Monica AN24 Research Articles

The Value of Non-invasive Electrocardiography in Assessing Fetal Status at Term Delivery.

The electrocardiograph (ECG) is efficient method for the accurate assessment of fetal heart rate. The barriers for accurate assessment are maternal heart rate, uterine contractions and abdominal muscles. Although previous monitoring methods have struggled to overcome these barriers, recent advances have led to a greater degree of success for listening and recording pulse-by-pulse fetal heart rate. A prospective cohort study evaluating the use, reliability and safety of non-invasive electrocardiography, in conjunction with Fetal Heart Rate parameters such as, Short Term Variability (STV) together with umbilical cord PH and Apgar score, during the active phase of childbirth. A total of 41 women with single, normal, full-term pregnancies had systematic obstetric monitoring with Monica AN24. 20 had only monitoring and 21 also had and arterial blood flow measurements. pH was measured and correlated with neonatal Apgar score at 1 and 5 min. The study also included a questionnaire about the safety and usability of obstetric monitoring. Statistical analysis was done using IBM SPSS v. 26.0. Mean age was 28.8 years, (SD ± 6.153). Electrocardiogram recordings (ECG) were classified as normal (71%) and suspicious (29%). Baseline between ECGs was different (p = 0.025) similarly for Short term variability (STV) (p <0.0001). BMI did not differentiate SVT rates. Only high acceleration (p <0.029) and small slowdowns had a statistically significant difference between normal and suspected cardiographs (p <0.029). APGAR score did not differ, whereas the umbilical cord pH was different in normal ECGs compared to the suspect (p = 0.012) and STV was also differentiated. A usability and safety survey was conducted after recording with MONIKA AN24, and the response to whether they would accept recording with the device again, was positive for 96% of the 30 responders. The present study shows that the use of electrocardiography in obstetrics allows to draw conclusions about the fetal hematopoiesis and oxygenation status. This method could be clinically applied and be an important tool for further screening in embryos that may be hypoxic and to decide whether to continue with a vaginal or cesarean delivery, thereby achieving the goal of reducing perinatal morbidity and mortality.

A Novel Method for the Extraction of Fetal ECG Signals from Wearable Devices.

The role of fetal surveillance for the prediction and timely assessment of fetal distress is widely established. Fetal ECG (fECG) monitoring via wearable devices is a feasible solution for performing continuous monitoring of fetal wellbeing and it has seen a net increase in popularity in recent years. In this paper, we propose a novel adaptation of the Smart AdaptiVe Ecg Recognition (SAVER) algorithm for the detection of fECG in long-duration recordings acquired in clinical as well as unconventional settings. The methodology was trained and tested on 50 recordings of duration 1 hour ( 59.33 ±5.54 min) obtained using the Monica AN24 fetal monitor. We validated the performance against the automatic extraction performed by the Monica DK software. Our results show superior reliability of the proposed methodology in extracting fECG and associated estimates of fetal heart rate (fHR). Clinical relevance- The proposed methodology provides an efficient and reliable approach for the extraction of fECG signals acquired via wearable technologies, enabling continuous monitoring of fECG in and outside clinical settings.

Measuring fetal heart rate and variability: Fetal cardiotocography versus electrocardiography.

Fetal heart rate variability is a key indicator of fetal neurodevelopment and well-being. Most studies have relied on Doppler-based fetal cardiotocography (fCTG) but recent technologies have made fetal electrocardiography (fECG) more widely available. We compared simultaneous recordings of fCTG and fECG in 131 fetuses twice during gestation (28 and 36weeks) using a commercially available device (Monica AN24). Within-individual correlations for fetal heart rate values, based on averaged data during 50-min recordings, neared 1.0. Continuous and episodic measures of variability were also correlated, particularly at 36weeks. Data collected during maternal polysomnography at 36weeks were used to evaluate reliability of variability measures collected during the 50-min recording. Both fCTG- and fECG-derived measures of variability exhibited correspondence with variability during maternal presleep wakefulness and most sleep states. Results did not appreciably differ by data source or method used to calculate variability. fECG monitoring presented challenges, particularly at 28weeks, when recordings with signal loss of ≤30% were available from only 27% of participants. Success rates improved to 84% at 36weeks. fCTG was successful in over 90% of participants at each gestational age. Considerations in the selection of fECG versus fCTG in developmental research are discussed.

