Evaluation and patient experience of wireless noninvasive fetal heart rate monitoring devices.

INTRODUCTION: In clinical practice, fetal heart rate monitoring is performed intermittently using Doppler ultrasound, typically for 30 minutes. In case of a non-reassuring heart rate pattern, monitoring is usually prolonged. Noninvasive fetal electrocardiography may be more suitable for prolonged monitoring due to improved patient comfort and signal quality. This study evaluates the performance and patient experience of four noninvasive electrocardiography devices to assess candidate devices for prolonged noninvasive fetal heart rate monitoring. MATERIAL AND METHODS: Non-critically sick women with a singleton pregnancy from 24 weeks of gestation were eligible for inclusion. Fetal heart rate monitoring was performed during standard care with a Doppler ultrasound device (Philips Avalon-FM30) alone or with this Doppler ultrasound device simultaneously with one of four noninvasive electrocardiography devices (Nemo Fetal Monitoring System, Philips Avalon-Beltless, Demcon Dipha-16 and Dräger Infinity-M300). Performance was evaluated by: success rate, positive percent agreement, bias, 95% limits of agreement, regression line, root mean square error and visual agreement using FIGO guidelines. Patient experience was captured using a self-made questionnaire. RESULTS: A total of 10 women were included per device. For fetal heart rate, Nemo performed best (success rate: 99.4%, positive percent agreement: 94.2%, root mean square error 5.1 BPM, bias: 0.5 BPM, 95% limits of agreement: -9.7 - 10.7 BPM, regression line: y = -0.1x + 11.1) and the cardiotocography tracings obtained simultaneously by Nemo and Avalon-FM30 received the same FIGO classification. Comparable results were found with the Avalon-Beltless from 36 weeks of gestation, whereas the Dipha-16 and Infinity-M300 performed significantly worse. The Avalon-Beltless, Nemo and Infinity-M300 closely matched the performance of the Avalon-FM30 for maternal heart rate, whereas the performance of the Dipha-16 deviated more. Patient experience scores were higher for the noninvasive electrocardiography devices. CONCLUSIONS: Both Nemo and Avalon-Beltless are suitable devices for (prolonged) noninvasive fetal heart rate monitoring, taking their intended use into account. But outside its intended use limit of 36 weeks' gestation, the Avalon-Beltless performs less well, comparable to the Dipha-16 and Infinity-M300, making them currently unsuitable for (prolonged) noninvasive fetal heart rate monitoring. Noninvasive electrocardiography devices appear to be preferred due to greater comfort and mobility.

Fetal heart rate responses in chronic hypoxaemia with superimposed repeated hypoxaemia consistent with early labour: a controlled study in fetal sheep.

OBJECTIVE: Deceleration area (DA) and capacity (DC) of the fetal heart rate can help predict risk of intrapartum fetal compromise. However, their predictive value in higher risk pregnancies is unclear. We investigated whether they can predict the onset of hypotension during brief hypoxaemia repeated at a rate consistent with early labour in fetal sheep with pre-existing hypoxaemia. DESIGN: Prospective, controlled study. SETTING: Laboratory. SAMPLE: Chronically instrumented, unanaesthetised near-term fetal sheep. METHODS: One-minute complete umbilical cord occlusions (UCOs) were performed every 5 minutes in fetal sheep with baseline pa O2 <17 mmHg (hypoxaemic, n = 8) and >17 mmHg (normoxic, n = 11) for 4 hours or until arterial pressure fell <20 mmHg. MAIN OUTCOME MEASURES: DA, DC and arterial pressure. RESULTS: Normoxic fetuses showed effective cardiovascular adaptation without hypotension and mild acidaemia (lowest arterial pressure 40.7 ± 2.8 mmHg, pH 7.35 ± 0.03). Hypoxaemic fetuses developed hypotension (lowest arterial pressure 20.8 ± 1.9 mmHg, P < 0.001) and acidaemia (final pH 7.07 ± 0.05). In hypoxaemic fetuses, decelerations showed faster falls in FHR over the first 40 seconds of UCOs but the final deceleration depth was not different to normoxic fetuses. DC was modestly higher in hypoxaemic fetuses during the penultimate (P = 0.04) and final (P = 0.012) 20 minutes of UCOs. DA was not different between groups. CONCLUSION: Chronically hypoxaemic fetuses had early onset of cardiovascular compromise during labour-like brief repeated UCOs. DA was unable to identify developing hypotension in this setting, while DC only showed modest differences between groups. These findings highlight that DA and DC thresholds need to be adjusted for antenatal risk factors, potentially limiting their clinical utility.

