Intrauterine exposure to SARS-CoV-2 infection and early newborn brain development.

Epidemiologic studies suggest that prenatal exposures to certain viruses may influence early neurodevelopment, predisposing offspring to neuropsychiatric conditions later in life. The long-term effects of maternal COVID-19 infection in pregnancy on early brain development, however, remain largely unknown. We prospectively enrolled infants in an observational cohort study for a single-site study in the Washington, DC Metropolitan Area from June 2020 to November 2021 and compared these infants to pre-pandemic controls (studied March 2014-February 2020). The primary outcomes are measures of cortical morphometry (tissue-specific volumes), along with global and regional measures of local gyrification index, and sulcal depth. We studied 210 infants (55 infants of COVID-19 unexposed mothers, 47 infants of COVID-19-positive mothers, and 108 pre-pandemic healthy controls). We found increased cortical gray matter volume (182.45 ± 4.81 vs. 167.29 ± 2.92) and accelerated sulcal depth of the frontal lobe (5.01 ± 0.19 vs. 4.40 ± 0.13) in infants of COVID-19-positive mothers compared to controls. We found additional differences in infants of COVID-19 unexposed mothers, suggesting both maternal viral exposures, as well as non-viral stressors associated with the pandemic, may influence early development and warrant ongoing follow-up.

Experience of early-life pain in premature infants is associated with atypical cerebellar development and later neurodevelopmental deficits.

BACKGROUND: Infants born very and extremely premature (V/EPT) are at a significantly elevated risk for neurodevelopmental disorders and delays even in the absence of structural brain injuries. These risks may be due to earlier-than-typical exposure to the extrauterine environment, and its bright lights, loud noises, and exposures to painful procedures. Given the relative underdeveloped pain modulatory responses in these infants, frequent pain exposures may confer risk for later deficits. METHODS: Resting-state fMRI scans were collected at term equivalent age from 148 (45% male) infants born V/EPT and 99 infants (56% male) born at term age. Functional connectivity analyses were performed between functional regions correlating connectivity to the number of painful skin break procedures in the NICU, including heel lances, venipunctures, and IV placements. Subsequently, preterm infants returned at 18 months, for neurodevelopmental follow-up and completed assessments for autism risk and general neurodevelopment. RESULTS: We observed that V/EPT infants exhibit pronounced hyperconnectivity within the cerebellum and between the cerebellum and both limbic and paralimbic regions correlating with the number of skin break procedures. Moreover, skin breaks were strongly associated with autism risk, motor, and language scores at 18 months. Subsample analyses revealed that the same cerebellar connections strongly correlating with breaks at term age were associated with language dysfunction at 18 months. CONCLUSIONS: These results have significant implications for the clinical care of preterm infants undergoing painful exposures during routine NICU care, which typically occurs without anesthesia. Repeated pain exposures appear to have an increasingly detrimental effect on brain development during a critical period, and effects continue to be seen even 18 months later.

Autonomic markers of extubation readiness in premature infants.

BACKGROUND: In premature infants, extubation failure is common and difficult to predict. Heart rate variability (HRV) is a marker of autonomic tone. Our aim is to test the hypothesis that autonomic impairment is associated with extubation readiness. METHODS: Retrospective study of 89 infants <28 weeks. HRV metrics 24 h prior to extubation were compared for those with and without extubation success within 72 h. Receiver-operating curve analysis was conducted to determine the predictive ability of each metric, and a predictive model was created. RESULTS: Seventy-three percent were successfully extubated. The success group had significantly lower oxygen requirement, higher sympathetic HRV metrics, and a lower parasympathetic HRV metric. α1 (measure of autocorrelation, related to sympathetic tone) was the best predictor of success-area under the curve (AUC) of .73 (p = 0.001), and incorporated into a predictive model had an AUC of 0.81 (p < 0.0001)-sensitivity of 81% and specificity of 78%. CONCLUSIONS: Extubation success is associated with HRV. We show an autonomic imbalance with low sympathetic and elevated parasympathetic tone in those who failed. α1, a marker of sympathetic tone, was noted to be the best predictor of extubation success especially when incorporated into a clinical model. IMPACT: This article depicts autonomic markers predictive of extubation success. We depict an autonomic imbalance in those who fail extubation with heightened parasympathetic and blunted sympathetic signal. We describe a predictive model for extubation success with a sensitivity of 81% and specificity of 78%.

