Articles

Monica Articles (use Ctrl+F to search for a key word or author)

Some of the evidence supporting the use of Monica's fetal ECG devices are listed below.  This citation list will be periodically updated to reflect new publications using or supporting the AN24 and Novii Systems.

Transabdominal Electrocardiography in Diagnostics of Fetal Critical Conditions in Placental Insufficiency

2014

G. Gudkov,  J. Pustovaya

Herald of municipal public health

Published 19.02.2014

http://vestnik.kmldo.ru/archive/25/

Details

Non-invasive registration techniques should be used in pregnancy and labor control because of invasive ECGmonitoring has insufficient safety.
Transabdominal electrocardiography (ECG) of the fetus with STAN technology application is the perspective trend of increasing the specificity of antenatal cardiotocography (CTG). Combined analysis of different variants ST-events (STAN) and CTG types in computer aided complex provides the high specificity of diagnostics and prediction chronic fetal hypoxia decompensation. It allows choosing the optimal tactics of delivery method for pregnant with placental insufficiency (PI).

Influence of maternal body mass index on accuracy and reliability of external fetal monitoring techniques

2014

Cohen. WR,  Hayes-Gill. B

Acta Obstet Gynecol Scand. 2014 Jun;93(6):590-5.

Details

Objective.
To evaluate the performance of external electronic fetal heart rate and uterine contraction monitoring according to maternal body mass index. Design. Secondary analysis of prospective equivalence study. Setting. Three US urban teaching hospitals. Sample. Seventy-four parturients with a normal term pregnancy.
Methods.
The parent study assessed performance of two methods of external fetal heart rate monitoring (abdominal fetal electrocardiogram and Doppler ultrasound) and of uterine contraction monitoring (electrohysterography and tocodynamometry) compared with internal monitoring with fetal scalp electrode and intrauterine pressure transducer. Reliability of external techniques was assessed by the success rate and positive percent agreement with internal methods. Bland–Altman analysis determined accuracy. We analyzed data from that study according to maternal body mass index. Main outcome measures. We assessed the relationship between body mass index and monitor performance with linear regression, using body mass index as the independent variable and measures of reliability and accuracy as dependent variables.
Results.
There was no significant association between maternal body mass index and any measure of reliability or accuracy for abdominal fetal electrocardiogram. By contrast, the overall positive percent agreement for Doppler ultrasound declined (p = 0.042), and the root mean square error from the Bland–Altman analysis increased in the first stage (p = 0.029) with increasing body mass index. Uterine contraction recordings from electrohysterography and tocodynamometry showed no significant deterioration related to maternal body mass index.
Conclusions.
Accuracy and reliability of fetal heart rate monitoring using abdominal fetal electrocardiogram was unaffected by maternal obesity, whereas performance of ultrasound degraded directly with maternal size. Both electrohysterography and tocodynamometry were unperturbed by obesity.

Intrapartum ST Segment Analyses (STAN) Using Simultaneous Invasive and Non-Invasive Fetal Electrocardiography: A Report of 6 Cases

2014

Reinhard. J, Hayes-Gill. B, Yuan. J, Schiermeier. S, Louwen. F

Z Geburtsh Neonatol 2014; 218: 1–5

Details

Objective:
The objective of this study was to analyze ST segment analyses (STAN) using simultaneous
traditional – gold standard invasive (fetal scalp electrode) and newly available non-invasive abdominal fetal electrocardiography (fECG) during delivery.
Study Design:
This was a prospective observational study of non-invasive fetal ECG using 5 abdominally sited electrodes (Monica AN24TM) against the traditional fetal scalp electrodes. (STAN S31TM) on 6 patients. Data were analyzed when the STAN S31TM found the baseline and when there was a baseline rise.
Results:
Successful fECG signal acquisition was achieved in 6/6 (100 %) patients. Using the noninvasive fECG, P and QRS waves were seen in all cases, and T waves in 3/6 (50 %). ST segment analysis analysis was possible in 6/6 (100 %) and 3/6 (50 %) using invasive and non-invasive fECG, respectively.
Conclusion:
This study demonstrates that ST segment analysis is feasible using invasive and non-invasive fECG. Further studies are warranted to confirm the preliminary results and improve ECG morphology of non-invasive fECG.

Fetal supraventricular tachycardia: a new approach to surveillance and treatment

2013

Fetal supraventricular tachycardia: a new approach to surveillance and treatment

Edwards. L, Cluver . CA,  Fung. A,  Walker. SP,  Wilson. D

Ultrasound in Obstetrics & Gynecology 2013; 42 (Suppl. 1): 113–179.

23rd World Congress on Ultrasound in Obstetrics and Gynecology

Details

Fetal cardiac arrhythmias occur in 1 to 2% of pregnancies with supraventricular tachycardia (SVT) the second most common type. Two-dimensional ultrasound provides the best assessment of fetal arrhythmias, with the ability to evaluate the cardiac anatomy, cardiac function, and look for the presence of hydrops fetalis simultaneously. M-mode aids in the diagnosis. Unfortunately ultrasound assessment is limited to the time it is being performed and is not routinely used for longer surveillance of fetal heart rate. External fetal heart rate monitoring, with standard cardiotocography (CTG) is widely available, but is cumbersome to use for long periods of time and the ability to reliably trace rapid tachyarrhythmias is impaired. We describe two cases of SVT that resulted in significant fetal hydrops. The first case was typical and was diagnosed at 34 weeks. The second case was an atypical presentation at 21 weeks gestation. In each case, the tachyarrhythmia was initially refractory to standard maternal treatment of Flecainide 150mg twice a day. Serial ultrasounds, fetal echocardiography and external heart rate monitoring with standard CTG monitoring were employed.Monica AN24 monitoring (Monica Healthcare Ltd) was then used and enabled a prolonged assessment of fetal heart rate (often overnight) and captured runs of fetal SVT that other investigations, such as intermittent auscultation, CTG monitoring and ultrasound, had previously not detected. This explained the limited resolution of hydrops in these cases, despite the fact that the fetus was thought to be back in sinus rhythm. Maternal treatment was then titrated to the findings on the Monica AN24 trace with resulting sinus rhythm confirmed on prolonged tracing. Maternal side effects were minimal, and regular assessments of maternal ECG, serum electrolytes and drug levels, were undertaken. We propose that the use of the Monica AN24 monitor may help improve surveillance and treatment of fetal arrhythmias.

Intrapartum Fetal and Maternal Heart Rate Ambiguity- a Comparison of Doppler Ultrasound CTG and the Abdominal Fetal Electrocardiogram with Maternal Electrocardiogram

2013

Reinhard J, Hayes-Gill BR, Schiermeier S, Hatzmann W, Heinrich TM, Louwen F.

Gynecologic and Obstetric Investigation

2013; 75: 101-8

Details

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

METHODS: A total of 144 simultaneous CTG (Corometrics 250 series©), abdominal fetal ECG (Monica AN24TM) and maternal ECG (Monica AN24TM) recordings were evaluated.

MAIN OUTCOME MEASURES: When the FHR is within 5 bpm of the maternal heart rate (MHR) acquired from the ECG it is classified as “MHR/FHR ambiguity”. Statistical analyses were performed with the Fisher’s exact and the Wilcoxon signed rank tests.

RESULTS: Comparison of abdominal fetal ECG against CTG demonstrates significantly less “  MHR/FHR ambiguity” in both the first stage (mean 0.70% versus 1.22%, p<0.001) and 2nd stage of labour (mean 3.30% versus 6.20%, p<0.001).

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

Non-invasive Fetal ECG registration using Monica AN24 fetal monitoring system

2012

Department of Obstetrics, Leiden University Medical Center

W.J. Kist, R. Franken,  S.Vink, N.Blom, L. Rozendaal, D.Oepkes

Poster presesentation at the 16th International Conference on Prenatal Diagnosis Miami, Florida, USA

3-6 June 2012

 

Details

Background: Reliable non-invasive recording of the fetal electrocardiogram (fECG) has been pursued by obstetric researchers for decades. Many fetal pathologic conditions could be monitored more accurately if fECG could be obtained. The Monica AN 24, a new, portable fetal monitoring device can make 20 hour recordings of fetal and maternal cardiac electrical signals and uterine activity with 5 abdominal stickers.

Objective: Aim of our study was to evaluate the feasibility of obtaining interpretable fECG signals of human fetuses in the second and third trimester.

Material and methods: Prospective cohort study in uncomplicated singleton pregnancies.  Registrations of 30 minutes were made from 14 to 38 weeks’ gestation. Primary outcome was success rate of obtaining a fECG with recognizable P-wave, QRS complex and ST segment, analyzable with the DK 1.4a software. Secondary outcome was influence of BMI and gestational age.

Results: In total 178 registrations were made in 82 pregnancies. In 138 (78%), a fECG could be analyzed. From 14-22 weeks (n=57), success-rate was 86%.BMI did not influence success-rate.

Conclusion: With the Monica AN 24 andDK 1.4a software, we could record and analyze a fetal ECG in almost 80% of pregnancies in the second and third trimester.BMI played no role. This device has the potential to become an important additional tool in fetal diagnosis and monitoring of the many conditions that affect fetal cardiac function.

Is the fetal heart rate affected by uterine contractions during pregnancy? A pilot study

2012

Sletten. J, Kiserud. T, Kessler. J

Acta Obstet Gyn Scan, 2012. 91(Supplement s159): p. 59-149

Poster presented at the Nordic meeting of Obstetrics and Gynecology in June 2012

 

Details

Background;  New monitoring technology enables long-term recording of the fetal heart rate without discomfort for the mother. The initial aim of this pilot study was to test the feasibility and success rate of a new fetal Holter monitor. We observed linear correlations between maternal and fetal heart rates, and hypothesised that uterine activity during pregnancy affects the fetal heart rate.

Method: Twelve pregnant women were monitored with a potable Holter device, which (Monica AN24, Monica Healthcare Ltd), which recorded the maternal and fetal electrocardiogram (ECG) and electrohystergram (EHG) by five abdominal electrodes. The recordings were performed outside the hospital and participants were not imposed any restrictions for their activities during the time of the recording.  Data on the fetal and maternal heart rates and the strength of uterine contractions was available in 2 seconds epoch during the entire recording. The EHG data were categorised into a basal level, and slightly, moderately or severely increased uterine activity (UA). Each participant’s data was analysed separately.

Results: The recordings lasted 18.8 hours (range 17.4-19.3) and were taken at a gestational age of 32+6 weeks (range 25+0-38+2). Data on maternal and fetal ECG was available for 99.9% and 73.1% of the recorded time, respectively. There was a linear correlation between maternal and fetal heart rates in 11/12 cases. Beta coefficient was at mean 0.189; for participants < 36 weeks (N=7) 0.106 and for those ≥ 36 weeks (N=5) 0.305. In all participants UA affected the fetal heart rate. Compared to the basal tone, mild, moderate and severe UA were associated with a mean increase of the fetal heart rate by 1.37, 4.1 and 5.9 beats/min respectively

Conclusion: The relationship between fetal and maternal heart rates could reflect a circadian rhythmicity in the mother and the fetus. Uterine contractions during pregnancy, accompanied by increased umbilical blood flow, may represent a physiological challenge for the development and adaptation of the fetal cardiovascular system.   

