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Maternal inflammation during gestation is associated with a later diagnosis of neurodevelopmental disorders including autism spectrum disorder (ASD). However, the specific impact of maternal immune activation (MIA) on placental and fetal brain development remains insufficiently understood. This study aimed to investigate the effects of MIA by analyzing placental and brain tissues obtained from the offspring of pregnant C57BL/6 dams exposed to polyinosinic: polycytidylic acid (poly I: C) on embryonic day 12.5. Cytokine and mRNA content in the placenta and brain tissues were assessed using multiplex cytokine assays and bulk-RNA sequencing on embryonic day 17.5. In the placenta, male MIA offspring exhibited higher levels of GM-CSF, IL-6, TNFα, and LT-α, but there were no differences in female MIA offspring. Furthermore, differentially expressed genes (DEG) in the placental tissues of MIA offspring were found to be enriched in processes related to synaptic vesicles and neuronal development. Placental mRNA from male and female MIA offspring were both enriched in synaptic and neuronal development terms, whereas females were also enriched for terms related to excitatory and inhibitory signaling. In the fetal brain of MIA offspring, increased levels of IL-28B and IL-25 were observed with male MIA offspring and increased levels of LT-α were observed in the female offspring. Notably, we identified few stable MIA fetal brain DEG, with no male specific difference whereas females had DEG related to immune cytokine signaling. Overall, these findings support the hypothesis that MIA contributes to the sex- specific abnormalities observed in ASD, possibly through altered neuron developed from exposure to inflammatory cytokines. Future research should aim to investigate how interactions between the placenta and fetal brain contribute to altered neuronal development in the context of MIA.

Objectives: To assess the feasibility, characteristics and prognostic value of prenatal visualization of the corticospinal tracts (CSTs) using diffusion‐weighted magnetic resonance imaging (MRI)‐based tractography in fetuses with intraventricular hemorrhage (IVH). Methods: This was a retrospective single‐center cohort study of singleton fetuses diagnosed with IVH on MRI from January 2011 to December 2018. The left and right CSTs were reconstructed according to an in‐utero diffusion tensor imaging sequence using a multi‐region of interest (ROI) deterministic tractography approach. The CSTs were segmented by two polygonal ROI: at the level of the posterior limb of the internal capsule and the crus cerebri. The morphology and integrity of the CSTs were assessed visually. Internal capsule and crus cerebri apparent diffusion coefficient and fractional anisotropy values were measured. Postnatal motor function data were obtained from the parents using the functional status scale. Results: A total of 35 fetuses with IVH (mean ± SD gestational age, 29.1 ± 5.1 (range, 19.9–38.9) weeks) were included in the analysis. Parenchymal involvement on T2‐weighted sequences was demonstrated in 19 (54%) of the cohort. CST involvement correlated significantly with the presence of parenchymal damage on T2‐weighted imaging (P = 0.02). Among liveborn cases, the rate of motor impairment was 14% (1/7) in children with intact CSTs compared with 100% (5/5) in cases in which the CSTs were impaired (P = 0.015). Conclusions: Fetal corticospinal tractography is feasible technically and offers valuable prognostic information. It enhances parental counseling by providing insights into potential motor outcome, underscoring its utility in complementing fetal neurosonography in cases of prenatal IVH. © 2024 The Author(s). Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology. [ABSTRACT FROM AUTHOR]

[Display omitted] • MIA leads to activation of T cells in pregnant mice and microglia in offspring mice, accompanied by upregulation of PD-1 expression on cell membranes. • PD-L1-Fc can effectively alleviate the long-term neuroinflammation in the prefrontal cortex of MIA offspring mice and to some extent improve ASD-like behaviors. • PD-L1-Fc can effectively alleviate MIA in pregnant mice and prevent offspring mice from exhibiting ASD-like behaviors. Autism Spectrum Disorder (ASD) is a neurodevelopmental disorder caused by the interaction of multiple pathogenic factors. Epidemiological studies and animal experiments indicate that maternal immune activation (MIA) is closely related to the development of ASD in offspring. A large number of pro-inflammatory cytokines are transferred from the placenta to the fetal brain during MIA, which impedes fetal neurodevelopment and is accompanied by activation of immune cells and microglia. Programmed cell death protein 1 (PD-1) can be highly expressed on the surface of various activated immune cells, when combined with programmed cell death-ligand 1 (PD-L1), it can activate the PD-1/PD-L1 pathway and exert powerful immunosuppressive effects, suggesting that this immune checkpoint may have the potential to treat MIA-induced ASD. This study combined bioinformatics analysis and experimental validation to explore the efficacy of Fc-fused PD-L1 (PD-L1-Fc) in treating MIA-induced ASD. Bioinformatics analysis results showed that in human placental inflammation, IL-6 was upregulated, T cells proliferated significantly, and the PD-1/PD-L1 pathway was significantly enriched. The experimental results showed that intraperitoneal injection of poly(I:C) induced MIA in pregnant mice resulted in significant expression of IL-6 in their serum, placenta, and fetal brain. At the same time, the expression of PD-1 and PD-L1 in the placenta and fetal brain increased, CD4+ T cells in the spleen were significantly activated, and PD-1 expression increased. Their offspring mice exhibited typical ASD-like behaviors. In vitro experiments on primary microglia of offspring mice have confirmed that the expression of IL-6, PD-1, and PD-L1 is significantly increased, and PD-L1-Fc effectively reduced their expression levels. In the prefrontal cortex of MIA offspring mice, there was an increase in the expression of IL-6, PD-1, and PD-L1; activation of microglial cells, and colocalization with PD-1. Then we administered brain stereotaxic injections of PD-L1-Fc to MIA offspring mice and intraperitoneal injections to MIA pregnant mice. The results indicated that PD-L1-Fc effectively suppressed neuroinflammation in the frontal cortex of offspring mice and partially ameliorated ASD-like behaviors; MIA in pregnant mice was significantly alleviated, and the offspring mice they produced did not exhibit neuroinflammation or ASD-like behaviors. In summary, we have demonstrated the therapeutic ability of PD-L1-Fc for MIA-induced ASD, aiming to provide new strategies and insights for the treatment of ASD. [ABSTRACT FROM AUTHOR]

Purpose: T1 mapping and T1‐weighted contrasts have a complimentary but currently under utilized role in fetal MRI. Emerging clinical low field scanners are ideally suited for fetal T1 mapping. The advantages are lower T1 values which results in higher efficiency and reduced field inhomogeneities resulting in a decreased requirement for specialist tools. In addition the increased bore size associated with low field scanners provides improved patient comfort and accessibility. This study aims to demonstrate the feasibility of fetal brain T1 mapping at 0.55T. Methods: An efficient slice‐shuffling inversion‐recovery echo‐planar imaging (EPI)‐based T1‐mapping and postprocessing was demonstrated for the fetal brain at 0.55T in a cohort of 38 fetal MRI scans. Robustness analysis was performed and placental measurements were taken for validation. Results: High‐quality T1 maps allowing the investigation of subregions in the brain were obtained and significant correlation with gestational age was demonstrated for fetal brain T1 maps (p<0.05$$ p<0.05 $$) as well as regions‐of‐interest in the deep gray matter and white matter. Conclusions: Efficient, quantitative T1 mapping in the fetal brain was demonstrated on a clinical 0.55T MRI scanner, providing foundations for both future research and clinical applications including low‐field specific T1‐weighted acquisitions. [ABSTRACT FROM AUTHOR]

We developed a computational pipeline (now provided as a resource) for measuring morphological similarity between cortical surface sulci to construct a sulcal phenotype network (SPN) from each magnetic resonance imaging (MRI) scan in an adult cohort (n = 34,725; 45–82 years). Networks estimated from pairwise similarities of 40 sulci on 5 morphological metrics comprised two clusters of sulci, represented also by the bimodal distribution of sulci on a linear-to-complex dimension. Linear sulci were more heritable and typically located in unimodal cortex, and complex sulci were less heritable and typically located in heteromodal cortex. Aligning these results with an independent fetal brain MRI cohort (n = 228; 21–36 gestational weeks), we found that linear sulci formed earlier, and the earliest and latest-forming sulci had the least between-adult variation. Using high-resolution maps of cortical gene expression, we found that linear sulcation is mechanistically underpinned by trans-sulcal gene expression gradients enriched for developmental processes. [Display omitted] • A pipeline is provided to extract 5 phenotypes for each of 40 sulci from brain MRI • Sulcal phenotype networks consistently find an axis of linear to complex shape • Adult sulcal complexity is linked to heritability, function, and fetal sulcation • Linear sulci demarcate zones of expression for developmentally enriched genes Snyder et al. develop measures of human cortical folding, revealing an axis of linear to complex sulcal shape across the adult cortex. This axis predicts the phased emergence of sulci in utero and boundaries of cortical gene expression, implicating these processes in the formation of mature cortical geometry. [ABSTRACT FROM AUTHOR]