Correlation of short-term variation derived from novel ambulatory fetal electrocardiography monitor with computerized cardiotocography.

OBJECTIVES: To compare short-term variation (STV) outputs from a novel self-applied non-invasive fetal electrocardiography (NIFECG) device with those obtained on computerized cardiotocography (cCTG). Technological and algorithmic limitations and mitigation strategies were also evaluated. METHODS: This was a prospective cohort study of women with a singleton pregnancy over 28 + 0 weeks' gestation attending a tertiary London hospital for cCTG assessment between June 2021 and June 2022. Women underwent concurrent monitoring with both NIFECG and cCTG for up to 1 h. Postprocessing of NIFECG data using various filtering methods produced NIFECG-STV (eSTV) values, which were compared with cCTG-STV (cSTV) outputs. Linear correlation, mean bias, precision and limits of agreement were assessed for STV derived by the different methods of computation and mathematical correction. RESULTS: Overall, 306 concurrent NIFECG and cCTG traces were collected from 285 women. Fully filtered eSTV was correlated very strongly with cSTV (r = 0.911, P < 0.001), but generated results only in 142/306 (46.4%) 1-h traces owing to the removal of traces with lower-quality signals. Partial filtering generated more eSTV data (98.4%), but with a weak correlation with cSTV (r = 0.337, P < 0.001). The difference in STV between the monitors (eSTV - cSTV) increased with signal loss; in traces with > 60% signal loss, the values became highly discrepant. Removal of traces with > 60% signal loss resulted in a stronger correlation with cSTV, while still generating eSTV results for 65% of traces. Correcting these remaining eSTV values for signal loss using linear regression analysis further improved correlation with cSTV (r = 0.839, P < 0.001). CONCLUSIONS: The discrepancy between STV computed by NIFECG and cCTG necessitates signal filtering, exclusion of poor-quality traces and eSTV correction. This study demonstrates that, with such correction, NIFECG is able to produce STV values that are strongly correlated with those of cCTG. This evidence base for NIFECG monitoring and interpretation is a promising step forward in the development of safe and effective at-home fetal heart-rate monitoring. © 2023 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

Phase-rectified signal averaging: correlation between two monitors and relationship with short-term variation of fetal heart rate.

OBJECTIVES: To establish the correlation between phase-rectified signal averaging (PRSA) outputs obtained from a novel self-applicable non-invasive fetal electrocardiography (NIFECG) monitor with those from computerized cardiotocography (cCTG). A secondary objective was to evaluate the potential for remote assessment of fetal wellbeing by determining the relationship between PRSA and short-term variation (STV). METHODS: This was a prospective observational study of women with a singleton pregnancy over 28 + 0 weeks' gestation attending a London teaching hospital for cCTG assessment. Participants underwent concurrent cCTG and NIFECG monitoring for up to 60 min. Averaged accelerative (AAC) and decelerative (ADC) capacities and STV were derived by postprocessing and filtration of signals, generating fully (F) and partially (P) filtered results. Linear correlation and accuracy and precision analysis were performed to assess the relationship between PRSA outputs from cCTG and NIFECG, using varying anchor thresholds, and their association with STV. RESULTS: A total of 306 concurrent cCTG and NIFECG traces were collected from 285 women. F-filtered NIFECG PRSA (eAAC/eADC) results were generated from 65% of traces, whereas cCTG PRSA (cAAC/cADC) outputs were generated from all. Strong correlations were observed between cAAC and F-filtered eAAC (r = 0.879, P < 0.001) and between cADC and F-filtered eADC (r = 0.895, P < 0.001). NIFECG anchor detection decreased significantly with increasing signal loss, and NIFECG PRSA indices showed considerable deviation from those of cCTG when derived from traces in which fewer than 100 anchors were detected. Removing anchor filters from NIFECG traces to generate P-filtered PRSA outputs weakened the correlation (AAC: r = 0.505, P < 0.001; ADC: r = 0.560, P < 0.001). Lowering the anchor threshold to 100 increased the yield of eAAC and eADC outputs to approximately 74%, whilst maintaining strong correlation with cAAC (r = 0.839, P < 0.001) and cADC (r = 0.815, P < 0.001), respectively. Both cAAC and cADC showed a very strong linear relationship with cCTG STV (r = 0.928, P < 0.001 and r = 0.911, P < 0.001, respectively). Similar findings were observed with eAAC (r = 0.825, P < 0.001) and eADC (r = 0.827, P < 0.001). CONCLUSIONS: PRSA appears to be a method of fetal assessment equivalent to STV, but, due to its innate ability to eliminate artifacts, it generates interpretable NIFECG traces with high accuracy at a higher rate. These findings raise the possibility of self-applied at-home or remote fetal heart-rate monitoring with automated reporting, thus enabling increased surveillance in high-risk women without impacting on service demand. © 2023 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

Computerized cardiotocography analysis during labor - A state-of-the-art review.