Antenatal architecture and activity of the human heart

2013

Pervolaraki. E,  Anderson. R, Benson. A, Hayes-Gill. B, Holden. A,  Moore. B.J.R,  Paley. M.N,  Zhang. H

Published online February 21, 2013 doi: 10.1098/​rsfs.2012.0065Interface Focus 6 April 2013 vol. 3 no. 2 20120065

Details

Abstract: We construct the components for a family of computational models of the electrophysiology of the human foetal heart from 60 days gestational age (DGA) to full term. This requires both cell excitation models that reconstruct the myocyte action potentials, and datasets of cardiac geometry and architecture. Fast low-angle shot and diffusion tensor magnetic resonance imaging (DT-MRI) of foetal hearts provides cardiac geometry with voxel resolution of approximately 100 µm. DT-MRI measures the relative diffusion of protons and provides a measure of the average intravoxel myocyte orientation, and the orientation of any higher order orthotropic organization of the tissue. Such orthotropic organization in the adult mammalian heart has been identified with myocardial sheets and cleavage planes between them. During gestation, the architecture of the human ventricular wall changes from being irregular and isotropic at 100 DGA to an anisotropic and orthotropic architecture by 140 DGA, when it has the smooth, approximately 120° transmural change in myocyte orientation that is characteristic of the adult mammalian ventricle. The DT obtained from DT-MRI provides the conductivity tensor that determines the spread of potential within computational models of cardiac tissue electrophysiology. The foetal electrocardiogram (fECG) can be recorded from approximately 60 DGA, and RR, PR and QT intervals between the P, R, Q and T waves of the fECG can be extracted by averaging from approximately 90 DGA. The RR intervals provide a measure of the pacemaker rate, the QT intervals an index of ventricular action potential duration, and its rate-dependence, and so these intervals constrain and inform models of cell electrophysiology. The parameters of models of adult human sinostrial node and ventricular cells that are based on adult cell electrophysiology and tissue molecular mapping have been modified to construct preliminary models of foetal cell electrophysiology, which reproduce these intervals from fECG recordings. The PR and QR intervals provide an index of conduction times, and hence propagation velocities (approx. 1–10 cm s−1, increasing during gestation) and so inform models of tissue electrophysiology. Although the developing foetal heart is small and the cells are weakly coupled, it can support potentially lethal re-entrant arrhythmia

Fetal Electrocardiogram (fECG) Gated MRI

2013

Paley, M.  Morris, J.  Jarvis, D.  Griffiths, P.

Sensors

23 August 2013

Sensors 2013, 13, 11271-11279; doi:10.3390/s130911271

Details

Abstract:
We have developed a Magnetic Resonance Imaging (MRI)-compatible system to enable gating of a scanner to the heartbeat of a foetus for cardiac, umbilical cord flow and other possible imaging applications. We performed radiofrequency safety testing prior to a fetal electrocardiogram (fECG) gated imaging study in pregnant volunteers (n = 3). A compact monitoring device with advanced software capable of reliably detecting both the maternal electrocardiogram (mECG) and fECG simultaneously was modified by the manufacturer (Monica Healthcare, Nottingham, UK) to provide an external TTL trigger signal from the detected fECG which could be used to trigger a standard 1.5 T MR (GE Healthcare, Milwaukee, WI, USA) gating system with suitable attenuation. The MR scanner was tested by triggering rapidly during image acquisition at a typical fetal heart rate (123 beats per minute) using a simulated fECG waveform fed into the gating system. Gated MR images were also acquired from volunteers who were attending for a repeat fetal Central Nervous System (CNS) examination using an additional rapid cardiac imaging sequence triggered from the measured fECG. No adverse safety effects were encountered. This is the first time fECG gating has been used with MRI and opens up a range of new possibilities to study a developing foetus.

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

2013

Sänger.N,  Louwen.F,  Reinhard.J,  Yuan.J,  Hanker. L

Maternal-Fetal Medicine: Arch Gynecol Obstet (2013) 288:1017–1020Published online: 24 April 2013

Details

Abstract
Objective: 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.

Study design: 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.

Results: 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).

Conclusion: 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 AN24TM).

Uterine electromyography for identification of first-stage labor arrest in term nulliparous women with spontaneous onset of labor

2013

Vasak B, Graatsma EM, Hekman-Drost E, Eijkemans MJ, van Leeuwen JH, Visser GH, Jacod BC.

Am J Obstet Gynecol. 2013 Sep;209(3):232.e1-8. doi: 10.1016/j.ajog.2013.05.056. Epub 2013 May 30

Details

Abstract

OBJECTIVE: We sought to study whether uterine electromyography (EMG) can identify inefficient contractions leading to first-stage labor arrest followed by cesarean delivery in term nulliparous women with spontaneous onset of labor.

STUDY DESIGN: EMG was recorded during spontaneous labor in 119 nulliparous women with singleton term pregnancies in cephalic position. Electrical activity of the myometrium during contractions was characterized by its power density spectrum (PDS).

RESULTS: Mean PDS peak frequency in women undergoing cesarean delivery for first-stage labor arrest was significantly higher (0.55 Hz), than in women delivering vaginally without (0.49 Hz) or with (0.51 Hz) augmentation of labor (P = .001 and P = .01, respectively). Augmentation of labor increased the mean PDS frequency when comparing contractions before and after start of augmentation. This increase was only significant in women eventually delivering vaginally.

CONCLUSION: Contraction characteristics measured by uterine EMG correlate with progression of labor and are influenced by labor augmentation.

Intrapartum signal quality with external fetal heart rate monitoring: a two way trial of external Doppler CTG ultrasound and the abdominal fetal electrocardiogram

2012

Reinhard.R,  Hayes-Gill. BR,  Schiermeier.S, Hatzmann.W, Herrmann.E, Heinrich.T, Louwen.F

Maternal-Fetal Medicine

Arch Gynecol Obstet

Published online 20.06.2012

Details

Abstract

The objective of this study was to assess the fetal heart rate (FHR) signal quality of non-invasive abdominal fetal electrocardiogram (fECG) in comparison to the Doppler ultrasound cardiotocogram (CTG) during the first and second stage of labour.

Study design: This was a prospective observational study of non-invasive fECG using five abdominally sited electrodes against the traditional Doppler ultrasound CTG probe on 144 patients. Data were analysed for signal quality before and after outlier removal.

Results: Abdominal fECG signal quality was significantly better during the first stage of labour in comparison to Doppler CTG (median fECG reliability of 95.7 % vs.median 87.3 % for Doppler, p.001), whereas during second stage of labour, equivalence was demonstrated(p[0.05). For the first and second stage of labour, fECG showed 106/135 (78.5 %) and 46/98 (46.9 %) women having fetal signal loss below 20 %, respectively. Similarly, Doppler ultrasound demonstrated 104/135 (77.0 %) and 51/98 (52.0 %) women having fetal signal loss below 20 % during first and second stage of labour, respectively.

Conclusion: The non-invasive abdominal fECG presents an improved FHR signal quality during the first stage of labour and an equivalent signal quality during the second stage.

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

2012

N. Sänger, B. R. Hayes-Gill, S. Schiermeier,W. Hatzmann, J. Yuan, E. Herrmann, F. Louwen, J. Reinhard
Geburtsh Frauenheilk 2012; 72: 630–633

Details

Introduction: This study aimed to evaluate foetal signal quality obtained using an antenatal foetal ECG system (Monica 24™) and compare it with Doppler ultrasound CTG monitoring (Corometrics ® 250 series).

Material and Methods: Seventy pregnant women (gestational age: between 20 + 0 weeks and 40 + 0 weeks) were examined using the Monica AN24™ system and also underwent Doppler CTG. The signal quality of both methods was compared and correlated with gestational age and pre-pregnancy body mass index (BMI).

Results: Overall, ECG had a signal quality of 77.4% and CTG had a signal quality of 73.1% (p > 0.05). In gestational weeks (GW) 20–26, the signal quality of ECG was significantly better compared to that obtained with CTG (75.5 vs. 45.3%; p = 0.003), while in GW 27–36, the signal quality was better with CTG (72.3 vs. 83.0%, p = 0.001). No difference in signal quality was found between the two methods after the 37th GW (87.7 vs. 86.1%; p > 0.05). CTG showed a statistically significant correlation with BMI (rho 0.25, p < 0.05) while ECG showed no such correlation.
Conclusion: The use of non-invasive ECG is particularly indicated in the early weeks of pregnancy, while CTG offers superior results during the vernix period. There was no difference in signal quality after the vernix period. The signal quality with ECG was found to be independent of BMI, while the signal quality of CTG deteriorated with increasing BMI.

Accuracy and reliability of fetal heart rate monitoring using maternal abdominal surface electrodes

2012

Cohen W, Ommani S, Hassan S, Mirza F, Solomon M, Brown R, Schifin B, Himsworth J, Hayes-Gill B

 August 2012

Acta Obstetricia et Gynecologica Scandinavica

2012 Nordic Federation of Societies of Obstetrics and Gynecology

Details

Abstract

Objective. Compare the accuracy and reliability of fetal heart rate identification from maternal abdominal fetal electrocardiogram signals (ECG) and Doppler ultrasound with a fetal scalp electrode.  Design. Prospective open method equivalence study. Setting. Three urban teaching hospitals in the Northeast United States. Sample. 75 women with normal pregnancies in labor at >37 weeks of gestation. Methods. Three fetal heart rate detection methods were used simultaneously in 75 parturients. The fetal scalp electrode was the standard against which abdominal fetal ECG and ultrasound were judged. Main outcome measures. The positive percent agreement with the fetal scalp electrode indicated reliability. Bland–Altman analysis determined accuracy. The confusion rate indicated how frequently the devices tracked the maternal heart rate.  Results. Positive percent agreement was 81.7 and 73% for the abdominal fetal ECG and ultrasound, respectively (p = 0.002). The abdominal fetal ECG had a lower root mean square error than ultrasound (5.2 vs. 10.6 bpm, p < 0.001). The confusion rate for ultrasound was 20-fold higher than for abdominal ECG (8.9 vs. 0.4%, respectively, p < 0.001). Conclusion. Compared with the fetal scalp electrode, fetal heart rate detection using abdominal fetal ECG was more reliable and accurate than ultrasound, and abdominal fetal ECG was less likely than ultrasound to display the maternal heart rate in place of the fetal heart rate.

Average acceleration and deceleration capacity of the fetal heart rate in normal pregnancy and in pregnancies complicated by fetal growth restriction

2012

E. M. Graatsma, E.J.H. Mulder, B. Vasak, S.M. Lobmaier, S. Pildner von Steinburg, K.T.M Schneider, G. Schmidt, G.H.A. Visser

The Journal of Maternal –Fetal and Neonatal Medicine, 2012;25(12):2517-2522

Details

Objective: To study fetal heart rate (FHR), its short term variability (STV), average acceleration capacity (AAC), and average deceleration capacity (ADC) throughout uncomplicated gestation, and to perform a preliminary comparison of these FHR parameters between small-for-dates (SFD) and control fetuses.  Method: Prospective observational study of 7 h FHR-recordings obtained with a fetal-ECG monitor in the second half of uncomplicated pregnancies (n=90) and pregnancies complicated by fetal SFD (n=30).  FHR and STV were calculated according to established analysis. True beat-to-beat FHR, recorded at 1 ms accuracy, was used to calculate AAC and ADC using Phase Rectified Signal Averaging (PRSA). Mean values of FHR, STV, AAC, and ADC derived from recordings in SFD fetuses were compared with the reference curves. Results: Compared with the control group the mean z-scores for STV, AAC, and ADC in SFD fetuses were lower by 1.0 SD, 1.5 SD, and 1.7 SD, respectively (p<0.0001 for all comparisons). In SFD fetuses, both the AAC and ADC z-scores were lower than the STV z-scores (p<0.02 and p<0.002, respectively). Conclusion: Analysis of the AAC and ADC as recorded with a high resolution fECG recorder may differentiate better between normal and SFD fetuses than STV.