The document explores the complexities of brain development and the key molecules and pathology involved in the process. It highlights the stages of neuron generation, differentiation, migration, axon guidance, synapse formation, and neural network establishment. Factors such as genetics, environment, lifestyle, and chemical influences play crucial roles in brain development from prenatal stages to adulthood. The document emphasizes the importance of proper nutrition, stimulation, and healthy lifestyle habits for optimal brain development, impacting future learning abilities and overall health. [Extracted from the article]

Arachnoid cysts (ACs) are frequently encountered as incidental findings in the brain, with most cases being asymptomatic and not requiring intervention. However, severe brain malformations caused by ACs are rare. In this study, we describe the case of an 8-day-old female infant with a left mandibular mass that was diagnosed as an insular operculum, which has become disconnected and herniated into the parapharyngeal space through an incompletely ossified greater wing of the sphenoid, caused by a fetal Galassi Type III AC. The newborn also exhibited left hearing impairment, which did not improve at the 6-month follow-up after the cyst peritoneal shunt. This report highlights that ACs that manifest during the early fetal period may protrude from the cranial cavity through an unossified skull, potentially affecting the development of brain tissues. [ABSTRACT FROM AUTHOR]

Diffusion-weighted imaging (DWI) is a technique used to probe the random microscopic motion of water protons in living tissue, represented by a parameter measurement of apparent diffusion coefficient (ADC) values. This study aimed to measure the ADC values of various fetal organs and placenta using 3T at various gestational ages. This was a prospective observational study. A total of 103 singleton pregnancies from 20 to 38 weeks of gestational age were included. Diffusion-weighted imaging was performed in the axial plane from the fetal head to the trunk with the following parameters: TR: 2000–2500 ms; TE: 88 ms; FOV: 250 mm; 256 matrix; slice thickness: 4 mm with a 0 mm gap; acquisition time: 1 min, 18 s. Diffusion gradient values were b = 0 and b = 700 s/mm2. ADC was measured in fetal brain regions (frontal white matter, occipital white matter, centrum semiovale, pons, thalamus, cerebellum, and fetal organs (lungs, kidney, and placenta). ANOVA was used to calculate the mean ADC values. Karl Pearson's coefficient of correlation was used to evaluate the correlation between ADC values and increasing gestational age. The mean ADC values of brain regions were: frontal white matter (1.64 ± 0.08 × 10− 3 mm2 /s, F-39.10,p-<0.001), occipital white matter (1.64 ± 0.06 × 10− 3 mm2/s, F-26.14, p-<0.001), centrum semiovale (1.62 ± 0.03 × 10− 3 mm2/s, F-49.88,p-<0.001, pons (1.23 ± 0.09 × 10− 3 mm2/s F-9.14,p-<0.001)), Thalamus (1.21 ± 0.07 × 10− 3 mm2/s, F-13.54,p-<0.001) and cerebellum (1.36 ± 0.10 × 10− 3 mm2 /s, F-4.19,p-<0.001). The mean ADC values of fetal organs were lung (1.92 ± 0.15 × 10− 3 mm2 /s, F-28.24, p-<0.001), kidney (1.34 ± 0.11 × 10− 3 mm2 /s, F-1.05, p- 0.37) and placenta (1.94 ± 0.11 × 10− 3 mm2 /s, F-160.33, p-<0.001). White-matter regions showed a significant positive correlation with increasing gestational age. Statistically, a negative correlation was observed between increasing gestational age and ADC measurements obtained in the thalamus, cerebellum, pons, and kidney. This will be one of the first few studies to provide the ADC values of the fetal brain and fetal organs using 3T MRI. The current study shows that diffusion-weighted MRI can offer a promising technique to evaluate the structural development of fetal organs and can potentially lead to a biomarker for predicting the functionality of the fetal organs in abnormalities. [ABSTRACT FROM AUTHOR]

Aims: Preterm birth (PTB), recognized as delivery before 37 weeks of gestation, is a multifactorial syndrome characterizing as the main cause of neonatal mortality. Reactive oxygen species (ROS) have been identified as proinflammatory factors to cause placental inflammation, thereby resulting in several pregnancy outcomes. To date, limited knowledge regarding the underlying mechanisms of ROS-induced PTB has been reported. In this study, we aimed to investigate the role of oxidative stress in PTB and the protective effects of mitochondria-targeted antioxidant MitoTEMPO (MT) on preterm labor and offspring mice. Results: In this study, we found that preterm placentas had abnormal mitochondrial function, oxidative stress, and inflammatory response. In the lipopolysaccharide (LPS)-induced PTB mouse model, MT inhibited PTB by ameliorating maternal oxidative stress and inflammation, especially in placentas, thus improving placental function to maintain pregnancy. Antenatal administration of MT prevented LPS-induced fetal brain damage in acute phase and improved long-term neurodevelopmental impairments. Furthermore, our in vitro investigations validated that MT retarded the ROS accumulation and inflammatory response in LPS-stimulated trophoblast cells by promoting Kelch-like ECH-associated protein 1 (Keap1) degradation and subsequently activating nuclear factor erythroid 2-related factor 2 (Nrf2). By inhibiting Nrf2 activation, we discovered that the anti-inflammation and protective characteristics of MT were Nrf2/ARE pathway dependent. Innovation and Conclusion: MT inhibited PTB and fetal brain injury by inhibiting maternal inflammation and improving placental function through Keap1/Nrf2/antioxidant response element signaling pathway. Our findings provide a novel therapeutic strategy for PTB. Antioxid. Redox Signal. 41, 597–615. [ABSTRACT FROM AUTHOR]

Background: The image resolution of fetal brain magnetic resonance imaging (MRI) is a critical factor in brain development measures, which is mainly determined by the physical resolution configured in the MRI sequence. However, fetal brain MRI are commonly reconstructed to 3D images with a higher apparent resolution, compared to the original physical resolution. Purpose: This work is to demonstrate that accurate segmentation can be achieved based on the MRI physical resolution, and the high apparent resolution segmentation can be achieved by a simple deep learning module. Methods: This retrospective study included 150 adult and 80 fetal brain MRIs. The adult brain MRIs were acquired at a high physical resolution, which were downsampled to visualize and quantify its impacts on the segmentation accuracy. The physical resolution of fetal images was estimated based on MRI acquisition settings and the images were downsampled accordingly before segmentation and restored using multiple upsampling strategies. Segmentation accuracy of ConvNet models were evaluated on the original and downsampled images. Dice coefficients were calculated, and compared to the original data. Results: When the apparent resolution was higher than the physical resolution, the accuracy of fetal brain segmentation had negligible degradation (accuracy reduced by 0.26%, 1.1%, and 1.8% with downsampling factors of 4/3, 2, and 4 in each dimension, without significant differences from the original data). Using a downsampling factor of 4 in each dimension, the proposed method provided 7× smaller and 10× faster models. Conclusion: Efficient and accurate fetal brain segmentation models can be developed based on the physical resolution of MRI acquisitions. [ABSTRACT FROM AUTHOR]

Objective: The cerebellum has a long, protracted developmental period; therefore, it is more sensitive to intrauterine and postnatal insults like nutritional deficiencies. Folate is an essential nutrient in fetal and postnatal brain development, and its supplementation during pregnancy is widely recommended. This study aimed to describe the effects of maternal folate intake on postnatal cerebellum development. Methods: Twelve adult female Rattus norwegicus (6–8 weeks old) rats were randomly assigned to one of four groups and given one of four premixed diets: a standard diet (2 mg/kg), a folate-deficient (folate 0 mg/kg), folate-supplemented (8 mg/kg), or folate supra-supplemented (40 mg/kg). The rats began consuming their specific diets 14 days before mating and were maintained on them throughout pregnancy and lactation. Five pups from each group were sacrificed, and their brains processed for light microscopic examination on postnatal days 1, 7, 21, and 35. The data gathered included the morphology of the cerebellar folia and an estimate of the volume of the cerebellar cortical layer using the Cavalieri method. Results: Folia of the folate-supplemented and supra-supplemented groups were thicker and showed extensive branching with sub-lobule formation. The folate-deficient diet group's folia were smaller, had more inter-folial spaces, or fused. When compared to the folate-deficient group, the volumes of the cerebellum and individual cerebellar cortical layers were significantly larger in the folate-supplemented and supra-supplemented groups (p<0.05). Conclusion: Folate supplementation during pregnancy and lactation improves the degree and complexity of the cerebellar folia and the volumes of individual cerebellar cortical layers. [ABSTRACT FROM AUTHOR]

