices are currently available that offer the potential to save lives in resource-constrained settings.

Perceptions and experiences of skilled birth attendants on using a newly developed strap-on electronic fetal heart rate monitor in Tanzania.

BACKGROUND: Regular fetal heart rate monitoring during labor can drastically reduce fresh stillbirths and neonatal mortality through early detection and management of fetal distress. Fetal monitoring in low-resource settings is often inadequate. An electronic strap-on fetal heart rate monitor called Moyo was introduced in Tanzania to improve intrapartum fetal heart rate monitoring. There is limited knowledge about how skilled birth attendants in low-resource settings perceive using new technology in routine labor care. This study aimed to explore the attitude and perceptions of skilled birth attendants using Moyo in Dar es Salaam, Tanzania. METHODS: A qualitative design was used to collect data. Five focus group discussions and 10 semi-structured in-depth interviews were carried out. In total, 28 medical doctors and nurse/midwives participated in the study. The data was analyzed using qualitative content analysis. RESULTS: The participants in the study perceived that the device was a useful tool that made it possible to monitor several laboring women at the same time and to react faster to fetal distress alerts. It was also perceived to improve the care provided to the laboring women. Prior to the introduction of Moyo, the participants described feeling overwhelmed by the high workload, an inability to adequately monitor each laboring woman, and a fear of being blamed for negative fetal outcomes. Challenges related to use of the device included a lack of adherence to routines for use, a lack of clarity about which laboring women should be monitored continuously with the device, and misidentification of maternal heart rate as fetal heart rate. CONCLUSION: The electronic strap-on fetal heart rate monitor, Moyo, was considered to make labor monitoring easier and to reduce stress. The study findings highlight the importance of ensuring that the device's functions, its limitations and its procedures for use are well understood by users.

Elevated umbilical cord arterial lactate at birth and electronic fetal monitoring characteristics on admission and in the active phase.

OBJECTIVE: To investigate the association between elevated umbilical arterial lactate at birth and electronic fetal monitoring (EFM) characteristics at admission and in the beginning of the active phase of labor. STUDY DESIGN: Nested case-control study within a prospective cohort of laboring patients at term who achieved active labor. Neonates with umbilical arterial lactate ≥ 4 mmol/L (cases, n = 119), were matched 1:1 to controls with lactate < 4 mmol/L. EFM patterns were compared with multivariable logistic regression. RESULT: There were no differences in EFM parameters in the first 60 minutes after admission. At the beginning of active labor, 13.5% of cases and 26.1% of controls had always category I tracings, adjusted odds ratio 0.48, 95% confidence interval 0.24-0.94). Cases were less likely to have an always category I tracing from admission into the active phase. CONCLUSION: Elevated umbilical arterial lactate at birth is associated with distinct EFM patterns early in the labor course.

A novel modality for intrapartum fetal heart rate monitoring.

BACKGROUND: Intrapartum fetal heart rate (FHR) monitoring is well recommended during labor to assess fetal wellbeing. Though commonly used, the external Doppler and fetal scalp electrode monitor have significant shortcomings. Lately, non-invasive technologies were developed as possible alternatives. OBJECTIVE: The objective of this study is to compare the accuracy of FHR trace using novel Electronic Uterine Monitoring (EUM) to that of external Doppler and fetal scalp electrode monitor. MATERIAL AND METHODS: A comparative study conducted in a single tertiary medical center. Intrapartum FHR trace was recorded simultaneously using three different methods: internal fetal scalp electrode, external Doppler, and EUM. The latter, a multichannel electromyogram (EMG) device acquires a uterine signal and maternal and fetal electrocardiograms. FHR traces obtained from all devices during the first and second stages of labor were analyzed. Positive percent of agreement (PPA) and accuracy (by measuring root means square error between observed and predicted values) of EUM and external Doppler were both compared to internal scalp electrode monitoring. A Bland-Altman agreement plot was used to compare the differences in FHR trace between all modalities. For momentary recordings of fetal heart rate <110 bpm or >160 bpm level of agreement, sensitivity, and specificity were also evaluated. RESULTS: Overall, 712,800 FHR momentary recordings were obtained from 33 parturients. Although both EUM and external Doppler highly correlated with internal scalp electrode monitoring (r2 = 0.98, p < .001 for both methods), the accuracy of EUM was significantly higher than external Doppler (99.0% versus 96.6%, p < .001). In addition, for fetal heart rate <110 bpm or >160 bpm, the PPA, sensitivity, and specificity of EUM as compared with internal fetal scalp electrode, were significantly greater than those of external Doppler (p < .001). CONCLUSION: Intrapartum FHR using EUM is both valid and accurate, yielding higher correlations with internal scalp electrode monitoring than external Doppler. As such, it may provide a good framework for non-invasive evaluation of intrapartum FHR.

