Maternal prenatal social disadvantage and neonatal functional connectivity: Associations with psychopathology symptoms at age 12 months.

Recent research has reported effects of socioeconomic status on neurobehavioral development as early as infancy, including positive associations between income and brain structure, functional connectivity, and behavior later in childhood (Ramphal, Whalen, et al., 2020; Triplett et al., 2022). This study extends this literature by investigating the relation of maternal prenatal social disadvantage (PSD) to neonatal amygdala and hippocampus functional connectivity and whether socioeconomic-related alterations in functional connectivity subsequently predict behavior at age 12 months in a large, socioeconomically diverse sample (N = 261 mother-infant dyads). PSD was assessed across gestation; neonatal magnetic resonance imaging was completed within the first weeks of life; and infant internalizing and externalizing symptoms were evaluated using the Infant-Toddler Social and Emotional Assessment at age 12 months. The results showed that PSD was significantly related to neonatal right amygdala and left hippocampus functional connectivity with prefrontal and motor-related regions. Social disadvantage-related right amygdala and left hippocampus functional connectivity with these regions was subsequently related to infant externalizing and internalizing symptoms at age 12 months. Building off an emerging literature exploring prenatal impacts on neonatal functional connectivity, this study further emphasizes the important role of the maternal environment during gestation on infant brain function and its relationship with externalizing and internalizing behavior in the first years of life. The results suggest that the prenatal socioeconomic environment may be a promising target for interventions aimed at improving infant neurobehavioral outcomes. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Functional parcellation of the neonatal cortical surface.

The cerebral cortex is organized into distinct but interconnected cortical areas, which can be defined by abrupt differences in patterns of resting state functional connectivity (FC) across the cortical surface. Such parcellations of the cortex have been derived in adults and older infants, but there is no widely used surface parcellation available for the neonatal brain. Here, we first demonstrate that existing parcellations, including surface-based parcels derived from older samples as well as volume-based neonatal parcels, are a poor fit for neonatal surface data. We next derive a set of 283 cortical surface parcels from a sample of n = 261 neonates. These parcels have highly homogenous FC patterns and are validated using three external neonatal datasets. The Infomap algorithm is used to assign functional network identities to each parcel, and derived networks are consistent with prior work in neonates. The proposed parcellation may represent neonatal cortical areas and provides a powerful tool for neonatal neuroimaging studies.

Prenatal exposure to maternal disadvantage-related inflammatory biomarkers: associations with neonatal white matter microstructure.

Prenatal exposure to heightened maternal inflammation has been associated with adverse neurodevelopmental outcomes, including atypical brain maturation and psychiatric illness. In mothers experiencing socioeconomic disadvantage, immune activation can be a product of the chronic stress inherent to such environmental hardship. While growing preclinical and clinical evidence has shown links between altered neonatal brain development and increased inflammatory states in utero, the potential mechanism by which socioeconomic disadvantage differentially impacts neural-immune crosstalk remains unclear. In the current study, we investigated associations between socioeconomic disadvantage, gestational inflammation, and neonatal white matter microstructure in 320 mother-infant dyads over-sampled for poverty. We analyzed maternal serum levels of four cytokines (IL-6, IL-8, IL-10, TNF-α) over the course of pregnancy in relation to offspring white matter microstructure and socioeconomic disadvantage. Higher average maternal IL-6 was associated with very low socioeconomic status (SES; INR < 200% poverty line) and lower neonatal corticospinal fractional anisotropy (FA) and lower uncinate axial diffusivity (AD). No other cytokine was associated with SES. Higher average maternal IL-10 was associated with lower FA and higher radial diffusivity (RD) in corpus callosum and corticospinal tracts, higher optic radiation RD, lower uncinate AD, and lower FA in inferior fronto-occipital fasciculus and anterior limb of internal capsule tracts. SES moderated the relationship between average maternal TNF-α levels during gestation and neonatal white matter diffusivity. When these interactions were decomposed, the patterns indicated that this association was significant and positive among very low SES neonates, whereby TNF-α was inversely and significantly associated with inferior cingulum AD. By contrast, among the more advantaged neonates (lower-to-higher SES [INR ≥ 200% poverty line]), TNF-α was positively and significantly associated with superior cingulum AD. Taken together, these findings suggest that the relationship between prenatal cytokine exposure and white matter microstructure differs as a function of SES. These patterns are consistent with a scenario where gestational inflammation's effects on white matter development diverge depending on the availability of foundational resources in utero.