Background/aim: Acetaminophen is frequently used as an analgesic during pregnancy. The purpose of the present study was to evaluate the effects of acetaminophen administered to pregnant mice on the fetal brain, attention, memory, and learning functions in the postnatal period, and genetic mechanisms in these mice. Materials and methods: The study was designed with two different groups. The first group consisted of pregnant mice that were injected with acetaminophen, while the second group was comprised of pregnant mice that were injected with saline. 1st, 2nd, and 3rd days of pregnancy, one of the mice was injected subcutaneously with 100 mg/kg acetaminophen, and the other mouse was injected subcutaneously with 0.9% saline. On the 21st day after birth, five female and five male mice were randomly selected for the experimental and control groups. Behavioral tests were performed on mice at 2 months of age. In addition, changes in the transcript levels of 93 genes were evaluated by Real-Time PCR in the hippocampus. Results: The control group showed more interest in the new object than the acetaminophen group (p=0.002). In the marble burying test, greater burying activity was observed in the control group than in the acetaminophen group (p=0.0345). No significant difference was observed between the control and acetaminophen groups in the social interaction and tail suspension tests. GABRG3, GRM3, PICK1, CEBPB, and EGR4 mRNA expression levels increased in the acetaminophen group (0.0317, 0.0159, 0.0069, 0.0457, 0.015, p value respectively). Conclusions: Prenatal acetaminophen exposure affected both behavioral tests and transcript levels. Therefore, the potential effects of prenatal acetaminophen exposure should be carefully investigated. [ABSTRACT FROM AUTHOR]

Purpose: To achieve high‐resolution fetal brain anatomical imaging without introducing image artifacts by reducing the FOV, and to demonstrate improved image quality compared to conventional full‐FOV fetal brain imaging. Methods: Reduced FOV was achieved by applying outer volume suppression (OVS) pulses immediately prior to standard single‐shot fast spin echo (SSFSE) imaging. In the OVS preparation, a saturation RF pulse followed by a gradient spoiler was repeated three times with optimized flip‐angle weightings and a variable spoiler scheme to enhance signal suppression. Simulations and phantom and in‐vivo experiments were performed to evaluate OVS performance. In‐vivo high‐resolution SSFSE images acquired using the proposed approach were compared with conventional and high‐resolution SSFSE images with a full FOV, using image quality scores assessed by neuroradiologists and calculated image metrics. Results: Excellent signal suppression in the saturation bands was confirmed in phantom and in‐vivo experiments. High‐resolution SSFSE images with a reduced FOV acquired using OVS demonstrated the improved depiction of brain structures without significant motion and blurring artifacts. The proposed method showed the highest image quality scores in the criteria of sharpness, contrast, and artifact and was selected as the best method based on overall image quality. The calculated image sharpness and tissue contrast ratio were also the highest with the proposed method. Conclusion: High‐resolution fetal brain anatomical images acquired using a reduced FOV with OVS demonstrated improved image quality both qualitatively and quantitatively, suggesting the potential for enhanced diagnostic accuracy in detecting fetal brain abnormalities in utero. [ABSTRACT FROM AUTHOR]

Background: Early pregnancy Zika virus (ZIKV) infection is associated with major brain damage in fetuses, leading to microcephaly in 0.6–5.0% of cases, but the underlying mechanisms remain largely unknown. Methods: To understand the kinetics of ZIKV infection during fetal development in a nonhuman primate model, four cynomolgus macaque fetuses were exposed in utero through echo-guided intramuscular inoculation with 103 PFU of ZIKV at 70–80 days of gestation, 2 controls were mock inoculated. Clinical, immuno-virological and ultrasound imaging follow-ups of the mother/fetus pairs were performed until autopsy after cesarean section 1 or 2 months after exposure (n = 3 per group). Results: ZIKV was transmitted from the fetus to the mother and then replicate in the peripheral blood of the mother from week 1 to 4 postexposure. Infected fetal brains tended to be smaller than those of controls, but not the femur lengths. High level of viral RNA ws found after the first month in brain tissues and placenta. Thereafter, there was partial control of the virus in the fetus, resulting in a decreased number of infected tissue sections and a decreased viral load. Immune cellular and humoral responses were effectively induced. Conclusions: ZIKV infection during the second trimester of gestation induces short-term brain injury, and although viral genomes persist in tissues, most of the virus is cleared before delivery. [ABSTRACT FROM AUTHOR]

Intrauterine growth restriction (IUGR) is a pregnancy complication impairing fetal growth and development. The compromised development is often attributed to disruptions of oxygen and nutrient supply from the placenta, resulting in a number of unfavourable physiological outcomes with impaired brain and organ growth. IUGR is associated with compromised development of both grey and white matter, predisposing the infant to adverse neurodevelopmental outcomes, including long‐lasting cognitive and motor difficulties. Cerebral thyroid hormone (TH) signalling, which plays a crucial role in regulating white and grey matter development, is dysregulated in IUGR, potentially contributing to the neurodevelopmental delays associated with this condition. Notably, one of the major TH transporters, monocarboxylate transporter‐8 (MCT8), is deficient in the fetal IUGR brain. Currently, no effective treatment to prevent or reverse IUGR exists. Management strategies involve close antenatal monitoring, management of maternal risk factors if present and early delivery if IUGR is found to be severe or worsening in utero. The overall goal is to determine the most appropriate time for delivery, balancing the risks of preterm birth with further fetal compromise due to IUGR. Drug candidates have shown either adverse effects or little to no benefits in this vulnerable population, urging further preclinical and clinical investigation to establish effective therapies. In this review, we discuss the major neuropathology of IUGR driven by uteroplacental insufficiency and the concomitant long‐term neurobehavioural impairments in individuals born IUGR. Importantly, we review the existing clinical and preclinical literature on cerebral TH signalling deficits, particularly the impaired expression of MCT8 and their correlation with IUGR. Lastly, we discuss the current evidence on MCT8‐independent TH analogues which mimic the brain actions of THs by being metabolised in a similar manner as promising, albeit underappreciated approaches to promote grey and white matter development and improve the neurobehavioural outcomes following IUGR. [ABSTRACT FROM AUTHOR]

Agenesis of the corpus callosum is a rare congenital condition, present at birth, characterized by the partial or complete absence of the corpus callosum. Although the exact causes are usually unknown, the condition can be inherited either as an autosomal recessive trait or as an X-linked dominant trait [1]. Alternatively, it may result from an infection or injury during the 20th to 22nd weeks of pregnancy, which can lead to disruptions in the development of the fetal brain, or it may be caused by toxic factors, such as fetal alcohol syndrome [2]. We present the case of a 2-month-old male patient with acute surgical pathology that began at birth and rapidly progressed to severe infection, requiring sustained antibiotic treatment and assisted respiration. The presence of muscular hypotonia and tonic-clonic seizures at home, following the first hospitalization, necessitated readmission to another university clinic, where he was also diagnosed with agenesis of the corpus callosum. The management of this case required special attention to clinical manifestations, rapid identification of complications, appropriate therapeutic management, and essential collaboration among members of the medical team. [ABSTRACT FROM AUTHOR]

Purpose: Widening the availability of fetal MRI with fully automatic real‐time planning of radiological brain planes on 0.55T MRI. Methods: Deep learning‐based detection of key brain landmarks on a whole‐uterus echo planar imaging scan enables the subsequent fully automatic planning of the radiological single‐shot Turbo Spin Echo acquisitions. The landmark detection pipeline was trained on over 120 datasets from varying field strength, echo times, and resolutions and quantitatively evaluated. The entire automatic planning solution was tested prospectively in nine fetal subjects between 20 and 37 weeks. A comprehensive evaluation of all steps, the distance between manual and automatic landmarks, the planning quality, and the resulting image quality was conducted. Results: Prospective automatic planning was performed in real‐time without latency in all subjects. The landmark detection accuracy was 4.2 ±$$ \pm $$ 2.6 mm for the fetal eyes and 6.5 ±$$ \pm $$ 3.2 for the cerebellum, planning quality was 2.4/3 (compared to 2.6/3 for manual planning) and diagnostic image quality was 2.2 compared to 2.1 for manual planning. Conclusions: Real‐time automatic planning of all three key fetal brain planes was successfully achieved and will pave the way toward simplifying the acquisition of fetal MRI thereby widening the availability of this modality in nonspecialist centers. [ABSTRACT FROM AUTHOR]

