Fetal Heart Rate Accelerations Research Articles

Early Diagnosis and Classification of Fetal Health Status from a Fetal Cardiotocography Dataset Using Ensemble Learning.

(1) Background: According to the World Health Organization (WHO), 6.3 million intrauterine fetal deaths occur every year. The most common method of diagnosing perinatal death and taking early precautions for maternal and fetal health is a nonstress test (NST). Data on the fetal heart rate and uterus contractions from an NST device are interpreted based on a trace printer's output, allowing for a diagnosis of fetal health to be made by an expert. (2) Methods: in this study, a predictive method based on ensemble learning is proposed for the classification of fetal health (normal, suspicious, pathology) using a cardiotocography dataset of fetal movements and fetal heart rate acceleration from NST tests. (3) Results: the proposed predictor achieved an accuracy level above 99.5% on the test dataset. (4) Conclusions: from the experimental results, it was observed that a fetal health diagnosis can be made during NST using machine learning.

Sporadic accelerations during labor strongly indicate normal pH, whereas periodic accelerations do not: a case–control study

Purpose To determine the association between the occurrence of sporadic and periodic fetal heart rate accelerations during labor and acidemia at birth. Materials and methods This is a case–control study of fetal heart rate patterns from 364 neonates with acidemia at birth (cord blood pH <7.05 at vaginal birth, or pH <7.10 at birth after first stage cesarean delivery) and 731 controls with pH ≥7.15. The last 30–60 min of the cardiotocographic traces before birth from the neonates born with acidemia and from the corresponding stage in labor for the controls were scrutinized. Odds ratios (OR) with 95% confidence interval for acidemia at birth were determined. Results During the first stage, ≥2 sporadic accelerations were present in 16% of cases and 78% of controls; OR for acidemia (compared to 0–1 accelerations) 0.05 (0.02–0.10). In the second stage, the corresponding rates were 13% and 60%, OR 0.09 (0.06–0.14). Isolated periodic accelerations were infrequent. A weak negative association between ≥2 periodic accelerations and acidemia (compared with 0–1 accelerations) was found in the second stage, OR 0.51 (0.30–0.86), but was not significant in the first stage, OR 0.24 (0.04–1.4). Even among fetuses with normal fetal heart rate variability (5–25 beats per minute) the occurrence of less than two sporadic accelerations was associated with an increased risk of acidemia, OR 10.3 (7.2–14.8). Conclusions Sporadic accelerations indicate a very low probability of acidosis but are absent in 40% of fetuses with normal pH during a 30–60 min second-stage recording.

Clinical associations of fetal heart rate accelerations as derived from transabdominal fetal electrocardiograms

ObjectiveTo determine the value of quantifying accelerations of the fetal heart rate (FHR), as collected non-invasively during pregnancy, as a proxy for fetal movements. Study DesignThe study consists of a prospective collection of research material with retrospective analyses of the collected fetal electrocardiograms (ECGs), done in a homogeneous population in a low socioeconomic residential area of Cape Town, South Africa, as part of the Safe Passage Study. Recruitment and follow-up were done from August 2007 to August 2016. Maternal and fetal ECGs were collected non-invasively at various gestational ages, for approximately 30–60 min at a time in 4418 pregnant women. After processing of the signal, the number and duration of accelerations and the area under the acceleration curve of the FHR were calculated and compared with the pulsatility index (PI) of the uterine, umbilical, and middle cerebral arteries, common medical conditions, tobacco, alcohol, marijuana, and methamphetamine use and z-scores of the birthweight (BWZS). ResultsOf the total, 2777, 691, and 3879 women were at gestational ages of 20–24, 28–32 and 34–38 weeks respectively. At 20–24 weeks duration of accelerations was significantly longer in women who used marijuana (p = 0.014) or methamphetamine (p < 0.001) when compared to nonusers. At 28–32 weeks the duration of accelerations was significantly shorter in hypertensive women (p = 0.003) and significantly longer in women who used methamphetamine (p = 0.015). At 34–38 weeks the number of accelerations were significantly less in women who had hypertension ((p = 0.01) or stillbirths (p = 0.028) and the duration significantly shorter in hypertensive women (p = 0.007) and significantly longer in women who used marjuana (p = 0.003) or methamphetamine (p = 0.028). The acceleration area was significantly smaller (p = 0.02) in women who has stillbirths. Duration of accelerations was significantly longer in users of nicotine and alcohol when compared with that of abstainers. Birthweight z-score correlated significantly with number of accelerations (p < 0.01) and the acceleration area (<0.01). There was a significant negative correlation between the number of accelerations (p < 0.01) and acceleration area (p < 0.01) and the PI of the uterine artery at 34–38 weeks. ConclusionsCalculation of the acceleration parameters of the FHR during pregnancy may provide useful information for evaluating fetal development.