A study of a fetal heart rate calculation system based on R-R interval.

BACKGROUND: Fetal electrocardiogram (FECG) can be obtained in a non-invasive manner to monitor fetal growth status.OBJECTIVE: In this study, a fetal heart rate (FHR) calculation system was proposed, which consists of the FECG recorder (MF-HOLTER) and the FECG monitoring software (FECG-MS). The abdomen electrocardiogram (AECG) of pregnant woman is acquired through the MF-HOLTER. The FECG-MS packs the AECG data and calls the FECG separation algorithm to obtain the separated FECG and the fetal QRS (FQRS) position. The FHR is further obtained by calculating the R-R interval value. At the same time, this study proposed a FQRS position correction algorithm to calculate the correct FHR values.METHOD: In order to verify the accuracy of the FHR calculation, the ECG signal of FLUKE’s PS320 FETAL SIMULATOR and clinical data were simultaneously tested.RESULTS: The accuracy rate is over 98% in processing the simulator’s data. In processing clinical data, the FHR values obtained by both the system proposed in this study and Monica AN24 are very close, and the difference is less than 1 bpm.CONCLUSION: The results show that the FHR calculation system is accurate and stable, and has a positive application value and prospect.

Fetal and maternal responses to yoga in the third trimester

Objective: The primary purpose of this study was to examine maternal and fetal responses to a typical, moderate-intensity yoga session in healthy pregnant women during the third trimester using continuous monitoring.Methods: This prospective observational study in low-risk, pregnant women used the Monica AN24 Abdominal ECG wireless maternal-fetal monitor to measure fetal heart rate, maternal heart rate, and uterine activity during a prenatal yoga session. Sessions included 4 time periods: (1) 20-minute rest, (2) 50 minutes standard prenatal yoga, (3) 10-minute meditation, (4) 20-minute recovery. Data were continuously recorded throughout the entire session, stored at 0.25-second intervals, and then averaged over 5-minute intervals. To evaluate changes over time, overall means for the four time periods (rest, yoga, meditation, recovery) were compared using one-way ANOVA with repeated measures. Post-hoc pairwise comparisons (Tukey’s) were used to probe significant differences between the four time points. Statistical significance was reached at p < .05.Results: Twenty participants were enrolled; 19 completed the yoga session. Mean gestational age was 35 weeks and 6 days (range of 32–0/7 to 38–6/7) with an average participant age of 32 ± 2.7 years. Maternal heart rates significantly increased during the yoga period (102 ± 11 bpm) compared to rest (90 ± 10), meditation (85 ± 12), and recovery (88 ± 10) (p < .01). The maximum maternal heart rate reached during the yoga session was 125 ± 13 bpm. While fetal heart rates fluctuated slightly over the course of the yoga session, there were no significant fetal heart rate decelerations to suggest deleterious fetal effects. There were no statistically significant differences among resting (138 ± 14 bpm), yoga (137 ± 11 bpm), meditation (139 ± 7 bpm), or recovery (135 ± 22 bpm) fetal heart rates (p = .814). Uterine activity was significantly greater during the yoga period compared with the other time points (p < .001).Conclusion: Yoga can be recommended for low-risk women during pregnancy as no adverse fetal or maternal heart rate changes were observed during a typical prenatal yoga session.

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

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). 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. 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). 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.

Modifying Maternal Sleep Position in Late Pregnancy Through Positional Therapy: A Feasibility Study.