Victims of a radiation terrorist event will include pregnant women and unborn fetuses. Mitochondrial dysfunction and oxidative stress are key pathogenic factors of fetal radiation injury. The goal of this preclinical study is to investigate the efficacy of mitigating fetal radiation injury by maternal administration of the mitochondrial-targeted gramicidin S (GS)-nitroxide radiation mitigator JP4-039. Pregnant female C57BL/6NTac mice received 3 Gy total-body irradiation (TBI) at mid-gestation embryonic day 13.5 (E13.5). Using novel time- and-motion-resolved 4D in utero magnetic resonance imaging (4D-uMRI), we found TBI caused extensive injury to the fetal brain that included cerebral hemorrhage, loss of cerebral tissue, and hydrocephalus with excessive accumulation of cerebrospinal fluid (CSF). Histopathology of the fetal mouse brain showed broken cerebral vessels and elevated apoptosis. Further use of novel 4D Oxy-wavelet MRI capable of probing in vivo mitochondrial function in intact brain revealed a significant reduction of mitochondrial function in the fetal brain after 3 Gy TBI. This was validated by ex vivo Oroboros mitochondrial respirometry. One day after TBI (E14.5) maternal administration of JP4-039, which passes through the placenta, significantly reduced fetal brain radiation injury and improved fetal brain mitochondrial respiration. Treatment also preserved cerebral brain tissue integrity and reduced cerebral hemorrhage and cell death. JP4-039 administration following irradiation resulted in increased survival of pups. These findings indicate that JP4-039 can be deployed as a safe and effective mitigator of fetal radiation injury from mid-gestational in utero ionizing radiation exposure. [ABSTRACT FROM AUTHOR]

Accurately predicting a fetus's gestational age (GA) is crucial in prenatal care. This study aimed to develop an artificial intelligence (AI) model to predict GA using biometric measurements from fetal brain magnetic resonance imaging (MRI). We assessed the significance of using different reference standards for interpreting GA predictions. Measurements of biparietal diameter (BPD), fronto-occipital diameter (FOD), and head circumference (HC) were obtained from 52 normal fetal MRI cases from Rush University. Both manual and AI-based methods were utilized, and comparisons were made using three reference standards (Garel, Freq, and Bio). The AI model showed a strong correlation with manual measurements, particularly for HC, which exhibited the highest correlation with actual values. Differences between GA predictions and picture archiving and communication system (PACS) records varied by reference, ranging from 0.47 to 2.17 weeks for BPD, 0.46 to 2.26 weeks for FOD, and 0.75 to 1.74 weeks for HC. Pearson correlation coefficients between PACS records and GA predictions exceeded 0.97 across all references. In conclusion, the AI model demonstrated high accuracy in predicting GA from fetal brain MRI measurements. This approach offers improved accuracy and convenience over manual methods, highlighting the potential of AI in enhancing prenatal care through precise GA estimation. [ABSTRACT FROM AUTHOR]

Abstract Diffusion-weighted imaging (DWI) is a technique used to probe the random microscopic motion of water protons in living tissue, represented by a parameter measurement of apparent diffusion coefficient (ADC) values. This study aimed to measure the ADC values of various fetal organs and placenta using 3T at various gestational ages. This was a prospective observational study. A total of 103 singleton pregnancies from 20 to 38 weeks of gestational age were included. Diffusion-weighted imaging was performed in the axial plane from the fetal head to the trunk with the following parameters: TR: 2000–2500 ms; TE: 88 ms; FOV: 250 mm; 256 matrix; slice thickness: 4 mm with a 0 mm gap; acquisition time: 1 min, 18 s. Diffusion gradient values were b = 0 and b = 700 s/mm2. ADC was measured in fetal brain regions (frontal white matter, occipital white matter, centrum semiovale, pons, thalamus, cerebellum, and fetal organs (lungs, kidney, and placenta). ANOVA was used to calculate the mean ADC values. Karl Pearson’s coefficient of correlation was used to evaluate the correlation between ADC values and increasing gestational age. The mean ADC values of brain regions were: frontal white matter (1.64 ± 0.08 × 10− 3 mm2 /s, F-39.10,p-

Accurately predicting a fetus’s gestational age (GA) is crucial in prenatal care. This study aimed to develop an artificial intelligence (AI) model to predict GA using biometric measurements from fetal brain magnetic resonance imaging (MRI). We assessed the significance of using different reference standards for interpreting GA predictions. Measurements of biparietal diameter (BPD), fronto-occipital diameter (FOD), and head circumference (HC) were obtained from 52 normal fetal MRI cases from Rush University. Both manual and AI-based methods were utilized, and comparisons were made using three reference standards (Garel, Freq, and Bio). The AI model showed a strong correlation with manual measurements, particularly for HC, which exhibited the highest correlation with actual values. Differences between GA predictions and picture archiving and communication system (PACS) records varied by reference, ranging from 0.47 to 2.17 weeks for BPD, 0.46 to 2.26 weeks for FOD, and 0.75 to 1.74 weeks for HC. Pearson correlation coefficients between PACS records and GA predictions exceeded 0.97 across all references. In conclusion, the AI model demonstrated high accuracy in predicting GA from fetal brain MRI measurements. This approach offers improved accuracy and convenience over manual methods, highlighting the potential of AI in enhancing prenatal care through precise GA estimation.

Abstract Background The SARS-CoV-2 virus activates maternal and placental immune responses. Such activation in the setting of other infections during pregnancy is known to impact fetal brain development. The effects of maternal immune activation on neurodevelopment are mediated at least in part by fetal brain microglia. However, microglia are inaccessible for direct analysis, and there are no validated non-invasive surrogate models to evaluate in utero microglial priming and function. We have previously demonstrated shared transcriptional programs between microglia and Hofbauer cells (HBCs, or fetal placental macrophages) in mouse models. Methods and results We assessed the impact of maternal SARS-CoV-2 on HBCs isolated from 24 term placentas (N = 10 SARS-CoV-2 positive cases, 14 negative controls). Using single-cell RNA-sequencing, we demonstrated that HBC subpopulations exhibit distinct cellular programs, with specific subpopulations differentially impacted by SARS-CoV-2. Assessment of differentially expressed genes implied impaired phagocytosis, a key function of both HBCs and microglia, in some subclusters. Leveraging previously validated models of microglial synaptic pruning, we showed that HBCs isolated from placentas of SARS-CoV-2 positive pregnancies can be transdifferentiated into microglia-like cells (HBC-iMGs), with impaired synaptic pruning behavior compared to HBC models from negative controls. Conclusion These findings suggest that HBCs isolated at birth can be used to create personalized cellular models of offspring microglial programming.

Usutu (USUV), West Nile (WNV), and Zika virus (ZIKV) are neurotropic arthropod-borne viruses (arboviruses) that cause severe neurological disease in humans. However, USUV-associated neurological disease is rare, suggesting a block in entry to or infection of the brain. We determined the replication, cell tropism and neurovirulence of these arboviruses in human brain tissue using a well-characterized human fetal organotypic brain slice culture model. Furthermore, we assessed the efficacy of interferon-β and 2′C-methyl-cytidine, a synthetic nucleoside analogue, in restricting viral replication. All three arboviruses replicated within the brain slices, with WNV reaching the highest titers, and all primarily infected neuronal cells. USUV- and WNV-infected cells exhibited a shrunken morphology, not associated with detectable cell death. Pre-treatment with interferon-β inhibited replication of all arboviruses, while 2′C-methyl-cytidine reduced only USUV and ZIKV titers. Collectively, USUV can infect human brain tissue, showing similarities in tropism and neurovirulence as WNV and ZIKV. These data suggest that a blockade to infection of the human brain may not be the explanation for the low clinical incidence of USUV-associated neurological disease. However, USUV replicated more slowly and to lower titers than WNV, which could help to explain the reduced severity of neurological disease resulting from USUV infection. [ABSTRACT FROM AUTHOR]