Preschool neurodevelopment in Zika virus-exposed children without congenital Zika syndrome.

BACKGROUND: Children with in utero Zika virus (ZIKV) exposure without congenital Zika syndrome (CZS) are at risk for abnormal neurodevelopment. Preschool-age outcomes for children with antenatal ZIKV exposure have not yet been established. METHODS: Children with in utero ZIKV exposure and non-exposed controls had neurodevelopmental evaluations at age 3-5 years in Sabanalarga, Colombia. Cases did not have CZS and were previously evaluated prenatally through age 18 months. Controls were born before ZIKV arrival to Colombia. Neurodevelopmental assessments included Pediatric Evaluation of Disability Inventory (PEDI-CAT), Behavior Rating Inventory of Executive Function (BRIEF-P), Bracken School Readiness Assessment (BSRA), and Movement Assessment Battery for Children (MABC). Family demographics and child medical history were recorded. RESULTS: Fifty-five ZIKV-exposed children were evaluated at mean age 3.6 years and 70 controls were evaluated at 5.2 years. Family demographics were similar between groups. BRIEF-P t-scores were higher for cases than controls in shift and flexibility domains. Cases had lower PEDI-CAT mobility t-scores compared to controls. There was no difference in MABC between groups. In 11% of cases and 1% of controls, parents reported child mood problems. CONCLUSIONS: Children with in utero ZIKV exposure without CZS may demonstrate emerging differences in executive function, mood, and adaptive mobility that require continued evaluation. IMPACT: Preschool neurodevelopmental outcome in children with in utero Zika virus exposure is not yet known, since the Zika virus epidemic occurred in 2015-2017 and these children are only now entering school age. This study finds that Colombian children with in utero Zika virus exposure without congenital Zika syndrome are overall developing well but may have emerging differences in executive function, behavior and mood, and adaptive mobility compared to children without in utero Zika virus exposure. Children with in utero Zika virus exposure require continued multi-domain longitudinal neurodevelopmental evaluation through school age.

In Utero MRI Identifies Impaired Second Trimester Subplate Growth in Fetuses with Congenital Heart Disease.

The subplate is a transient brain structure which plays a key role in the maturation of the cerebral cortex. Altered brain growth and cortical development have been suggested in fetuses with complex congenital heart disease (CHD) in the third trimester. However, at an earlier gestation, the putative role of the subplate in altered brain development in CHD fetuses is poorly understood. This study aims to examine subplate growth (i.e., volume and thickness) and its relationship to cortical sulcal development in CHD fetuses compared with healthy fetuses by using 3D reconstructed fetal magnetic resonance imaging. We studied 260 fetuses, including 100 CHD fetuses (22.3-32 gestational weeks) and 160 healthy fetuses (19.6-31.9 gestational weeks). Compared with healthy fetuses, CHD fetuses had 1) decreased global and regional subplate volumes and 2) decreased subplate thickness in the right hemisphere overall, in frontal and temporal lobes, and insula. Compared with fetuses with two-ventricle CHD, those with single-ventricle CHD had reduced subplate volume and thickness in right occipital and temporal lobes. Finally, impaired subplate growth was associated with disturbances in cortical sulcal development in CHD fetuses. These findings suggested a potential mechanistic pathway and early biomarker for the third-trimester failure of brain development in fetuses with complex CHD. SIGNIFICANCE STATEMENT: Our findings provide an early biomarker for brain maturational failure in fetuses with congenital heart disease, which may guide the development of future prenatal interventions aimed at reducing neurological compromise of prenatal origin in this high-risk population.