Cardiotocography is defined as the recording of fetal heart rate and uterine contractions and is widely used during labor as a screening tool to determine fetal wellbeing. The visual interpretation of the cardiotocography signals by the practitioners, following common guidelines, is subject to a high interobserver variability, and the efficiency of cardiotocography monitoring is still debated. Since the 1990s, researchers and practitioners work on designing reliable computer-aided systems to assist practitioners in cardiotocography interpretation during labor. Several systems are integrated in the monitoring devices, mostly based on the guidelines, but they have not clearly demonstrated yet their usefulness. In the last decade, the availability of large clinical databases as well as the emergence of machine learning and deep learning methods in healthcare has led to a surge of studies applying those methods to cardiotocography signals analysis. The state-of-the-art systems perform well to detect fetal hypoxia when evaluated on retrospective cohorts, but several challenges remain to be tackled before they can be used in clinical practice. First, the development and sharing of large, open and anonymized multicentric databases of perinatal and cardiotocography data during labor is required to build more accurate systems. Also, the systems must produce interpretable indicators along with the prediction of the risk of fetal hypoxia in order to be appropriated and trusted by practitioners. Finally, common standards should be built and agreed on to evaluate and compare those systems on retrospective cohorts and to validate their use in clinical practice.

Effectiveness of ambulatory non-invasive fetal electrocardiography: impact of maternal and fetal characteristics.

INTRODUCTION: Non-invasive fetal electrocardiography (NIFECG) has potential benefits over the computerized cardiotocography (cCTG) that may permit its development in remote fetal heart-rate monitoring. Our study aims to compare signal quality and heart-rate detection from a novel self-applicable NIFECG monitor against the cCTG, and evaluate the impact of maternal and fetal characteristics on both devices. MATERIAL AND METHODS: This prospective observational study took place in a university hospital in London. Women with a singleton pregnancy from 28 + 0 weeks' gestation presenting for cCTG were eligible. Concurrent monitoring with both NIFECG and cCTG were performed for up to 60 minutes. Post-processing of NIFECG produced signal loss, computed in both 0.25 (E240)- and 3.75 (E16)-second epochs, and fetal heart-rate and maternal heart-rate values. cCTG signal loss was calculated in 3.75-second epochs. Accuracy and precision analysis of 0.25-second epochal fetal heart-rate and maternal heart-rate were compared between the two devices. Multiple regression analyses were performed to assess the impact of maternal and fetal characteristics on signal loss. CLINICALTRIALS: gov Identifier: NCT04941534. RESULTS: 285 women underwent concurrent monitoring. For fetal heart-rate, mean bias, precision and 95% limits of agreement were 0.1 beats per minute (bpm), 4.5 bpm and -8.7 bpm to 8.8 bpm, respectively. For maternal heart-rate, these results were -0.4 bpm, 3.3 bpm and -7.0 to 6.2 bpm, respectively. Median NIFECG E240 and E16 signal loss was 32.0% (interquartile range [IQR] 6.5%-68.5%) and 17.3% (IQR 1.8%-49.0%), respectively. E16 cCTG signal loss was 1.0% (IQR 0.0%-3.0%). For NIFECG, gestational age was negatively associated with signal loss (beta = -2.91, 95% CI -3.69 to -2.12, P < 0.001). Increased body mass index, fetal movements and lower gestational age were all associated with cCTG signal loss (beta = 0.30, 95% CI 0.17-0.43, P < 0.001; beta = 0.03, 95% CI 0.01-0.05, P = 0.014; and beta = -0.28, 95% CI -0.51 to -0.05, P = 0.017, respectively). CONCLUSIONS: Although NIFECG is complicated by higher signal loss, it does not appear to be influenced by increased body mass index or fetal movement. NIFECG signal loss varies according to method of computation, and standards of signal acceptability need to be defined according to the ability of the device to produce clinically reliable physiological indices. The high accuracy of heart-rate indices is promising for NIFECG usage in the remote setting.