ABSTRACT Introduction Methods Results Conclusion In the context of adverse in utero environments, the fetal brain might be preserved at the expense of other tissues. This trade‐off, brain sparing, has not been studied in the context of maternal infection. We investigated cases of maternal syphilis in the early 20th century and influenza during the 1918–1920 pandemic, in the Swiss city of Lausanne, a relatively high‐income setting. We tested the brain sparing hypothesis, that head circumference is protected at the expense of birth weight.A total of 8530 individual birth records from 1911 to 1922 from the University Maternity Hospital of Lausanne were used. We fitted generalized linear and additive linear models to explain how neonatal size varies under disease exposure.Influenza reduced head circumference and birth weight among livebirths similarly, by −0.11 and −0.14 standard deviation (SD) units respectively. Conversely, for syphilis‐exposed infants, head circumference was affected more than birth weight (−0.61 SD vs. −0.46 SD). Stillborn infants exposed to syphilis experienced a much greater reduction in head circumference (−1.92 SD) than liveborn infants. After adjustment for gestational age, these findings persisted in the case of influenza, but the effects of syphilis were reduced. Furthermore, half of syphilis‐exposed infants were born before term, suggesting that lower infant size was partly mediated by shorter gestation. Nevertheless, head circumference among stillbirths exposed to syphilis was still substantially reduced, even after adjustment for gestational age (−1.26 SD).Our findings do not support the brain sparing hypothesis. Moreover, the substantial reduction in head circumference among syphilis‐exposed fetuses might help explain why a quarter of them were stillborn. [ABSTRACT FROM AUTHOR]

Brain development involves a sequence of structural changes from early stages of the embryo until several months after birth. Currently, ultrasound is the established technique for screening due to its ability to acquire dynamic images in real-time without radiation and to its cost-efficiency. However, identifying abnormalities remains challenging due to the difficulty in interpreting foetal brain images. In this work we present a set of 104 2D foetal brain ultrasound images acquired during the 20th week of gestation that have been co-registered to a common space from a rough skull segmentation. The images are provided both on the original space and template space centred on the ellipses of all the subjects. Furthermore, the images have been annotated to highlight landmark points from structures of interest to analyse brain development. Both the final atlas template with probabilistic maps and the original images can be used to develop new segmentation techniques, test registration approaches for foetal brain ultrasound, extend our work to longitudinal datasets and to detect anomalies in new images. [ABSTRACT FROM AUTHOR]

The effects of neurotoxicant cadmium (Cd) exposure on brain development have not been well elucidated. To investigate this, we have herein subjected pregnant mice to low-dose Cd throughout gestation. Using single-cell RNA sequencing (scRNA-seq), we explored the cellular responses in the embryonic brain to Cd exposure, and identified 18 distinct cell subpopulations that exhibited varied responses to Cd. Typically, Cd exposure impeded the development and maturation of cells in the brain, especially progenitor cells such as neural progenitor cells (NPCs) and oligodendrocyte progenitor cells (OPCs). It also caused significant cell subpopulation shifts in almost all the types of cells in the brain. Additionally, Cd exposure reduced the dendritic sophistication of cortical neurons in the offspring. Importantly, these changes led to aberrant Ca2+ activity in the cortex and neural behavior changes in mature offspring. These data contribute to our understanding of the effects and mechanisms of Cd exposure on brain development and highlight the importance of controlling environmental neurotoxicant exposure at the population level. Prenatal cadmium exposure impeded the development and maturation of cells in the brain and induced cell subpopulation shifts, which lead to aberrant Ca2+ activities in the cortex and neural behavioral dysfunction in mature offspring. [ABSTRACT FROM AUTHOR]

During development, embryos and foetuses may be exposed to maternally ingested antiseizure medications (ASM), valproate and lamotrigine, essential in some patients to control their epilepsy symptoms. Often, the two drugs are co‐administered to reduce required doses of valproate, a known potential teratogen. This study used Genetic Absence Epilepsy Rat from Strasbourg to evaluate transfer of valproate and lamotrigine across late gestation placenta and their entry into cerebrospinal fluid (CSF) and brain of developing rats, in mono‐ and combination therapies. Animals at embryonic day (E) 19, postnatal day (P) 0, 4 and 21, and adults were administered valproate (30 mg/kg) or lamotrigine (6 mg/kg) with their respective [3H]‐tracers, either alone or in combination. In chronic experiments, females consumed valproate‐containing diet from 2 weeks prior to mating until offspring were used at E19 and P0. Drugs were injected 30 min before blood, CSF and brain samples were collected from terminally anaesthetised animals. Radioactivity in samples was measured. In acute monotherapy brain entry of valproate was higher in foetal than postnatal animals, correlating with its plasma protein binding. Brain entry of lamotrigine was not age‐dependent. Combination therapy enhanced entry of lamotrigine into the adult brain but had no effects on brain and CSF entry of valproate. Following chronic valproate exposure, placental transfer of valproate decreased in combination therapy; however, foetal brain entry increased. Results suggest that during pregnancy, the use of combination therapy of valproate and lamotrigine may mitigate overall foetal exposure to valproate but potential risks to foetal brain development are less clear. [ABSTRACT FROM AUTHOR]

Background: Epidemiological studies have linked low birth weight to psychiatric disorders, including substance use disorders. Genomic analyses suggest a role of placental physiology on psychiatric risk. We investigated whether this association is causally related to impaired trophoblast function. Methods: We conducted a two-sample summary-data Mendelian randomization study using as instrumental variables those genetic variants strongly associated with birth weight, whose effect is exerted through the fetal genome, and are located near genes with differential expression in trophoblasts. Eight psychiatric and substance use disorders with >10,000 samples were included as outcomes. The inverse variance weighted method was used as the main analysis and several sensitivity analyses were performed for those significant results. Results: The inverse variance weighted estimate, based on 14 instrumental variables, revealed an association, after correction for multiple tests, between birth weight and broadly defined depression (β = -0.165, 95% CI = -0.282 to -0.047, P = 0.0059). Sensitivity analyses revealed the absence of heterogeneity in the effect of instrumental variables, confirmed by leave-one-out analysis, MR_Egger intercept, and MR_PRESSO. The effect was consistent using robust methods. Reverse causality was not detected. The effect was specifically linked to genetic variants near genes involved in trophoblast physiology instead of genes with fetal effect on birth weight or involved in placenta development. Conclusion: Impaired trophoblast functioning, probably leading to reduced fetal brain oxygen and nutrient supply, is causally related to broadly defined depression. Considering the therapeutic potential of some agents to treat fetal growth restriction, further research on the effect of trophoblast physiology on mental disorders may have future implications in prevention. [ABSTRACT FROM AUTHOR]

Background: The hypothalamic–pituitary–adrenal (HPA) and -gonadal (HPG) axes are two major pathways that connect the neural and endocrine systems in vertebrates. Factors such as prenatal stress and maternal exposure to exogenous steroids have been shown to affect these pathways during fetal development. Another less studied factor is the transfer of hormones across fetuses in multifetal pregnancies. This form of transfer has been shown to influence the morphology, anatomy, physiology, and behavior of the offspring in litter-bearing mammals, an influence termed the intrauterine position (IUP) effect. In this study, we sought to delineate how the IUP effects HPA and HPG brain receptors, peptides, and enzymes (hereafter components) in utero and how these influences may differ between males and females. Methods: We utilized the unconventional model of culled free-ranging nutria (Myocastor coypus), with its large natural variation. We collected brain tissues from nutria fetuses and quantified the expression of key HPA and HPG components in three brain regions: prefrontal cortex, hypothalamus, and striatum. Results: We found an interaction between sex and IUP in the mineralocorticoid receptor (MR), gonadotropin-releasing hormone receptor (GNRHR), androgen receptor (AR), and estrogen receptor alpha (ESR1). IUP was significant in both gonadotropin-releasing hormone (GnRH) and its receptor GNRHR, but in different ways. In the hypothalamus, fetuses adjacent to same-sex neighbors had higher expression of GnRH than fetuses neighboring the opposite sex. Conversely, in the cortex, GNRHR exhibited the inverse pattern, and fetuses that were neighboring the opposite sex had higher expression levels than those neighboring the same sex. Regardless of IUP, in most components that showed significant sex differences, female fetuses had higher mRNA expression levels than male fetuses. We also found that HPA and HPG components were highly related in the early stages of gestation, and that there was an interaction between sex and developmental stage. In the early stages of pregnancy, female component expression levels were more correlated than males', but in the last trimester of pregnancy, male components were more related to each other than female's. Conclusions: This study suggests that there are sexually different mechanisms to regulate the HPA and HPG axes during fetal development. Higher mRNA expression levels of endocrine axes components may be a mechanism to help females cope with prolonged androgen exposure over a long gestational period. Additionally, these findings suggest different coordination requirements of male and female endocrine axes during stages of fetal development. Highlights: This study is the first to analyze HPA and HPG axes receptors, peptides, and enzyme mRNA expression levels in the brains of fetuses in the wild. Higher HPA and HPG axes receptors mRNA expression levels in females hint towards alternative sex-specific mechanisms that regulate endocrine axes during fetal development. Coordination of HPA and HPG axes components' expression levels is different between males and females at different stages of gestation. Plain language summary: In litter-bearing mammals, the positioning of a fetus in the uterus relative to other fetuses of the same or opposite sex has been shown to directly influence fetal morphology and physiology, and later behavior, reproductive success, and survival in adults. In this study, we sought to understand the mechanisms by which the location in the uterus influences two major neuroendocrine pathways in fetal brains. We quantified expression of multiple receptors and an enzyme (referred to as 'components') of the endocrine axes in three different brain regions in fetal free-ranging nutrias. Our results showed higher expression in females than in males for some endocrine axes components. The location inside the uterus was also related to the expression of some components. Lastly, coordination between the axes was higher earlier on in gestation, and females were more coordinated than males in the second trimester, whereas males were more coordinated than females in the third trimester. The results of this study point to the mechanisms by which the sexes regulate key neuroendocrine pathways during fetal development. [ABSTRACT FROM AUTHOR]