Acquiring Knowledge about the Use of a Newly Developed Electronic Fetal Heart Rate Monitor: A Qualitative Study Among Birth Attendants in Tanzania.

In an effort to reduce newborn mortality, a newly developed strap-on electronic fetal heart rate monitor was introduced at several health facilities in Tanzania in 2015. Training sessions were organized to teach staff how to use the device in clinical settings. This study explores skilled birth attendants' perceptions and experiences acquiring and transferring knowledge about the use of the monitor, also called Moyo. Knowledge about this learning process is crucial to further improve training programs and ensure correct, long-term use. Five Focus group discussions (FGDs) were carried out with doctors and nurse-midwives, who were using the monitor in the labor ward at two health facilities in Tanzania. The FGDs were analyzed using qualitative content analysis. The study revealed that the participants experienced the training about the device as useful but inadequate. Due to high turnover, a frequently mentioned challenge was that many of the birth attendants who were responsible for training others, were no longer working in the labor ward. Many participants expressed a need for refresher trainings, more practical exercises and more theory on labor management. The study highlights the need for frequent trainings sessions over time with focus on increasing overall knowledge in labor management to ensure correct use of the monitor over time.

Fetal heart rate short term variation during labor in relation to scalp blood lactate concentration.

INTRODUCTION: Fetal heart rate short term variation (STV) decreases with severe chronic hypoxia in the antenatal period. However, only limited research has been done on STV during labor. We have tested a novel algorithm for a valid baseline estimation and calculated STV. To explore the value of STV during labor, we compared STV with fetal scalp blood (FBS) lactate concentration, an early marker in the hypoxic process. MATERIAL AND METHODS: Software was developed which estimates baseline frequency using a novel algorithm and thereby calculates STV according to Dawes and Redman in up to four 30-minute blocks prior to each FBS. Cardiotocography traces from 1070 women in labor who had had FBS performed on 2134 occasions were analyzed. RESULTS: In acidemic cases (lactate >4.8 mmol/L; Lactate Pro™), median STV 30 minutes prior to FBS was 7.10 milliseconds compared with 6.09 milliseconds in the preacidemic (4.2-4.8 mmol/L) and 5.23 milliseconds in the normal (<4.2 mmol/L) groups (P < .05). There was a positive correlation between lactate and STV (rho = 0.16-0.24; P < .05). Median lactate concentration in cases with STV <3.0 milliseconds (n = 160) was 2.3 mmol/L. When 2 FBS were performed within 60 minutes the change rate of lactate correlated to STV (rho = 0.33; P < .001). Cases with increasing lactate concentration had a median STV of 5.29 milliseconds vs 4.41 milliseconds in those with decreasing lactate (P < .001). CONCLUSIONS: In the early stages of intrapartum hypoxia, STV increases, contrary to findings regarding chronic hypoxia in the antenatal period. The increase in the adrenergic surge is a likely explanation.

Resolution of severe fetal distress following treatment of maternal diabetic ketoacidosis.