Improved obstetric management after implementation of a scaled-up quality improvement intervention: A nested before-after study in three public hospitals in Nepal.

BACKGROUND: We assessed the change in obstetric management after implementation of a quality improvement intervention, the Nepal Perinatal Quality Improvement Package (NePeriQIP). METHODS: The Nepal Perinatal Quality Improvement Package was a stepped-wedge cluster-randomized controlled trial conducted in 12 public hospitals in Nepal between April 2017 and October 2018. In this study, three hospitals allocated at different time points to the intervention were selected for a nested before-after analysis. We used bivariate and multivariate analyses to compare obstetric management in the control vs intervention group. RESULTS: There were 25 977 deliveries in the three hospitals during the study period: 10 207 (39%) in the control and 15 770 (61%) in the intervention group. After adjusting for maternal age, ethnicity, education, gestational age, stage of labor at admission, complications during labor, and birthweight, the intervention group had a higher proportion of fetal heart rate monitoring performed as per protocol (adjusted odds ratio [aOR] 1.19, 95% confidence interval [CI] 1.12-1.27), shorter time intervals between each fetal heart rate monitoring (aOR 2.09, 95% CI 1.96-2.23), a higher likelihood of abnormal fetal heart rate being detected (aOR 1.53, 95% CI 1.25-1.68), progress of labor more often being recorded immediately after per vaginal examination (aOR 2.73, 95% CI 2.55-2.93), and partograph filled as per standards (aOR 3.18, 95% CI 2.98-3.50). The cesarean birth rate was 2.5% in the control group and 8.2% in the intervention group (aOR 3.12, 95% CI 2.64-3.68). CONCLUSIONS: The NePeriQIP intervention has potential to improve obstetric care, especially intrapartum fetal surveillance, in similar low-resource settings.

Fetal heart rate patterns complicated by chorioamnionitis and subsequent cerebral palsy in Japan.

AIM: This retrospective study was performed to investigate whether certain fetal heart rate patterns were associated with subsequent cerebral palsy (CP) in infants with chorioamnionitis at or near term. METHODS: We used cases registered by the Japan Obstetric Compensation System for CP, which is a nationwide population-based database. Among them, 133 infants with chorioamnionitis who were born at ≥34 weeks of gestation were enrolled. All infants underwent magnetic resonance imaging (MRI), and all fetal heart rate charts had been interpreted according to the National Institute of Child Health and Human Development criteria, focusing on antepartum and immediately before delivery. RESULTS: The incidence of CP after chorioamnionitis at ≥34 weeks of gestation was 0.3 per 10 000 in Japan. Between the clinical (24%) and subclinical groups (76%), the incidence of abnormal fetal heart rate patterns did not differ. According to the MRI classification, 88% of the infants with CP showed hypoxic-ischemic encephalopathy. Half of the infants with CP experienced terminal bradycardia, leading to severe acidosis and exclusively to hypoxic-ischemic encephalopathy. In another half, who did not experience bradycardia, 80% had moderate acidosis (pH 7.00-7.20) resulting in hypoxic-ischemic encephalopathy, and the remaining 20% showed non-acidosis resulting in brain damage other than hypoxic-ischemic encephalopathy. The fetal heart rate patterns before the terminal bradycardia showed that the incidence rates of late deceleration or decreased variability were high (>60%). CONCLUSION: Fifty percent of pregnant women with chorioamnionitis-related CP had terminal bradycardia that exclusively resulted in hypoxic-ischemic encephalopathy.

Diagnostic Tests in the Prediction of Neonatal Outcome in Early Placental Fetal Growth Restriction.

Background and Objectives: Monitoring pregnancies with fetal growth restriction (FGR) presents a challenge, especially concerning the time of delivery in cases of early preterm pregnancies below 32 weeks. The aim of our study was to compare different diagnostic parameters in growth-restricted preterm neonates with and without morbidity/mortality and to determine sensitivity and specificity of diagnostic parameters for monitoring preterm pregnancies with early preterm fetal growth restriction below 32 weeks. Materials and Methods: Our clinical study evaluated 120 cases of early preterm deliveries, with gestational age ≤ 32 + 0 weeks, with prenatally diagnosed placental FGR. All the patients were divided into three groups of 40 cases each based on neonatal condition,: I-Neonates with morbidity/mortality (NMM); II-Neonates without morbidity with acidosis/asphyxia (NAA); III-Neonates without neonatal morbidity/acidosis/asphyxia (NWMAA). Results: Amniotic fluid index (AFI) was lower in NMM, while NWMAA had higher biophysical profile scores (BPS). UA PI was lower in NWMAA. NWMAA had higher MCA PI and CPR and fewer cases with CPR <5th percentile. NMM had higher DV PI, and more often had ductus venosus (DV) PI > 95th‱ or absent/reversed A wave, and pulsatile blood flow in umbilical vein (UV). The incidence of pathological fetal heart rate monitoring (FHRM) was higher in NMM and NAA, although the difference was not statistically significant. ROC calculated by defining a bad outcome as NMM and a good outcome as NAA and NWMAA showed the best sensitivity in DV PIi. ROC calculated by defined bad outcome in NMM and NAA and good outcome in NWMAA showed the best sensitivity in MCA PI. Conclusions: In early fetal growth restriction normal cerebral blood flow strongly predicts good outcomes, while pathological venous blood flow is associated with bad outcomes. In fetal growth restriction before 32 weeks, individualized expectant management remains the best option for the optimal timing of delivery.