To test whether a customized positional therapy device, PrenaBelt, would reduce time spent sleeping supine and evaluate any change in maternal or fetal parameters, in a group of healthy pregnant women in the third trimester of pregnancy. Participants underwent an in-home, overnight sleep study during late pregnancy (32-38 weeks). Participants were observed over 2 nights: 1 night when the PrenaBelt was not worn (nonintervention or control) and 1 night when it was (intervention). The intervention night was randomly allocated, and the study nights were consecutive. On the control night, participants were filmed using a night-capable (infrared) video camera, maternal sleep was measured by the Watch-PAT200, and the fetus was continuously monitored using the Monica AN24. On the intervention night, video, maternal, and fetal monitoring were repeated with the addition of the mother wearing the PrenaBelt. A total of 25 healthy pregnant women were studied. Four had missing data for the Watch-PAT or Monica, and eight had missing or disrupted video data. Video-determined time in bed was not significantly different during intervention and control nights (P = .196, r = -.23). Median time spent supine during the intervention night was reduced from 48.3 minutes, to 28.5 minutes during the control night (P = .064, r = -.33). The difference in the proportion of time spent supine was significant (P = .039). There was no significant difference in objectively estimated sleep time (P = .651, r = -.07). Improvement was observed in both maternal and fetal parameters during the intervention night with an increase in median minimum maternal oxygen saturations (control = 91.6%, intervention = 92.4%, P = .006, r = -.42), fewer maternal oxygen desaturations (control = 7.1, intervention = 5.9, P = .095, r = -.26), and fewer fetal heart rate decelerations (control = 14.0, intervention = 10.4, P = .045, r = -.31) compared to the control night. Results provide preliminary evidence that an intervention to reduce supine sleep in late pregnancy may provide maternal and fetal health benefits, with minimal effect on maternal perception of sleep quality and objectively estimated sleep time. Further research to explore relationships between objectively determined maternal sleep position, maternal respiratory indices, and fetal well-being is warranted.

Maternal heart rate patterns under resting conditions in late pregnancy.

Objectives:To describe maternal heart rate patterns observed during antenatal monitoring under resting conditions between the gestational ages of 34 to 38 weeks and to demonstrate its associations with uterine activity.Methods:Each participant had five high quality ECG electrodes attached to her anterior abdominal wall which were connected to the Monica AN24 device to collect raw electrical signals from the maternal and fetal ECG and signals of uterine activity. Proprietary software was then used to download the raw data and extract the maternal and fetal heart rate patterns and uterine activity.Results:Several distinct maternal heart rate patterns were observed. These included unusually high or low levels of variability, tachycardia, bradycardia, regular and irregular periodic changes and sporadic changes where the heart rate suddenly decreased or increased. Some of the fluctuations, especially decelerations of maternal heart rate, seemed to be associated with uterine activity.Conclusion:The clinical implications of these different patterns, for both the mother and fetus, needs to be explored further. There is a need for computerized analyses of the different maternal patterns during different gestational ages to determine its relevance.SynopsisVarious maternal heart rate patterns under resting conditions in late pregnancy are described.

Women's experiences of continuous fetal monitoring - a mixed-methods systematic review.

Antepartum stillbirth is often preceded by detectable signs of fetal compromise, including changes in fetal heart rate and movement. It is hypothesized that continuous fetal monitoring could detect these signs more accurately and objectively than current forms of fetal monitoring and allow for timely intervention. This systematic review aimed to explore available evidence on women's experiences of continuous fetal monitoring to investigate its acceptability before clinical implementation and to inform clinical studies. Systematic searching of four electronic databases (Embase, PsycINFO, MEDLINE and CINAHL), using key terms defined by initial scoping searches, identified a total of 35 studies. Following title and abstract screening by two independent researchers, five studies met the inclusion criteria. Studies were not excluded based on language, methodology or quality assessment. An integrative methodology was used to synthesize qualitative and quantitative data together. Forms of continuous fetal monitoring used included Monica AN24 monitors (n=4) and phonocardiography (n=1). Four main themes were identified: practical limitations of the device, negative emotions, positive perceptions, and device implementation. Continuous fetal monitoring was reported to have high levels of participant satisfaction and was preferred by women to intermittent cardiotocography. This review suggests that continuous fetal monitoring is accepted by women. However, it has also highlighted both the paucity and heterogeneity of current studies and suggests that further research should be conducted into women's experiences of continuous fetal monitoring before such devices can be used clinically.