Hippocampal rotation is associated with ventricular atrial size.

BACKGROUND: Fetal ventriculomegaly is a source of apprehension for expectant parents and may present prognostic uncertainty for physicians. Accurate prenatal counseling requires knowledge of its cause and associated findings as the differential diagnosis is broad. We have observed an association between ventriculomegaly and incomplete hippocampal inversion. OBJECTIVE: To determine whether ventricular size is related to incomplete hippocampal inversion. MATERIALS AND METHODS: We retrospectively evaluated pre- and postnatal brain MRIs in normal subjects (mean GA, 31 weeks; mean postnatal age, 27 days) and patients with isolated ventriculomegaly (mean GA, 31 weeks; mean postnatal age, 68 days) at a single academic medical center. Lateral ventricular diameter, multiple qualitative and quantitative markers of hippocampal inversion, and evidence of intraventricular hemorrhage were documented. RESULTS: Incomplete hippocampal inversion and ventricular size were associated in both normal subjects (n=51) and patients with ventriculomegaly (n=32) (P<0.05). Severe ventriculomegaly was significantly associated with adverse clinical outcome in postnatal (P=0.02) but not prenatal (P=0.43) groups. In all additional cases of isolated ventriculomegaly, clinical outcome was normal over the time of assessment (mean 1±1.9 years; range 0.01 to 10 years). CONCLUSION: Lateral ventricular atrial diameter and incomplete hippocampal inversion are associated. Less hippocampal inversion correlates with larger atria. For every 1-mm increase in fetal ventricular size, the odds of incomplete hippocampal inversion occurring increases by a factor of 1.6 in normal controls and 1.4 in patients with ventriculomegaly.

Autonomic development in preterm infants is associated with morbidity of prematurity.

BACKGROUND: Previous studies have described an association between preterm birth and maturation of the autonomic nervous system (ANS); however, this may be impacted by multiple factors, including prematurity-related complications. Our aim was to evaluate for the effect of prematurity-related morbidity on ANS development in preterm infants in the NICU. METHODS: We compared time and frequency domains of heart rate variability (HRV) as a measure of ANS tone in 56 preterm infants from 2 NICUs (28 from each). One cohort was from a high-morbidity regional referral NICU, the other from a community-based inborn NICU with low prematurity-related morbidity. Propensity score matching was used to balance the groups by a 1:1 nearest neighbor design. ANS tone was analyzed. RESULTS: The two cohorts showed parallel maturational trajectory of the alpha 1 time-domain metric, with the cohort from the high-morbidity NICU having lower autonomic tone. The maturational trajectories between the two cohorts differed in all other time-domain metrics (alpha 2, RMS1, RMS2). There was no difference between groups by frequency-domain metrics. CONCLUSIONS: Prematurity-associated morbidities correlate with autonomic development in premature infants and may have a greater impact on the extrauterine maturation of this system than birth gestational age. IMPACT: Autonomic nervous system development measured by time-domain metrics of heart rate variability correlate with morbidities associated with premature birth. This study builds upon our previously published work that showed that development of autonomic tone was not impacted by gestational age at birth. This study adds to our understanding of autonomic nervous system development in a preterm extrauterine environment. Our study suggests that gestational age at birth may have less impact on autonomic nervous system development than previously thought.

In infants with congenital heart disease autonomic dysfunction is associated with pre-operative brain injury.