Digital fetal scalp stimulation (dFSS) versus fetal blood sampling (FBS) to assess fetal wellbeing in labour—a multi-centre randomised controlled trial: Fetal Intrapartum Randomised Scalp Stimulation Trial (FIRSST NCT05306756)

BackgroundCardiotocography (CTG) is a screening test used to detect fetal hypoxia in labour. It has a high false positive rate resulting in many potentially unnecessary caesarean sections. Fetal blood sampling (FBS) is a second-line test of the acid-base status of the fetus. It is used to provide either reassurance that it is safe for labour to continue or objective evidence of compromise so that delivery can be expedited. Digital fetal scalp stimulation (dFSS) to elicit a fetal heart rate acceleration is an alternative less invasive second-line test of fetal wellbeing. This study aims to provide robust evidence on the role of these two second-line tests in assessing fetal wellbeing and potentially preventing operative delivery.MethodsA multi-centre parallel group randomised controlled trial (RCT) is planned in four maternity centres in Ireland. The study aims to recruit 2500 nulliparous women with a term (≥37+0 weeks) singleton pregnancy who require a second-line test of fetal wellbeing in labour due to an abnormal CTG. Women will be allocated randomly to dFSS or FBS on a 1:1 ratio. The primary outcome is caesarean section. With 1250 women in each arm, the study will have 90% power to detect a difference of 5–6%, at a two-sided alpha significance level of 5%, assuming a caesarean section rate of at least 20% in the dFSS group.DiscussionIf the proposed study shows evidence that dFSS is a safe, reliable and effective alternative to FBS, this would have ground-breaking implications for labour management worldwide. It could potentially lead to a reduction in invasive procedures and emergency caesarean sections.Trial registrationClinicalTrials.gov NCT05306756. Registered on 31 March 2022. The trial commenced enrolment on 10 May 2022. Ethical committee approval has been granted by the Research Ethics Committee (REC) of each hospital: Dublin/CWIUH REC: 12.06.2019; Cork/UCC REC: 29.11.2019; Galway/NUIG REC: 06.09.2019; Limerick/UL REC: 30.09.2019.

Outstanding research paper awards of the Journal of the Chinese Medical Association in 2021.

Outstanding research paper awards of the Journal of the Chinese Medical Association in 2021.

Multiparametric Investigation of Dynamics in Fetal Heart Rate Signals.

In the field of electronic fetal health monitoring, computerized analysis of fetal heart rate (FHR) signals has emerged as a valid decision-support tool in the assessment of fetal wellbeing. Despite the availability of several approaches to analyze the variability of FHR signals (namely the FHRV), there are still shadows hindering a comprehensive understanding of how linear and nonlinear dynamics are involved in the control of the fetal heart rhythm. In this study, we propose a straightforward processing and modeling route for a deeper understanding of the relationships between the characteristics of the FHR signal. A multiparametric modeling and investigation of the factors influencing the FHR accelerations, chosen as major indicator of fetal wellbeing, is carried out by means of linear and nonlinear techniques, blockwise dimension reduction, and artificial neural networks. The obtained results show that linear features are more influential compared to nonlinear ones in the modeling of HRV in healthy fetuses. In addition, the results suggest that the investigation of nonlinear dynamics and the use of predictive tools in the field of FHRV should be undertaken carefully and limited to defined pregnancy periods and FHR mean values to provide interpretable and reliable information to clinicians and researchers.