Scorpion envenomation is one of the severe public health problems, particularly children and pregnant women. Increased oxidative stress in the brain during the first couple of weeks in the gestational period may limit the efficacy of antioxidants after the scorpion envenomation. High ROS activity during brain organogenesis may damage the forebrain and midbrain of fetuses. In this study, we examined cellular alterations in the fetal brain and cotyledon of in utero exposure to scorpion venom and antivenom during pregnancy in rats. The study focused on establishing a correlation between fetal brain and cotyledonary lesions due to altered oxidative stress. Eighteen pregnant Wistar albino rats were randomly divided into three groups envenomated group (EG) by Androctonus turkiyensis Yagmur venom, antivenom group (AVG), and physiological saline solution (1 mL, PSS: NaCl 0.85%) treated control group (CG). Pregnant rats in the EG (n=6) were injected sublethal doses of A. turkiyensis every day between 7-13th days of pregnancy. AVG, pregnant rats (n=6) were envenomed with A. crassicauda venom. After 4 h of each venom injection, these pregnant rats were administered a specific antivenom. The pregnant rats in groups were operated aseptically on the 21st day of pregnancy. Ovariohysterectomy was performed to remove the fetus with cotyledons. Fetal central nervous systems and cotyledons were examined histopathologically and immunohistochemically. To demonstrate ROS-related damages, iNOS, 8-OHdG, 4HNE and RIPK3 were quantified and analysed statistically. As a result, expressions correspondingly to venom administration were increased in EG despite of a decrease in AVG. In conclusion, it was found that the antivenom administration regarding scorpion envenomations can diminish ROS-related-cotyledonary and neuronal damages. [ABSTRACT FROM AUTHOR]

• Intrauterine position influences multiple outcomes of MIA in mice. • Being flanked by male neighbors in utero attenuates the impact of MIA. • Intrauterine position contribute to within-litter variability in mouse MIA models. Rodent models of maternal immune activation (MIA) are increasingly used as experimental tools in preclinical research of immune-mediated neurodevelopmental disorders and mental illnesses. Using a viral-like MIA model that is based on prenatal poly(I:C) exposure in mice, we have recently identified the existence of subgroups of MIA-exposed offspring that show dissociable behavioral, transcriptional, brain network and inflammatory profiles even under conditions of genetic homogeneity and identical MIA. Here, we tested the hypothesis that the intrauterine positions of fetuses, which are known to shape individual variability in litter-bearing mammals through variations in fetal hormone exposure, may contribute to the variable outcomes of MIA in mice. MIA was induced by maternal administration of poly(I:C) on gestation day 12 in C57BL/6N mice. Determining intrauterine positions using delivery by Cesarean section (C-section), we found that MIA-exposed offspring developing between female fetuses only (0M-MIA offspring) displayed significant deficits in sociability and sensorimotor gating at adult age, whereas MIA-exposed offspring developing between one or two males in utero (1/2M-MIA offspring) did not show the same deficits. These intrauterine position effects similarly emerged in male and female offspring. Furthermore, while MIA elevated fetal brain levels of pro- and anti-inflammatory cytokines independently of the precise intrauterine position and sex of adjacent fetuses during the acute phase, fetal brain levels of TNF-α remained elevated in 0M-MIA but not 1/2M-MIA offspring until the post-acute phase in late gestation. As expected, 1/2M offspring generally showed higher testosterone levels in the fetal brain during late gestation as compared to 0M offspring, confirming the transfer of testosterone from male fetuses to adjacent male or female fetuses. Taken together, our findings identify a novel source of within-litter variability contributing to heterogeneous outcomes of short- and long-term effects in a mouse model of MIA. In broader context, our findings highlight that individual differences in fetal exposure to hormonal and inflammatory signals may be a perinatal factor that shapes risk and resilience to MIA. [ABSTRACT FROM AUTHOR]

[Display omitted] • Stress during pregnancy leads to behavioral changes in adulthood. • Stress causes alteration in maternal gut microbiota. • Maternal gut microbiota leads to the changes of metabolism. • The stress-induced increase of β-guanidinopropionic acid (GPA) results in neurodevelopment effects. • Probiotics reverses prenatal stress-induced cognitive impairment in rat offspring. Stress during pregnancy is often linked with increased incidents of neurodevelopmental disorders, including cognitive impairment. Here, we report that stress during pregnancy leads to alterations in the intestinal flora, which negatively affects the cognitive function of offspring. Cognitive impairment in stressed offspring can be reproduced by transplantation of cecal contents of stressed pregnant rats (ST) to normal pregnant rats. In addition, gut microbial dysbiosis results in an increase of β-guanidinopropionic acid in the blood, which leads to an activation of the adenosine monophosphate-activated protein kinase (AMPK) and signal transducer and activator of transcription 3 (STAT3) in the fetal brain. Moreover, β-guanidinopropionic acid supplementation in pregnant rats can reproduce pregnancy stress-induced enhanced glial differentiation of the fetal brain, resulting in impaired neural development. Using probiotics to reconstruct maternal microbiota can correct the cognitive impairment in the offspring of pregnant stressed rats. These findings suggest that microbial reconstitution reverses gestational stress-induced cognitive impairment and synaptic deficits in male rat offspring. [ABSTRACT FROM AUTHOR]

Purpose: We propose a quantitative framework for motion‐corrected T2 fetal brain measurements in vivo and validate the single‐shot fast spin echo (SS‐FSE) sequence to perform these measurements. Methods: Stacks of two‐dimensional SS‐FSE slices are acquired with different echo times (TE) and motion‐corrected with slice‐to‐volume reconstruction (SVR). The quantitative T2 maps are obtained by a fit to a dictionary of simulated signals. The sequence is selected using simulated experiments on a numerical phantom and validated on a physical phantom scanned on a 1.5T system. In vivo quantitative T2 maps are obtained for five fetuses with gestational ages (GA) 21–35 weeks on the same 1.5T system. Results: The simulated experiments suggested that a TE of 400 ms combined with the clinically utilized TEs of 80 and 180 ms were most suitable for T2 measurements in the fetal brain. The validation on the physical phantom confirmed that the SS‐FSE T2 measurements match the gold standard multi‐echo spin echo measurements. We measured average T2s of around 200 and 280 ms in the fetal brain grey and white matter, respectively. This was slightly higher than fetal T2* and the neonatal T2 obtained from previous studies. Conclusion: The motion‐corrected SS‐FSE acquisitions with varying TEs offer a promising practical framework for quantitative T2 measurements of the moving fetus. [ABSTRACT FROM AUTHOR]

Background: Congenital heart disease (CHD) is common and is associated with impaired early brain development and neurodevelopmental outcomes, yet the exact mechanisms underlying these associations are unclear. Purpose: To utilize MRI data from a cohort of fetuses with CHD as well as typically developing fetuses to test the hypothesis that expected cerebral substrate delivery is associated with total and regional fetal brain volumes. Study Type: Retrospective case–control study. Population: Three hundred eighty fetuses (188 male), comprising 45 healthy controls and 335 with isolated CHD, scanned between 29 and 37 weeks gestation. Fetuses with CHD were assigned into one of four groups based on expected cerebral substrate delivery. Field Strength/Sequence: T2‐weighted single‐shot fast‐spin‐echo sequences and a balanced steady‐state free precession gradient echo sequence were obtained on a 1.5 T scanner. Assessment: Images were motion‐corrected and reconstructed using an automated slice‐to‐volume registration reconstruction technique, before undergoing segmentation using an automated pipeline and convolutional neural network that had undergone semi‐supervised training. Differences in total, regional brain (cortical gray matter, white matter, deep gray matter, cerebellum, and brainstem) and brain:body volumes were compared between groups. Statistical Tests: ANOVA was used to test for differences in brain volumes between groups, after accounting for sex and gestational age at scan. PFDR‐values <0.05 were considered statistically significant. Results: Total and regional brain volumes were smaller in fetuses where cerebral substrate delivery is reduced. No significant differences were observed in total or regional brain volumes between control fetuses and fetuses with CHD but normal cerebral substrate delivery (all PFDR > 0.12). Severely reduced cerebral substrate delivery is associated with lower brain:body volume ratios. Data Conclusion: Total and regional brain volumes are smaller in fetuses with CHD where there is a reduction in cerebral substrate delivery, but not in those where cerebral substrate delivery is expected to be normal. Evidence Level: 3 Technical Efficacy: Stage 3 [ABSTRACT FROM AUTHOR]

