Fetal Heart Rate Variability Research Articles

Decreased fetal heart rate variability and maternal combined dose of sodium valproate and phenytoin.

A 32-year-old Japanese woman was admitted at 38 weeks' gestation with regular uterine contractions. She was diagnosed with frontal lobe epilepsy at the age of 17, and she had been treated with several anti-epileptic drugs (AEDs) since then but complied poorly due mainly to nausea and frequent seizure attacks.

Maternal Serotonin Reuptake Inhibitor Antidepressants Have Acute Effects on Fetal Heart Rate Variability in Late Gestation.

Background: Prenatal exposure to serotonin reuptake inhibitor (SRI) antidepressants increases risk for adverse neurodevelopmental outcomes, yet little is known about whether effects are present before birth. In relation to maternal SRI pharmacokinetics, this study investigated chronic and acute effects of prenatal SRI exposure on third-trimester fetal heart rate variability (HRV), while evaluating confounding effects of maternal depressed mood.Methods: At 36-weeks' gestation, cardiotocograph measures of fetal HR and HRV were obtained from 148 pregnant women [four groups: SRI-Depressed (n = 31), SRI-Non-Depressed (n = 18), Depressed (unmedicated; n = 42), and Control (n = 57)] before, and ~5-h after, typical SRI dose. Maternal plasma drug concentrations were quantified at baseline (pre-dose) and four time-points post-dose. Mixed effects modeling investigated group differences between baseline/pre-dose and post-dose fetal HR outcomes. Post hoc analyses investigated sex differences and dose-dependent SRI effects.Results: Maternal SRI plasma concentrations were lowest during the baseline/pre-dose fetal assessment (trough) and increased to a peak at the post-dose assessment; concentration-time curves varied widely between individuals. No group differences in fetal HR or HRV were observed at baseline/pre-dose; however, following maternal SRI dose, short-term HRV decreased in both SRI-exposed fetal groups. In the SRI-Depressed group, these post-dose decreases were displayed by male fetuses, but not females. Further, episodes of high HRV decreased post-dose relative to baseline, but only among SRI-Non-Depressed group fetuses. Higher maternal SRI doses also predicted a greater number of fetal HR decelerations. Fetuses exposed to unmedicated maternal depressed mood did not differ from Controls.Conclusions: Prenatal SRI exposure had acute post-dose effects on fetal HRV in late gestation, which differed depending on maternal mood response to SRI pharmacotherapy. Importantly, fetal SRI effects were sex-specific among mothers with persistent depressive symptoms, as only male fetuses displayed acute HRV decreases. At trough (pre-dose), chronic fetal SRI effects were not identified; however, concurrent changes in maternal SRI plasma levels suggest that fetal drug exposure is inconsistent. Acute SRI-related changes in fetal HRV may reflect a pharmacologic mechanism, a transient impairment in autonomic functioning, or an early adaption to altered serotonergic signaling, which may differ between males and females. Replication is needed to determine significance with postnatal development.

Effects of acute tocolysis using ritodrine hydrochloride on foetal heart rate patterns in intrauterine foetal resuscitation: a retrospective, single-centre observational study

No consistent recommendations concerning the preferred tocolytic agents for intrauterine foetal resuscitation are available. We evaluated the effects of acute tocolysis (AT) using ritodrine hydrochloride on foetal heart rate (FHR) patterns and neonatal outcomes. We retrospectively analysed the data of patients undergoing emergency caesarean section because of non-reassuring foetal status indicated by foetal scalp electrodes. Patients were classified into AT (ritodrine hydrochloride approximately 500 µg/min) and control groups with 15 and 12 participants, respectively. FHR patterns, Apgar scores, umbilical arterial analysis, and neonatal admission were compared. All participants had FHR category II; decelerations disappeared in all foetuses in the AT group, with no significant difference in neonatal outcomes. The AT group had a higher baseline FHR and lower short-term FHR variability than the control group, indicating foetal autonomic responses. Further studies are needed to clarify the effects of AT on FHR patterns, neonatal outcomes, and foetal and neonatal autonomic responses. Impact statement What is already known on this subject? The usefulness of acute tocolysis using ritodrine hydrochloride has been well-documented in several studies; however, such an application often induces side effects, such as maternal tachycardia, palpitations, and tremors. What the results of this study add? The short-term administration of ritodrine hydrochloride eliminated decelerations, with no significant difference in neonatal outcomes in pregnant women with foetal heart rate category II. Meanwhile, there were higher foetal heart rate and lower short-term foetal heart rate variability in pregnant women administered with ritodrine hydrochloride, indicating foetal autonomic responses. What the implications are of these findings for clinical practice and/or further research? Ritodrine hydrochloride administration, even for short-term, appears to be associated with foetal autonomic responses. Further studies with stratification of patient groups based on the severity and aetiology of non-reassuring foetal status, including pregnant women with foetal category III, would elucidate the risk and benefit of acute tocolysis using ritodrine hydrochloride, based on foetal heart rate patterns, neonatal outcomes, and foetal and neonatal autonomic responses.