Disentangling Socioeconomic Status and Race in Infant Brain, Birth Weight, and Gestational Age at Birth: A Neural Network Analysis.

Background: Race is commonly used as a proxy for multiple features including socioeconomic status. It is critical to dissociate these factors, to identify mechanisms that affect infant outcomes, such as birth weight, gestational age, and brain development, and to direct appropriate interventions and shape public policy. Methods: Demographic, socioeconomic, and clinical variables were used to model infant outcomes. There were 351 participants included in the analysis for birth weight and gestational age. For the analysis using brain volumes, 280 participants were included after removing participants with missing magnetic resonance imaging scans and those matching our exclusion criteria. We modeled these three different infant outcomes, including infant brain, birth weight, and gestational age, with both linear and nonlinear models. Results: Nonlinear models were better predictors of infant birth weight than linear models (R2 = 0.172 vs. R2 = 0.145, p = .005). In contrast to linear models, nonlinear models ranked income, neighborhood disadvantage, and experiences of discrimination higher in importance than race while modeling birth weight. Race was not an important predictor for either gestational age or structural brain volumes. Conclusions: Consistent with the extant social science literature, the findings related to birth weight suggest that race is a linear proxy for nonlinear factors related to structural racism. Methods that can disentangle factors often correlated with race are important for policy in that they may better identify and rank the modifiable factors that influence outcomes.

Newborn Brain Function and Early Emerging Callous-Unemotional Traits.

Importance: Children with high callous-unemotional traits are more likely to develop severe and persistent conduct problems; however, the newborn neurobiology underlying early callous-unemotional traits remains unknown. Understanding the neural mechanisms that precede the development of callous-unemotional traits could help identify at-risk children and encourage development of novel treatments. Objective: To determine whether newborn brain function is associated with early-emerging empathy, prosociality, and callous-unemotional traits. Design, Setting, and Participants: In this prospective, longitudinal cohort study, pregnant women were recruited from obstetric clinics in St Louis, Missouri, from September 1, 2017, to February 28, 2020, with longitudinal data collected until March 20, 2023. Mothers were recruited during pregnancy. Newborns underwent brain magnetic resonance imaging shortly after birth. Mothers completed longitudinal follow-up when the children were aged 1, 2, and 3 years. Exposures: The sample was enriched for exposure to socioeconomic disadvantage. Main Outcome and Measure: Functional connectivity between hypothesized brain regions was assessed using newborn-specific networks and voxel-based connectivity analyses. Children's callous-unemotional traits were measured using the Inventory of Callous-Unemotional Traits. Empathy and prosociality were assessed using the Infant and Toddler Socio-Emotional Assessment. Results: A total of 283 children (mean [SD] gestational age, 38 [2] weeks; 159 male [56.2%]; 2 Asian [0.7%], 171 Black [60%], 7 Hispanic or Latino [2.5%], 106 White [38%], 4 other racial or ethnic group [1.4%]) were included in the analysis. Stronger newborn functional connectivity between the cingulo-opercular network (CO) and medial prefrontal cortex (mPFC) was associated with higher callous-unemotional traits at age 3 years (ß = 0.31; 95% CI, 0.17-0.41; P < .001). Results persisted when accounting for parental callous-unemotional traits and child externalizing symptoms. Stronger newborn CO-mPFC connectivity was also associated with lower empathy and lower prosociality at ages 1, 2, and 3 years using multilevel models (ß = -0.12; 95% CI, -0.21 to -0.04; P = .004 and ß = -0.20; 95% CI, -0.30 to -0.10; P < .001, respectively). Conclusions and Relevance: Newborn functional connectivity was associated with early-emerging empathy, prosociality, and callous-unemotional traits, even when accounting for parental callous-unemotional traits and child externalizing symptoms. Understanding the neurobiological underpinnings of empathy, prosociality, and callous-unemotional traits at the earliest developmental point may help early risk stratification and novel intervention development.

Neighborhood Crime and Externalizing Behavior in Toddlers: A Longitudinal Study With Neonatal fMRI and Parenting.