Experience with home-based, remote non-stress tests, including automatic decision support for interpretation of reactivity

The fetal non-stress test (NST) for antepartum surveillance involves frequent, burdensome in-office visits. INVUTM is a wireless, remote, FDA-cleared monitoring device, designed to perform self-administered NST from home. Here, we present (1) our initial experience with INVUTM home NST monitoring, and (2) a novel machine learning decision support system (DSS) to detect fetal heart rate (FHR) accelerations, with the potential to alert clinicians on NST reactivity. A single-center, prospective, open label study was conducted, in which women with ≥32 week high-risk singleton gestations performed self-administered NST using the INVUTM device at home, replacing in-clinic NSTs. NSTs were reviewed by clinicians via the INVUTM web application who determined clinically interpretability and reactivity. Interpretable sessions were retrospectively analyzed by the DSS for reactivity and compared to clinician assessment (Figure). The time to reactivity as analyzed by the DSS was compared to the session length until reactivity was determined by clinicians. Of the first 30 INVUTM sessions (across 9 subjects), clinicians deemed 27 (90%) interpretable, and 27/27 as reactive (100%). The DSS correctly classified 92.6% (25/27) of the interpretable NSTs compared with clinicians. In the 2 cases where DSS did not match the clinician decision, DSS did not rule the NST reactive, whereas the clinician did. On review, these cases may have been due to clinician averaging the FHR baseline from which accelerations are measured, compared to the conservative nature of the DSS. In the cases deemed reactive by DSS, time to reactivity was reduced by 14.72±13.79 min as compared to clinician determination. Early clinical experience conducting self-administered, remote NSTs at home using the INVUTM device supports the feasibility of bringing this telehealth solution to high risk pregnancy care. In addition, a novel DSS tool accurately identifies reactivity, which could reduce the length of NST sessions and improve clinician workflow.

Differences in the Asymmetry of Beat-to-Beat Fetal Heart Rate Accelerations and Decelerations at Preterm and Term Active Labor.

The fetal autonomic nervous system responds to uterine contractions during active labor as identified by changes in the accelerations and decelerations of fetal heart rate (FHR). Thus, this exploratory study aimed to characterize the asymmetry differences of beat-to-beat FHR accelerations and decelerations in preterm and term fetuses during active labor. In an observational study, we analyzed 10 min of fetal R-R series collected from women during active preterm labor (32–36 weeks of pregnancy, n = 17) and active term labor (38–40 weeks of pregnancy, n = 27). These data were used to calculate the Deceleration Reserve (DR), which is a novel parameter that quantifies the asymmetry of the average acceleration and deceleration capacity of the heart. In addition, relevant multiscale asymmetric indices of FHR were also computed. Lower values of DR, calculated with the input parameters of T = 50 and s = 10, were associated with labor occurring at the preterm condition (p = 0.0131). Multiscale asymmetry indices also confirmed significant (p < 0.05) differences in the asymmetry of FHR. Fetuses during moderate premature labor may experience more decaying R-R trends and a lower magnitude of decelerations compared to term fetuses. These differences of FHR dynamics might be related to the immaturity of the fetal cardiac autonomic nervous system as identified by this system response to the intense uterine activity at active labor.

Intrapartum Resuscitation Interventions for Category II Fetal Heart Rate Tracings and Improvement to Category I.