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.

Distance to Healthy Metabolic and Cardiovascular Dynamics From Fetal Heart Rate Scale-Dependent Features in Pregnant Sheep Model of Human Labor Predicts the Evolution of Acidemia and Cardiovascular Decompensation.

The overarching goal of the present work is to contribute to the understanding of the relations between fetal heart rate (FHR) temporal dynamics and the well-being of the fetus, notably in terms of predicting the evolution of lactate, pH and cardiovascular decompensation (CVD). It makes uses of an established animal model of human labor, where 14 near-term ovine fetuses subjected to umbilical cord occlusions (UCO) were instrumented to permit regular intermittent measurements of metabolites lactate and base excess, pH, and continuous recording of electrocardiogram (ECG) and systemic arterial blood pressure (to identify CVD) during UCO. ECG-derived FHR was digitized at the sampling rate of 1,000 Hz and resampled to 4 Hz, as used in clinical routine. We focused on four FHR variability features which are tunable to temporal scales of FHR dynamics, robustly computable from FHR sampled at 4 Hz and within short-time sliding windows, hence permitting a time-dependent, or local, analysis of FHR which helps dealing with signal noise. Results show the sensitivity of the proposed features for early detection of CVD, correlation to metabolites and pH, useful for early acidosis detection and the importance of coarse time scales (2.5–8 s) which are not disturbed by the low FHR sampling rate. Further, we introduce the performance of an individualized self-referencing metric of the distance to healthy state, based on a combination of the four features. We demonstrate that this novel metric, applied to clinically available FHR temporal dynamics alone, accurately predicts the time occurrence of CVD which heralds a clinically significant degradation of the fetal health reserve to tolerate the trial of labor.

Maternal corticosteroids and depression during gestation and decreased fetal heart rate variability.

Maternal depression during gestation is an adverse factor in fetal brain development that manifests in later childhood behavioral problems. Fetal heart rate variability (FHRV) mediated by parasympathetic input is a marker of gestational nervous system development. Biological mediators of adverse effects of maternal depression may involve the mother's corticosteroids; however, links between depression, corticosteroids, and early nervous system development remain inconclusive. Heart rate was recorded in 23 fetuses by transabdominal Doppler at 28-33 weeks gestation. The SD of interbeat intervals over 20 min assessed FHRV. Maternal depression ratings and hair concentrations of cortisol and cortisone were assayed. An auditory sensory gating paradigm assessed newborn development of cerebral inhibition. Parents rated their infant's temperament characteristics on the Infant Behavior Questionnaire-Revised Short Form (IBQ-R). Maternal depression was associated with lower FHRV, especially for male fetuses, β = -0.633, P = 0.045. Maternal depression was associated with lower cortisol to total corticosteroids ratios, β = -0.519, P = 0.033. Lower cortisol ratios were associated with decreased FHRV, β = 0.485, P = 0.019. Decreased FHRV was associated with increased newborn sensory gating deficits, β = -0.992, P = 0.035, indicating poorer development of cerebral inhibition. Higher FHRV was related to increased infant IBQ-R self-regulatory behaviors, r = 0.454, P = 0.029. Maternal depression is associated via corticosteroids with decreased development of nervous system control of fetal heart rate. Decreased FHRV indicates developmental alterations in gestation that correlate with altered brain function and subsequent regulatory challenges in early infancy.