Effect of uterine contractions on fetal heart rate in pregnancy: a prospective observational study.

The new Holter monitoring technology enables long-term electrocardiographic recording of the fetal heart rate without discomfort for the mother. The aim of the study was to assess the feasibility of a fetal Holter monitor. This technology was further used to study fetal heart rate outside the hospital setting during normal daily activities and to test the hypothesis that uterine activity during pregnancy influences fetal heart rate. Prospective observational study including 12 healthy pregnant women at 20-40weeks of gestation. Data were collected using the Monica AN24 system. Outcome measures were fetal heart rate, maternal heart rate, and uterine activity categorized according to the strength of the electrohysterographic signal. The recordings had a median length of 18.8h, and fetal heart rate and maternal heart rate were obtained with success rates of 73.1 and 99.9%, respectively. Uterine activity was found to affect fetal heart rate in all participants. Compared with the basal tone and mild levels of uterine activity, moderate and strong levels of uterine activity were associated with increases in fetal heart rate of 4.0 and 5.7beats/min, respectively. At night, the corresponding increases were 4.9 and 7.6beats/min. Linear correlations were found between maternal heart rate and fetal heart rate in 11 of the 12 cases, with a mean coefficient beta of 0.189. Both maternal heart rate and fetal heart rate exhibitedadiurnal pattern, with lower heart rates being recorded at night. Uterine activity during pregnancy is associated with a graded response in fetal heart rate and may represent a physiological challenge for the development and adaptation of the fetal cardiovascular system.

Circadian changes and sex-related differences in fetal heart rate parameters.

BackgroundPrevious researchers have studied circadian changes in the fetal heart rate (FHR) on small sample sizes and in a strictly controlled environment. This study was undertaken to investigate these changes during the late second and third trimesters, using a portable fetal electrocardiogram recording device (Monica AN24) in pregnant women in home and hospital environments with unrestricted mobility.MethodsThis was a prospective cohort study of 54 pregnant women with uncomplicated singleton pregnancies between 25 and 40 weeks gestation. FHR recordings were made up to 16 h at home or in the hospital setting in the United Kingdom. FHR data over 90 min periods were averaged and the day (7:00 am–11:00 pm) and night (11:00 pm–7:00 am) data from the same individual were compared. Data were examined for evidence of sex-related differences.ResultsDuring the night, there was a significant reduction in basal heart rate (bFHR) and a significant increase in short term variation (STV) and long term variation (LTV) (P < 0.05). Basal FHR decreased (P < 0.002), whereas LTV increased (P = 0.014) with advancing gestation. Male fetuses showed greater day: night variation than females regardless of gestation (P = 0.014). There was a higher bFHR in fetuses monitored during the day in hospital (P = 0.04).ConclusionThis study demonstrates that there are sex-, environment and time-related differences in the FHR parameters measured. These differences may need to be considered taken when interpreting FHR data.

Comparison of fetal and maternal heart rate measures using electrocardiographic and cardiotocographic methods

PurposeTo determine the reliability at term of: (1) two methods of measuring fetal heart rate (HR), electrocardiographic (ECG, the ‘gold standard’) and cardiotocographic (CTG) and (2) two ECG methods of measuring maternal HR variability over relatively brief periods of time (s–min). MethodsDuring 20min of rest (N=39) and during 2min of auditory stimulation (mother's recorded voice, n=19), fetal HR data were collected using an ECG (Monica AN24) and a Hewlett-Packard Model 1351A CTG. Simultaneously, maternal HR data (n=37) were collected using the same ECG device (Monica AN24) and a second stand-alone cardiac monitor (Spacelab 514T cardiac monitor with a QRS detector). ResultsDuring 20min of maternal rest, correlations of individual fetal CTG with ECG measures of HR at each second were moderate to high (r=.57–.97) for 77% of fetuses. Correlations of HR averaged over fetuses and over each of the 20min were high (r=.93–.97); fetal HR averaged over 20min varied between devices from 0.0 to 0.8bpm. During 2min of maternal voice presentation, correlations of fetal HR over each second were moderate to high (r=.54–.99) for 95% of fetuses and high (all rs=.99) when averaged across fetuses in 30s or 2min epochs. Average fetal HR between devices over the 2min voice varied from 0.0 to 0.6bpm. Correlations and/or % agreement between the two ECG methods of measuring maternal HR were high. Average maternal HR over 10min showed 81% of pairs with a difference of ≤1bpm; correlations for HR variability measures varied from r=.89 to .97. ConclusionsGood reliability was demonstrated between individual spontaneous and auditory induced fetal CTG and ECG with high correlations when HR data were averaged over fetuses or in 30–120s epochs. High reliability of maternal HR measures was obtained using two ECG devices.