BACKGROUND: Brain injury is a serious and common complication of critical congenital heart disease (CHD). Impaired autonomic development (assessed by heart rate variability (HRV)) is associated with brain injury in other high-risk neonatal populations. OBJECTIVE: To determine whether impaired early neonatal HRV is associated with pre-operative brain injury in CHD. METHODS: In infants with critical CHD, we evaluated HRV during the first 24 h of cardiac ICU (CICU) admission using time-domain (RMS 1, RMS 2, and alpha 1) and frequency-domain metrics (LF, nLF, HF, nHF). Pre-operative brain magnetic resonance imaging (MRI) was scored for injury using an established system. Spearman's correlation coefficient was used to determine the association between HRV and pre-operative brain injury. RESULTS: We enrolled 34 infants with median birth gestational age of 38.8 weeks (IQR 38.1-39.1). Median postnatal age at pre-operative brain MRI was 2 days (IQR 1-3 days). Thirteen infants had MRI evidence of brain injury. RMS 1 and RMS 2 were inversely correlated with pre-operative brain injury. CONCLUSIONS: Time-domain metrics of autonomic function measured within the first 24 h of admission to the CICU are associated with pre-operative brain injury, and may perform better than frequency-domain metrics under non-stationary conditions such as critical illness. IMPACT: Autonomic dysfunction, measured by heart rate variability (HRV), in early transition is associated with pre-operative brain injury in neonates with critical congenital heart disease. These data extend our earlier findings by providing further evidence for (i) autonomic dysfunction in infants with CHD, and (ii) an association between autonomic dysfunction and brain injury in critically ill neonates. These data support the notion that further investigation of HRV as a biomarker for brain injury risk is warranted in infants with critical CHD.

Maternal mental distress and cortisol levels in pregnancies with congenital heart disease.

OBJECTIVES: Prenatal maternal stress is associated with adverse offspring outcomes, which may be mediated by maternal stress hormones. However, evidence supporting the association between maternal stress and cortisol levels in high-risk pregnancies is limited. This study aims to determine the relationship between self-reported maternal mental distress and maternal salivary cortisol levels in pregnancies complicated by foetal CHD compared with healthy pregnancies. METHODS: We recruited women with pregnancies complicated by foetal CHD and healthy pregnancies. Maternal saliva was collected between 22 and 40 gestational weeks. Standardized questionnaires measuring stress, depression, and anxiety were completed by patients. Generalized estimating equation was used to evaluate associations between maternal mental distress scales and cortisol levels. RESULTS: We studied 165 women (55 CHD, 110 controls) and collected 504 cortisol samples (160 CHD, 344 controls). Women carrying CHD foetuses had higher stress, anxiety, and depression scores compared to women carrying healthy foetuses. However, maternal cortisol levels did not significantly differ in CHD and controls. Cortisol levels were higher in women carrying foetuses with functionally single-ventricle versus two-ventricle CHD. In both CHD and controls, there was no significant association between maternal stress, depression or anxiety scores and cortisol levels. CONCLUSION: Our data suggest that self-reported maternal stress, anxiety, and depression are not associated with maternal salivary cortisol levels in CHD and healthy pregnancies. The impact of maternal mental distress on foetal health may be through other mediating pathways other than maternal cortisol concentrations.

GABA and glutamate in the preterm neonatal brain: In-vivo measurement by magnetic resonance spectroscopy.

Cognitive and behavioral disabilities in preterm infants, even without obvious brain injury on conventional neuroimaging, underscores a critical need to identify the subtle underlying microstructural and biochemical derangements. The gamma-aminobutyric acid (GABA) and glutamatergic neurotransmitter systems undergo rapid maturation during the crucial late gestation and early postnatal life, and are at-risk of disruption after preterm birth. Animal and human autopsy studies provide the bulk of current understanding since non-invasive specialized proton magnetic resonance spectroscopy (1H-MRS) to measure GABA and glutamate are not routinely available for this vulnerable population due to logistical and technical challenges. We review the specialized 1H-MRS techniques including MEscher-GArwood Point Resolved Spectroscopy (MEGA-PRESS), special challenges and considerations needed for interpretation of acquired data from the developing brain of preterm infants. We summarize the limited in-vivo preterm data, highlight the gaps in knowledge, and discuss future directions for optimal integration of available in-vivo approaches to understand the influence of GABA and glutamate on neurodevelopmental outcomes after preterm birth.

Autonomic nervous system maturation in the premature extrauterine milieu.