Labour Induction Methods: An Overview

Overall the rate of induced labours has increased and almost 25% of women undergo labour induction worldwide. Cervical ripening and cervical preparedness is necessary before labour can be induced. The status of the cervix is traditionally assessed with help of Bishop’s score. Labour induction becomes necessary when the cervix is not favourable as noted on the cervical scoring system. Mechanical or surgical methods or a combination of both can be sued for labour induction. These include Foley’s catheter induction, sweeping of membranes, amniotomy etc. Pharmacological agents like oxytocin, prostaglandins PGE1 & PGE2 and newer agents like mifepristone can be used. Mechanical methods like Foley’s catheter induction are associated with lesser FHR variability and decreased rates of caesarean section as compared with oxytocin infusion or prostaglandins used locally. Oxytocin is the most widely used pharmacological method used for induction of labour. Proper titration of oxytocin can result in contractions that mimic normal labour. Oxytocin is often combined with amniotomy. Prostaglandins PGE1 & PGE2 are safe and effective options for labour induction. Prostaglandin PGE1 or misoprostol is used in the dose of 25 microgram mcg given orally or vaginally or via the sub-lingual route. Prostaglandin PGE2 or dinoprostone is used intra-cervically or vaginally in the posterior fornix. The newer drug mifepristone is being studied as cervical ripening agents because of its anti-progesterone effect.

The use of ultrasonographic measurement of the heart size and fetal heart rate variation for gestational age determination in local Bulgarian goats.

BackgroundDetermination of gestational age in goats was performed using ultrasound measurements of different fetal biometric parameters. There are no data showing quadratic and exponential dependence between fetal heart parameters and gestational age.ObjectivesThe objective of the present study was to test the significance of the defined indicators (fetal heart rate, longitudinal and transverse fetal heart axes) for determining gestational age in local Bulgarian goats.MethodsA total of 24 pregnant local Bulgarian goats, aged between 2 and 5 years, body weight 42–50 kg were included in the study. Ultrasonographic examinations were performed weekly on gestational days 21, 28, 35, 42 and 49. After gestational day 49 until parturition, scans were performed biweekly. The data from the measurements were subjected to linear (y = a + bx), quadratic (y = aх 2 + bх + c) and exponential (y = ax n) correlation. Results: Average fetal heart rate values decreased with pregnancy progression. The coefficient of determination (R2) and standard error of estimate (SEE) of the heart rate indicator were 0.72, 0.75, 0.58 and 15.1, 14.4, 19.2 days, respectively, for the three correlations. Longitudinal diameter (long axis) had the following values for R2 = 0.94, 0.96, 0.96 and for SEE = 7.0, 5.5, 5.5 days, for the linear, quadratic and exponential correlations, respectively, while the values of the fetal heart transverse diameter (short axis) were higher than those of the external one (R2 = 0.95, 0.97, 0.97). Simultaneously, SEE is lower (SEE = 6.1, 4.9, 5.0 days) compared to that found for the long heart fetal axis.ConclusionsFor precise estimation of gestational age, use of longitudinal (long) and transverse (short) axes is recommended. Fetal heart rate is not an exact indicator but can be used as a reference for gestational age along with changes in the heart size and echogenicity.

Fetal Heart Rate Variability Before and After Antenatal Corticosteroids in Patients at High Risk of Preterm Labor

Background: Premature birth (PTB) occurs in one in ten pregnancies. There are about 13 million PTBs annually worldwide. Antenatal corticosteroids are administered to enhance fetal lung maturation in cases of threatened preterm delivery between 24- and 34-weeks’ gestational age (GA). Objective: This study aimed to study the cardiotocograp (CTG) before and after antenatal corticosteroids administration in patients at high risk of preterm labor to reduce preterm risks. Patients and Methods: A prospective cohort study included 52 women who were at risk of premature birth. Each woman received the recommended course of corticosteroids consists of 4 doses of dexamethasone 6 mg for 48 hours (Dexamethasone 8 ml intramuscularly, 12 h apart). CTG examination: Fetal heart rate was monitored with fetal monitor cardiotocogram machine. Cardiotocography strips were interpreted visually. Results: In our study we recorded decrease in baseline fetal heart rate and increase in fetal heart rate variability (LTV, STV) after dexamethasone course by 24 hours, which were statistically significant. The number of accelerations showed a slight increase, which was significant. Decelerations were not present at all before or after the course. The STV showed a significant change before the course, all participants had moderate STV, but after the course, 8 (15.4%) showed marked variability, which was significant. We found that most of participants (90.4%) had decreased fetal kicks after injection relying on maternal perception. Conclusion: There was a decrease in baseline fetal heart rate and increase in fetal heart rate variability (LTV, STV) after dexamethasone course by 24 hours, which were statistically significant. The number of accelerations showed a slight increase, which was significant.