Previous studies have reported sex differences in cortical gyrification. Since most cortical folding is principally defined in utero, sex chromosomes as well as gonadal hormones are likely to influence sex‐specific aspects of local gyrification. Classic congenital adrenal hyperplasia (CAH) causes high levels of androgens during gestation in females, whereas levels in males are largely within the typical male range. Therefore, CAH provides an opportunity to study the possible effects of prenatal androgens on cortical gyrification. Here, we examined the vertex‐wise absolute mean curvature—a common estimate for cortical gyrification—in individuals with CAH (33 women and 20 men) and pair‐wise matched controls (33 women and 20 men). There was no significant main effect of CAH and no significant CAH‐by‐sex interaction. However, there was a significant main effect of sex in five cortical regions, where gyrification was increased in women compared to men. These regions were located on the lateral surface of the brain, specifically left middle frontal (rostral and caudal), right inferior frontal, left inferior parietal, and right occipital. There was no cortical region where gyrification was increased in men compared to women. Our findings do not only confirm prior reports of increased cortical gyrification in female brains but also suggest that cortical gyrification is not significantly affected by prenatal androgen exposure. Instead, cortical gyrification might be determined by sex chromosomes either directly or indirectly—the latter potentially by affecting the underlying architecture of the cortex or the size of the intracranial cavity, which is smaller in women. [ABSTRACT FROM AUTHOR]

During the second-to-third trimester, the neuronal pathways of the fetal brain experience rapid development, resulting in the complex architecture of the interwired network at birth. While diffusion MRI-based tractography has been employed to study the prenatal development of structural connectivity network (SCN) in preterm neonatal and postmortem fetal brains, the in utero development of SCN in the normal fetal brain remains largely unknown. In this study, we utilized in utero dMRI data from human fetuses of both sexes between 26 and 38 gestational weeks to investigate the developmental trajectories of the fetal brain SCN, focusing on intrahemispheric connections. Our analysis revealed significant increases in global efficiency, mean local efficiency, and clustering coefficient, along with significant decrease in shortest path length, while small-worldness persisted during the studied period, revealing balanced network integration and segregation. Widespread short-ranged connectivity strengthened significantly. The nodal strength developed in a posterior-to-anterior and medial-to-lateral order, reflecting a spatiotemporal gradient in cortical network connectivity development. Moreover, we observed distinct lateralization patterns in the fetal brain SCN. Globally, there was a leftward lateralization in network efficiency, clustering coefficient, and small-worldness. The regional lateralization patterns in most language, motor, and visual-related areas were consistent with prior knowledge, except for Wernicke’s area, indicating lateralized brain wiring is an innate property of the human brain starting from the fetal period. Our findings provided a comprehensive view of the development of the fetal brain SCN and its lateralization, as a normative template that may be used to characterize atypical development. [ABSTRACT FROM AUTHOR]

Small non-coding RNAs (sncRNAs) make up ~1% of the transcriptome; nevertheless, they play significant roles in regulating cellular processes. Given the complexity of the central nervous system, sncRNAs likely hold particular importance in the human brain. In this study, we provide sncRNA transcriptomic profiles in a range of adult and prenatal brain regions, with a focus on piRNAs, due to their underexplored expression in somatic cells and tissue-specific nature. Using the WIND workflow, which combines two detection methods, we found 1333 (731 miRNAs, 249 piRNAs, 285 snoRNAs, and 68 other sncRNAs) and 1445 unique sncRNAs (770 miRNAs, 307 piRNAs, 289 snoRNAs, and 79 other sncRNAs) in developing and adult brains, respectively. Significant variations were found upon comparison of fetal and adult brain groups, with 82 miRNAs, 17 piRNAs, and 70 snoRNAs enriched in fetal brains and 22 miRNAs, 11 piRNAs in adult brains. This dataset represents a valuable resource for exploring the sncRNA roles in brain function, their involvement in neurological diseases, and the molecular mechanisms behind brain region interactions. [ABSTRACT FROM AUTHOR]

The Kurjak antenatal neurodevelopment test (KANET) is a pioneering prenatal diagnostic tool designed to evaluate fetal neurodevelopment using high-resolution ultrasonography and detailed neuroimaging analysis. This review provides an in-depth analysis of KANET's methodology, clinical applications, and its significant role in enhancing prenatal care. By integrating advanced imaging techniques with precise neurodevelopmental assessments, KANET enables early detection and intervention for neurodevelopmental disorders, potentially improving long-term outcomes. The review also discusses KANET's validation across diverse populations, its comparative effectiveness with traditional diagnostic methods, and the future potential for incorporating emerging technologies to further refine prenatal diagnostics. [ABSTRACT FROM AUTHOR]

The development of the human central nervous system initiates in the early embryonic period until long after delivery. It has been shown that several neurological and neuropsychiatric diseases originate from prenatal incidents. Mathematical models offer a direct way to understand neurodevelopmental processes better. Mathematical modelling of neurodevelopment during the embryonic period is challenging in terms of how to 'Approach', how to initiate modelling and how to propose the appropriate equations that fit the underlying dynamics of neurodevelopment during the embryonic period while including the variety of elements that are built-in naturally during the process of neurodevelopment. It is imperative to answer where and how to start modelling; in other words, what is the appropriate 'Approach'? Therefore, one objective of this study was to tackle the mathematical issue broadly from different aspects and approaches. The approaches were divided into three embryonic categories: cell division, neural tube growth and neural plate growth. We concluded that the neural plate growth approach provides a suitable platform for simulation of brain formation/neurodevelopment compared to cell division and neural tube growth. We devised a novel equation and designed algorithms that include geometrical and topological algorithms that could fit most of the necessary elements of the neurodevelopmental process during the embryonic period. Hence, the proposed equations and defined mathematical structure would be a platform to generate an artificial neural network that autonomously grows and develops. [ABSTRACT FROM AUTHOR]

Fetal cerebral ventriculomegaly is one of the most common fetal neurological disorders identified prenatally by neuroimaging. The challenges in the evolving landscape of conditions like fetal cerebral ventriculomegaly involve accurate diagnosis and how best to provide prenatal counseling regarding prognosis as well as postnatal management and care of the infant. The purpose of this narrative review is to discuss the literature on fetal ventriculomegaly, including postnatal management and neurodevelopmental outcome, and to provide practice recommendations for pediatric neurologists. [ABSTRACT FROM AUTHOR]

Neonates with congenital heart disease (CHD) have smaller brain volume at birth. High rates of placental vascular malperfusion lesions may play a role in disrupted brain development. This is a single-center retrospective cohort study of infants born between 2010 and 2019 who were diagnosed with a major cardiac defect requiring surgery in the first year of life. Doppler ultrasound RI of the middle cerebral artery (MCA) and anterior cerebral artery were calculated within the first 72 hours of life. Placentas were evaluated using a standardized approach. Over the study period, there were 52 patients with hypoplastic left heart syndrome (HLHS), 22 with single-ventricle right ventricular outflow tract obstruction (SV-RVOTO), 75 with a two-ventricle cardiac defect (2V), and 25 with transposition of the great arteries (TGA). MCA Doppler RI were significantly higher for all subgroups of CHD compared with control subjects (0.68 ± 0.11 in control subjects compared with 0.78 ± 0.13 in HLHS, P = 0.03; 0.77 ± 0.10 in SV-RVOTO, P = 0.002; 0.78 ± 0.13 in 2V, P = 0.03; and 0.80 ± 0.14 in TGA; P = 0.001) with the highest average MCA RI in the TGA group. In subgroup analyses, placental fetal vascular malperfusion in the 2V group was associated with higher MCA RI, but this relationship was not present in other subgroups, nor in regards to maternal vascular malperfusion. Major forms of CHD are associated with significantly higher cerebral artery RI postnatally, but placental vascular malperfusion lesions may not contribute to this hemodynamic adaptation. [ABSTRACT FROM AUTHOR]