Accuracy and Reliability of Uterine Contraction Identification Using Abdominal Surface Electrodes

2012

Barrie Hayes-Gill, Sarmina Hassan, Fadi G. Mirza, Sophia Ommani, John Himsworth, Molham Solomon, Raymond Brown, Barry S. Schifrin and Wayne R. Cohen

Clinical Medicine Insights: Women’s Health 2012:5 65–75

Details

Abstract
Objective: To compare the accuracy and reliability of uterine contraction identification from maternal abdominal electrohysterogram and tocodynamometer with an intrauterine pressure transducer.
Methods: Seventy-four term parturients had uterine contractions monitored simultaneously with electrohysterography, tocodynamometry, and intrauterine pressure measurement.
Results: Electrohysterography was more reliable than tocodynamometry when compared to the intrauterine method (97.1 versus 60.9 positive percent agreement; P , 0.001). The root mean square error was lower for electrohysterography than tocodynamometry in the first stage (0.88 versus 1.22 contractions/10 minutes; P , 0.001), and equivalent to tocodynamometry in the second. The positive predictive values for tocodynamometry and electrohysterography (84.1% versus 78.7%) were not significantly different, nor were the false positive rates (21.3% versus 15.9%; P = 0.052). The sensitivity of electrohysterography was superior to that of tocodynamometry (86.0 versus 73.6%; P , 0.001).
Conclusion: The electrohysterographic technique was more reliable and similar in accuracy to tocodynamometry in detecting intrapartum uterine contractions.

Uterine Activity Monitoring during Labour – A Multi-Centre, Blinded Two-Way Trial of External Tocodynamometry against Electrohysterography

2011

J. Reinhard , B. R. Hayes-Gill , S. Schiermeier , H. Löser , L. M. Niedballa , E. Haarmann , A. Sonnwald ,
W. Hatzmann , T. M. Heinrich , F. Louwen

10.1055/s-0031-1291210 Z Geburtsh Neonatol 2011; 215: 199–204

Details

Purpose: The aim of this study was to determine the quality of intrapartum uterine activity (UA) monitoring in daily practice during the first and second stages of labour. The total duration of inadequate UA monitoring is quantified in relation to the technique applied, namely, external tocodynamometry (TOCO) or electrohysterography (EHG).

Material and Methods: 144 UA recordings, collected from deliveries at the Marien-Hospital Witten, Germany, were analysed by obstetricians based at different centres. The included recordings were from singleton and simultaneously with external TOCO and EHG monitored pregnancies. External TOCO and EHG UA recordings were blinded.

Results: The percentages of “ adequate ” UA recordings in the first and second stages of labour were much higher for the external EHG than the external TOCO mode (p < 0.001). All doctors evaluated the UA assessment as “ easier ” (p < 0.001) using the EHG compared with TOCO .

Conclusion: Intrapartum UA monitoring in daily practice via the EHG mode provides a more recognisable UA trace than the TOCO.

Read the full article on PubMed http://www.ncbi.nlm.nih.gov/pubmed/22028060

Home Labour Induction with Retrievable Prostaglandin Pessary and Continuous Telemetric Trans-Abdominal Fetal ECG Monitoring

2011

Zubair Rauf, Ediri O’Brien, Tamara Stampalija, Florin P. Ilioniu, Tina Lavender, Zarko Alfirevic

PLoS ONE 6(11): e28129. doi:10.1371/journal.pone.0028129

Details

Objective: To evaluate the feasibility of continuous telemetric trans-abdominal fetal electrocardiogram (a-fECG) in women undergoing labour induction at home.

Study Design: Low risk women with singleton term pregnancy undergoing labour induction with retrievable, slow-release dinoprostone pessaries (n = 70) were allowed home for up to 24 hours, while a-fECG and uterine activity were monitored in hospital via wireless technology. Semi-structured diaries were analysed using a combined descriptive and interpretive approach.

Results: 62/70 women (89%) had successful home monitoring; 8 women (11%) were recalled because of signal loss. Home monitoring lasted between 2–22 hours (median 10 hours). Good quality signal was achieved most of the time (86%, SD 10%). 3 women were recalled back to hospital for suspicious a-fECG. In 2 cases suspicious a-fECG persisted, requiring Caesarean section after recall to hospital. 48/51 women who returned the diary coped well (94%); 46/51 were satisfied with home monitoring (90%).

Conclusions: Continuous telemetric trans-abdominal fetal ECG monitoring of ambulatory women undergoing labour induction is feasible and acceptable to women.

Read the full article on PubMed http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0028129

Function organization of extracardial effects on the fetus cardiac rhythm and studies of their formation during the antenatal development

2011

Gudkov.GV, Pustovaya.JN, Turichenko.O,

Kuban state medical university, Krasnodar, Russia

19.12.2011

http://vestnik.kmldo.ru/archive/18/

Details

Results obtained allowed to recommend for using in obstetrics the new technologies for fetus cardiac rhythm variable till the moment of sonography visualization of systole (10-12 weeks). The EGK halter using allowed to perform the cardiotokographic studies in earlier gestation periods (from 20-23 weeks vs 28-30 weeks in routine CTG), to obtain the additional information about cardiac oxygenation by morphologic analysis of bioelectrical cardiac activity. The data obtained combined with literature data suggested that fetus cardiac monitoring in earlier gestation periods revealed the studies of physiological development of its adaptative-regulatory systems and to diagnose the feto-placentar disturbances.

Maternal and fetal heart rate confusion during labour

2010

Bhogal.K, Reinhard.J
British Journal of Midwifery. Vol 18, No, 7: 424-428. July 2010

Details

This article gives an overview of the pattern of the MHR during labour in continuous maternal and fetal heart rate monitoring using an abdominal maternal and fetal electrocardiograph monitor (abfECG) in contrast with more traditional Doppler methods.

The exploration of the pattern of the MHR during labour and delivery demonstrates how an incorrect assessment of fetal wellbeing could be made if the monitor was used in isolation and the MHR was being reported rather than the FHR.

This article also explores how midwives can minimise the risk of such incidents occurring.

Maternal Body Mass Index Does Not Affect Performance of Fetal Electrocardiography

2010

Graatsma EM, Miller J, Mulder EJ, Harman C, Baschat AA, Visser GH.

Am J Perinatol. 2010 Aug;27(7):573-7. Epub 2010 Mar 1.

Details

The obesity epidemic challenges traditional antenatal fetal heart rate (FHR) monitoring technologies. Doppler signals in particular are attenuated. We sought to evaluate whether the performance of a novel transabdominal fetal electrocardiogram (fECG) device (AN24, Monica Healthcare) is influenced by body mass index (BMI). We performed a prospective observational study of singleton pregnancies (gestational age [GA] 20 to 41 weeks) monitored overnight with fECG. Recording quality ([RQ] %) of both the best hour and the total recording time of the FHR record were related to BMI. Two hundred four women were monitored. BMI ranged from 16.0 to 50.7 (median BMI 26.9). The correlation coefficient (with 95% confidence interval [CI]) between BMI and RQ was -0.35 (CI -0.60; -0.03) for the gestational age group 20(+0) to 25(+6) weeks, -0.08 (CI -0.28; 0.13) for GA 26(+0) to 33(+6) weeks, and -0.20 (CI -0.40; 0.03) for GA group > or =34(+0) weeks. Median RQ in obese women (BMI > or =30 kg/m(2)) was 97.4, 98.9, and 100%, respectively. BMI has no clinically significant influence on recording quality of FHR monitored with fECG. It can therefore be considered a good method for monitoring the fetal condition in pregnancies of obese women
 

Comparison of non-invasive fetal electrocardiogram to Doppler cardiotocogram during the 1st stage of labor

2010

Reinhard. J,  Hayes-Gill. B, Yi. Q,  Hatzmann. H, Schiermeier. S

J. Perinat. Med. 38 (2010) 179–185
 

Details

Abstract

Objective: We compared a non-invasive fetal electrocardiogram (fECG) to Doppler cardiotocogram (CTG) during the 1st stage of labor. Study design: This was a prospective observational study of non-invasive fECG using five abdominal electrodes and one Doppler ultrasound probe in 27 patients. Data were analyzed for reliability, clinical and statistical equivalence. Results: The fECG was similar to the traditional Doppler method. The fECG characterizes a fetal heart rate (FHR) trace in a similar way with regards to acceleration count, decelerations count and coincidence, variability and baseline. The FHR was overall correlated (Pearson’s rs0.91). Conclusion:This non-invasive fECG presents an alternative, reliable and accurate assessment for fetal well-being during the 1st stage of labor.

A validation of electrohysterography for uterine activity monitoring during labour

2009

Benoit C.J, Gtaatsma E.M, Van Hagen E, Visser G.H
The Journal of Maternal-Fetal and Neonatal Medicine. 2009; 00(0): 1-6
Department of Obstetrics, University Medical Centre, Utrecht, The Netherlands

Details

Objective: Validation of electrohysterography (EHG) as a method for uterine activity monitoring during labour by comparing with intra-uterine pressure catheter (IUCP) recordings. Prospective observational study. Population of the study was thirty-two women in labour, simultaneous recording of uterine activity with EHG and IUCP for at least 30 min.

Results: EHG detects uterine contractions accurately.

Conclusion: EHG detects uterine contractions accurately during labour but the contraction’s characteristics it measures are directly comparable with that of IUCP.

Read the full article on PubMed http://www.ncbi.nlm.nih.gov/pubmed/19672790

Signal Quality of Non-Invasive Foetal Electrocardiogram (ECG) During Labour

2009

J. Reinhard1, B. R. Hayes-Gill2, Q. Yi3, H. Hatzmann1, S. Schiermeier1

1 Universität Witten/Herdecke, Akademisches Lehrkrankenhaus der Ruhr-Universität Bochum, Frauenheilkunde,
Marien-Hospital Witten
2 School of Electrical and Electronic Engineering, University of Nottingham, University Park, Nottingham,
NG7 2 RD, United Kingdom
3 Monica Healthcare Ltd, Biocity, Pennyfoot Street, Nottingham, NG1 1GF, United Kingdom

Geburtsh Frauenheilk 2009; 69: 1–5

Details

Introduction: During labour non-invasive foetal heart rate monitoring is a routine method for the assessment of foetal well-being. This study examines an alternative assessment by foetal ECG during labour.

Materials and Methods: 32 pregnant women admitted for delivery gave informed consent and were connected to the Monica AN24™. Foetal and maternal ECG signals, noise and patient satisfaction were evaluated during the 1st and 2nd stages of labour.

