Supporting Evidence

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Monica AN24 - Clinical Paper Review

The evidence supporting the use of the AN24 fetal ECG is rapidly growing, an overview of medical publications supporting its use has been provided. Please select your area of interest using the drop down menu below. This citation list will be periodically updated to reflect new publications supporting the benefits of the AN24.

AN24 Specific Publications

Year	Citation	Area	Link
2010	Maternal and fetal heart rate confusion during labour Bhogal.K, Reinhard.J British Journal of Midwifery. Vol 18, No, 7: 424-428. July 2010	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.
2010	Maternal Body Mass Index Does Not Affect Performance of Fetal Electrocardiography 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.	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
2009	Fetal Heart Rate Variability in Obstetric Cholestasis Jayawardane, DBIA. Hayes–Gill, BR. Loughna, PV. Broughton Pipkin,F. Paper presented at Fetal and Neonatal Physiological Society, USA 36th Annual Meeting September 2009	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.
2009	A validation of electrohysterography for uterine activity monitoring during labour 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	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.
2009	Extraction and Analysis of Fetal ECG by transabdominal recording using Monica AN24 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	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
2009	Signal Quality of Non-Invasive Foetal Electrocardiogram (ECG) During Labour 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	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.
2008	Non-invasive detection of significant uterine activity American Journal of Obstetrics and Gynecology, Volume 199, Issue 6, Pages S225-S225 J. Miller, K. Ty-Torredes, M. Schindel, C. Harman, A. Baschat	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.
2008	Fetal electrocardiography: feasibility of long-term fetal heart rate recording 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	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.
2008	Obesity in Obstetrics, New Challenges and Solutions Using Abdominal Fetal ECG 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	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.
2008	4th International Symposium on Diabetes and Pregnancy 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;	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.
2008	NON-INVASIVE TRANSABDOMINAL MONITORING OF FECG AND UTERINE CONTRACTIONS IN SECOND HALF OF GESTATION 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	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).
2008	Foetal electrocardiogram (EKG) is an alternative to Doppler ultrasound cardiotocogram (CTG) for antenatal assessment of foetal well-being – preliminary results 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)	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
2007	ANTENATAL TRANSABDOMINAL FETAL ECG FOR HEART RATE MONITORING: QUALITY ASSESSMENT OF A RENEWED MONITORING TECHNIQUE 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	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.