To evaluate intrapartum resuscitation interventions and improvement in category II fetal heart rate (FHR) tracings. This secondary analysis of a randomized trial of intrapartum fetal electrocardiographic ST-segment analysis included all participants with category II FHR tracings undergoing intrauterine resuscitation: maternal oxygen, intravenous fluid bolus, amnioinfusion, or tocolytic administration. Fetal heart rate pattern-recognition software was used to confirm category II FHR tracings 30 minutes before intervention and to analyze the subsequent 60 minutes. The primary outcome was improvement to category I within 60 minutes. Secondary outcomes included FHR tracing improvement to category I 30-60 minutes after the intervention and composite neonatal outcome. Of 11,108 randomized participants, 2,251 (20.3%) had at least one qualifying intervention for category II FHR tracings: 63.7% improved to category I within 60 minutes and 50.5% improved at 30-60 minutes. Only 3.4% underwent cesarean delivery and 4.1% an operative vaginal delivery for nonreassuring fetal status within 60 minutes after the intervention. Oxygen administration was the most common intervention (75.4%). Among American College of Obstetricians and Gynecologists-defined subgroups that received oxygen, the absent FHR accelerations and absent-minimal FHR variability subgroup (n=332) was more likely to convert to category I within 60 minutes than the FHR accelerations or "moderate FHR variability" subgroup (n=1,919) (77.0% vs 63.0%, odds ratio [OR] 2.0, 95% CI 1.4-2.7). The incidence of composite neonatal adverse outcome for category II tracings was 2.9% (95% CI 2.2-3.7%) overall; 2.8% (95% CI 2.0-3.8%) for improvement to category I within 60 minutes (n=1,433); and 3.2% (95% CI 2.1-4.6%) for no improvement within 60 minutes (n=818). However, the group with improvement had 29% lower odds for higher level neonatal care (11.8% vs 15.9%, OR 0.71, 95% CI 0.55-0.91). Nearly two thirds of category II FHR tracings improved to category I within 60 minutes of intervention with a relatively low overall rate of the composite neonatal adverse outcome. Funded in part by Neoventa Medical.

Application and Clinical Analysis of Remote Fetal Heart Rate Monitoring Platform in Continuous Fetal Heart Rate Monitoring Images.

Fetal heart sound is an important part of fetal monitoring and has attracted extensive research and attention from scholars at home and abroad in recent years. The fetal heart rate, extracted from the fetal heart sound signal, is one of the important indicators that reflect the health of the fetus in the womb. In this study, a maternal-fetal Holter monitor based on f ECG technology was used to collect maternal heart rate, fetal heart rate, and uterine contractions signals, isolate the fetal heart rate, and design an algorithm to extract the fetal heart rate baseline, acceleration, variation, wake-up cycle, and nonlinear parameters. Using statistical methods to analyze the average value and range of various characteristic parameters of fetal heart rate under continuous long-term monitoring, the results show that the baseline has a downward trend from 10 o'clock in the night to 4 o'clock in the morning and is the lowest around 2 o'clock in the morning. The area and acceleration time were significantly higher than those in the suspicious group. However, there was no significant difference in the number of acceleration values between the two groups; the proportion of small mutations in the normal group was lower than that of the suspicious group and the proportion of medium mutations was higher than that of the suspicious group. There is no statistically significant difference in maternal age, gestational age at childbirth, pregnancy comorbidities, and complication rates in the five-level interpretation system of ACOG (2009), RCOG (2007), SOGC (2007), and the United States (2007). The difference of pregnancy and parity in various images was statistically significant, P < 0.05. The second type of fetal heart rate monitoring images appeared in the highest among the diagnostic standards, and the difference in the second type of fetal heart rate monitoring images between the various diagnostic standards was statistically significant, P ≤ 0.001.