Results: The median gestational age was 40 weeks (range 34–42). The women had a median BMI of 28.4 (range 24.0–49.5) and the medianbirth weight was 3400 g (range 1915–4470 g). The median total recording time was five hours and 18 minutes (range 38 minutes – 74 hours and 6 minutes). There was a statistical increase of noise from the beginning of the 1st stage of labour to the end of 1st stage of labour (p = 0.03) and until the end of the 2nd stage (p = 0.025). However, foetal and maternal ECG signal quality remained constant throughout labour. No correlation was identified between foetal and maternal ECG, noise and BMI as well as foetal birth weight.

Conclusion: The results show that foetal and maternal ECG signal stays constant throughout labour. Even though noise significantly increases throughout labour, especially during the crowning phase, the foetal and maternal ECG signal can still be differentiated.

Obesity in Obstetrics, New Challenges and Solutions Using Abdominal Fetal ECG

2008

Karnie Bhogal RM RGN, Clinical Specialist Monica Healthcare, Dr. Indu Asanka Jayawardane, Research Fellow Nottingham City Hospital

Midwives

Journal of the Royal College of Midwives

Dec 2008/Jan 2009

Details

Abstract
Obesity is now an important health problem and pregnancy coupled with obesity can result in the pregnancy being classified as high risk. Careful and close monitoring is therefore necessary. This article highlights some of the problems with Doppler ultrasound (CTG), in monitoring obese mothers, and how by using the technology of abdominal fetal ECG monitoring the quality of care in relation to fetal heart rate monitoring to this cohort can be improved. A study of 120 pregnancies, ranging from a body mass index (BMI) of 18 – 44, showed that obesity did not affect the success rate of the fetal heart rate (FHR) data.

Keywords: Obesity; Pregnancy; Doppler Ultrasound; Fetal Electrocardiogram (Fetal ECG); Long-term Monitoring.
Obesity is emerging as an important global health problem. Obese pregnant women are at high risk throughout the antenatal, intrapartum and postpartum period. Confidential Enquiries into Maternal and Child Health (CEMACH) Perinatal Mortality 2006 Report reveals that ‘of the women who had a stillbirth and a recorded BMI, 26% were obese (BMI >30).’ Obesity in pregnancy has been selected as CEMACH’s principle project with a maternal health focus for 2008-2011. There is currently no national clinical guideline available in the UK with regard to clinical care in obesity in pregnancy.

Read the full article on PubMed http://www.rcm.org.uk/magazines/web-only-papers/obesity-on-obstetrics-new-challenges-and-solutions-using-abdominal-fetal-ecg/

Fetal electrocardiography: feasibility of long-term fetal heart rate recording

2008

Graatsma E, Jacod B, van Egmond L, Mulder E, Visser G. Fetal electrocardiography: feasibility of long-term fetal heart rate recordings. BJOG 2009;116:334–338.

Department of Perinatology and Gynaecology, University Medical Center Utrecht, Utrecht, the Netherlands

Details

The feasibility and accuracy of long-term transabdominal fetal electrocardiogram (fECG) recordings throughout pregnancy were studied using a portable fECG monitor. Fifteen-hour recordings of fetal heart rate (FHR) were performed in 150 pregnant women at 20–40 weeks of gestation and 1-hour recordings were performed in 22 women in labour and compared with simultaneous scalp electrode recordings. When ‡60% of fECG signals was present, the recording was defined as good. Eighty-two percent (123/150) of antenatal recordings were of good quality. This percentage increased to 90.7 (136/150 recordings) when only the night part (11 p.m.–7 a.m.) was considered. Transabdominal measurement of FHR and its variability correlated well with scalp electrode recordings (r = 0.99, P < 0.01; r = 0.79, P < 0.01, respectively). We demonstrated the feasibility and accuracy of long-term
transabdominal fECG monitoring.

Read the full article on PubMed http://www.ncbi.nlm.nih.gov/pubmed/19076966

CONTINUOUS SIMULTANEOUS MATERNAL GLUCOSE AND FETAL HEART RATE MONITORING IN DIABETIC PREGNANCY

2008

4th International Symposium on Diabetes and Pregnancy
Hilton Istanbul Hotel March 29th – 31st Istanbul Turkey

E.M. Graatsma 1, E.J. Mulder 1, H.W. de Valk 2, G.H. Visser 1
1 Department Of Perinatology & Gynaecology; 
2 Department Of Internal Medicine, University Medical Center Utrecht The Netherlands

Details

Antenatal fetal heart rate (FHR) monitoring is usually restricted to relatively short-lasting periods, often one hour at a maximum. In women with diabetes glucose values vary largely over the day (1). Fetal compromise is likely to occur in case of maternal hyperglycaemia (and fetal hyperglycaemia) leading to fetal lactate accumulation. It is therefore of importance to monitor these fetuses especially during such episodes, to assess the capability of the fetus to cope with such situations. This requires prolonged FHR recordings and frequent glucose measurements.

Recently, a novel non-invasive technique for continuous FHR monitoring has been developed based on the electric fetal heart signal (fECG) as obtained from electrodes placed on the maternal abdomen. With this method (Monica Healthcare) prolonged recordings (8-15 hours) can be made, that are of good quality especially during the night. 
Thus, combined assessment of maternal glucose using the continuous glucose monitoring system (CGMS) and numerical analysis of FHR traces obtained with the fECG-monitor gives the opportunity to study the effect of varying maternal glucose levels on FHR.

Here we present preliminary data of continuous simultaneous measurements of maternal glucose and fetal heart rate, testing the hypothesis that FHR is related to maternal glucose levels. If further studies prove that the fECG-monitor is of additional value, a novel tool can be added to the arsenal of monitoring possibilities in pregnant women with diabetes.

(1) Kerssen A, de Valk HW, Visser GHA. Day-to-day glucose variability during pregnancy in women with type1 diabetes mellitus BJOG 2004;111:919-924.

Fetal supraventricular tachycardia: a new approach to surveillance and treatment

2013

Edwards. L, Cluver . CA,  Fung. A,  Walker. SP,  Wilson. D

Ultrasound in Obstetrics & Gynecology 2013; 42 (Suppl. 1): 113–179.

23rd World Congress on Ultrasound in Obstetrics and Gynecology

Details

Fetal cardiac arrhythmias occur in 1 to 2% of pregnancies with supraventricular tachycardia (SVT) the second most common type. Two-dimensional ultrasound provides the best assessment of fetal arrhythmias, with the ability to evaluate the cardiac anatomy, cardiac function, and look for the presence of hydrops fetalis simultaneously. M-mode aids in the diagnosis. Unfortunately ultrasound assessment is limited to the time it is being performed and is not routinely used for longer surveillance of fetal heart rate. External fetal heart rate monitoring, with standard cardiotocography (CTG) is widely available, but is cumbersome to use for long periods of time and the ability to reliably trace rapid tachyarrhythmias is impaired. We describe two cases of SVT that resulted in significant fetal hydrops. The first case was typical and was diagnosed at 34 weeks. The second case was an atypical presentation at 21 weeks gestation. In each case, the tachyarrhythmia was initially refractory to standard maternal treatment of Flecainide 150mg twice a day. Serial ultrasounds, fetal echocardiography and external heart rate monitoring with standard CTG monitoring were employed.Monica AN24 monitoring (Monica Healthcare Ltd) was then used and enabled a prolonged assessment of fetal heart rate (often overnight) and captured runs of fetal SVT that other investigations, such as intermittent auscultation, CTG monitoring and ultrasound, had previously not detected. This explained the limited resolution of hydrops in these cases, despite the fact that the fetus was thought to be back in sinus rhythm. Maternal treatment was then titrated to the findings on the Monica AN24 trace with resulting sinus rhythm confirmed on prolonged tracing. Maternal side effects were minimal, and regular assessments of maternal ECG, serum electrolytes and drug levels, were undertaken. We propose that the use of the Monica AN24 monitor may help improve surveillance and treatment of fetal arrhythmias.

Non-invasive Fetal ECG registration using Monica AN24 fetal monitoring system

2012

Department of Obstetrics, Leiden University Medical Center

W.J. Kist, R. Franken,  S.Vink, N.Blom, L. Rozendaal, D.Oepkes

Poster presesentation at the

16th International Conference on Prenatal Diagnosis 

Miami, Florida, USA

3-6 June 2012

Details

Background: Reliable non-invasive recording of the fetal electrocardiogram (fECG) has been pursued by obstetric researchers for decades. Many fetal pathologic conditions could be monitored more accurately if fECG could be obtained. The Monica AN 24, a new, portable fetal monitoring device can make 20 hour recordings of fetal and maternal cardiac electrical signals and uterine activity with 5 abdominal stickers.

Objective: Aim of our study was to evaluate the feasibility of obtaining interpretable fECG signals of human fetuses in the second and third trimester.

Material and methods: Prospective cohort study in uncomplicated singleton pregnancies.  Registrations of 30 minutes were made from 14 to 38 weeks’ gestation. Primary outcome was success rate of obtaining a fECG with recognizable P-wave, QRS complex and ST segment, analyzable with the DK 1.4a software. Secondary outcome was influence of BMI and gestational age.

Results: In total 178 registrations were made in 82 pregnancies. In 138 (78%), a fECG could be analyzed. From 14-22 weeks (n=57), success-rate was 86%.BMI did not influence success-rate.

Conclusion: With the Monica AN 24 andDK 1.4a software, we could record and analyze a fetal ECG in almost 80% of pregnancies in the second and third trimester.BMI played no role. This device has the potential to become an important additional tool in fetal diagnosis and monitoring of the many conditions that affect fetal cardiac function.

Is the fetal heart rate affected by uterine contractions during pregnancy? A pilot study

2012

Sletten. J, Kiserud. T, Kessler. J

Acta Obstet Gyn Scan, 2012.91(Supplement s159): p. 59-149

Poster presented at the Nordic meeting of Obstetrics and Gynecology in June 2012

Details

Background;  New monitoring technology enables long-term recording of the fetal heart rate without discomfort for the mother. The initial aim of this pilot study was to test the feasibility and success rate of a new fetal Holter monitor. We observed linear correlations between maternal and fetal heart rates, and hypothesised that uterine activity during pregnancy affects the fetal heart rate.

Method: Twelve pregnant women were monitored with a potable Holter device, which (Monica AN24, Monica Healthcare Ltd), which recorded the maternal and fetal electrocardiogram (ECG) and electrohystergram (EHG) by five abdominal electrodes. The recordings were performed outside the hospital and participants were not imposed any restrictions for their activities during the time of the recording.  Data on the fetal and maternal heart rates and the strength of uterine contractions was available in 2 seconds epoch during the entire recording. The EHG data were categorised into a basal level, and slightly, moderately or severely increased uterine activity (UA). Each participant’s data was analysed separately.

Results: The recordings lasted 18.8 hours (range 17.4-19.3) and were taken at a gestational age of 32+6 weeks (range 25+0-38+2). Data on maternal and fetal ECG was available for 99.9% and 73.1% of the recorded time, respectively. There was a linear correlation between maternal and fetal heart rates in 11/12 cases. Beta coefficient was at mean 0.189; for participants < 36 weeks (N=7) 0.106 and for those ≥ 36 weeks (N=5) 0.305. In all participants UA affected the fetal heart rate. Compared to the basal tone, mild, moderate and severe UA were associated with a mean increase of the fetal heart rate by 1.37, 4.1 and 5.9 beats/min respectively

Conclusion: The relationship between fetal and maternal heart rates could reflect a circadian rhythmicity in the mother and the fetus. Uterine contractions during pregnancy, accompanied by increased umbilical blood flow, may represent a physiological challenge for the development and adaptation of the fetal cardiovascular system.