Effect of oxytocin injection on fetal heart rate based on multifractal analysis

Abstract Background: Oxytocin is a short acting drug, which needs continuous intravenous drip to maintain the effect of uterine contraction. Excessive uterine contraction may lead to abnormal blood supply of fetal placenta and fetal hypoxia. It is necessary to take care of the injection, and observe the fetal heart rate and uterine contraction, yet there is little research on potential effects on fetal by analyzing the electrocardiogram (ECG) signal from the perspective of nonlinear dynamic system. Aims: To explore the effectiveness of multifractal theory in analyzing the mechanism of oxytocin injection on the stability of fetal heart rate (FHR). Subjects: 20 healthy young parturient women who have normal singleton fetuses in full term pregnancy, they are numbered from 1 to 20, which cover the age from 20 to 40 years old. From standard obstetric observation, all of the maternals have no diabetes mellitus, smoking experience, hypertension, administration of cardiovascular effective drugs and cardiovascular diseases. Exclusion criteria: Fetal arrhythmia, intrauterine growth restriction, previous exposure to synthetic steroids in the utero and non-stress non-reassuring test on ECG. Method: multifractal detrended fluctuation analysis (MF-DFA). Results: The widths of Δ H ( q ) (0.5536 and 0.5607) and Δ α (0.7074 and 0.7153) before and during oxytocin injection, respectively, indicating that the strength of the multifractality of the FHR variability signal during oxytocin injection is slightly graeter than before, but the difference is not very significant. In addition, long-range correlation and a fat-tailed distribution contribute to multifractality, which is the most important source that can be confirmed by shuffling and surrogating the FHR signals. To document the major source of multifractality, we shuffle and surrogate the series, and the results indicate that the fat-tailed distribution contributes to the multifractality of times series before and during oxytocin injection. Conclusions: Oxytocin injection may affect autonomic nervous system of fetus. With the increase of time, oxytocin intravenous infusion may increase the risk of fetal heart instability, while the effect is very little compared with that before oxytocin injection.

Fetal neuromaturation in late gestation is affected by maternal sleep disordered breathing and sleep disruption in pregnant women with obesity.

Maternal sleep disordered breathing and sleep disruption have adverse effects on pregnancy outcomes through multiple potential pathophysiologic pathways. We hypothesize that disordered maternal sleep also adversely impacts the neuromaturation of the fetus. Participants in this prospective observational study included 102 obese pregnant women (pre-pregnancy body mass index [BMI] of 30 or higher) at 36weeks of pregnancy. Fetal neuromaturation, defined through measures of fetal heart rate variability, motor activity, and motor-cardiac coupling, was quantified through digitized fetal actocardiography during an afternoon recording. Maternal sleep measures were collected overnight through polysomnography. Data analysis focused on multiple regression, controlling for maternal BMI, blood pressure, and diabetes. Indicators of higher sleep disordered breathing were associated with delayed fetal neuromaturation and greater fetal motor activity. Less maternal sleep disruption (shorter rapid eye movement [REM] latency, more REM sleep, and/or fewer transitions) was associated with higher fetal heart rate variability and coupling-based neuromaturation. Characteristics of disordered maternal sleep affect the developing fetal nervous system. It is unknown whether these results extend to populations that are not characterized by obesity. The influence of maternal sleep on the developing fetal nervous system has been understudied and may yield effects that persist beyond pregnancy.

Assessment of human fetal cardiac autonomic nervous system development using color tissue Doppler imaging.

ObjectivesFunctional development of the fetal cardiac autonomic nervous system (cANS) plays a key role in fetal maturation and can be assessed through fetal heart rate variability (fHRV)‐analysis, with each HRV parameter representing different aspects of cANS activity. Current available techniques, however, are unable to assess the fHRV parameters accurately throughout the whole pregnancy. This study aims to test the feasibility of color tissue Doppler imaging (cTDI) as a new ultrasound technique for HRV analysis. Secondly, we explored time trends of fHRV parameters using this technique.Methods18 healthy singleton fetuses were examined sequentially every 8 weeks from 10 weeks GA onwards. From each examination, 3 cTDI recordings of the four‐chamber view of 10 seconds were retrieved to determine accurate beat‐to‐beat intervals. The fHRV parameters SDNN, RMSSD, SDNN/RMSSD, and pNN10, each representing different functional aspects of the cANS, were measured, and time trends during pregnancy were explored using spline functions within a linear mixed‐effects model.ResultsIn total, 77% (95% Cl 66–87%) of examinations were feasible for fHRV analysis from the first trimester onwards, which is a great improvement compared to other techniques. The technique is able to determine different maturation rates of the fHRV parameters, showing that cANS function, presumably parasympathetic activity, establishes around 20 weeks GA and matures rapidly until 30 weeks GA.ConclusionsThis is the first study able to assess cANS function through fHRV analysis from the first trimester onwards. The use of cTDI to determine beat‐to‐beat intervals seems feasible in just 3 clips of 10 seconds, which holds promise for future clinical use in assessing fetal well‐being.