Computerized analysis of fetal heart rate pattern in the third trimester of low-risk pregnancy by long-range electronic fetal monitoring

Background With computerized analysis of fetal heart rate(FHR) data from long-range monitoring, we aimed to comprehensively clarify the characteristics of FHR with increasing gestational age in low-risk pregnant women during the third trimester of pregnancy. Methods This was an observational study. 85 fetuses of low-risk pregnant women were included. The data covered 28 ∼ 40 weeks of gestation, and 125 cases of FHR monitoring from 85 fetuses were totally collected. The FHR baseline rate, variability, and acceleration were computationally calculated, analyzed and compared. Results The average effective monitoring time for each case was 13.9 ± 4.3 h. FHR baseline gradually decreased as the gestational age progressed, and the maximum FHR baseline appeared at 28–29 weeks, which was 137.5 (133.0, 141.3) bpm, whereas the minimum FHR baseline appeared at 38–39 weeks, that was 132.8 (128.1, 138.4) bpm. FHR variability fluctuated in (4–12）bpm. It gradually increased from 28 to 33 weeks of gestation, reached the maximum of 7.6 (6.0–9.4) bpm, and then decreased until full-term pregnancy. The moderate variability proportion of FHR gradually increased from 28 weeks of gestation, peaked at 32–33 weeks as 65.8%, and then gradually decreased to 56.2% at 37 weeks, which was maintained at this level until 39 weeks. The variation tendency of minimal variability proportion was opposite to moderate variability proportion. When it reached 40 weeks, the minimal and moderate variability proportions were 50.0% and 49.0%, respectively. The FHR acceleration area showed no trend change during the third trimester, while fluctuated in (29.5–42.4) lattices/h. Conclusion This study revealed that the characteristics of FHR gradually changed with increasing gestational age, and the most obvious change was observed at 32–33 weeks, demonstrating that the specific gestational weeks may be an important period for the physiological bias of FHR tends to mature.

424 High short-term variability of fetal heart-rate reflects maternal-fetal metabolic syndrome

The cause of antepartum fetal heart rate (FHR) short-term variability (STV) interfetal differences and their interaction with the biological environment are poorly understood. We suggest that: i) norepinephrine increases baseline STV (inducing the high frequency component while the low frequency component is due to parasympathetic co-activation, see figure), and ii) transient epinephrine release induces transient FHR accelerations. The norepinephrine/epinephrine ratio is known to increase after childbirth in adults with uncomplicated obesity. To test our hypothesis, we studied the relationship between higher antepartum STV values and several maternal-fetal metabolic syndrome criteria. Our study included 477 unselected single pregnancies (initial weight 62±12 kg) involved in an enhanced prenatal care program (7 FHR tracings per pregnancy; high-risk cases included). STV was calculated by SisPorto version 3.6. As we suspected that some low STV tracings could introduce bias, we focused on the highest STV level of one antepartum tracing, rather than the highest level of the average of all tracings. The case group was defined by the greatest STV ≥ 97th percentile, as well as a low FHR acceleration score. The remaining cases were assigned to the control group. A univariate descriptive analysis was used to compare the case group (12 pregnancies) with the control group data. We observed the following significant higher values in the case group: initial maternal weight (> 100 kg 25% vs. 1%, > 80 kg 17% vs. 7%, p<0.001), gestational diabetes mellitus (42% vs. 7%, p<0.002), incidence of glycemia > 90th percentile at one-hour post second trimester load (36% vs. 9%, p<0.02), and, lastly, infant birth weight (3,717g ± 591 vs. 3,385g ± 470, p<0.03). We confirm the relationship between high antepartum STV and maternal-fetal metabolic syndrome. It supports our hypothesis concerning the respective effects of norepinephrine and epinephrine on FHR. Improved antepartum FHR analysis could help to detect maternal-fetal metabolic syndromes, insulin resistance, and delayed lung maturity.