Continuous Remote Fetal Monitoring With MONICA AN24

2011

Rauf. Z, O’ Brien. E, Popescu.F, Stampalija. T, Lavender. T, Alfirevic. Z

Paper presented at the Meeting of Society for Maternal-Fetal Medicine (SMFM) California USA

The 31st Annual Meeting February 2011

Details

Aim: To evaluate the feasibility of trans-abdominal ECG (aECG) monitoring with portable device (Monica AN24) during outpatient labor induction.

Methods: Low risk post term women induced with slow release dinoprostone pessaries (10mg) were allowed home for up to 24 hours, whilst aECG, uterine activity and maternal heart rate were continuously monitored. aECG signal was transmitted from a portable device to a hospital PC via ordinary mobile phone (Bluetooth) using Trium CTG Online. aECG traces were displayed in real time on a hospital PC and intermittently reviewed by hospital staff. Women were asked to complete diaries and a subgroup was invited for face to face interview.

Results: 70 recruited women went home during the induction. 17 (24%) woman stayed at home for >5 hours, 19 (27%) between 5-10, and 34 (49%) women for >10 hours. 52 (74%) women returned with ruptured membranes, spontaneous labor, fallen pessary. 8 (11%) were recalled for signal loss, 3 (4%) with non- reassuring trace and 7 (10%) electively after 24 hours. 55 (79%) women had a vaginal delivery.

51 diaries were returned. Participants preference showed that, during labour induction, women would rather be at home (92%) than in hospital (94%); they were very comfortable wearing the device (90%) and were very satisfied with outpatient monitoring (90%).

Conclusion: Continuous aECG monitoring of ambulatory women undergoing induction of labor at home is feasible and acceptable to women. The quality of remote signal was of sufficient quality to allow clinical decision making in real time.

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

2011

Stampalija. T, Eleuteri. A, Signaroldi. M, Mastroianni. C, Fisher. A, Ferrazzi. E, Alfirevic. Z

Paper presented at the Meeting of Society for Maternal-Fetal Medicine (SMFM) California USA

The 31st Annual Meeting February 2011

Details

Obective: To evaluate fetal heart rate, obtained by trans-abdominal ECG R-R intervals, by power spectral density (PSD), and compare normal values with findings obtained in acidemic fetuses.

Methods: Trans-abdominal fetal ECG with Monica AN24 device was performed in labour in uncomplicated term pregnancies. Thirty-six 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 5 minutes 10-10). Comparative analysis was performed with two cases with adverse outcome (pH< 7.0, BE> 12, Apgar at 5 minute ≤ 7). Thirty minutes records were used for each patient. Due to non-uniformity sampled data a Lomb-Scargle peridogram was used to estimate the power spectral density at ultra-low (0.00083-0.003 Hz), very-low (0.003-0.04 Hz), low (0.04-0.15 Hz), high (0.15-0.4 Hz) and very-high frequencies (0.4-0.92 Hz).

Results; 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 outliner. The two fetuses with an abnormal hypoxic outcome did not show any difference in power analysis values since their findings fitted within the interquartile range of normal cases.

Conclusion: This is the first reported analysis in non-uniformly sampled data by means of Lomb-Scargle periodgram.

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 stage of labour. This findings suggests that possible change of the autonomous nervous system balance may not present early in labour in cases where intra-partum asphyxia confirmed at birth develops progressively during the labour.

Fetal and maternal heart rate confusion during intra-partum monitoring: comparison of trans-abdominal fetal ECG and Doppler telemetry

2011

Stampalija. T, SignaroldI. M, Mastroianni. C, Rosti. E, Loi.G, Ferrazzi. E

Paper presented at the Meeting of Society for Maternal-Fetal Medicine (SMFM) California USA

The 31st Annual Meeting February 2011

Details

Objective: to compare the FHR performance and FHR /MHR confusion of non invasive trans-abdominal fetal ECG (tafECG)) with standard Doppler telemetry during labour.

Study design: Patients with uneventful term pregnancies were simultaneously monitored during labour with ta-fECG (Monica AN24) and leadless Doppler system (Phililps Avalon CTS). The FHR and MHR ¼ sec data values from both systems were logged digitally. The overall success rate (SR) and FHR/MHR confusion rate (CR) were evaluated. While none of the above systems represent the gold standard, FHR/MHR confusion was considered to have occurred when the FHR value was within 5 beats of the MHR value.

Results: 41 patients were recruited. Two cases were excluded when no fetal ECG signal was obtained by Monica AN24 due to high electrical noise. The analysis was performed on 39 patients. Overall (1st and 2nd stage) SR in labour for ta-fECG was 83% and 89% for Doppler leadless system.

Conclusion: ta-fECG monitoring in labour is feasible and represents more comfortable solution for the patient. Although, in our cohort, the overall SR from leadless Doppler system is better, the confusion of FHR/MHR is significantly higher in comparison with Ta-fECG, especially in II stage. By displaying simultaneously FHR and MHR traces, trans-abdominal ECG system allows instant recognition of possible FHR/MHR confusion that could otherwise cause hesitation or inappropriate obstetrical intervention.

Intrapartum External Fetal Monitoring in Obese Women

2011

Rauf.  Z,  Ommani. S,  Payne. B,  Brown. R,  Hassan. S,  Hayes-Gill. B R,  Cohen. W,  Alfirevic. Z

Paper presented at cThe Perinatal Medicine 2011 15-17 June 2011

Harrogate International Centre, UK

Details

Objectives:  To evaluate the success of intrapartum external fetal monitoring in obese women.

Methods: Group 1 ( Liverpool Women’s Hospital): A retrospective analysis of data for 400 labouring women with singleton pregnancies at ≥37+0 weeks gestation, stratified into four BMI groups (<30, 30-34.9, 35-39.9; ≥40). For each group we calculated the rate of suboptimal CTG recordings defined as the need for fetal scalp electrode (FSE).

Group 2 (Temple University Hospital Pennsylvania & Queens University Hospital New York)

19 obese women simultaneously monitored in labour with Doppler ultrasound (conventional external CTG), FSE (internal CTG-FSE) and wireless external abdominal fetal (aECG) monitoring device (MONICA AN24).

Reliability was assessed with Positive Percent Agreement defined as the percentage of the time when external fetal monitoring (aECG or CTG) gave an interpretable trace within 10% of the value reported by FSE.

Results: Conventional external CTG monitoring in women with high BMI was associated with high percentage of labours requiring FSE monitoring (2% for BMI<30, 23% for BMI 30-34.9; 32% for BMI 35-39.9; and 45% for BMI>40).

When FSE recordings from 19 labouring women with BMI >35 were compared with simultaneously obtained aECG and external CTG recordings, the Positive Percent Agreement was 88.4% for aECG and 68.7% for the CTG.

Conclusion: The external ECG monitoring with Monica AN24 may provide a useful alternative to Doppler CTG for women with high BMI.

Fetal Heart Rate Variability in Obstetric Cholestasis

2009

Jayawardane, DBIA. Hayes–Gill, BR. Loughna, PV. Broughton Pipkin,F.

Paper presented at Fetal and Neonatal Physiological Society, USA

36th Annual Meeting September 2009

Details

Introduction: Unexpected intrauterine fetal death in late gestation has been repeatedly reported in women with OC. This could be a consequence of altered cardiac conduction, presumably induced by increased bile acid concentration (BAC).

Methods: FHR was derived from the RR interval. The trans-abdominal fetal e.c.g. was acquired over ~12h using a Monica AN24 FHR monitor. The short term variability (STV) was calculated according to Dawes and Redman based on the 3.75second FHR averages. The root mean square of successive difference (RMSSD), a measure of true beat-to-beat variability, was also calculated. Data are summarised as mean ± s.d. or median [IQR].

Results and Discussion: Technically-satisfactory recordings of the fetal e.c.g. were obtained from 17 women with OC (pruritus with serum BAC >14μmol/L or ALT >100U/L) and 17 women with uncomplicated pregnancies (NP).
We believe this to be the first time that a link has been observed between raised BAC and an alteration in an index of fetal vagal cardiac control, the RMSSD. The ability to record the beat-to-beat fetal e.c.g. transabdominally with the very small Monica AN24 monitor has allowed us to record for up to 16 hours overnight, with minimal maternal inconvenience.

Comment: This will facilitate the identification of subtle changes in FHR variability and could reduce or abolish the need for alternate day use of antenatal cardiotocography in women with OC.

Extraction and Analysis of Fetal ECG by transabdominal recording using Monica AN24

2009

Stampalja T, Elevnen A, Fisher A, Dewhurst C, Alfirevic Z.

Hospital and University of Liverpool, UK

Presented at the 13th Annual BMFMS Conference 2009, Liverpool, UK

Details

Objective: To introduce a novel robust measure of fetal heart rate variability and report an initial longitudinal series of 19 healthy fetuses

Results: in 17 out of 19 cases, HRV power remained constant over a period of 2 hours. In two cases, there was a significant upward trend.

Conclusion: We have demonstrated that fetal HRV power can be estimated non-invasively from the transabdominal fECG. The changes in HRV power potentially provide a sophisticated method of assessing fetal condition before and during labour

Non-Invasive Transabdominal Monitoring of FECG and Uterine Contractions in Second Half of Gestation

2008

M. Graatsma, E. Mulder, L. van Egmond, G. Visser
University Medical Center Utrecht, Perinatology & Gynaecology, Utrecht, Netherlands

Abstract 90

THE JOURNAL OF MATERNAL-FETAL & NEONATAL MEDICINE
VOLUME 21 SUPPLEMENT 1 SEPTEMBER 2008
BOOK OF ABSTRACTS XXI European Congress of Perinatal Medicine
Istanbul, Turkey September 10–13, 2008

Details

Electrical activity as present over the pregnant abdomen can be used to record maternal and fetal electrocardiograms (ECG), as well as the electrohysterogram. The signals, recorded noninvasively by five electrodes, can provide prognostic information on the fetal condition and uterine activity from early pregnancy until term. Reliability and accuracy was confirmed in 25 women in early labour by recording fetal heart rate (FHR) and uterine contractions measured by the AN24 monitor (Monica Healthcare, Nottingham, UK) and compared it to simultaneously recorded data from the scalp electrode and intrauterine pressure catheter.

After validity assessment proved to be successful, we performed another 150 overnight recordings (5pm–8am) in women with singleton pregnancies at 20–40 weeks gestation. 80/150 women with uncomplicated pregnancies used the monitor in their home environment, while the remaining 70/150 recordings concerned at risk pregnancies (hypertensive disorders, growth restriction, diabetes) and were performed either at home or in hospital. Quality assessment of the FHR recordings showed that signal quality was optimal when the recording was performed overnight (11pm–7am). Signal quality was (non-significantly) influenced by gestational age with a slight decline between 26–32 weeks, and was not influenced by body mass index (mean 26.9, range 16.0–43.8).
In conclusion, the validity assessment has proven the accuracy and feasibility of this proposed method throughout the second half of (patho) physiological pregnancy. We now report our first data on the development of diurnal rhythms of FHR in healthy controls and that in growth restricted fetuses (n¼20) and fetuses of women with diabetes (n¼20).