Placental growth factor level is correlated with intrapartum fetal heart rate findings.

OBJECTIVE: Here, we tested the correlation between maternal placental growth factor (PlGF) and fetal heart rate (FHR) monitoring findings. METHODS: We included 35 women with single pregnancies from 35 to 42 weeks of gestation who were hospitalized owing to onset of labor. Blood samples were collected at the start of labor. Intrapartum FHR monitoring parameters included total deceleration area, average deceleration area (mean deceleration area per 10 min), and five-tier classification level. RESULTS: Of the 35 women, 26 (74%) had vaginal delivery and 9 (26%) had cesarean section. After excluding 2 women who had cesarean section for arrest of labor, we analyzed 26 women who had vaginal delivery (VD group) and 7 who had cesarean section for fetal indications (CSF group). PlGF level was significantly higher in the VD group (157 ± 106 pg/ml) than in the CSF group (74 ± 62 pg/ml) (P = 0.03). There were no significant correlations between PlGF and total (r = -0.07) or average (r = -0.08) deceleration area.　There was a significant negative correlation (r = -0.42, P = 0.01) between PlGF and the percentage of level 3 or higher in the five-level classification. CONCLUSION: PlGF was correlated with FHR monitoring findings and might be a promising biomarker of intrapartum fetal function.

Implementation of a revised classification for intrapartum fetal heart rate monitoring and association to birth outcome: A national cohort study.

INTRODUCTION: A revised intrapartum cardiotocography (CTG) classification was introduced in Sweden in 2017. The aims of the revision were to adapt to the international guideline published in 2015 and to adjust the classification of CTG patterns to current evidence regarding intrapartum fetal physiology. This study aimed to investigate adverse neonatal outcomes before and after implementation of the revised CTG classification. MATERIAL AND METHODS: A before-and-after design was used. Cohort I (n = 160 210) included births from June 1, 2014 through May 31, 2016 using the former CTG classification, and cohort II (n = 166 558) included births from June 1, 2018 through May 31, 2020 with the revised classification. Data were collected from the Swedish Pregnancy and Neonatal Registers. The primary outcome was moderate to severe neonatal hypoxic ischemic encephalopathy (HIE 2-3). Secondary outcomes were birth acidemia (umbilical artery pH <7.05 and base excess < -12 mmol/L or pH <7.00), A-criteria for neonatal hypothermia treatment, 5-min Apgar scores <4 and <7, neonatal seizures, meconium aspiration, neonatal mortality and delivery mode. Logistic regression was used (period II vs period I), and results are presented as adjusted odds ratios (aORs) with 95% confidence intervals (95% CIs). RESULTS: There were no statistically significant differences in HIE 2-3 (aOR 1.27; 95% CI 0.97-1.66), proportion of neonates meeting A-criteria for hypothermia treatment (aOR 0.96; 95% CI 0.89-1.04) or neonatal mortality (aOR 0.68; 95% CI 0.39-1.18) between the cohorts. Birth acidemia (aOR 1.36; 95% CI 1.25-1.48), 5-min Apgar scores <7 (aOR 1.27; 95% CI 1.18-1.36) and <4 (aOR 1.40; 95% CI 1.17-1.66) occurred more often in cohort II. The absolute risk difference for HIE 2-3 was 0.02% (95% CI 0.00-0.04). Operative delivery (vacuum or cesarean) rates were lower in cohort II (aOR 0.82; 95% CI 0.80-0.85 and aOR 0.94; 95% CI 0.91-0.97, respectively). CONCLUSIONS: Although not statistically significant, a small increase in the incidence of HIE 2-3 after implementation of the revised CTG classification cannot be excluded. Operative deliveries were fewer but incidences of acidemia and low Apgar scores were higher in the latter cohort. This warrants further in-depth analyses before a full re-evaluation of the revised classification can be made.

