Intrapartum Fetal Electrocardiogram in Small- and Large-for-Gestational Age Fetuses

Objective This study aimed to evaluate whether intrapartum fetal electrocardiogram (ECG) tracings with ST-elevation or depression occur more frequently in each stage of labor in small-for-gestational age (SGA) or large-for-gestational age (LGA), as compared with appropriate-for-gestational age (AGA) fetuses. Study Design We conducted a secondary analysis of a large, multicenter trial in which laboring patients underwent fetal ECG waveform-analysis. We excluded participants with diabetes mellitus and major fetal anomalies. Birth weight was categorized as SGA (<10th percentile), LGA (>90th percentile), or AGA (10–90th percentile) by using a gender and race/ethnicity specific nomogram. In adjusted analyses, the frequency of ECG tracings with ST-depression or ST-elevation without depression was compared according to birthweight categories and labor stage. Results Our study included 4,971 laboring patients in the first stage and 4,074 in the second stage. During the first stage of labor, there were no differences in the frequency of ST-depression in SGA fetuses compared with AGA fetuses (6.7 vs. 5.5%; adjusted odds ratio [aOR]: 1.41, 95% confidence interval [CI]: 0.93–2.13), or in ST-elevation without depression (35.8 vs. 34.1%; aOR: 1.17, 95% CI: 0.94–1.46). During the second stage, there were no differences in the frequency of ST-depression in SGA fetuses compared with AGA fetuses (1.6 vs. 2.0%; aOR: 0.69, 95% CI: 0.27–1.73), or in ST-elevation without depression (16.2 vs. 18.1%; aOR: 0.90, 95% CI: 0.67–1.22). During the first stage of labor, there were no differences in the frequency of ST-depression in LGA fetuses compared with AGA fetuses (6.3 vs. 5.5%; aOR: 0.97, 95% CI: 0.60–1.57), or in ST-elevation without depression (33.1 vs. 34.1%; aOR: 0.80, 95% CI: 0.62–1.03); during the second stage of labor, the frequency of ST-depression in LGA compared with AGA fetuses (2.5 vs. 2.0%, aOR: 1.36, 95% CI: 0.61–3.03), and in ST-elevation without depression (15.5 vs. 18.1%; aOR: 0.83, 95% CI: 0.58–1.18) were similar as well. Conclusion The frequency of intrapartum fetal ECG tracings with ST-events is similar among SGA, AGA, and LGA fetuses. Key Points

Fetal Electrocardiogram Extraction from the Mother’s Abdominal Signal Using the Ensemble Kalman Filter

Fetal electrocardiogram (fECG) assessment is essential throughout pregnancy to monitor the wellbeing and development of the fetus, and to possibly diagnose potential congenital heart defects. Due to the high noise incorporated in the abdominal ECG (aECG) signals, the extraction of fECG has been challenging. And it is even a lot more difficult for fECG extraction if only one channel of aECG is provided, i.e. in a compact patch device. In this paper, we propose a novel algorithm based on the Ensemble Kalman Filter (EnKF) for non-invasive fECG extraction from a single-channel aECG signal. To assess the performance of the proposed algorithm, we used our own clinical data, obtained from a pilot study with 10 subjects each of 20 min recording, and data from the PhysioNet 2013 Challenge bank with labeled QRS complex annotations. The proposed methodology shows the average positive predictive value (PPV) of 97.59%, sensitivity (SE) of 96.91%, and F1-score of 97.25% from the PhysioNet 2013 Challenge bank. Our results also indicate that the proposed algorithm is reliable and effective, and it outperforms the recently proposed Extended Kalman Filter (EKF) based algorithm.

FETAL QRS-COMPLEXES DETECTECTIONS IN ABDOMINAL SIGNAL BY USING WAVELET-BISPECTRUM

Fetal hypoxia or distress is a physical stress experienced by a fetus due to a lack of oxygen. Intrauterine hypoxia and the resultant perinatal brain damages may lead to extraordinary effects, including continuous lifelong treatments. One of the ways for detecting symptoms of hypoxia is monitoring of the fetus heart activity. At present, the basic method of monitoring the condition of unborn baby is the ultrasound cardiotocography (CTG). Considerably more information for early detection of the fetal hypoxia may be obtained by analyzing fetal electrocardiogram (FECG).

Non-Invasive Fetal Electrocardiogram Monitoring Techniques: Potential and Future Research Opportunities in Smart Textiles

During the pregnancy, fetal electrocardiogram (FECG) is deployed to analyze fetal heart rate (FHR) of the fetus to indicate the growth and health of the fetus to determine any abnormalities and prevent diseases. The fetal electrocardiogram monitoring can be carried out either invasively by placing the electrodes on the scalp of the fetus, involving the skin penetration and the risk of infection, or non-invasively by recording the fetal heart rate signal from the mother’s abdomen through a placement of electrodes deploying portable, wearable devices. Non-invasive fetal electrocardiogram (NIFECG) is an evolving technology in fetal surveillance because of the comfort to the pregnant women and being achieved remotely, specifically in the unprecedented circumstances such as pandemic or COVID-19. Textiles have been at the heart of human technological progress for thousands of years, with textile developments closely tied to key inventions that have shaped societies. The relatively recent invention of smart textiles is set to push boundaries again and has already opened the potential for garments relevant to medicine, and health monitoring. This paper aims to discuss the different technologies and methods used in non-invasive fetal electrocardiogram (NIFECG) monitoring as well as the potential and future research directions of NIFECG in the smart textiles area.