Fetal heart rate variability (fHRV) is an essential source of information to monitor fetal well-being during pregnancy. This study aimed to apply a nonlinear approach, known as symbolic dynamics (SD), for comparing human fHRV in the third trimester of pregnancy during active fetal state (TT) and active labor at term (P).We performed a longitudinal, prospective, descriptive, and comparative study composed of 42 longitudinal recordings of 5-minutes of fetal heartbeat interval series. Recordings were collected from 21 low-risk, healthy, pregnant women attending the Maternal and Child Research Center (CIMIGen), Mexico City.We calculated relevant linear parameters of fHRV between TT and P stages, such as the percentage of differences between adjacent RR intervals >5 ms (PRR5, related to vagal modulations) and other SD parameters such as the percentage of no variations between three successive symbols (%0V, reflects sympathetic modulations) and the probability of low variability with a threshold of 4 ms (POLVAR4, associated with a low variability).We identified statistical differences for PRR5 between .76%], p ¼ 0.03), respectively. Also, for 0V% (65.
The emergent Coronavirus Disease 2019 (COVID-19) caused by the Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) could produce a maternal immune activation (MIA) via the inflammatory response during gestation that may impair fetal neurodevelopment and lead to postnatal and adulthood mental illness and behavioral dysfunctions. However, so far, limited evidence exists regarding long-term physiological, immunological, and neurodevelopmental modifications produced by the SARS-CoV-2 in the human maternal-fetal binomial and, particularly, in the offspring. Relevant findings derived from epidemiological and preclinical models show that a MIA is indeed linked to an increased risk of neurodevelopmental disorders in the offspring. We hypothesize that a gestational infection triggered by SARS-CoV-2 increases the risks leading to neurodevelopmental disorders of the newborn, which can affect childhood and the long-term quality of life. In particular, disruption of either the maternal or the fetal cholinergic anti-inflammatory pathway (CAP) could cause or exacerbate the severity of COVID-19 in the maternal-fetal binomial. From a translational perspective, in this paper, we discuss the possible manifestation of a MIA by SARS-CoV-2 and the subsequent neurodevelopmental disorders considering the role of the fetal-maternal cytokine cross-talk and the CAP. Specifically, we highlight the urgent need of preclinical studies as well as multicenter and international databanks of maternal-fetal psychophysiological data obtained pre-, during, and post-infection by SARS-CoV-2 from pregnant women and their offspring.
Labor is regarded as increased myometrial activity with a regular contractility pattern. At this final stage of pregnancy, myometrial quiescence is lost, accompanied by altered immune homeostasis. It is well known that the interleukin (IL)-10 family of cytokines modulates immunological responses mainly in epithelial cells, including the endometrium. To investigate their inflammatory profile during labor, we performed a longitudinal study in a group of healthy pregnant women (n = 20) with uncomplicated pregnancies in the third trimester of pregnancy and during active labor. Blood was sampled from pregnant women in the third trimester (gestational age 32-38 weeks, mean 36 ± 2 weeks) and during active labor (39-41 weeks of gestation, mean 40 ± 1 weeks). Serum levels of several cytokines were measured using multiplex immunoassays for both stages, indicating that the concentrations of IL-10, IL-20, IL-22, IL-28A, and interferon (IFN)-γ were significantly decreased during active labor in comparison with third-trimester levels (p < 0.05). Our analysis did not find significant correlations between IL-10, IL-20, IL-22, IL-28A, and IFN-γ levels and gestational age. However, our data suggest that the systemic downregulation of several members of the IL-10 family of cytokines plays an important role in the activation of myometrial smooth cells associated with uterine contractions during active labor. Downregulation of this IL-10 family of cytokines seems to coincide with the well-reported functional progesterone withdrawal during labor. Likewise, lower plasma IFN-γ concentrations may indicate a role for IFN-γ in 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 or 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.
The study of cardiovascular function with galvanic vestibular stimulation has provided evidence on the neural structures that are involved in the vestibulo-autonomic reflex. This study determined if the effect on heart rate using galvanic vestibular stimulation persists after provoking a sympathetic response and if this response differs when using unilateral or transmastoid (bilateral) stimulation. We analysed heart rate and heart rate variability using unilateral and transmastoid galvanic vestibular stimulation combined with cardiovascular reflex evoked by postural change in 24 healthy human subjects. Three electrode configurations were selected for unilateral stimulation considering the anatomical location of each semicircular canal. We compared recordings performed in seated and standing positions, and with unilateral and transmastoid stimulation. With subjects seated, a significant transient decrease in heart rate was observed with unilateral stimulation. With transmastoid stimulation, heart rate decreased in both seated and standing positions. Average intervals between normal heartbeats recorded with stimulation resemble parasympathetic cardiac function induced by auricular vagal nerve stimulation. Our results indicate that unilateral stimulation does not eliminate the natural heart rate increase caused by orthostatic hypotension. In contrast, transmastoid stimulation provoked a transient reduction in heart rate, even when subjects were standing. These responses should be considered while performing experiments with galvanic vestibular stimulation and subsequent effects in cardiac regulation mechanisms.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.