Intrauterine fetal death during COVID-19 pregnancy: Typical fetal heart rate changes, coagulopathy, and placentitis.

Although various perinatal outcomes in coronavirus disease 2019 (COVID-19) pregnancies have been reported, the fetal and neonatal consequences of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection remain unclear. Several reports of miscarriages and stillbirths have been recorded, but vertical transmission by SARS-CoV-2 is considered very rare, and the cause remains unknown. We report a case of a 22-year-old uncomplicated Japanese woman infected with SARS-CoV-2 during the second trimester, resulting in intrauterine fetal death due to placental insufficiency associated with COVID-19 placentitis. This report emphasizes the importance of longitudinal assessment of fetal well-being by fetal heart rate monitoring and early detection of maternal coagulation dysfunction representing SARS-CoV-2 inflammation to manage COVID-19 in pregnancy.

Deceleration area and capacity during labour-like umbilical cord occlusions identify evolving hypotension: a controlled study in fetal sheep.

OBJECTIVE: Cardiotocography is widely used to assess fetal well-being during labour. The positive predictive value of current clinical algorithms to identify hypoxia-ischaemia is poor. In experimental studies, fetal hypotension is the strongest predictor of hypoxic-ischaemic injury. Cohort studies suggest that deceleration area and deceleration capacity of the fetal heart rate trace correlate with fetal acidaemia, but it is not known whether they are indices of fetal arterial hypotension. DESIGN: Prospective, controlled study. SETTING: Laboratory. SAMPLE: Near-term fetal sheep. METHODS: One minute of complete umbilical cord occlusions (UCOs) every 5 minutes (1:5 min, n = 6) or every 2.5 minutes (1:2.5 min, n = 12) for 4 hours or until fetal mean arterial blood pressure fell <20 mmHg. MAIN OUTCOME MEASURES: Deceleration area and capacity during the UCO series were related to evolving hypotension. RESULTS: The 1:5 min group developed only mild metabolic acidaemia, without hypotension. By contrast, 10/12 fetuses in the 1:2.5-min group progressively developed severe metabolic acidaemia and hypotension, reaching 16.8 ± 0.9 mmHg after 71.2 ± 6.7 UCOs. Deceleration area and capacity remained unchanged throughout the UCO series in the 1:5-min group, but progressively increased in the 1:2.5-min group. The severity of hypotension was closely correlated with both deceleration area (P < 0.001, R2  = 0.66, n = 18) and capacity (P < 0.001, R2  = 0.67, n = 18). Deceleration area and capacity predicted development of hypotension at a median of 103 and 123 minutes before the final occlusion, respectively. CONCLUSIONS: Both deceleration area and capacity were strongly associated with developing fetal hypotension, supporting their potential to improve identification of fetuses at risk of hypotension leading to hypoxic-ischaemic injury during labour. TWEETABLE ABSTRACT: Deceleration area and capacity of fetal heart rate identify developing hypotension during labour-like hypoxia.

An integrated approach based on advanced CTG parameters and Doppler measurements for late growth restriction management.

BACKGROUND: The clinical diagnosis of late Fetal Growth Restriction (FGR) involves the integration of Doppler ultrasound data and Fetal Heart Rate (FHR) monitoring through computer assisted computerized cardiotocography (cCTG). The aim of the study was to evaluate the diagnostic power of combined Doppler and cCTG parameters by contrasting late FGR -and healthy controls. METHODS: The study was conducted from January 2018 to May 2020. Only pregnant women who had the last Doppler measurement obtained within 1 week before delivery and cCTG performed within 24 h before delivery were included in the study. Two hundred forty-nine pregnant women fulfilling the inclusion criteria were enrolled in the study; 95 were confirmed as late FGR and 154 were included in the control group. RESULTS: Among the extracted cCTG parameters, Delta Index, Short Term Variability (STV), Long Term Variability (LTV), Acceleration and Deceleration Phase Rectified Slope (APRS, DPRS) values were lower in the late FGR participants compared to the control group. In the FGR cohort, Delta, STV, APRS, and DPRS were found different when stratifying by MCA_PI (MCA_PI <5th centile or > 5th centile). STV and DPRS were the only parameters to be found different when stratifying by (UA_PI >95th centile or UA_PI <95th centile). Additionally, we measured the predictive power of cCTG parameters toward the identification of associated Doppler measures using figures of merit extracted from ROC curves. The AUC of ROC curves were accurate for STV (0,70), Delta (0,68), APRS (0,65) and DPRS (0,71) when UA_PI values were > 95th centile while, the accuracy attributable to the prediction of MCA_PI was 0.76, 0.77, 0.73, and 0.76 for STV, Delta, APRS, and DPRS, respectively. An association of UA_PI>95th centile and MCA_PI<5th centile with higher risk for NICU admission, was observed, while CPR < 5th centile resulted not associated with any perinatal outcome. Values of STV, Delta, APRS, DPRS were significantly lower for FGR neonates admitted to NICU, compared with the uncomplicated FGR cohort. CONCLUSIONS: The results of this study show the contribution of advanced cCTG parameters and fetal Doppler to the identification of late FGR and the association of those parameters with the risk for NICU admission. TRIAL REGISTRATION: Retrospectively registered.