Diabetic ketoacidosis (DKA) during pregnancy is a serious metabolic complication of diabetes with high mortality and morbidity if not detected and treated immediately. We report a case of a woman with type 1 diabetes mellitus who had poorly controlled diabetes in the first half of pregnancy and developed DKA at 29 weeks gestation. At presentation, she had a pathological fetal heart tracing but delivery was delayed for maternal stabilisation and reversal of acidosis. Once hyperglycaemia, acidosis and maternal stabilisation were achieved, fetal compromise resolved and delivery was no longer indicated. The patient was subsequently discharged home. She delivered vaginally a 2400 g baby at 34 weeks gestation after presenting with spontaneous rupture of membranes.

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.

Fetal cardiac time intervals in healthy pregnancies - an observational study by fetal ECG (Monica Healthcare System).

BACKGROUND: Fetal electrocardiogram (fECG) can detect QRS signals in fetuses from as early as 17 weeks' gestation; however, the technique is limited by the minute size of the fetal signal relative to noise ratio. The aim of this study was to evaluate precise fetal cardiac time intervals (fCTIs) with the help of a newly developed fetal ECG device (Monica Healthcare System). METHODS: In a prospective manner we included 15-18 healthy fetuses per gestational week from 32 weeks onwards. The small and wearable Monica AN24 monitoring system uses standard ECG electrodes placed on the maternal abdomen to monitor fECG, maternal ECG and uterine electromyogram (EMG). Fetal CTIs were estimated on 1000 averaged fetal heart beats. Detection was deemed successful if there was a global signal loss of less than 30% and an analysis loss of the Monica AN24 signal separation analysis of less than 50%. Fetal CTIs were determined visually by three independent measurements. RESULTS: A total of 149 fECGs were performed. After applying the requirements 117 fECGs remained for CTI analysis. While the onset and termination of P-wave and QRS-complex could be easily identified in most ECG patterns (97% for P-wave, PQ and PR interval and 100% for QRS-complex), the T-wave was detectable in only 41% of the datasets. The CTI results were comparable to other available methods such as fetal magnetocardiography (fMCG). CONCLUSIONS: Although limited and preclinical in its use, fECG (Monica Healthcare System) could be an additional useful tool to detect precise fCTIs from 32 weeks' gestational age onwards.

Functionality and acceptability of a wireless fetal heart rate monitoring device in term pregnant women in rural Southwestern Uganda.

BACKGROUND: Over 3 million stillbirths occur annually in sub Saharan Africa; most occur intrapartum and are largely preventable. The standard of care for fetal heart rate (FHR) assessment in most sub-Saharan African settings is a Pinard Stethoscope, limiting observation to one person, at one point in time. We aimed to test the functionality and acceptability of a wireless FHR monitor that could allow for expanded monitoring capacity in rural Southwestern Uganda. METHODS: In a mixed method prospective study, we enrolled 1) non-laboring healthy term pregnant women to wear the device for 30 min and 2) non-study clinicians to observe its use. The battery-powered prototype uses Doppler technology to measure fetal cardiotocographs (CTG), which are displayed via an android device and wirelessly transmit to cloud storage where they are accessible via a password protected website. Prototype functionality was assessed by the ability to obtain and transmit a 30-min CTG. Three obstetricians independently rated CTGs for readability and agreement between raters was calculated. All participants completed interviews on acceptability. RESULTS: Fifty pregnant women and 7 clinicians were enrolled. 46 (92.0%) CTGs were successfully recorded and stored. Mean scores for readability were 4.71, 4.71 and 4.83 (out of 5) with high agreement (intra class correlation 0.84; 95% CI 0.74 to 0.91). All pregnant women reported liking or really liking the device, as well as high levels of comfort, flexibility and usefulness of the prototype; all would recommend it to others. Clinicians described the prototype as portable, flexible, easy-to-use and a time saver. Adequate education for clinicians and women also seemed to improve correct usage and minimise concerns on safety of the device. CONCLUSIONS: This prototype wireless FHR monitor functioned well in a low-resource setting and was found to be acceptable and useful to both pregnant women and clinicians. The device also seemed to have potential to improve the experience of the users compared with standard of care and expand monitoring capacity in settings where bulky, wired or traditional equipment are unreliable. Further research needs to investigate the potential impact and cost of such innovations to improve perinatal outcomes.