Effect of Dexamethasone on Antepartum Cardiotocography

Objective: The purpose of this study was to evaluate the effect of dexamethasone on fetal heart rate parameters using the standard dose regimen. Study Design: A prospective cohort study conducted in the Maternity Department, Suez Canal University hospitals. Sixty- eight pregnant women with gestational age between 28 and 34 weeks were recruited. Patients received 4 doses of dexamethasone 6 mg every 12 hours for threatened preterm delivery due to preterm premature rupture of membranes, placenta previa or history of preterm labor. Computerized cardiotocography was recorded for 60 minutes on day 0 (before dexamethasone administration), day 2 and day 4 after administration. Cardiotocography monitoring was performed between 11 am and 1 pm to avoid diurnal rhythm of fetal heart rate. Outcome measure included changes in fetal heart rate accelerations, variability and fetal movements following dexamethasone injection. Results: Sixty-eight patients were enrolled in the study. Fetal heart rate accelerations (P=0.0001), short-term variation (P=0.01), episodes of high variation (P=0.003) and fetal movements (P=0.0001) were significantly reduced on day 2 after dexamethasone. No significant changes were found on baseline fetal heart rate (P=0.18), long-term variation (P=0.1) and number of decelerations (P=0.1). All parameters returned to baseline values on Day 4 after administration. Conclusion: Dexamethasone induces transient suppression of fetal heart rate parameters on day 2 after administration that mimics fetal compromise. Awareness of this phenomenon is important to avoid iatrogenic delivery of preterm fetuses.

Role of non stress test in monitoring antenatal fetal well being in high risk pregnancy

Antepartum evaluation of the fetus at risk for damage or death in utero remains a major challenge in modern obstetrics. Freeman &amp; Lee (1975) and colleagues introduced the non-stress test to describe acceleration of fetal heart rate is a sign of fetal health in response to fetal movement. Role of Non stress test in antepartum fetal surveillance and perinatal outcome in high risk pregnancy. To prove the efficacy of NST as an effective tool for evaluation of fetal well-being. To decrease perinatal morbidity and mortality. Hospital based prospective study. 50 pregnant women with high risk factors as study group and 50 healthy pregnant women as control group were randomly selected from period of July 2015 to December 2015 in the department of Obst &amp; Gynae Dr. S. N. Medical college Jodhpur. Non stress test performed and results were analysed.Non stress test as screening test for antenatal fetal surveillance has high specificity and high negative predictive value.The ideal test for fetal reserve should be safe, inexpensive, readily available, quickly exerted and devoid of either false positive or false negative results. As yet no such test exists which is perfect, still NST has been shown to be most acceptable modality for evaluating the fetus in utero.

Use of sound-elicited fetal heart rate accelerations to assess fetal hearing in the second and third trimester

ObjectivesWe previously reported that fetal heart rate (FHR) accelerations could be obtained after fetal sound stimulation. We examined FHR accelerations during 20–37 weeks gestational age (GA) in order to assess the optimal time for the test. MethodsThe fetus was stimulated from the maternal abdomen with pure tone 2000 Hz, 90 dB, 5 s. Changes in the FHR before and after the sound stimulation were measured by a cardiotocometer. ResultsCompared with the positive rate of FHR accelerations at 20–21 weeks GA, significant increases were recognized in 26–27, 28 to 29, 30 to 31, and 34–35 weeks GA. Comparing the positive rate of FHR accelerations between the minimal and moderate variability of FHR baseline, no significant differences were observed at 20–27 weeks GA. On the other hand, at 28–37 weeks GA, the positive rate to detect FHR accelerations due to sound stimulation was 100% in moderate FHR baseline variability. ConclusionConsidering development of human fetal hearing, the method should be performed between 28 and 37 weeks GA and during moderate FHR variability corresponding to active sleep conditions. The method developed in the present study may provide a promising tool for evaluating the fetal hearing.