Can we improve our ability to interpret category II fetal heart rate tracings using additional clinical parameters?

OBJECTIVES: This study examined predictive factors, in addition to Category II Fetal Herat Rate (FHR) monitoring that might imply fetal acidosis and risk of asphyxia. METHODS: This retrospective cohort study compared three groups of patients with Category II FHR monitoring indicating need for imminent delivery. Groups were divided based on fetal cord blood pH: pH≤7.0, 7.0

Accuracy of predicting neonatal distress using a five-level classification of fetal heart rate monitoring.

AIM: To assess the accuracy of neonatal distress prediction using the five-level classification of fetal heart rate (FHR) and management protocol of the Japan Society of Obstetrics and Gynecology (JSOG). METHODS: A case-control study was conducted. Vertex singleton pregnant women who delivered after 37 weeks' gestation from 2013 to 2015 were enrolled. The participants were categorized into two groups; controls were levels 1-3 (n = 1184), whereas cases were levels 4-5 (n = 117) group. Neonatal distress was defined as Apgar score < 8 points at 5 min or umbilical cord artery pH < 7.1. RESULTS: There were 117 cases (9.0%). The frequency of the neonatal distress was observed in 1.3% controls and 6.8% cases (P < 0.01). Diagnostic accuracy of neonatal distress for cases showed a 6.8% positive-predictive value, 34.8% sensitivity, 91.5% specificity and 98.7% negative-predictive value. Among various obstetrical conditions, high sensitivity (100%) for prediction of neonatal distress was observed in women with chromosome abnormalities, placental abruption, umbilical cord abnormalities and excessive labor pain. Conversely, relatively low specificity (<50%) was observed in cases with oligohydramnios and excessive labor pain. CONCLUSION: The five-level classification scheme was efficient for neonatal distress prediction. However, depending on the obstetric condition, the FHR findings and neonatal condition might be independent.

Dedicated Algorithm for Unobtrusive Fetal Heart Rate Monitoring Using Multiple Dry Electrodes.

Multi-channel measurements from the maternal abdomen acquired by means of dry electrodes can be employed to promote long-term monitoring of fetal heart rate (fHR). The signals acquired with this type of electrode have a lower signal-to-noise ratio and different artifacts compared to signals acquired with conventional wet electrodes. Therefore, starting from the benchmark algorithm with the best performance for fHR estimation proposed by Varanini et al., we propose a new method specifically designed to remove artifacts typical of dry-electrode recordings. To test the algorithm, experimental textile electrodes were employed that produce artifacts typical of dry and capacitive electrodes. The proposed solution is based on a hybrid (hardware and software) pre-processing step designed specifically to remove the disturbing component typical of signals acquired with these electrodes (triboelectricity artifacts and amplitude modulations). The following main processing steps consist of the removal of the maternal ECG by blind source separation, the enhancement of the fetal ECG and identification of the fetal QRS complexes. Main processing is designed to be robust to the high-amplitude motion artifacts that corrupt the acquisition. The obtained denoising system was compared with the benchmark algorithm both on semi-simulated and on real data. The performance, quantified by means of sensitivity, F1-score and root-mean-square error metrics, outperforms the performance obtained with the original method available in the literature. This result proves that the design of a dedicated processing system based on the signal characteristics is necessary for reliable and accurate estimation of the fHR using dry, textile electrodes.

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.

Management of clinical chorioamnionitis: an evidence-based approach.