Visit Blackwell Synergy http://www.blackwell-synergy.com/

Feasibility of Noninvasive Fetal Electrocardiographic Monitoring in a Clinical Setting

2015

Arya. B, Govindan. R, Krishnan. A, Duplessis. A, Donofrio. MT

Pediatr Cardiol. 2015 Jun; 36(5):1042-9. Epub 2015 Jan 22.

Details

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.

Thus, combined assessment of maternal glucose using the continuous glucose monitoring system (CGMS) and numerical analysis of FHR traces obtained with the fECG-monitor gives the opportunity to study the effect of varying maternal glucose levels on FHR.

Here we present preliminary data of continuous simultaneous measurements of maternal glucose and fetal heart rate, testing the hypothesis that FHR is related to maternal glucose levels. If further studies prove that the fECG-monitor is of additional value, a novel tool can be added to the arsenal of monitoring possibilities in pregnant women with diabetes.

(1) Kerssen A, de Valk HW, Visser GHA. Day-to-day glucose variability during pregnancy in women with type1 diabetes mellitus BJOG 2004;111:919-924.

Foetal electrocardiogram (EKG) is an alternative to Doppler ultrasound cardiotocogram (CTG) for antenatal assessment of foetal well-being – preliminary results

2008

J.Reinhard, H. Hatzmann, S. Schiermeier
Frauenklinik der Universität Witten/Herdecke, Marien-Hospital, 58452 Witten

Zeitschrift für Geburtshilfe und Neonatologie (Z Geburtsh Neonatol) (In Press)

Details

Abstract - English

Introduction
Computer analysing software is required for assessment of CTGs, because of the low sensitivity and high intra- and interobserver variability. The German Society of Gynaecology and Obstetrics advices using computer analysing CTG software. This study is aimed at evaluating the use of a new foetal EKG analysis system as an alternative to the traditional Doppler ultrasound CTGs in the setting of a university labour suite.
Materials and Methods
10 pregnant women after 32nd weeks’ gestation, who were admitted to hospital and gave informed consent to this study, were connected to the foetal EKG monitor system Monica AN24TM. Patient satisfaction, maternal and foetal EKG detection rates and time required to connect the patient were evaluated.
Results
8 out of 10 women would prefer the Monica AN24TM monitor system than the traditional Doppler ultrasound CTG. In total mean foetal EKG detection rate was 62.3% (SD ± 30.4) during the recorded time interval; at rest detection rate was 75.3% (SD ± 33.2); during night time (23:00 to 07:00) detection rate was 78.3% (SD ± 25.4); during night time and at rest detection rate was 82.2% (SD ± 24.3). Mean recorded time interval was 6 hours and 54 minutes (SD ± 2 hours and 43 minutes). In total maternal EKG detection rate was at 99.7% (SD ± 0.4). Mean time required applying the Monica AN24TM monitor system was 3.2 minutes (SD ± 0.6).
Conclusion
Foetal EKG monitor system may be a good alternative to Doppler ultrasound CTGs. With perspective to analyse beat to beat of foetal EKG heart rates this new monitor system should be superior to Doppler ultrasound CTGs, however further larger studies are needed to confirm this hypothesis.
Key words: Foetal electrocardiogram (EKG), Doppler ultrasound cardiotocogram (CTG), antenatal assessment

Abstract - German

Einleitung
Wegen der niedrigen Spezifität des CTGs und der hohen Intra- und Interobservervariabilität wird der Einsatz additiver Überwachungsmethoden gefordert. Die computergestützte CTG-Analyse wird in den Leitlinien der DGGG empfohlen. In dieser Studie soll die Alternative einer antepartualen fetalen EKG Überwachung in einer geburtshilflichen Abteilung geprüft werden.
Material und Methode
Bei 10 Schwangeren die aus unterschiedlichen Gründen vor der Geburt(nach der 32. SSW), stationär aufgenommen wurden und nach entsprechender Aufklärung der Studie zustimmten, wurde das Monica AN24TM-Überwachungssystem angeschlossen. Patientenzufriedenheit, fetale EKG Detektion und Anlegezeit des AN24 TM wurden ausgewertet.
Ergebnisse
8 von 10 Schwangeren präferierten das neue AN24® im Vergleich zum CTG. Die fetale EKG-Überwachungsfrequenz war im Durchschnitt in 62,3% (SD ± 30,40) der Überwachungszeit möglich, in Ruhe 75,3% (SD ± 33,2), während der Nacht (23:00 bis 07:00) in 78,3% (SD ± 25,4), sowie bei Ruhe nachts in 82,2% (SD ± 24,3). Die Durchschnittszeit der fetalen Ableitung lag bei 6 Stunden und 54 Minuten (SD ± 2 Stunden und 43 Minuten). Insgesamt betrug die mütterliche EKG-Detektionsrate 99,7% (SD ± 0,40). Die Anlegezeit der Elektroden und des Monica AN24TM Systems betrug im Durchschnitt 3,2 Minuten (SD ± 0,6).
Schlussfolgerung
Die fetale EKG-Überwachung kann in der modernen Schwangerenüberwachung eine Alternative zum CTG sein. Das fetale EKG ist durch die Möglichkeit einer Analyse einer Schlag-zu-Schlag-Variabilität des fetalen Herzschlags dem Doppler CTG überlegen. Vor allem auch intrapartual und bei besonderen Fragestellungen sind weitere Studien zur Effektivität des Verfahrens erforderlich.
Schlüsselwörter: fetales Elektrokardiogramm (EKG), Doppler-Kardiotokografie (CTG), antepartualen Überwachung

Read the full article http://www.reference-global.com/doi/pdfplus/10.1515/JPME.2009.635

Non-invasive detection of significant uterine activity

2008

American Journal of Obstetrics and Gynecology, Volume 199, Issue 6, Pages S225-S225

J. Miller, K. Ty-Torredes, M. Schindel, C. Harman, A. Baschat

Details


OBJECTIVE: Intrapartum monitoring of uterine contractions with an intrauterine pressure catheter (IUPC) invasively provides direct evidence of contraction frequency and strength but is neither without risk nor available for all patients. We sought to determine if uterine electromyography (EMG) using the AN24 (Monica Healthcare, Nottingham, UK) reliably detects contractions.

STUDY DESIGN: Prospective observational study of laboring patients monitored with an IUPC and the AN24 simultaneously. Only good quality IUPC contractions with clear baseline and contour were used for comparison.
Contractions were matched between the two devices and measurements were taken in mmHg or mV as indicated at 5 points-baseline at beginning and end, peak, and midway along the upstroke and downstroke. Peak contraction values were correlated and a ROC curve was constructed.

RESULTS: 297 IUPC contractions were measured in 17 patients (range 5-20, median 20). The AN24 detected an additional 5 contractions not documented by the IUPC. Overall correlation between mmHg and mV was Pearson 0.644, p<0.0001 and the relationship between the two was best expressed by a 3rd order polynomial regression graph (F=628.170, r 0.455). The polynomial fit was due to differences in the correlation at different contraction strengths: <50 mmHg (Pearson 0.531, linear fit F=396.829, r2 0.282, all p<0.0001) and >50 mmHg (Pearson 0.333, linear fit F=61.784, r2 0.111, all p<0.0001).

Using a cutoff of 99.0 mV, contraction intensity in excess of Braxton-Hicks contractions are detected with 70.5% sensitivity and 74.5% specificity (ROC AUC 0.826 95%CI 0.806-0.857, p<0.0001).

CONCLUSION: The AN24 is a non-invasive monitor with the capability to distinguish meaningful contractions from Braxton-Hicks.

Read the full article http://www.ajog.org/article/S0002-9378(08)01957-1/abstract

AN24 has the capability to distinguish meaningful contractions from Braxton-Hicks

2007

Volume 197, Issue 6, Supplement 1, December 2007, Page S181
ELISABETH M. GRAATSMA, EDUARD J.H. MULDER, GERARD H A VISSER,

University Medical Center, Utrecht, Netherlands
 

Details

OBJECTIVE: Non-invasive fetal heart rate (FHR) monitoring using the fetal-ECG signal as obtained from the maternal abdomen has the advantage of obtaining prolonged recordings, when compared to FHR monitoring using ultrasound.

RESULTS: When total recording time was considered, 103/120 (86%) recordings were of good quality. This percentage increased to 92% (111/120 recordings) when only the night part (11pm-7am) was considered. Lower recording quality was obtained at 26-28 weeks (73%).

CONCLUSION: We demonstrated the feasibility of a renewed fetal monitoring technique. Recording quality was optimal during the 8-hours overnight recording. In the future, continuous FHR monitoring with the non-invasive fECG monitor can be of additional value in high-risk pregnancies. Recordings can be performed in both the clinical and home environment.

Read the full article http://linkinghub.elsevier.com/retrieve/pii/S0002937807018625

4th International Symposium on Diabetes and Pregnancy

2008

Hilton Istanbul Hotel March 29th – 31st Istanbul Turkey
CONTINUOUS SIMULTANEOUS MATERNAL GLUCOSE AND FETAL HEART RATE MONITORING IN DIABETIC PREGNANCY
E.M. Graatsma 1, E.J. Mulder 1, H.W. de Valk 2, G.H. Visser 1
1 Department Of Perinatology & Gynaecology;
2 Department Of Internal Medicine, University Medical Center Utrecht The Netherlands;

Details

Antenatal fetal heart rate (FHR) monitoring is usually restricted to relatively short-lasting periods, often one hour at a maximum. In women with diabetes glucose values vary largely over the day (1). Fetal compromise is likely to occur in case of maternal hyperglycaemia (and fetal hyperglycaemia) leading to fetal lactate accumulation. It is therefore of importance to monitor these fetuses especially during such episodes, to assess the capability of the fetus to cope with such situations. This requires prolonged FHR recordings and frequent glucose measurements.

Recently, a novel non-invasive technique for continuous FHR monitoring has been developed based on the electric fetal heart signal (fECG) as obtained from electrodes placed on the maternal abdomen. With this method (Monica Healthcare) prolonged recordings (8-15 hours) can be made, that are of good quality especially during the night.

Thus, combined assessment of maternal glucose using the continuous glucose monitoring system (CGMS) and numerical analysis of FHR traces obtained with the fECG-monitor gives the opportunity to study the effect of varying maternal glucose levels on FHR.

Here we present preliminary data of continuous simultaneous measurements of maternal glucose and fetal heart rate, testing the hypothesis that FHR is related to maternal glucose levels. If further studies prove that the fECG-monitor is of additional value, a novel tool can be added to the arsenal of monitoring possibilities in pregnant women with diabetes.

(1) Kerssen A, de Valk HW, Visser GHA. Day-to-day glucose variability during pregnancy in women with type1 diabetes mellitus BJOG 2004;111:919-924.

Visit Blackwell Synergy http://www.blackwell-synergy.com/

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

2016

Barbara S. Kisilevsky, C. Ann Brown

 Infant B ehavior and Development.  Volume 42, February 2016, Pages 142–151

Details

Purpose

To 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).

Methods

During 20 min of rest (N = 39) and during 2 min 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).

Results

During 20 min 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 20 min were high (r = .93–.97); fetal HR averaged over 20 min varied between devices from 0.0 to 0.8 bpm. During 2 min 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 30 s or 2 min epochs. Average fetal HR between devices over the 2 min voice varied from 0.0 to 0.6 bpm. Correlations and/or % agreement between the two ECG methods of measuring maternal HR were high. Average maternal HR over 10 min showed 81% of pairs with a difference of ≤1 bpm; correlations for HR variability measures varied fromr = .89 to .97.