RF Safety Analysis of a Novel Ultra-wideband Fetal Monitoring System.

The LifeWave Ultra-Wideband RF sensor (LWUWBS) is a monitoring solution for a variety of physiologic assessment applications, including maternal fetal monitoring in both the antepartum and intrapartum periods. The system uses extremely low power radio frequency (RF) ultra-wide band (UWB) signals to provide continuous fetal heart rate and contractions monitoring during labor and delivery. Even with the incorporation of three very conservative assumptions, (1) concentration of the RF energy in 1 cm, (2) minimal (2.5 cm) maternal tissue attenuation of fetal exposure, and (3) absence of normal thermoregulatory compensation, the maternal whole body spatial-averaged specific absorption rate (WBSAR) would be 34,000 times below the FCC public exposure limit of 0.08 W kg and, at 8 wk or more gestation, the peak spatial-averaged specific absorption rate (PSSAR) in the fetus would be more than 160 times below the localized exposure limit of 1.6 mW g. Even when using very conservative assumptions, an analysis of the LWUWBS's impact on tissue heating is a factor of 7 lower than what is allowed for fetal ultrasound and at least a factor of 650 compared to fetal MRI. The actual transmitted power levels of the LWUWBS are well below all Federal safety standards, and the potential for tissue heating is substantially lower than associated with current ultrasonic fetal monitors and MRI.

Intermittent auscultation (IA) of fetal heart rate in labour for fetal well-being.