Fetal Cardiovascular Decompensation During Labor Predicted From the Individual Heart Rate Tracing: A Machine Learning Approach in Near-Term Fetal Sheep Model.

Background: When exposed to repetitive umbilical cord occlusions (UCO) with worsening acidemia, fetuses eventually develop cardiovascular decompensation manifesting as pathological hypotensive arterial blood pressure (ABP) responses to fetal heart rate (FHR) decelerations. Failure to maintain cardiac output during labor is a key event leading up to brain injury. We reported that the timing of the event when a fetus begins to exhibit this cardiovascular phenotype is highly individual and was impossible to predict.Objective: We hypothesized that this phenotype would be reflected in the individual behavior of heart rate variability (HRV) as measured by root mean square of successive differences of R-R intervals (RMSSD), a measure of vagal modulation of HRV, which is known to increase with worsening acidemia. This is clinically relevant because HRV can be computed in real-time intrapartum. Consequently, we aimed to predict the individual timing of the event when a hypotensive ABP pattern would emerge in a fetus from a series of continuous RMSSD data.Study Design: Fourteen near-term fetal sheep were chronically instrumented with vascular catheters to record fetal arterial blood pressure, umbilical cord occluder to mimic uterine contractions occurring during human labor and ECG electrodes to compute the ECG-derived HRV measure RMSSD. All animals were studied over a ~6 h period. After a 1–2 h baseline control period, the animals underwent mild, moderate, and severe series of repetitive UCO. We applied the recently developed machine learning algorithm to detect physiologically meaningful changes in RMSSD dynamics with worsening acidemia and hypotensive responses to FHR decelerations. To mimic clinical scenarios using an ultrasound-based 4 Hz FHR sampling rate, we recomputed RMSSD from FHR sampled at 4 Hz and compared the performance of our algorithm under both conditions (1,000 Hz vs. 4 Hz).Results: The RMSSD values were highly non-stationary, with four different regimes and three regime changes, corresponding to a baseline period followed by mild, moderate, and severe UCO series. Each time series was characterized by seemingly randomly occurring (in terms of timing of the individual onset) increase in RMSSD values at different time points during the moderate UCO series and at the start of the severe UCO series. This event manifested as an increasing trend in RMSSD values, which counter-intuitively emerged as a period of relative stationarity for the time series. Our algorithm identified these change points as the individual time points of cardiovascular decompensation with 92% sensitivity, 86% accuracy and 92% precision which corresponded to 14 ± 21 min before the visual identification. In the 4 Hz RMSSD time series, the algorithm detected the event with 3 times earlier detection times than at 1,000 Hz, i.e., producing false positive alarms with 50% sensitivity, 21% accuracy, and 27% precision. We identified the overestimation of baseline FHR variability by RMSSD at a 4 Hz sampling rate to be the cause of this phenomenon.Conclusions: The key finding is demonstration of FHR monitoring to detect fetal cardiovascular decompensation during labor. This validates the hypothesis that our HRV-based algorithm identifies individual time points of ABP responses to UCO with worsening acidemia by extracting change point information from the physiologically related fluctuations in the RMSSD signal. This performance depends on the acquisition accuracy of beat to beat fluctuations achieved in trans-abdominal ECG devices and fails at the sampling rate used clinically in ultrasound-based systems. This has implications for implementing such an approach in clinical practice.

Induction of labor in late FGR.