BACKGROUND: In premature infants, we investigated whether the duration of extrauterine development influenced autonomic nervous system (ANS) maturation. METHODS: We performed a longitudinal cohort study of ANS maturation in preterm infants. Eligibility included birth gestational age (GA) < 37 weeks, NICU admission, and expected survival. The cohort was divided into three birth GA groups: Group 1 (≤29 weeks), Group 2 (30-33 weeks), and Group 3 (≥34 weeks). ECG data were recorded weekly and analyzed for sympathetic and parasympathetic tone using heart rate variability (HRV). Quantile regression modeled the slope of ANS maturation among the groups by postnatal age to term-equivalent age (TEA) (≥37 weeks). RESULTS: One hundred infants, median (Q1-Q3) birth GA of 31.9 (28.7-33.9) weeks, were enrolled: Group 1 (n = 35); Group 2 (n = 40); and Group 3 (n = 25). Earlier birth GA was associated with lower sympathetic and parasympathetic tone. However, the rate of autonomic maturation was similar, and at TEA there was no difference in HRV metrics across the three groups. The majority of infants (91%) did not experience significant neonatal morbidities. CONCLUSION: Premature infants with low prematurity-related systemic morbidity have maturational trajectories of ANS development that are comparable across a wide range of ex-utero durations regardless of birth GA. IMPACT: Heart rate variability can evaluate the maturation of the autonomic nervous system. Metrics of both the sympathetic and parasympathetic nervous system show maturation in the premature extrauterine milieu. The autonomic nervous system in preterm infants shows comparable maturation across a wide range of birth gestational ages. Preterm newborns with low medical morbidity have maturation of their autonomic nervous system while in the NICU. Modern NICU advances appear to support autonomic development in the preterm infant.

Prenatal diagnosis of diencephalic-mesencephalic junction dysplasia: Fetal magnetic resonance imaging phenotypes, genetic diagnoses, and outcomes.

OBJECTIVE: Report a single-center 12-year experience in the fetal diagnosis of diencephalic-mesencephalic junction dysplasia (DMJD) to expand the phenotype with Magnetic resonance imaging (MRI)-based classification, evaluate genetic etiologies, and ascertain outcomes. METHODS: Retrospective medical record and imaging review of all fetal MRI exams with DMJD were performed at our institution. RESULTS: Thirty-three pregnancies with fetal MRI findings of DMJD at 24 (18-37) weeks gestational age were studied; 70% were referred for fetal hydrocephalus. Three fetal MRI patterns were recognized. Type A (butterfly/hypothalamus-midbrain union) was seen in two cases (6%), Type B (partial thalamus-midbrain union) in 22 fetuses (70%), and Type C (complete/near complete midbrain-thalamic continuity) in nine fetuses (24%). L1CAM mutations were identified in four cases, and biallelic VRK1 variants in another. Among 14 live-born cases, 11 survived infancy, and 10 underwent postnatal brain MRI which confirmed the fetal MRI diagnosis in all but one case. Development was delayed in all surviving infants, most with additional neurological sequelae. CONCLUSIONS: DMJD may be identified by prenatal MRI as early as 18 weeks gestation. We propose three distinct phenotypic forms of DMJD, Types A-C. Next-generation sequencing provides an underlying molecular diagnosis in some patients, but further studies on associated genetic diagnoses and clinical outcomes are indicated.

Taenia-tela choroidea complex and choroid plexus location help distinguish Dandy-Walker malformation and Blake pouch cysts.

