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

Abstract

Introduction !In the last 30 years cardiotocography (CTG) has become the most common method to monitor foetal health during birth [1,2].The benefits of electronic foetal monitoring are still discussed [3][4][5]. To solve the problem of high inter-and intra-observer variability [1,[6][7][8], guidelines and computer-assisted analysis pro- Abstract !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. A recently licensed non-invasive ECG system which monitors foetal heart rate while simultaneously monitoring maternal heart rate could be useful in this context. This method would allow episodes in which the maternal heart rate is mistaken for the foetal heart rate to be identified. Alternatively, there are also CTG devices available which are used to monitor twin pregnancies. They give an acoustic warning signal when the heart rates of the twins coincide. It would be theoretically possible to use such a twin CTG device so that maternal and foetal heart rates could be recorded simultaneously, with a warning signal appearing when the heart rates coincide. Other proposals include the use of pulse oximetry or more frequent monitoring of the maternal pulse rate by the midwife as well as more attention to be focused on capturing the "typical" acoustic sounds of the foetal heart. This study aimed to investigate which monitoring method offers a better foetal signal quality in gestational weeks 20 + 0 to 40 + 0 before carrying out a larger study which will analyse the risk of misidentifying the foetal heart rate. Zusammenfassung Material and Methods !The Monica AN24™ system is a small, portable, battery-operated, electrophysiological monitoring system which detects fo...

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

“…, who found that ≥60% of fECG signals were present in 82% of 150 pregnant women. Other studies found antenatal success rates of 62% , 77.4% , and 92.9% , respectively. In the latter studies, recordings were relatively short (up to eight hours), and they were performed in a hospital setting.…”

A systematic scoping review to identify the design and assess the performance of devices for antenatal continuous fetal monitoring

“…Ten of the 43 studies were from the UK [25][26][27]35,[37][38][39]49,50,55], 22 from other European countries [24,[28][29][30][31][32][33]36,40,[42][43][44]48,[51][52][53][54]56,57,61,64,65], five from Japan [41,59,60,62,63], one from India [45], one from Australia [66], three from the United States of America (USA) [46,47,58], and one study from both the Netherlands and USA [34]. The included studies were heterogeneous, they had a median sample size of 34.5 participants (range 1-657) and a median number of recordings of 63 (range 1-657).…”

Non-Adaptive Methods for Fetal ECG Signal Processing: A Review and Appraisal

“… Accurate—these methods allow accurate detection of fHR, i.e., Se ≤ 85%, PPV ≤ 95%, ACC ≤ 85%, F1 ≤ 90%. Very Accurate—these methods enable a very accurate determination of fHR and, in this case, it is a full replacement of the conventional CTG [ 31 , 40 , 119 ], i.e., Se ≤ 95%, PPV ≤ 95%, ACC ≤ 95%, F1 ≤ 95%. Morphological analysis (T/QRS; QT)—this parameter classifies the efficacy of the investigated methods from a deeper morphological analysis of fECG.…”

“…Very Accurate—these methods enable a very accurate determination of fHR and, in this case, it is a full replacement of the conventional CTG [ 31 , 40 , 119 ], i.e., Se ≤ 95%, PPV ≤ 95%, ACC ≤ 95%, F1 ≤ 95%.…”

“…The summary implies that NI-fECG is a very promising method. This approach is very safe, simple and cheap, and, based on some recent studies [ 40 , 41 ], fECG achieves better results than the conventional CTG. Additionally, it also appears to be a more accurate method to be used with patients with higher body mass index (BMI).…”