This review aimed to examine the existing evidence about interventions proposed for the treatment of clinical chorioamnionitis, with the goal of developing an evidence-based contemporary approach for the management of this condition. Most trials that assessed the use of antibiotics in clinical chorioamnionitis included patients with a gestational age of ≥34 weeks and in labor. The first-line antimicrobial regimen for the treatment of clinical chorioamnionitis is ampicillin combined with gentamicin, which should be initiated during the intrapartum period. In the event of a cesarean delivery, patients should receive clindamycin at the time of umbilical cord clamping. The administration of additional antibiotic therapy does not appear to be necessary after vaginal or cesarean delivery. However, if postdelivery antibiotics are prescribed, there is support for the administration of an additional dose. Patients can receive antipyretic agents, mainly acetaminophen, even though there is no clear evidence of their benefits. Current evidence suggests that the administration of antenatal corticosteroids for fetal lung maturation and of magnesium sulfate for fetal neuroprotection to patients with clinical chorioamnionitis between 24 0/7 and 33 6/7 weeks of gestation, and possibly between 23 0/7 and 23 6/7 weeks of gestation, has an overall beneficial effect on the infant. However, delivery should not be delayed to complete the full course of corticosteroids and magnesium sulfate. Once the diagnosis of clinical chorioamnionitis has been established, delivery should be considered, regardless of the gestational age. Vaginal delivery is the safer option and cesarean delivery should be reserved for standard obstetrical indications. The time interval between the diagnosis of clinical chorioamnionitis and delivery is not related to most adverse maternal and neonatal outcomes. Patients may require a higher dose of oxytocin to achieve adequate uterine activity or greater uterine activity to effect a given change in cervical dilation. The benefit of using continuous electronic fetal heart rate monitoring in these patients is unclear. We identified the following promising interventions for the management of clinical chorioamnionitis: (1) an antibiotic regimen including ceftriaxone, clarithromycin, and metronidazole that provides coverage against the most commonly identified microorganisms in patients with clinical chorioamnionitis; (2) vaginal cleansing with antiseptic solutions before cesarean delivery with the aim of decreasing the risk of endometritis and, possibly, postoperative wound infection; and (3) antenatal administration of N-acetylcysteine, an antioxidant and antiinflammatory agent, to reduce neonatal morbidity and mortality. Well-powered randomized controlled trials are needed to assess these interventions in patients with clinical chorioamnionitis.

The burden of and factors associated with misclassification of intrapartum stillbirth: Evidence from a large scale multicentric observational study.

INTRODUCTION: Global estimates suggest 2.6 million stillbirths and 2.5 million neonatal deaths occur annually worldwide. The majority of these deaths occur in low resource settings where analysis of health metrics and outcomes measurements may be challenging. We examined the misclassification of documented intrapartum stillbirth and factors associated with misclassification. MATERIAL AND METHODS: A prospective observational study was performed in 12 public hospitals in Nepal. Data were extracted from the medical records of all births that occurred during the 6-month period of the study. For the study purpose, we classified birth outcome based on the presence of fetal heart sound (FHS) at admission and use of neonatal resuscitation. The health worker-documented intrapartum stillbirths were considered potentially misclassified when there were FHS present at admission and no resuscitation initiated after birth. The association between potentially misclassified intrapartum stillbirth and complications during labor, birthweight and gestational age was assessed using Pearson's chi-square test, bivariate and multivariate logistic regression. RESULTS: A total of 39 562 mother-infant dyads were enrolled in the study, all of whom had FHS at admission. Among the 391 intrapartum stillbirths recorded during the study, 180 (46.0%) of them had FHS at admission with no resuscitation initiated after birth and were considered potentially misclassified intrapartum stillbirths. Among these potentially misclassified intrapartum stillbirths, 170 (43.5%) had FHS present 15 minutes before birth and 10 had no FHS 15 minutes before birth Among the potentially misclassified intrapartum stillbirths, 23.3% had complications during labor, 93.3% had birthweight less than 2500 g and 90.0% were born preterm. The risk of intrapartum misclassification was nearly four times higher among low birthweight babies (adjusted odds ratio [aOR] 3.5, 95% confidence interval [CI] 1.8 to 7.0, P < 0.001) and five times higher among preterm babies (aOR 5.3, 95% CI 3.0 to 9.3, P < 0.001). CONCLUSIONS: We estimate that 46% of intrapartum stillbirths were potentially misclassified intrapartum stillbirths. Improving quality of both FHS monitoring and neonatal resuscitation as well as measurement of the care will reduce the risk of potentially misclassified intrapartum stillbirth and consequently intrapartum stillbirth.