BACKGROUND: Dandy-Walker malformation and Blake pouch cysts can have overlapping imaging features. The choroid plexus and associated taenia-tela choroidea complex are displaced inferolaterally in Dandy-Walker malformation and below the vermis in Blake pouch cysts. OBJECTIVE: To determine the normal fetal and postnatal MR appearance of the choroid plexus and taenia-tela choroidea complex, and whether their location can help distinguish Dandy-Walker malformation from Blake pouch cysts. MATERIALS AND METHODS: In this retrospective study, we evaluated brain MR exams from normal-appearing fetuses (gestational age 19-38 weeks) and infants, fetal and postnatal exams in Blake pouch cysts and Dandy-Walker malformation, and ambiguous cases equivocal for mild Dandy-Walker malformation and Blake pouch cysts. We documented choroid plexus and the taenia-tela choroidea complex location and axial and sagittal angles in each case. Then we contrasted and compared the original and updated fetal diagnoses based on taenia-tela choroidea complex and choroid plexus positions. RESULTS: The choroid plexus location and the taenia-tela choroidea complex location and angles varied significantly among normal exams, Blake pouch cyst exams and Dandy-Walker malformation exams (P<0.01). Dandy-Walker malformation showed inferolateral displacement of the taenia-tela choroidea complex and choroid plexus distant from the vermis. Adding the taenia-tela choroidea complex and choroid plexus into the assessment improved diagnostic accuracy, especially in ambiguous cases. CONCLUSION: The location of the taenia-tela choroidea complex and choroid plexus provided additional diagnostic neuroimaging clues that could be used in conjunction with other conventional findings to distinguish Dandy-Walker malformation and Blake pouch cysts. Normal, Blake pouch cyst, and Dandy-Walker malformation cases differed with regard to taenia-tela choroidea complex and choroid plexus position. Inferolateral taenia-tela choroidea complex displacement distant from the vermian margin was characteristic of Dandy-Walker malformation.

Altered local cerebellar and brainstem development in preterm infants.

BACKGROUND: Premature birth is associated with high prevalence of neurodevelopmental impairments in surviving infants. The putative role of cerebellar and brainstem dysfunction remains poorly understood, particularly in the absence of overt structural injury. METHOD: We compared in-utero versus ex-utero global, regional and local cerebellar and brainstem development in healthy fetuses (n â€‹= â€‹38) and prematurely born infants without evidence of structural brain injury on conventional MRI studies (n â€‹= â€‹74) that were performed at two time points: the first corresponding to the third trimester, either in utero or ex utero in the early postnatal period following preterm birth (30-40 weeks of gestation; 38 control fetuses; 52 premature infants) and the second at term equivalent age (37-46 weeks; 38 control infants; 58 premature infants). We compared 1) volumetric growth of 7 regions in the cerebellum (left and right hemispheres, left and right dentate nuclei, and the anterior, neo, and posterior vermis); 2) volumetric growth of 3 brainstem regions (midbrain, pons, and medulla); and 3) shape development in the cerebellum and brainstem using spherical harmonic description between the two groups. RESULTS: Both premature and control groups showed regional cerebellar differences in growth rates, with the left and right cerebellar hemispheres showing faster growth compared to the vermis. In the brainstem, the pons grew faster than the midbrain and medulla in both prematurely born infants and controls. Using shape analyses, premature infants had smaller left and right cerebellar hemispheres but larger regional vermis and paravermis compared to in-utero control fetuses. For the brainstem, premature infants showed impaired growth of the superior surface of the midbrain, anterior surface of the pons, and inferior aspects of the medulla compared to the control fetuses. At term-equivalent age, premature infants had smaller cerebellar hemispheres bilaterally, extending to the superior aspect of the left cerebellar hemisphere, and larger anterior vermis and posteroinferior cerebellar lobes than healthy newborns. For the brainstem, large differences between premature infants and healthy newborns were found in the anterior surface of the pons. CONCLUSION: This study analyzed both volumetric growth and shape development of the cerebellum and brainstem in premature infants compared to healthy fetuses using longitudinal MRI measurements. The findings in the present study suggested that preterm birth may alter global, regional and local development of the cerebellum and brainstem even in the absence of structural brain injury evident on conventional MRI.

Fetal acute cerebral vasoreactivity to maternal hyperoxia in low-risk pregnancies: a cross-sectional study.