Conclusions

Good 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 30–120 s epochs. High reliability of maternal HR measures was obtained using two ECG devices.

Fetal heart rate patterns at 20 to 24 weeks gestation as recorded by fetal electrocardiography

2014

Hofmeyr F1, Groenewald CA, Nel DG, Myers MM, Fifer WP, Signore C, Hankins GD, Odendaal HJ; PASS Network.

J Matern Fetal Neonatal Med. 2014 May;27(7):714-8.

Details

INTRODUCTION:

With advancing technology it has become possible to accurately record and assess fetal heart rate (FHR) patterns from gestations as early as 20 weeks. The aim of our study was to describe early patterns of FHR, as recorded by transabdominal fetal electrocardiogram according to the Dawes-Redman criteria. Accordingly, short-term variability, basal heart rate, accelerations and decelerations were quantified at 20-24 weeks gestation among women with uncomplicated pregnancies.

METHODS:

This study was conducted in a subset of participants enrolled in a large prospective pregnancy cohort study. Our final data set consisted of 281 recordings of women with good perinatal outcomes who had undergone fetal electrocardiographic assessment as part of the Safe Passage Study.

RESULTS:

The success rate of the recordings was 95.4%. The mean frequency of small and large accelerations was 0.5 and 0.1 per 10 min, respectively and that of small and large decelerations 0.3 and 0.008 per 10 min, respectively. The mean and basal heart rates were both equal to 148.0 bpm at a median gestation of 161 days. The mean short term variation was 6.2 (SD 1.4) ms and mean minute range 35.1 (SD 7.1) ms.

CONCLUSION:

The 20-24-week fetus demonstrates FHR patterns with more accelerations and decelerations, as well as higher baseline variability than was anticipated. Information from this study provides an important foundation for further, more detailed, studies of early FHR patterns.

Free PMC Article http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4064125/

Change of Spectral Analysis of Fetal Heart Rate During Clinical Hypnosis: a Prospective Randomised Trial from the 20th Week of Gestation Till Term

2012

Reinhard, J.  Hayes-Gill, BR.  Schiermeier, S.  Hatzmann, W.  Heinrich, TM.  Hüsken-Janßen, H.  Herrmann, E.  Louwen, F.

Geburtshilfe Frauenheilk. 2012 Apr;72(4):316-321.

Details

Objective: To investigate the functional adaptive process of the fetal autonomic nervous system during hypnosis from the 20th week of gestation till term. Are there changes in the power spectrum analysis of fetal heart rate when the mother is having a clinical hypnosis or control period?

Study Design: Fourty-nine FHR recordings were analysed. Included recordings were from singletons and abdominal fetal ECG-monitored pregnancies. All women were randomised to receive clinical hypnosis followed by a period with no intervention or vice versa. Statistical analyses were performed with the Wilcoxon signed ranks and Spearman rho correlation tests. 

Results: There was a significant difference found between fetal heart rate at baseline (144.3 ± 6.0) and hypnosis (142.1 ± 6.4). A difference was also detected between the standard deviation of the heart rate between baseline (6.7 ± 1.9) and hypnosis (6.8 ± 3.5). LFnu was smaller during baseline (80.2 ± 5.3) than during hypnosis (82.1 ± 5.7), whereas HFnu was significantly larger (19.8 ± 5.3 vs. 17.9 ± 5.7). There was no correlation between the gestation age and the change in LFnu, HFnu or ratio LF/HF due to the hypnosis intervention. Conclusion: The functional adaptive process of the fetal autonomic system during hypnosis is reflected by a sympathovagal shift towards increased sympathetic modulation.

Evaluation of standardized, computerized Dawes/Redman heart-rate analysis based on different recording methods and in relation to fetal beat-to-beat heart rate variability

2015

Seliger, G.  Stenzel, A.  Kowalski, EM. Hoyer, D. Nowack, S.  Seeger, S.  Schneider, U.

J Perinat Med. 2015 Nov 19

Details

Dawes and Redman (DR) based their definition of short-term variation (STV) on the successive differences of mean inter-beat intervals dividing 1 min of cardiotocography recordings in 16 epochs of 3.75 s each. In contrast, heart rate variability (HRV) is based on the inter-beat intervals of discrete R peaks, also referred to as normal-to-normal (NN) intervals. Despite the historical achievements of DR in providing a robust method with the equipment available at the time to encourage the widespread use and creation of large databases, one must ask whether the STV (DR) parameter is reproducible using a different method of recording, and how much temporal information is actually lost by applying the averaging algorithm sketched above. We simultaneously performed both standard Oxford cardiotocography and transabdominal fetal electrocardiography recordings in 26 patients with low-risk singletons. In addition, we revisited our database of 418 standard fetal magnetocardiographic recordings, applying the DR algorithm to the fetal NN data and compared them to standard HRV parameters. The correlation between STV (DR) from cardiotocography and fetal electrocardiography was stronger that of either with short term fHRV from NN intervals. The methodological trade-off to gain STV as a robust parameter from heart rate traces of limited temporal resolution is accompanied by a loss of temporal information that, at the moment, only fetal magnetocardiography and, to a lesser extent, fetal electrocardiography may provide.

Autonomic regulation in fetuses with congenital heart disease

2015

Siddiqui, S.  Wilpers, A.  Myers, M. Nugent, JD. 
Fifer, WP.  Williams, IA.

Early Hum Dev. 2015 Mar;91(3):195-198
 

Details

Background: Exposure to antenatal stressors affects autonomic regulation in fetuses. Whether the presence of congenital heart disease (CHD) alters the developmental trajectory of autonomic regulation is not known.

Aims/Study Design: This prospective observational cohort study aimed to further characterize autonomic regulation in fetuses with CHD; specifically hypoplastic left heart syndrome (HLHS), transposition of the great arteries (TGA), and tetralogy of Fallot (TOF).

Subjects: From 11/2010 to 11/2012, 92 fetuses were enrolled: 41 controls and 51 with CHD consisting of 19 with HLHS, 12 with TGA, and 20 with TOF. Maternal abdominal fetal electrocardiogram (ECG) recordings were obtained at 3 gestational ages: 19-27 weeks (F1), 28-33 weeks (F2), and 34-38 weeks (F3).

Outcome Measures: Fetal ECG was analyzed for mean heart rate along with 3 measures of autonomic variability of the fetal heart rate: interquartile range, standard deviation, and root mean square of the standard deviation of the heart rate (RMSSD), a measure of parasympathetic activity.

Results: During F1 and F2 periods, HLHS fetuses demonstrated significantly lower mean HR than controls (p<0.05). Heart rate variability at F3, as measured by standard deviation, interquartile range, and RMSSD was lower in HLHS than controls (p<0.05). Other CHD subgroups showed a similar, though non-significant trend towards lower variability.

Conclusions: Autonomic regulation in CHD fetuses differs from controls, with HLHS fetuses most markedly affected.

Influence of gestational age and time of day in baseline and heart rate variation of foetuses

2016

Li, G.  Zhang, S.  Yang, L.  Li, S.  Wang, Y.  Hao, D.  Yang, Y.  Li, X.  Zhang, L. Xu, M.​

Technol Health Care. 2016 Apr 29; 24 Suppl 2:S471-6.
 

Details

Background: Fetal electrocardiography (FECG) places electrodes on the maternal abdomen to convert the fetal electrocardiosignals into fetal heart rate (FHR), improving the accuracy and comfort of pregnant woman. At the same time, FECG simplifies the procedure of long term monitoring in the perinatal period.

Objective: Investigating the influence of gestational age and time of day on FHR features to distinguish between non-stress test (NST) normal fetuses and NST suspicious fetuses.

Methods: A novel method of FHR baseline estimation was presented; then baseline value and fetal heart rate variation (FHRV) were analyzed in the time domain using FHR signals recorded from 52 fetuses.

Results: Baseline values in 1:00, 2:00, 4:00, 5:00 and heart rate variation (HRV) distribution showed a significant difference (p< 0.05) between NST normal fetuses and NST suspicious fetuses.

Conclusions: The results suggest that NST normal and suspicious fetuses had same outcome and different FHR features. Accurately distinguishing normal fetuses and suspicious fetuses is important for lowering the false positive rate and reducing unnecessary clinical intervention.

Assessment of Cardiac Rate and Rhythm in Fetuses with Arrhythmia via Maternal Abdominal Fetal Electrocardiography

2015

Narayan, HK. Vignola, EF. Fifer, WP. Williams, IA.  

Am J Perinatol Rep 2015;5:e176–e182.

Details

Objective: This study aims to report our experience using the Monica AN24 (Monica Healthcare Ltd., Nottingham, United Kingdom), a maternal transabdominal fetal electrocardiographic monitor, in a case series of fetuses with arrhythmias.

Study: Design We recorded fetal electrocardiograms (fECGs) on subjects with fetal arrhythmias diagnosed by fetal echocardiogram. Fetal heart rate and rhythm were determined via manual fECG analysis. Results Overall, 20 fECGs were recorded from a pool of 13 subjects. Fetal heart rate acquisition was determined to be high, medium, and poor quality in 10, 3, and 7 tracings, respectively. High-quality tracings were obtained in 9 of 11 subjects with gestational age < 26 or > 34 weeks. P waves were detectable in five tracings.

Conclusion: In subjects < 26 or > 34 weeks’ gestational age, there was reasonable success in fetal heart rate acquisition. Further study is warranted to determine the potential role of this device in the monitoring of subjects with fetal arrhythmias.

Correlating multidimensional fetal heart rate variability analysis with acid-base balance at birth

2014

Frasch, MG.  Xu, Y.  Stampalija, T.  Durosier, LD.  Herry, C. Wang, X.  Casati, D. Seely, AJE.  Alfirevic, Z.  Gao, X.  Ferrazzi, E.

Physiol. Meas. 35 (2014) L1–L12

Details

Fetal monitoring during labour currently fails to accurately detect acidemia. We developed a method to assess the multidimensional properties of fetal heart rate variability (fHRV) from trans-abdominal fetal electrocardiogram (fECG) during labour. We aimed to assess this novel bioinformatics approach for correlation between fHRV and neonatal pH or base excess (BE) at birth.

We enrolled a prospective pilot cohort of uncomplicated singleton pregnancies at 38–42 weeks’ gestation in Milan, Italy, and Liverpool, UK. Fetal monitoring was performed by standard cardiotocography. Simultaneously, with fECG (high sampling frequency) was recorded. To ensure clinician blinding, fECG information was not displayed. Data from the last 60 min preceding onset of second-stage labour were analyzed using clinically validated continuous individualized multiorgan variability analysis (CIMVA) software in 5 min overlapping windows. CIMVA allows simultaneous calculation of 101 fHRV measures across five fHRV signal analysis domains. We validated our mathematical prediction model internally with 80:20 cross validation split, comparing results to cord pH and BE at birth.

The cohort consisted of 60 women with neonatal pH values at birth ranging from 7.44 to 6.99 and BE from −0.3 to −18.7 mmol L−1. Our model predicted pH from 30 fHRV measures (R2 = 0.90, P < 0.001) and BE from 21 fHRV measures (R2 = 0.77, P < 0.001).

