Longitudinally Tracking Maternal Autonomic Modulation During Normal Pregnancy With Comprehensive Heart Rate Variability Analyses

Changes in the maternal autonomic nervous system are essential in facilitating the physiological changes that pregnancy necessitates. Insufficient autonomic adaptation is linked to complications such as hypertensive diseases of pregnancy. Consequently, tracking autonomic modulation during progressing pregnancy could allow for the early detection of emerging deteriorations in maternal health. Autonomic modulation can be longitudinally and unobtrusively monitored by assessing heart rate variability (HRV). Yet, changes in maternal HRV (mHRV) throughout pregnancy remain poorly understood. In previous studies, mHRV is typically assessed only once per trimester with standard HRV features. However, since gestational changes are complex and dynamic, assessing mHRV comprehensively and more frequently may better showcase the changing autonomic modulation over pregnancy. Subsequently, we longitudinally (median sessions = 8) assess mHRV in 29 healthy pregnancies with features that assess sympathetic and parasympathetic activity, as well as heart rate (HR) complexity, HR responsiveness and HR fragmentation. We find that vagal activity, HR complexity, HR responsiveness, and HR fragmentation significantly decrease. Their associated effect sizes are small, suggesting that the increasing demands of advancing gestation are well tolerated. Furthermore, we find a notable change in autonomic activity during the transition from the second to third trimester, highlighting the dynamic nature of changes in pregnancy. Lastly, while we saw the expected rise in mean HR with gestational age, we also observed increased autonomic deceleration activity, seemingly to counter this rising mean HR. These results are an important step towards gaining insights into gestational physiology as well as tracking maternal health via mHRV

Evidence and clinical relevance of maternal-fetal cardiac coupling:A scoping review

BACKGROUND: Researchers have long suspected a mutual interaction between maternal and fetal heart rhythms, referred to as maternal-fetal cardiac coupling (MFCC). While several studies have been published on this phenomenon, they vary in terms of methodologies, populations assessed, and definitions of coupling. Moreover, a clear discussion of the potential clinical implications is often lacking. Subsequently, we perform a scoping review to map the current state of the research in this field and, by doing so, form a foundation for future clinically oriented research on this topic.METHODS: A literature search was performed in PubMed, Embase, and Cochrane. Filters were only set for language (English, Dutch, and German literature were included) and not for year of publication. After screening for the title and the abstract, a full-text evaluation of eligibility followed. All studies on MFCC were included which described coupling between heart rate measurements in both the mother and fetus, regardless of the coupling method used, gestational age, or the maternal or fetal health condition.RESULTS: 23 studies remained after a systematic evaluation of 6,672 studies. Of these, 21 studies found at least occasional instances of MFCC. Methods used to capture MFCC are synchrograms and corresponding phase coherence indices, cross-correlation, joint symbolic dynamics, transfer entropy, bivariate phase rectified signal averaging, and deep coherence. Physiological pathways regulating MFCC are suggested to exist either via the autonomic nervous system or due to the vibroacoustic effect, though neither of these suggested pathways has been verified. The strength and direction of MFCC are found to change with gestational age and with the rate of maternal breathing, while also being further altered in fetuses with cardiac abnormalities and during labor.CONCLUSION: From the synthesis of the available literature on MFCC presented in this scoping review, it seems evident that MFCC does indeed exist and may have clinical relevance in tracking fetal well-being and development during pregnancy.</p