Feasibility of noninvasive fetal electrocardiographic monitoring in a clinical setting.

Cardiac rhythm is an essential component of fetal cardiac evaluation. The Monica AN24 is a fetal heart rate monitor that may provide a quick, inexpensive modality for obtaining a noninvasive fetal electrocardiogram (fECG) in a clinical setting. The fECG device has the ability to acquire fECG signals and allow calculation of fetal cardiac time intervals between 16- and 42-week gestational age (GA). We aimed to demonstrate the feasibility of fECG acquisition in a busy fetal cardiology clinic using the Monica fetal heart rate monitor. This is a prospective observational pilot study of fECG acquired from fetuses referred for fetal echocardiography. Recordings were performed for 5-15 min. Maternal signals were attenuated and fECG averaged. fECG and fetal cardiac time intervals (PR, QRS, RR, and QT) were evaluated by two cardiologists independently and inter-observer reliability was assessed using intraclass coefficient (ICC). Sixty fECGs were collected from 50 mothers (mean GA 28.1 ± 6.1). Adequate signal-averaged waveforms were obtained in 20 studies with 259 cardiac cycles. Waveforms could not be obtained between 26 and 30 weeks. Fetal cardiac time intervals were measured and were reproducible for PR (ICC = 0.89; CI 0.77-0.94), QRS (ICC = 0.79; CI 0.51-0.91), and RR (ICC = 0.77; CI 0.53-0.88). QT ICC was poor due to suboptimal T-wave tracings. Acquisition of fECG and measurement of fetal cardiac time intervals is feasible in a clinical setting between 19- and 42-week GA, though tracings are difficult to obtain, especially between 26 and 30 weeks. There was high reliability in fetal cardiac time intervals measurements, except for QT. The device may be useful for assessing atrioventricular/intraventricular conduction in fetuses from 20 to 26 and >30 weeks. Techniques to improve signal acquisition, namely T-wave amplification, are ongoing.

OC07.06: Differences in fetal electrocardiographic intervals among fetuses with normal cardiac anatomy and fetuses with CHD as measured using the MONICA AN24

<scp>OC</scp>07.06: Differences in fetal electrocardiographic intervals among fetuses with normal cardiac anatomy and fetuses with <scp>CHD</scp> as measured using the <scp>MONICA AN24</scp>

Signal quality of non-invasive fetal electrocardiogram in vaginal breech delivery: a case–controlled study

Recently, a non-invasive fetal electrocardiogram monitor has been approved for clinical usage in labour and delivery. To determine the fetal signal quality of vaginal breech deliveries in comparison with a case-controlled cephalic group during labour. This case-control study was carried out at the Department of Obstetrics and Gynecology of the University Hospital Frankfurt between 1st July 2012 and 30th September 2012. A total of seven breech deliveries were evaluated. A case-controlled cephalic group with same gestational age and parity were selected from a previous trial. During first stage of labour, vaginal breech and cephalic delivery had no significant different fetal signal success rates (mean 87.8 vs. 85.7 %; p > 0.05). There was a trend of higher fetal signal success rates in the vaginal breech delivery group during second stage of labour (78.4 vs. 55.4 %; p = 0.08). Similar fetal signal success rates in vaginal breech delivery in comparison to cephalic presentation were demonstrated using the new commercially available non-invasive abdominal fECG device (the Monica AN24(TM)).