OBJECTIVE: To establish whether fetal cerebral vasoreactivity (CVRO2 ), following maternal hyperoxia, is predicted by fetal cerebral and uteroplacental Doppler pulsatility indices (PI) at baseline, fetal pulmonary vasoreactivity to oxygen (PVRO2 ), gestational age (GA), or sex. METHODS: Pulsatility index of middle (MCA), anterior (ACA), posterior cerebral (PCA), umbilical (UA), uterine (UtA), and branch of the pulmonary arteries (PA) were obtained, by ultrasound, before (baseline), during (hyperoxia) and after 15 minutes of maternal administration of 8 L/min of 100% oxygen, through a non-rebreathing face mask, in normal singleton pregnancies within 20 to 38 weeks' gestation. CVRO2 was defined as changes greater than zero in z score of PI of the cerebral arteries from baseline to hyperoxia. Logistic modeling was applied to identify CVRO2 predictors. RESULTS: A total of 97 pregnancies were eligible. In the overall population, median z scores of PI of MCA, ACA, and PCA did not differ between study phases. Based on the logistic model, baseline z scores for cerebral PI and GA were the best predictors of CVRO2 . CONCLUSIONS: In low-risk pregnancies, fetal CVRO2 to hyperoxia does not occur uniformly but depends on cerebral PI and GA at baseline. These findings may provide useful reference points when oxygen is administered in high-risk pregnancies.

Heart rate variability is depressed in the early transitional period for newborns with complex congenital heart disease.

PURPOSE: To compare early changes in autonomic nervous system (ANS) tone between newborns with complex congenital heart disease (CHD) and newborns without CHD. METHODS: We performed a case-control study of heart rate variability (HRV) in newborns with complex CHD [transposition of the great arteries (TGA) or hypoplastic left heart syndrome (HLHS)] and low-risk control newborns without CHD. Cases with CHD were admitted following birth to a pediatric cardiac intensive care unit and had archived continuous ECG data. Control infants were prospectively enrolled at birth. ECG data in cases and controls were analyzed for HRV in the time and frequency domains at 24 h of age. We analyzed the following HRV metrics: alpha short (αs), alpha long (αL), root mean square short and long (RMSs and RMSL), low-frequency (LF) power, normalized LF (nLF), high-frequency (HF) power, and normalized HF (nHF). We used ANOVA to compare HRV metrics between groups and to control for medication exposures. RESULTS: HRV data from 57 infants with CHD (TGA, n = 33 and HLHS, n = 24) and from 29 controls were analyzed. The HRV metrics αS, RMSL, LF, and nLF were significantly lower in infants with CHD than in the controls. Due to the effect of normalization, nHF was higher in CHD infants (P < 0.0001), although absolute HF was lower (P = 0.0461). After adjusting for medications, αS and nLF remained lower and nHF higher in newborns with CHD (P < 0.0005). CONCLUSIONS: Infants with complex CHD have depressed autonomic balance in the early postnatal period, which may complicate the fetal-neonatal transition.

Autonomic nervous system development and its impact on neuropsychiatric outcome.

The central autonomic nervous system (ANS) is essential for maintaining cardiovascular and respiratory homeostasis in the newborn and has a critical role in supporting higher cortical functions. At birth, the central ANS is maturing and is vulnerable to adverse environmental and physiologic influences. Critical connections are formed early in development between the ANS and limbic system to integrate psychological and body responses. The Polyvagal Theory, developed by Stephen Porges, describes how modulation of the autonomic vagal impulse controls social responses and that a broad range of neuropsychiatric disorders may be due to impaired vagal balance, with either deficient vagal tone or excessive vagal reactivity. Under additional circumstances of prematurity, growth restriction, and environmental stress in the fetus and newborn, the immature ANS may undergo "dysmaturation". Maternal stress and health as well as the intrauterine environment are also quite important and have been implicated in causing ANS changes in the infant and neuropsychiatric diseases in children. This review will cover the aspects of ANS development and maturation that have been associated with neuropsychiatric disorders in children.

The effect of unilateral stroke on autonomic function in the term newborn.