An analysis of the respiratory dynamics of preterm infants

Thesis (MEng)--Stellenbosch University, 2019ENGLISH ABSTRACT: Poor understanding of preterm infant physiology attributes to the high infant mortality rates, as well as its corresponding financial burden. Prematurity compromises the respiratory and regulatory systems of infants. This manifests itself in characteristic respiratory dynamics consisting of apneas, periodic breathing and regular breathing. These dynamics, if captured, quantified and visualised have potential to track maturational changes in infants. This can aid physicians in the difficult task of assessing a preterm infant’s level of physiological maturity and offer insight into the infant’s regulatory systems. The primary objective of this study was to develop a transition model representing the behaviour of and temporal relationship between the different respiratory states of preterm infants. Secondary objectives consisted of the following: Analysing 2 – 5 s cessations, their contribution to breathing cessation and relationship to apnea; temporally tracking the respiratory stability of preterm infants; and studying the relationship between breathing cessations and heart rate behaviour. Transition models were developed that adequately represented the respiratory dynamics of preterm infants. It showed that respiratory events are related in time, but that periodic breathing rarely precedes apnea of prematurity. On average 9% of breathing cessation and less than 1% of periodic breathing was found in the dataset. It was found that the contribution of short cessations were large, and that there is a temporal periodicity to the percentage cessations in the respiratory signal. Coupling between the respiratory and cardiac systems could be observed, with an apparent common temporal periodicity between some heart rate variability measures and percentage cessation in breathing signal. In conclusion, all objectives were successfully addressed and greater insight was gained into the physiology of preterm infants. Future value exists in applying these analyses on a larger, more longitudinal and clinically annotated dataset.AFRIKAANSE OPSOMMING: Swak begrip van premature kinderfisiologie dra by tot wêreldwye hoë kindersterftesyfers, asook die ooreenstemmende finansiële las. Prematuriteit kompromieer die respiratoriese en regulatoriese stelsels van babas. Dit manifesteer in kenmerkende respiratoriese dinamieke wat bestaan uit apnee, periodiese asemhaling en normale asemhaling. Indien hierdie dinamieke gemonitor, gekwantifiseer en gevisualiseer kan word, het dit die potensiaal om die volwassewording van premature babas te monitor. Dit kan dokters help in die moeilike taak om 'n premature kind se vlak van fisiologiese volwassenheid te bepaal. Dit kan ook insig gee rakende die regulatoriese stelsels van die baba. Die primêre doel van hierdie studie was om 'n oorgangsmodel te ontwikkel wat die gedrag van en tydelike verband tussen die verskillende respiratoriese toestande van premature babas verteenwoordig. Sekondêre doelwitte het bestaan uit die volgende: Studie van 2 - 5 s asemhalingstakings, hul bydrae tot die totale asemhalingstaking en verhouding tot apnee; om die respiratoriese stabiliteit van premature babas relatief tot tyd te bestudeer; en die verband tussen asemhalingstake en variasie in hartklop te observeer. 'n Oorgangsmodel is ontwikkel wat die respiratoriese dinamika van premature babas voldoende verteenwoordig het. Dit het getoon dat respiratoriese gebeure verbonde is in tyd, maar dat apnee van prematuriteit selde deur periodiese asemhaling voorafgegaan word. Gemiddeld is 9% asemhalingstaking en minder as 1% periodieke asemhaling in die datastel gevind. Daar is bevind dat die bydrae van kort asemhalingstakings groot was en dat daar 'n temporale periodisiteit is vir die persentasie stakings in die respiratoriese sein. Koppeling tussen die respiratoriese en kardiale stelsels kon waargeneem word, met 'n skynbare algemene temporale periodisiteit tussen sommige hartklopveranderings-maatreëls en persentasie staking in die asemhalingssein. Ten slotte is alle doelwitte suksesvol aangespreek en is meer insig verkry in die fisiologie van premature babas. Toekomstige waarde bestaan in die toepassing van hierdie ontledings op 'n groter, meer longitudinale en klinies geannoteerde datastel

A study of short cessations and temporal dynamics of breathing in preterm infants

The current clinical definition of Apnea of Prematurity (AOP) in infants is cessations of breathing exceeding 20 s, or at least 10 s accompanied by bradycardia under 100 beats per minute (bpm) or desaturation below 80%. AOP has a negative effect on infant health as it can increase the risk of hypoxemia, hypoglycaemia, neurological injury and sepsis. However, the detrimental effects of AOP are poorly understood, in large part because apneas are difficult to monitor owing to limitations in the current modalities for monitoring respiration. This study investigates the respiratory dynamics of preterm infants by implementing, with modifications, a pre-existing breathing cessation-detection algorithm. Unlike other studies, we also analyze short cessations in breathing (2-5 s), so as to better quantify respiratory dynamics, temporally track respiratory stability and to investigate whether short cessations in breathing are related to apnea. We found that isolated 2-5 s cessations have a significant impact on the total time of breathing cessation, increasing it from 3.0% to 4.3%. Furthermore, short cessations in breathing are positively correlated to apnea. Finally, there are multiple periodic increases in cessations of breathing within a day

A study of short cessations and temporal dynamics of breathing in preterm infants