Late-onset FGR is a peculiar condition characterized by the inability for the fetus to reach its growth potential diagnosed from 32 weeks of gestation. Placental insufficiency is among the leading causes of late FGR and is commonly due to a primary maternal cardiovascular non-adaptation potentially leading to fetal decompensation during labor especially once exposed to uterine hyperstimulation. Abnormalities that usually characterize late FGR include reduced fetal growth, decreased Amniotic Fluid Index, and loss of fetal heart rate variability at CTG. Fetal hemodynamics study by Doppler ultrasound significantly improved management of pregnancies affected by fetal growth restriction. A major issue when dealing with pregnancies complicated by late FGR is how to induce these women. Induction of labor (IOL) can be essentially accomplished by pharmacological and non-pharmacological agents. Recent studies suggested that the pregnancies complicated by late FGR should undergo a tailored approach for IOL in view of the higher risk of fetal decompensation following uterine hyperstimulation. The present review aims to provide an up to date on the different types of IOL which can guide clinical management.

Transient effects of forebrain ischemia on fetal heart rate variability in fetal sheep.

Fetal heart rate variability (FHRV) is a key index of antenatal and intrapartum fetal well-being. FHRV is well established to be mediated by both arms of the autonomic nervous system, but it remains unknown whether higher centers in the forebrain contribute to FHRV. We tested the hypothesis that selective forebrain ischemia would impair the generation of FHRV. Sixteen chronically instrumented near-term fetal sheep were subjected to either forebrain ischemia induced by bilateral carotid occlusion or sham-ischemia for 30 min. Time, frequency, and nonlinear measures of FHRV were assessed during and for seven days after ischemia. Ischemia was associated with profound suppression of electroencephalographic (EEG) power, which remained suppressed throughout the recovery period (P < 0.001). During the first 5 min of ischemia, multiple time and frequency domain measures were increased (all P < 0.05) before returning back to sham levels. A delayed increase in sample entropy was observed during ischemia (P < 0.05). For the first 3 h after ischemia, there was moderate suppression of two measures of FHRV (very-low frequency power and the standard deviation of RR-intervals, both P < 0.05) and increased sample entropy (P < 0.05). Thereafter, all measures of FHRV returned to control levels. In conclusion, profound forebrain ischemia sufficient to lead to severe neural injury had only transient effect on multiple measures of FHRV. These findings suggest that the forebrain makes a limited contribution to FHRV. FHRV therefore primarily originates in the hindbrain and is unlikely to provide meaningful information on forebrain neurodevelopment or metabolism.

Analysis of the results of a retrospective cohort study of the course of pregnancy, childbirth and the postpartum period in high-risk patients to identify factors of unfavorable outcomes and build a predictive model of fetal loss

Prenatal prognosis is an important part of obstetric care, which aims to reduce fetal and neonatal losses. A differentiated approach to the management of different risk groups allows you to optimize existing approaches.The objective: to identify antenatal factors that correlate with perinatal losses, by conducting a retrospective cohort study of women at high perinatal risk, to build a multifactorial prognostic model of adverse pregnancy outcomes.Materials and methods. A retrospective cohort study was conducted from 2014 to 2016 on the basis of the medical center LLC «Uniclinic», Medical Genetics Center «Genome», Clinic of Reproductive Genetics «Victoria», Kyiv City Maternity Hospital №2. 2154 medical cards of pregnant women from the group of high perinatal risk were selected and analyzed. Of these, 782 pregnant women were included in the final protocol after verification of compliance with the criteria.Results. Cesarean delivery occurred in 115 cases (14.7%). In 50 cases (6.4%) the caesarean section was performed in a planned manner, in 65 (8.3%) – in an emergency. In 39 (5%) cases, the indication for surgical delivery was acute fetal distress. Antenatal fetal death occurred in 11 (1.4%) cases: one case in terms of &lt;34 weeks and &lt;37 weeks of gestation, the remaining 9 cases – in terms of&gt; 37 weeks. Intranatal death of two fetuses (0.3%) was due to acute asphyxia on the background of placental insufficiency. In the early neonatal period, 14 (1.8%) newborns died. Hospitalization of the newborn to the intensive care unit for the first 7 days was registered in 64 (8.2%) cases.The need for mechanical ventilation was stated in 3.96% (31/782) of newborns. The method of construction and analysis of multifactor models of logistic regression was used in the analysis of the relationship between the risk of perinatal losses (antenatal death, intranatal death, early neonatal death) and factor characteristics.Conclusion. Signs associated with the risk of perinatal loss: the presence of chronic hypertension, preeclampsia in previous pregnancies, type of fertilization (natural or artificial), the concentration of PAPP-A (MoM), the concentration of free β-HCG (MoM) in the second trimester, average PI in the uterine arteries in 28–30 weeks of pregnancy, PI in the middle cerebral arteries in 28–30 weeks of pregnancy, episodes of low fetal heart rate variability in the third trimester of pregnancy, episodes of high fetal heart rate variability in the third trimester of pregnancy. The model, built on selected features, allows with a sensitivity of 73.1% (95% CI: 52.2% – 88.4%) and a specificity of 72.7% (95% CI: 69.3% – 75.9%) to predict risk perinatal loss.