Intrapartum external fetal monitoring in obese women

ObjectivesTo evaluate the success of intrapartum external fetal monitoring in obese women.MethodsGroup 1 (Liverpool Women's Hospital): A retrospective analysis of data for 400 labouring women with singleton pregnancies at ≥37+0...

Remote fetal ECG monitoring and outpatient labour induction

AimTo evaluate the feasibility of trans-abdominal fetal ECG (aECG) monitoring with portable device (MONICA AN24) during outpatient labour induction.MethodsLow risk post-term women induced with slow release PG E2 pessaries (10...

666: Continuous remote fetal monitoring with MONICA AN24 during home induction of labor

666: Continuous remote fetal monitoring with MONICA AN24 during home induction of labor

662: Power spectral analysis of trans-abdominal fetal ECG at the beginning of labour as a predictor of adverse pregnancy outcome

To evaluate fetal heart rate, obtained by trans-abdominal ECG-RR intervals, by power spectral density (PSD) and compare normal values with findings obtained in acidemic fetuses Non invasive transabdominal fetal ECG with Monica AN24 device was performed in labour in uncomplicated term pregnancies. Thirty-six fetal ECG traces were collected at the beginning of labour from patients that delivered neonates with normal outcome (pH>7.20, BE<5, Apgar at 1 and 5min 10-10). Comparative analysis was performed with two cases with adverse outcome (pH<7.0, BE>12, Apgar at 5 min ≤7). Thirty minutes records were used for each patient. Due to non-uniformly sampled data a Lomb-Scargle periodogram was used to estimate the power spectral density at ultra low (0.00083 – 0.003), very low (0.003 – 0.04), low (0.04 – 0.15 Hz), high (0.15 – 0.4 Hz) and very high frequencies (0.4 – 0.92 Hz). The graph shows the data represented through box plots. The boxes represent the inter-quartile range and the whiskers represent the most extreme data points, which are not considered outliers. The two fetuses with an abnormal hypoxic outcome did not show any difference in power spectral analysis values since their findings fitted within the interquartile range of normal cases. This is the first reported PSD analysis in non-uniformly sampled data by means of Lomb-Scargle periodogram. We were able to define the relative power spectral analysis of ultra low, very low, low, high and very high frequencies of trans-abdominal fetal ECG in early labour in healthy fetuses. Two fetuses that subsequently developed acidemia did not show any difference in power spectral densities in early stages of labour. This finding suggests that possible changes of the autonomous nervous system balance may not present early in labour in cases where intrapartum asphyxia, confirmed at birth, develops progressively during the labour.

OC29.09: Abnormal brain microstructure in small for gestational age term fetuses with normal umbilical artery Doppler

acquisition. Aim of this study was to compare the performance of the AN24 with Doppler FHR monitoring in high risk patients requiring prolonged testing. Study design: Prospective observational study of singletons admitted for fetal monitoring. Each AN24 session was matched 2 : 1 for gestational age (GA), body mass index (BMI), and time of day with a control recording using external Doppler. Percentage of FHR capture was compared for both methods. Results: 93 monitoring sessions (31 cases, 62 controls) were analyzed after verifying proper matching by ANOVA. GA median was 29.0wks [23.1–39.5], median BMI 26.6 [20.1–42.2] and mean monitoring duration 751 minutes [73-1410]. Rate of good capture recordings (>60%) was similar p>0.05. Overall percentage capture of the FHR was better with Doppler (88% vs 58%, Mann Whitney <0.001). This difference was primarily due to sessions with low AN24 capture between 26–33.6wks (** =p<0.001, table). Outside this gestational age window both devices perform similar. Conclusion: Monica AN24 fetal ECG monitoring is equivalent Doppler technology early and late in gestation. For extended monitoring between 26–34 weeks, the AN24 technology requires improvement to overcome FHR capture limitations that are most likely due to increased vernix caseosa formation.