\u3cp\u3eThe current clinical definition of Apnea of Prematurity (AOP) in infants is cessations of breathing exceeding 20 s, or at least 10 s accompanied by bradycardia under 100 beats per minute (bpm) or desaturation below 80%. AOP has a negative effect on infant health as it can increase the risk of hypoxemia, hypoglycaemia, neurological injury and sepsis. However, the detrimental effects of AOP are poorly understood, in large part because apneas are difficult to monitor owing to limitations in the current modalities for monitoring respiration. This study investigates the respiratory dynamics of preterm infants by implementing, with modifications, a pre-existing breathing cessation-detection algorithm. Unlike other studies, we also analyze short cessations in breathing (2-5 s), so as to better quantify respiratory dynamics, temporally track respiratory stability and to investigate whether short cessations in breathing are related to apnea. We found that isolated 2-5 s cessations have a significant impact on the total time of breathing cessation, increasing it from 3.0% to 4.3%. Furthermore, short cessations in breathing are positively correlated to apnea. Finally, there are multiple periodic increases in cessations of breathing within a day.\u3c/p\u3

The Effects of Advancing Gestation on Maternal Autonomic Response

Important changes occur in the maternal autonomic nervous system with advancing gestation. Tracking maternal autonomic modulation with heart rate variability (HRV) may hold opportunities for early detection of pregnancy complications such as hypertensive disorders of pregnancy (HPD) since these are associated with autonomic dysfunction. However, traditional HRV features often show conflicting trends over gestation. In this paper we implement phase rectified signal averaging (PRSA) to longitudinally track autonomic response throughout gestation. Since other fields of investigation have shown attenuated autonomic responsivity in healthy pregnancy, we hypothesized that assessing PRSA longitudinally over pregnancy would elicit a clearer trajectory of autonomic modulation. We found that autonomic responsiveness becomes significantly attenuated towards the end of pregnancy, although not to a degree that is comparable to diseased states. PRSA features show clear downward trends across pregnancy, with an uptick right before pregnancy ends, perhaps showing increased autonomic activity in preparation for delivery. We conclude that longitudinal analysis using PRSA holds promise as a potential screening tool for high-risk pregnancies

Longitudinal Assessment of Fetal Heart Rate Variability During Pregnancy

Inadequate development of the fetal autonomic nervous system (ANS) during gestation can lead to health problems not only in the perinatal period but well into adulthood. Assessing fetal heart rate variability (fHRV) may allow for tracking fetal autonomic development and identification of abnormalities. A HRV methodology which is well-suited to this purpose is phase rectified signal averaging (PRSA). While PRSA has been used in assessing autonomic dysfunction related to complications such as fetal growth restriction, knowledge on how PRSA features change with gestational age is limited. In this paper, we use PRSA to analyze a dataset comprising of repeated abdominal ECG measurements acquired throughout healthy pregnancy (29 participants, 184 recordings) to capture how PRSA features evolve over the second half of gestation. Results show that all features change significantly (p &lt; 0.01), typically increasing from 22 to around 31 weeks (likely due to quicker signaling between nerve cells, corresponding to the rapidly maturing parasympathetic nervous system) and then stabilizing or slightly decreasing thereafter owing to better control of the heart rate by the mature fetal ANS. We conclude that PRSA features change with progressing gestation and may be a useful tool for tracking the maturation of the fetal ANS.</p

Changes in Maternal Heart Rate and Autonomic Regulation following the Antenatal Administration of Corticosteroids: A Secondary Analysis

While the effect of antenatally administered corticosteroids on fetal heart rate (HR) and heart rate variability (HRV) is well established, little information is available on how these drugs affect maternal physiology. In this secondary analysis of a prospective, observational cohort study, we quantify how corticosteroids affect maternal HR and HRV, which serve as a proxy measure for autonomic regulation. Abdominal ECG measurements were recorded before and in the five days following the administration of betamethasone-a corticosteroid commonly used for fetal maturation-in 46 women with singleton pregnancies. Maternal HR and HRV were determined from these recordings and compared between these days. HRV was assessed with time- and frequency-domain features, as well as non-linear and complexity features. In the 24 h after betamethasone administration, maternal HR was significantly increased (p &lt; 0.01) by approximately 10 beats per minute, while HRV features linked to parasympathetic activity and HR complexity were significantly decreased (p &lt; 0.01 and p &lt; 0.001, respectively). Within four days after the initial administration of betamethasone, HR decreases and HRV features increase again, indicating a diminishing effect of betamethasone a few days after administration. We conclude that betamethasone administration results in changes in maternal HR and HRV, despite the heterogeneity of the studied population. Therefore, its recent administration should be considered when evaluating these cardiovascular metrics