ANTENATAL BETAMETHASONE COMPARED WITH DEXAMETHASONE IN TERMS OF FETAL HEART RATE VARIABILITY AND FETAL BODY MOVEMENTS

Introduction: Preterm labor occurs between 20th and 37th gestational week which is regardless of the birth weight. The incidence of preterm birth is increasing and continues to be the leading cause of neonatal mortality and morbidity. Antenatal corticosteroids are used for pregnant women at risk of preterm labor to reduce fetal mortality and morbidity by increasing fetal lung maturation and preventing the fetus from respiratory distress syndrome. In this study, we aimed to evaluate the effects of antenatal dexamethasone and betamethasone on fetal heart rate variability and fetal body movements. Material and method: The pregnant women applied to clinic due to the risk of preterm labor between November 2003 and May 2004 hospitalised due to the risk of preterm labor and tocolytic treatment. The glucocorticoids to be initiated and to provide lung maturation were included in the study. Included in the study pregnant women were randomly divided into two groups. 24 hours for 20 pregnant women in the first group, 12 mg betamethasone was administered intramuscularly. 20 in the second group 6 mg dexamethasone was administered intramuscularly every 12 hours. NSTs for later evaluation of fetal well-being and baby movements were compared. Results: Pregnant women in betamethasone and dexamethasone groups compared in terms of age, gravida, parity and gestational week, there was no significant difference between the two groups (p&gt; 0.05). At the time of first glucocorticoid application (onset) and 24 hours after the last dose of betamethasone/dexamethasone therapy, fetal heart rate, acceleration, deceleration and fetal movement counts were calculated for 3 days in the morning and evening. A significant increase was observed at heart rate in the betamethasone group after treatment, but there was no change in basal heart rate in the dexamethasone group. In the number of acceleration; significant increase was observed in betamethasone group while there was no statistically significant change was observed in the dexamethasone group. Fetal body movements were changed significantly in both groups compared with the basal movements. Conclusion: Antenatal glucocorticoid application (especially betamethasone) caused a temporary suppression in the NST and fetal movements that were used to determine fetal well-being. It should be kept in mind that these temporary changes may be misdiagnosed as fetal distress. Both dexamethasone and betamethasone can be applied in preterm delivery as a safe manner.

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.

The effect of different positions during non-stress test on maternal hemodynamic parameters, satisfaction, and fetal cardiotocographic patterns.

Maternal position is one of the most important factors to be considered during Non-Stress Test (NST). It should be a part of practice guidelines, where the appropriate maternal position reduces test-related errors and false-positive results. This study aimed to investigate the effect of different maternal positions during NST on maternal hemodynamic parameters, satisfaction, and fetal Cardiotocographic (CTG) pattern. A quasi-experimental research design was conducted at NST clinic, outpatient department/ Maternal and Children hospital at Najran city, Saudi Arabia. The study comprised a convenience sample of 118 low-risk pregnant women in their third trimester of pregnancy. Data was collected from January to June 2020. All women were assessed in the three different positions; supine, left lateral, and semi-fowler position concerning CTG pattern, maternal hemodynamic parameters, and satisfaction. The study results indicated a higher Fetal Heart Rate (FHR), increased accelerations, and fetal movement in the left lateral position, followed by a semi-fowler position compared to the supine position with statistically significant differences. No statistically significant differences (P>0.05) were observed regarding FHR variability and NST reactivity in the three positions. In addition, there were statistically significant differences (P <0.05) between the different maternal positions regarding maternal heart rate, systolic Blood pressure (BP), diastolic BP, and maternal satisfaction. The current study concluded that left lateral and semi- fowler positions were associated with a more favorable CTG pattern, maternal hemodynamic parameters, and satisfaction than the supine position. Left lateral and semi-fowler positions during the NST test should be standardized to reduce practical variations among health care providers, which, in turn, may reduce the need for unnecessary, expensive, and even hazardous interventions.