631: Noninvasive fetal heart rate monitoring: Abdominal fetal ECG v. Doppler ultrasound cardiotocogram in obese patients

Noninvasive fetal echocardiography (fECG) is a unique method of fetal heart rate (FHR) monitoring. We aim to investigate the clinical utility of a novel noninvasive abdominal fECG device as compared to the standard of care Doppler ultrasound cardiotocography (CTG) in obese patients. We conducted a prospective observational study of women from December 2018 to July 2019. Inclusion criteria: maternal BMI > 30 kg/m2, nonanomalous, singleton gestation. Patients were monitored simultaneously with the noninvasive fECG and CTG device for thirty minutes. Two blinded obstetricians independently analyzed the tracings. The primary outcome: average number of uninterpretable minutes of tracing of the fECG device as compared to CTG. Secondary outcomes included a comparison of baseline FHR, variability, number and onset of FHR accelerations and decelerations. The generalized estimating equation normal and Poisson models with identity and log links were used to calculate outcomes. Kappa indices between the two observers were computed for each outcome. 55 patients were recruited. Nine patients were excluded from analysis due to technical error of the fECG device and poor signal quality. Monitoring with the devices simultaneously yielded a total of 1303.66 minutes of tracing. On average, the fECG device had 2.71 minutes more of uninterpretable tracing (effect estimate 2.71, (0.45, 4.98), p=0.02) as compared to CTG. Overall, the fECG device was no different in its ability to detect baseline FHR (effect size 0.1 (-1.00, 1.20) p=0.86), variability, and number of FHR accelerations/decelerations (effect size 0.87 (0.69, 1.1) p=0.25). A Kappa agreement index for the timing of onset of accelerations/decelerations was calculated to be 0.18 (-0.23, 0.59). Noninvasive fECG yielded on average 2.71 minutes more of uninterpretable tracing out of 30 min compared to the CTG device. In all other parameters of FHR tracing it performed similarly. Given that the noninvasive fECG device is wireless and therefore allows ambulation, consideration should be given to its use as an alternative to Doppler CTG.View Large Image Figure ViewerDownload Hi-res image Download (PPT)

The effect of prenatal exposure to music on fetal movements and fetal heart rate: a pilot study

Objective To assess and compare fetal cardiac parameters of fetuses listening to music before and during nonstress test, only during the test or never. Study design Thirty healthy mother-fetus dyads were randomized in a 1:1:1 ratio to one of three groups: group A in which fetuses were submitted to prelistening phase (33rd + 0 to 36th + 3 week) and listening sessions during 4 nonstress tests, group B in which fetuses were submitted to listening sessions during 4 nonstress tests, and group C receiving 4 nonstress tests without any listening. We assessed mean fetal heart rate, fetal heart rate accelerations, fetal heart rate decelerations, fetal movements and uterine contractility. Results Fetuses of the group A, who had already listened to a particular piece of music during previous sessions, had significantly increased their heart rate accelerations and movements during the music listening session of the last nonstress test. No significant changes were observed in the number of uterine contractions. Conclusions Our findings show that fetuses slightly respond to that music they know, but they do not significantly respond to unknown music.

Multiscale Coupling of Uterine Electromyography and Fetal Heart Rate as a Novel Indicator of Fetal Neural Development.