Novel bioinformatics approach (CIMVA) applied to fHRV derived from trans-abdominal fECG during labor correlated well with acid-base balance at birth. Further refinement and validation in larger cohorts are needed. These new measurements of fHRV might offer a new opportunity to predict fetal acid-base balance at birth.

Sampling frequency of fetal heart rate impacts the ability to predict pH and BE at birth: a retrospective multi-cohort study

2015

Li, X.  Xu, Y.  Herry, C. L D, Durosier, L D.  Casati, D.  Stampalija, T.  Maisonneuve, E.  Seely, AJE.  Audibert, F.  Alfirevic, Z.  Ferrazzi, E.  Wang, X.  Frasch, MG.

Institute of Physics and Engineering in Medicine
Physiol. Meas. 36 (2015) L1

Details

Fetal heart rate (FHR) sampling rate used on the bedside is equal or less than 4 Hz. Current FHR analysis methods fail to detect incipient fetal acidemia. In a fetal sheep model of human labour we showed that FHR sampling rates near 1000 Hz are needed to detect fetal acidemia. Trans-abdominal fetal ECG (t-a fECG) sampling FHR at 900 Hz combined with a complex signals bioinformatics approach showed promise in a human cohort. Here we validate this finding in a retrospective human cohort study by comparing the performance of the same bioinformatics approach to predict pH and BE at birth in the cohorts with FHR sampled either at 4 Hz or at 900 Hz. The 4 Hz FHR recording data sets consisted of the open access intrapartum CTG data base with n = 552 subjects used to develop the predictive model and another cohort of prospectively recruited n = 11 labouring women to then validate it. 900 Hz FHR data set comprised two prospectively recruited t-a fECG cohorts of n = 60 and n = 23 subjects. Recruitment criteria were similar across the cohorts. We have determined the goodness of fit (R2) and root mean square error (RMSE) as the performance indicators of the model on each cohort.

The clinical characteristics of all cohorts were similar (gestational age 280 } 8 d; gender 50% male; birth body weight 3.5 } 0.5 kg; pH and BE at birth 7.25 } 0.1 and −5.7 } 3.4 mmol L − 1, respectively; 1′ and 5′ Apgar scores at birth 8.5 } 1.4 and 9.4 } 0.6, respectively). The 4 Hz FHR cohort rendered—for pH and BE—R2 = 0.26 and 0.2 and RMSE = 0.087 and 3.44, respectively. This could not be confirmed in the validation cohort for neither pH nor BE prediction. The 900 Hz FHR cohort rendered—for pH and BE—R2 = 0.9 and 0.77 and RMSE = 0.03 and 1.70, respectively, and the pH prediction was validated.

In our model, lower FHR sampling rate increased the predicted error range ~3–4 fold. We show that increasing FHR sampling rate to 900 Hz improves prediction of fetal pH and BE at birth. This should improve early identification of babies at risk of brain injury.

Brain sparing effect in growth-restricted fetuses is associated with decreased cardiac acceleration and deceleration capacities: a case-control study.

2016

Stampalija,T.   Casati, D.  Monasta, L.  Sassi, R.  Rivolta, MW.  Muggiasca, ML.                   Bauer, A.  Ferrazzi, E.

BJOG. 2016 Nov;123(12)

Details

Objective: Phase rectified signal averaging (PRSA) is a new method of fetal heart rate variability (fHRV) analysis that quantifies the average acceleration (AC) and deceleration capacity (DC) of the heart. The aim of this study was to evaluate AC and DC of fHR [recorded by trans-abdominal fetal electrocardiogram (ta-fECG)] in relation to Doppler velocimetry characteristics of intrauterine growth restriction (IUGR).

Design: Prospective case-control study.

Setting: Single third referral centre.

Population: IUGR (n = 66) between 25 and 40 gestational weeks and uncomplicated pregnancies (n = 79).

Methods: In IUGR the nearest ta-fECG monitoring to delivery was used for PRSA analysis and Doppler velocimetry parameters obtained within 48 hours. AC and DC were computed at s = T = 9. The relation was evaluated between either AC or DC and Doppler velocimetry parameters adjusting for gestational age at monitoring, as well as the association between either AC or DC and IUGR with or without brain sparing.

Results: In IUGRs there was a significant association between either AC and DC and middle cerebral artery pulsatility index (PI; P = 0.01; P = 0.005), but the same was not true for uterine or umbilical artery PI (P > 0.05). Both IUGR fetuses with and without brain sparing had lower AC and DC than controls, but this association was stronger for IUGRs with brain sparing.

Conclusions: Our study observed for the first time that AC and DC at PRSA analysis are associated with middle cerebral artery PI, but not with uterine or umbilical artery PI, and that there is a significant decrease of AC and DC in association with brain sparing in IUGR fetuses from 25 weeks of gestation to term.

Parameters influence on acceleration and deceleration capacity based on trans-abdominal ECG in early fetal growth restriction at different gestational age epochs

2015

Stampalija, T.  Casati, D.  Montico, M.   Sassi.  MW, Rivolta.  Maggi, V.  Bauer, A.  Ferrazzi, E.

Details

Objective; Intrauterine growth restriction (IUGR) is characterized by chronic nutrient deprivation and hypoxemia that alters the autonomous nervous system regulation of fetal heart rate variability (fHRV). Phase-rectified signal averaging (PRSA) is a new algorithm capable to identify periodic and quasi-periodic patterns of HR, and which is used to quantify the average acceleration and deceleration capacity (AC/DC) of the heart. The computation of AC/DC depends on the parameters T and s, which we set so that s = T. T and s determine the periodicities that can be detected (the larger T the smaller the frequency of oscillations for which the method is most sensitive). The aim of the study was to evaluate the influence of the parameter T on PRSA computation, based on trans-abdominally acquired fetal ECG (ta-fECG), in early IUGR (<34 weeks of gestation) at two different gestational age epochs.

Study design; AC/DC were calculated for different T values (1 ÷ 45) on fetal RR intervals derived from ta-fECG in 22 IUGR and in 37 appropriate for gestational age (AGA) fetuses matched for gestational age, in two gestational age epochs: very preterm group (≥26 ÷ <30 weeks), and preterm group (≥30 ÷ <34 weeks), respectively.

Results; AC/DC were significantly lower in IUGR than in AGA fetuses for all T ≥ 5 values (p < 0.05). The best area under the receiver operating characteristic curve (AUC) in identifying IUGR at time of recording was observed for T9 [AUC AC-T9 0.87, 95% confidence interval (CI) 0.77–0.96; and AUC DC-T9 0.89, 95% CI 0.81–0.98), and in range of T 7 ÷ 15. In the same T interval, AC/DC were significantly lower in very preterm than in preterm IUGR group (p < 0.05), while there were no differences in AGA fetuses at two gestational age epochs (p > 0.05), respectively. The AUCs of AC-T9 and DC-T9 significantly outperformed that obtained by short-term variation (AUC 0.77, 95% CI 0.65–0.90; p = 0.009 and p = 0.003, respectively).

Conclusions; Our study shows that within the range of T parameter 1 ÷ 45, T = 9 proved to be the best value to discriminate the AC and DC of the fetal heart rate of IUGR from AGA fetuses prior to 34 weeks of gestation. These significant differences are emphasized in very preterm gestational age epochs.

Effect of maternal position on fetal behavioural state and heart rate variability in healthy late gestation pregnancy

2016

Journal of  Physiology  (Lond)  2016, Nov 21

Stone, P.  Burgess, W.  McIntyre, J.  Gunn,  A.  Lear, C.   Bennet, L.  Mitchell, E.  Thompson, J.

Details

Background: Fetal behavioural states (FBS) are measures of fetal wellbeing. In acute hypoxemia, the human fetus adapts to a lower oxygen consuming state with changes in the cardiotocograph and reduced fetal activity. Recent studies of late gestation stillbirth described the importance of sleep position in the risk of intrauterine death. We designed this study to assess the effects of different maternal positions on FBS in healthy late gestation pregnancies under controlled conditions.

Method: Twenty nine healthy women had continuous fetal ECG recordings under standardized conditions in 4 randomly allocated positions, left lateral, right lateral, supine and semi-recumbent. Two blinded observers, assigned fetal states in 5 minute blocks. Measures of fetal heart rate variability were calculated from ECG beat to beat data. Results: Compared to state 2F, state 4F was less likely to occur when women were semi-recumbent (OR = 0.11 95%CI 0 02, 0. 55), and supine (OR = 0. 27 95%CI 0.07, 1.10).State 1F was more likely on the right (OR = 2.36 95%CI 1.11, 5.04) or supine (OR = 4.99 95%CI 2.41, 10.43) compared to the left. State change was more likely when the mother was semi-recumbent (OR = 2.17 95%CI 1.19, 3.95) or supine (OR = 2.67 95%CI 1.46, 4.85).There was a significant association of maternal position to mean fetal heart rate. The measures of variability (SDNN and RMSSD) were reduced in both semi-recumbent and supine positions.

Conclusion: In healthy late gestation pregnancy, maternal position affects FBS and heart rate variability. These effects are likely fetal adaptations to positions which may produce a mild hypoxic stress.

Assessment of Coupling between Trans-Abdominally Acquired Fetal ECG and Uterine Activity by Bivariate Phase-Rectified Signal Averaging Analysis

2014

Casati. D,  Stampalija. T,  Rizas. K,  Ferrazzi. E,   Mastroianni. C,  Rosti. E, 

Quadrifoglio. M, Bauer. A

PLoS One. 2014 Apr 23;9(4):e94557.

Details

Abstract

Couplings between uterine contractions (UC) and fetal heart rate (fHR) provide important information on fetal condition during labor. At present, couplings between UC and fHR are assessed by visual analysis and interpretation of cardiotocography. The application of computerized approaches is restricted due to the non-stationarity of the signal, missing data and noise, typical for fHR. Herein, we propose a novel approach to assess couplings between UC and fHR, based on a signal-processing algorithm termed bivariate phase-rectified signal averaging (BPRSA).

Methods: Electrohysterogram (EHG) and fetal electrocardiogram (fECG) were recorded non-invasively by a trans-abdominal device in 73 women at term with uneventful singleton pregnancy during the first stage of labor. Coupling between UC and fHR was analyzed by BPRSA and by conventional cross power spectral density analysis (CPSD). For both methods, degree of coupling was assessed by the maximum coefficient of coherence (CPRSA and CRAW, respectively) in the UC frequency domain. Coherence values greater than 0.50 were consider significant. CPRSA and CRAW were compared by Wilcoxon test.

Results: At visual inspection BPRSA analysis identified coupled periodicities in 86.3% (63/73) of the cases. 11/73 (15%) cases were excluded from further analysis because no 30 minutes of fECG recording without signal loss was available for spectral analysis. Significant coupling was found in 90.3% (56/62) of the cases analyzed by BPRSA, and in 24.2% (15/62) of the cases analyzed by CPSD, respectively. The difference between median value of CPRSA and CRAW was highly significant (0.79 [IQR 0.69-0.90] and 0.29 [IQR 0.17-0.47], respectively; p<0.0001).

Conclusion: BPRSA is a novel computer-based approach that can be reliably applied to trans-abdominally acquired EHG-fECG. It allows the assessment of correlations between UC and fHR patterns in the majority of labors, overcoming the limitations of non-stationarity and artifacts. Compared to standard techniques of cross-correlations, such as CPSD, BPRSA is significantly superior.