BACKGROUND: The mature cerebral cortex has a topographically organized influence on reflex autonomic centers of the brainstem and diencephalon and sympathetic activation coming primarily from the right hemisphere and parasympathetic activation from the left. In the term newborn, the maturational status of this central autonomic system remains poorly understood. METHODS: Sixteen term newborns admitted to Children's National with unilateral middle cerebral artery (MCA) strokes (n = 8 left, n = 8 right) had archived continuous electrocardiograph (EKG) signals available. We compared stroke laterality and severity with indices of autonomic function, as measured by heart rate variability. We performed both time- and frequency-domain analyses on the R-R interval (RRi) over 24h of continuous EKG data at around 7 days of age. RESULTS: Right MCA stroke significantly increased sympathetic tone, while left MCA stroke increased parasympathetic tone. Regardless of laterality, stroke severity was associated inversely with sympathetic tone and positively with parasympathetic tone. Surprisingly, injury to either insular region had no significant autonomic effect. Phenobarbital blood levels were positively associated with sympathetic tone and inversely related to parasympathetic tone. CONCLUSION: Based on these findings, it is difficult to reconcile the functional topography of the central autonomic system in term newborns with that currently proposed for the normal mature brain. Further investigation is clearly needed.

Prenatal diagnosis of holoprosencephaly.

Holoprosencephaly is a spectrum of congenital defects of forebrain development characterized by incomplete separation of the cerebral hemispheres. In vivo diagnosis can be established with prenatal brain imaging and disease severity correlates with extent of abnormally developed brain tissue. Advances in magnetic resonance imaging (MRI) over the past 25 years and their application to the fetus have enabled diagnosis of holoprosencephaly in utero. Here, we report on the prenatal diagnosis of holoprosencephaly using MRI as part of a diagnostic and management evaluation at a tertiary and quaternary referral center. Using an advanced MRI protocol and a 1.5-Tesla magnet, we show radiographic data diagnostic for the holoprosencephaly spectrum, including alobar, semilobar, lobar, middle interhemispheric, and septopreoptic variant. Accurate prenatal evaluation is important because the severity of imaging findings correlates with postnatal morbidity and mortality in holoprosencephaly. Therefore, this work has implications for the evaluation, diagnosis, management, and genetic counseling that families can receive during a pregnancy.

In vivo placental MRI shape and textural features predict fetal growth restriction and postnatal outcome.

PURPOSE: To investigate the ability of three-dimensional (3D) MRI placental shape and textural features to predict fetal growth restriction (FGR) and birth weight (BW) for both healthy and FGR fetuses. MATERIALS AND METHODS: We recruited two groups of pregnant volunteers between 18 and 39 weeks of gestation; 46 healthy subjects and 34 FGR. Both groups underwent fetal MR imaging on a 1.5 Tesla GE scanner using an eight-channel receiver coil. We acquired T2-weighted images on either the coronal or the axial plane to obtain MR volumes with a slice thickness of either 4 or 8 mm covering the full placenta. Placental shape features (volume, thickness, elongation) were combined with textural features; first order textural features (mean, variance, kurtosis, and skewness of placental gray levels), as well as, textural features computed on the gray level co-occurrence and run-length matrices characterizing placental homogeneity, symmetry, and coarseness. The features were used in two machine learning frameworks to predict FGR and BW. RESULTS: The proposed machine-learning based method using shape and textural features identified FGR pregnancies with 86% accuracy, 77% precision and 86% recall. BW estimations were 0.3 ± 13.4% (mean percentage error ± standard error) for healthy fetuses and -2.6 ± 15.9% for FGR. CONCLUSION: The proposed FGR identification and BW estimation methods using in utero placental shape and textural features computed on 3D MR images demonstrated high accuracy in our healthy and high-risk cohorts. Future studies to assess the evolution of each feature with regard to placental development are currently underway. LEVEL OF EVIDENCE: 2 Technical Efficacy: Stage 2 J. Magn. Reson. Imaging 2018;47:449-458.