Fetal nerve maturation is a dynamic process, which is reflected in fetal movement and fetal heart rate (FHR) patterns. Classical FHR variability (fHRV) indices cannot fully reflect their complex interrelationship. This study aims to provide an alternative insight for fetal neural development by using the coupling analysis of uterine electromyography (UEMG) and FHR acceleration. We investigated 39 normal pregnancies with appropriate for gestational age (AGA) and 19 high-risk pregnancies with small for gestational age (SGA) at 28–39 weeks. The UEMG and FHR were recorded simultaneously by a trans-abdominal device during the night (10 p.m.−8 a.m.). Cross-wavelet analysis was used to characterize the dynamic relationship between FHR and UEMG. Subsequently, a UEMG-FHR coupling index (UFCI) was extracted from the multiscale coupling power spectrum. We examined the gestational-age dependency of UFCI by linear/quadratic regression models, and the ability to screen for SGA using binary logistic regression. Also, the performances of classical fHRV indices, including short-term variation (STV), averaged acceleration capacity (AAC), and averaged deceleration capacity (ADC), time- and frequency- domain indices, and multiscale entropy (MSE), were compared as references on the same recordings. The results showed that UFCI provided a stronger age predicting value with R2 = 0.480, in contrast to the best value among other fHRV indices with R2 = 0.335, by univariate regression models. Also, UFCI achieved superior performance for predicting SGA with the area under the curve (AUC) of 0.88, compared with 0.79 for best performance of other fHRV indices. The present results indicate that UFCI provides new information for early detection and comprehensive interpretation of intrauterine growth restriction in prenatal diagnosis, and helps improve the screening of SGA.

Automatic Cardiotocography Diagnostic System Based on Hilbert Transform and Adaptive Threshold Technique

The visual analysis of cardiotocographic examinations is a very subjective process. The accurate detection and segmentation of the fetal heart rate (FHR) features and their correlation with the uterine contractions in time allow a better diagnostic and the possibility of anticipation of many problems related to fetal distress. This paper presents a computerized diagnostic aid system based on digital signal processing techniques to detect and segment changes in the FHR and the uterine tone signals automatically. After a pre-processing phase, the FHR baseline detection is calculated. An auxiliary signal called detection line is proposed to support the detection and segmentation processes. Then, the Hilbert transform is used with an adaptive threshold for identifying fiducial points on the fetal and maternal signals. For an antepartum (before labor) database, the positive predictivity value (PPV) is 96.80% for the FHR decelerations, and 96.18% for the FHR accelerations. For an intrapartum (during labor) database, the PPV found was 91.31% for the uterine contractions, 94.01% for the FHR decelerations, and 100% for the FHR accelerations. For the whole set of exams, PPV and SE were both 100% for the identification of FHR DIP II and prolonged decelerations.

Diurnal rhythm of fetal heart rate in third trimester of pregnancy

Objective: To investigate the diurnal rhythms of fetal heart rate in third trimester of pregnancy. Methods: From June 2014 and October 2017, 97 cases of low-risk pregnancy women who received antenatal care and deliveried in Peking University Third Hospital were collected. Totally 130 cases of fetal heart rate and maternal holter monitoring data were analyzed. All cases were singleton pregnancy, cephalic position and had normal perinatal outcome. They were divided into three groups based on gestational age, 29 cases (22.3%,29/130) in pregnancy 28-33(+6) weeks, 37 cases (28.5%,37/130) in 34-36(+6) weeks, and 64 cases (49.2%, 64/130) in 37-40(+6) weeks. Fetal heart baseline (FHB) , fetal heart baseline variation (FHBV) , fetal heart rate acceleration area and maternal heart rate were acquired by computer, their diurnal rhythms and the differences among three groups were analyzed. Results: FHB、FHBV、fetal heart rate acceleration area and maternal heart rate all presented diurnal rhythms. (1) FHB rose in daytime and decreased at night with the minimum value at 2:00-5:00, and didn't decline further at night with the advancing of gestational age (P=0.548). (2) FHBV was similar to FHB, which rose in daytime and decreased at night, but declined smaller at night with the advancing of gestational age, especially after 37 weeks (P<0.01). (3) Fetal heart rate acceleration area reduced in daytime and enlarged at night, and enlarged more with the advancing of gestational age. (4) The diurnal rhythm of maternal heart rate was consistent with fetal heart rate. FHB lagged behind maternal heart rate for 1-2 hours when declining to the nocturnal nadir but been basically in sync with maternal heart rate when recovered. Conclusion: The basic characteristics of fetal heart rate in normal pregnancy exist obviously diurnal rhythms, and change in different trends with the advancing of gestational age.