New human life begins in the uterus in a period of both extreme plasticity and sensitivity to environmental disturbances. The fetal stage is also a vital period for central nervous system development, with experiences at this point profoundly and permanently shaping brain structure and function. As such, some brain disorders may originate in utero. Glucocorticoids, a class of essential stress hormones, play indispensable roles in fetal development, but overexposure may have lasting impacts on the brain. In this review, we summarize data from recent clinical and non-clinical studies regarding alterations in fetal brains due to prenatal glucocorticoid overexposure that are associated with nervous system disorders. We discuss relevant changes to brain structure and cellular functions and explore the underlying molecular mechanisms. In addition, we summarize factors that may cause differential outcomes between varying brain regions, and outline clinically feasible intervention strategies that are expected to minimize negative consequences arising from fetal glucocorticoid overexposure. Finally, we highlight the need for experimental evidence aided by new technologies to clearly determine the effects of excessive prenatal glucocorticoid exposure. This review consolidates diverse findings to help researchers better understand the relationship between the prenatal glucocorticoid overexposure and the effects it has on various fetal brain regions, promoting further development of critical intervention strategies. [ABSTRACT FROM AUTHOR]

Objectives: To investigate the advantage of T1-weighted fast fluid-attenuated inversion-recovery MRI sequence without (T1-FFLAIR) and with compressed sensing technology (T1-FFLAIR-CS), which shows improved T1-weighted contrast, over standard used T1-weighted fast field echo (T1-FFE) sequence for the assessment of fetal myelination. Materials and methods: This retrospective single-center study included 115 consecutive fetal brain MRI examinations (63 axial and 76 coronal, mean gestational age (GA) 28.56 ± 5.23 weeks, range 19–39 weeks). Two raters, blinded to GA, qualitatively assessed a fetal myelin total score (MTS) on each T1-weighted sequence at five brain regions (medulla oblongata, pons, mesencephalon, thalamus, central region). One rater performed region-of-interest quantitative analysis (n = 61) at the same five brain regions. Pearson correlation analysis was applied for correlation of MTS and of the signal intensity ratios (relative to muscle) with GA on each T1-weighted sequence. Fetal MRI–based results were compared with myelination patterns of postmortem fetal human brains (n = 46; GA 18 to 42), processed by histological and immunohistochemical analysis. Results: MTS positively correlated with GA on all three sequences (all r between 0.802 and 0.908). The signal intensity ratios measured at the five brain regions correlated best with GA on T1-FFLAIR (r between 0.583 and 0.785). T1-FFLAIR demonstrated significantly better correlations with GA than T1-FFE for both qualitative and quantitative analysis (all p < 0.05). Furthermore, T1-FFLAIR enabled the best visualization of myelinated brain structures when compared to histology. Conclusion: T1-FFLAIR outperforms the standard T1-FFE sequence in the visualization of fetal brain myelination, as demonstrated by qualitative and quantitative methods. Clinical relevance statement: T1-weighted fast fluid-attenuated inversion-recovery sequence (T1-FFLAIR) provided best visualization and quantification of myelination in utero that, in addition to the relatively short acquisition time, makes feasible its routine application in fetal MRI for the assessment of brain myelination. Key Points: • So far, the assessment of fetal myelination in utero was limited due to the insufficient contrast. • T1-weighted fast fluid-attenuated inversion-recovery sequence allows a qualitative and quantitative assessment of fetal brain myelination. • T1-weighted fast fluid-attenuated inversion-recovery sequence outperforms the standard used T1-weighted sequence for visualization and quantification of myelination in utero. [ABSTRACT FROM AUTHOR]

• Reduced fetal brain biometrics are associated with unfavorable neonatal prognosis in IUGR. • Fetal fronto-occipital diameter has an excellent discrimination capacity. • Fetal transverse cerebellar diameter is reduced in the unfavorable neonatal group. Show a prognostic value of brain changes in fetuses with intra uterine growth restriction (IUGR) on early neonatal outcome. We prospectively recruited pregnant women whose fetuses presented fetal weight < 5th centile. A brain MRI was performed between 28 and 32 weeks of gestation (WG). Several brain biometrics were measured (as fronto-occipital diameter (FOD) and transverse cerebellar diameter (TCD)). Neonatal prognosis was evaluated according to a composite criterion. Of the 78 patients included, 62 had a fetal brain MRI. The mean centile value of FOD was lower in the unfavorable outcome group (n = 9) compared to the favorable outcome group (n = 53) (24.5 ± 16.8 vs. 8.6 ± 13.2, p = 0.004). The ROC curve for predicting risk of unfavorable neonatal outcome based on FOD presented an area under the curve of 0.81 (95 % CI, [0.63–––0.99]) and a threshold determined at the 3rd centile was associated with sensitivity of 0.78 and a specificity of 0.89. In multivariate analysis, a FOD less than the 3rd centile was significantly associated with an unfavorable neonatal risk. There also was a reduction in TCD (25.5 ± 21.5 vs. 10.4 ± 10.4, p = 0.03) in the unfavorable neonatal outcome group. We found an association between a reduction in FOD and TCD in fetal MRIs conducted between 28 and 32 WG in fetuses monitored for IUGR with an unfavorable neonatal outcome. Our results suggest that these biometric changes could constitute markers of poor neonatal prognosis. [ABSTRACT FROM AUTHOR]

Background: Intrauterine inflammation and the requirement for mechanical ventilation independently increase the risk of perinatal brain injury and adverse neurodevelopmental outcomes. We aimed to investigate the effects of mechanical ventilation for 24h, with and without prior exposure to intrauterine inflammation, on markers of brain inflammation and injury in the preterm sheep brain. Methods: Chronically instrumented fetal sheep at ~115 days of gestation were randomly allocated to receive a single intratracheal dose of 1 mg lipopolysaccharide (LPS) or isovolumetric saline, then further randomly allocated 1 h after to receive mechanical ventilation with room air or no mechanical ventilation (unventilated control + saline [UVC, n = 7]; in utero mechanical ventilation + saline [VENT, n = 8], unventilated control + intratracheal LPS [UVC + LPS, n = 7]; in utero ventilation + intratracheal LPS [VENT + LPS, n = 7]). Serial fetal blood and plasma samples were collected throughout the experimental protocol for assessment of blood biochemistry and plasma interleukin (IL)-6 levels. After 24 h of mechanical ventilation, fetal brains were collected for RT-qPCR and immunohistochemical analyses. Results: LPS exposure increased numbers of microglia and upregulated pro-inflammatory related genes within the cortical gray matter (GM) and subcortical white matter (SCWM) (pLPS < 0.05). Mechanical ventilation alone increased astrocytic cell density in the periventricular white matter (PVWM) (pVENT = 0.03) but had no effect on pro-inflammatory gene expression. The combination of ventilation and LPS increased plasma IL-6 levels (p < 0.02 vs. UVC and VENT groups), and exacerbated expression of pro-inflammatory-related genes (IL1β, TLR4, PTGS2, CXCL10) and microglial density (p < 0.05 vs. VENT). Conclusion: This study demonstrates that 24 h of mechanical ventilation after exposure to intrauterine inflammation increased markers of systemic and brain inflammation and led to the upregulation of pro-inflammatory genes in the white matter. We conclude that 24 h of mechanical ventilation following intrauterine inflammation may precondition the preterm brain toward being more susceptible to inflammation-induced injury. [ABSTRACT FROM AUTHOR]

Microglia are the resident macrophages of the central nervous system (CNS) that control brain development, maintain neural environments, respond to injuries, and regulate neuroinflammation. Despite their significant impact on various physiological and pathological processes across mammalian biology, there remains a notable gap in our understanding of how microglia perceive and transmit mechanical signals in both normal and diseased states. Recent studies have revealed that microglia possess the ability to detect changes in the mechanical properties of their environment, such as alterations in stiffness or pressure. These changes may occur during development, aging, or in pathological conditions such as trauma or neurodegenerative diseases. This review will discuss microglial Piezo1 mechanosensitive channels as potential therapeutic targets for Alzheimer's disease (AD). The structure, function, and modulation of Piezo1 will be discussed, as well as its role in facilitating microglial clearance of misfolded amyloid-b (Ab) proteins implicated in the pathology of AD. [ABSTRACT FROM AUTHOR]