BACKGROUND: The goal of fetal monitoring in labour is the early detection of a hypoxic baby. There are a variety of tools and methods available for intermittent auscultation (IA) of the fetal heart rate (FHR). Low- and middle-income countries usually have only access to a Pinard/Laënnec or the use of a hand-held Doppler device. Currently, there is no robust evidence to guide clinical practice on the most effective IA tool to use, timing intervals and length of listening to the fetal heart for women during established labour. OBJECTIVES: To evaluate the effectiveness of different tools for IA of the fetal heart rate during labour including frequency and duration of auscultation. SEARCH METHODS: We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (19 September 2016), contacted experts and searched reference lists of retrieved articles. SELECTION CRITERIA: All published and unpublished randomised controlled trials (RCTs) or cluster-RCTs comparing different tools and methods used for intermittent fetal auscultation during labour for fetal and maternal well-being. Quasi-RCTs, and cross-over designs were not eligible for inclusion. DATA COLLECTION AND ANALYSIS: All review authors independently assessed eligibility, extracted data and assessed risk of bias for each trial. Data were checked for accuracy. MAIN RESULTS: We included three studies (6241 women and 6241 babies), but only two studies are included in the meta-analyses (3242 women and 3242 babies). Both were judged as high risk for performance bias due to the inability to blind the participants and healthcare providers to the interventions. Evidence was graded as moderate to very low quality; the main reasons for downgrading were study design limitations and imprecision of effect estimates. Intermittent Electronic Fetal Monitoring (EFM) using Cardiotocography (CTG) with routine Pinard (one trial)There was no clear difference between groups in low Apgar scores at five minutes (reported as < six at five minutes after birth) (risk ratio (RR) 0.66, 95% confidence interval (CI) 0.24 to 1.83, 633 babies, very low-quality evidence). There were no clear differences for perinatal mortality (RR 0.88, 95% CI 0.34 to 2.25; 633 infants, very low-quality evidence). Neonatal seizures were reduced in the EFM group (RR 0.05, 95% CI 0.00 to 0.89; 633 infants, very low-quality evidence). Other important infant outcomes were not reported: mortality or serious morbidity (composite outcome), cerebral palsy or neurosensory disability. For maternal outcomes, women allocated to intermittent electronic fetal monitoring (EFM) (CTG) had higher rates of caesarean section for fetal distress (RR 2.92, 95% CI 1.78 to 4.80, 633 women, moderate-quality evidence) compared with women allocated to routine Pinard. There was no clear difference between groups in instrumental vaginal births (RR 1.46, 95% CI 0.86 to 2.49, low-quality evidence). Other outcomes were not reported (maternal mortality, instrumental vaginal birth for fetal distress and or acidosis, analgesia in labour, mobility or restriction during labour, and postnatal depression). Doppler ultrasonography with routine Pinard (two trials)There was no clear difference between groups in Apgar scores < seven at five minutes after birth (reported as < six in one of the trials) (average RR 0.76, 95% CI 0.20 to 2.87; two trials, 2598 babies, I2 = 72%, very low-quality evidence); there was high heterogeneity for this outcome. There was no clear difference between groups for perinatal mortality (RR 0.69, 95% CI 0.09 to 5.40; 2597 infants, two studies, very low-quality evidence), or neonatal seizures (RR 0.05, 95% CI 0.00 to 0.91; 627 infants, one study, very low-quality evidence). Other important infant outcomes were not reported (cord blood acidosis, composite of mortality and serious morbidity, cerebral palsy, neurosensory disability). Only one study reported maternal outcomes. Women allocated to Doppler ultrasonography had higher rates of caesarean section for fetal distress compared with those allocated to routine Pinard (RR 2.71, 95% CI 1.64 to 4.48, 627 women, moderate-quality evidence). There was no clear difference in instrumental vaginal births between groups (RR 1.35, 95% CI 0.78 to 2.32, 627 women, low-quality evidence). Other maternal outcomes were not reported. Intensive Pinard versus routine Pinard (one trial)One trial compared intensive Pinard (a research midwife following the protocol in a one-to-one care situation) with routine Pinard (as per protocol but midwife may be caring for more than one woman in labour). There was no clear difference between groups in low Apgar score (reported as < six this trial) (RR 0.90, 95% CI 0.35 to 2.31, 625 babies, very low-quality evidence). There were also no clear differences identified for perinatal mortality (RR 0.56, 95% CI 0.19 to 1.67; 625 infants, very low-quality evidence), or neonatal seizures (RR 0.68, 95% CI 0.24 to 1.88, 625 infants, very low-quality evidence)). Other infant outcomes were not reported. For maternal outcomes, there were no clear differences between groups for caesarean section or instrumental delivery (RR 0.70, 95% CI 0.35 to 1.38, and RR 1.21, 95% CI 0.69 to 2.11, respectively, 625 women, both low-quality evidence)) Other outcomes were not reported. AUTHORS' CONCLUSIONS: Using a hand-held (battery and wind-up) Doppler and intermittent CTG with an abdominal transducer without paper tracing for IA in labour was associated with an increase in caesarean sections due to fetal distress. There was no clear difference in neonatal outcomes (low Apgar scores at five minutes after birth, neonatal seizures or perinatal mortality). Long-term outcomes for the baby (including neurodevelopmental disability and cerebral palsy) were not reported. The quality of the evidence was assessed as moderate to very low and several important outcomes were not reported which means that uncertainty remains regarding the use of IA of FHR in labour.As intermittent CTG and Doppler were associated with higher rates of caesarean sections compared with routine Pinard monitoring, women, health practitioners and policy makers need to consider these results in the absence of evidence of short- and long-term benefits for the mother or baby.Large high-quality randomised trials, particularly in low-income settings, are needed. Trials should assess both short- and long-term health outcomes, comparing different monitoring tools and timing for IA.