OBJECTIVE: Prenatal exposure to neighborhood crime has been associated with weaker neonatal frontolimbic connectivity; however, associations with early childhood behavior remain unclear. We hypothesized that living in a high-crime neighborhood would be related to higher externalizing symptoms at age 1 and 2 years, over and above other adversities, and that neonatal frontolimbic connectivity and observed parenting behaviors at 1 year would mediate this relationship. METHOD: Participants included 399 pregnant women, recruited as part of the Early Life Adversity, Biological Embedding, and Risk for Developmental Precursors of Mental Disorders (eLABE) study. Geocoded neighborhood crime data was obtained from Applied Geographic Solution. A total of 319 healthy, non-sedated neonates underwent scanning using resting-state functional magnetic resonance imaging (fMRI) on a Prisma 3T scanner and had ≥10 minutes of high-quality data. Infant-Toddler Socioemotional Assessment Externalizing T scores were available for 274 mothers of 1-year-olds and 257 mothers of 2-year-olds. Observed parenting behaviors were available for 202 parent-infant dyads at 1 year. Multilevel and mediation models tested longitudinal associations. RESULTS: Living in a neighborhood with high violent (ß = 0.15, CI = 0.05-0.27, p = .004) and property (ß = 0.10, CI = 0.01-0.20, p = .039) crime was related to more externalizing symptoms at 1 and 2 years, controlling for other adversities. Weaker frontolimbic connectivity was also associated with higher externalizing symptoms at 1 and 2 years. After controlling for other adversities, parenting behaviors mediated the specific association between crime and externalizing symptoms, but frontolimbic connectivity did not. CONCLUSION: These findings provide evidence that early exposure to neighborhood crime and weaker neonatal frontolimbic connectivity may influence later externalizing symptoms, and suggest that parenting may be an early intervention target for families in high-crime areas. DIVERSITY & INCLUSION STATEMENT: We worked to ensure race, ethnic, and/or other types of diversity in the recruitment of human participants. We worked to ensure that the study questionnaires were prepared in an inclusive way. One or more of the authors of this paper self-identifies as a member of one or more historically underrepresented racial and/or ethnic groups in science. One or more of the authors of this paper self-identifies as a member of one or more historically underrepresented sexual and/or gender groups in science. We actively worked to promote sex and gender balance in our author group. We actively worked to promote inclusion of historically underrepresented racial and/or ethnic groups in science in our author group. While citing references scientifically relevant for this work, we also actively worked to promote sex and gender balance in our reference list. While citing references scientifically relevant for this work, we also actively worked to promote inclusion of historically underrepresented racial and/or ethnic groups in science in our reference list. The author list of this paper includes contributors from the location and/or community where the research was conducted who participated in the data collection, design, analysis, and/or interpretation of the work.

Functional parcellation of the neonatal brain.

The cerebral cortex is organized into distinct but interconnected cortical areas, which can be defined by abrupt differences in patterns of resting state functional connectivity (FC) across the cortical surface. Such parcellations of the cortex have been derived in adults and older infants, but there is no widely used surface parcellation available for the neonatal brain. Here, we first demonstrate that adult- and older infant-derived parcels are a poor fit with neonatal data, emphasizing the need for neonatal-specific parcels. We next derive a set of 283 cortical surface parcels from a sample of n=261 neonates. These parcels have highly homogenous FC patterns and are validated using three external neonatal datasets. The Infomap algorithm is used to assign functional network identities to each parcel, and derived networks are consistent with prior work in neonates. The proposed parcellation may represent neonatal cortical areas and provides a powerful tool for neonatal neuroimaging studies.

Neonatal neural responses to novelty related to behavioral inhibition at 1 year.

Behavioral inhibition (BI), an early-life temperament characterized by vigilant responses to novelty, is a risk factor for anxiety disorders. In this study, we investigated whether differences in neonatal brain responses to infrequent auditory stimuli relate to children's BI at 1 year of age. Using functional magnetic resonance imaging (fMRI), we collected blood-oxygen-level-dependent (BOLD) data from N = 45 full-term, sleeping neonates during an adapted auditory oddball paradigm and measured BI from n = 27 of these children 1 year later using an observational assessment. Whole-brain analyses corrected for multiple comparisons identified 46 neonatal brain regions producing novelty-evoked BOLD responses associated with children's BI scores at 1 year of age. More than half of these regions (n = 24, 52%) were in prefrontal cortex, falling primarily within regions of the default mode or frontoparietal networks or in ventromedial/orbitofrontal regions without network assignments. Hierarchical clustering of the regions based on their patterns of association with BI resulted in two groups with distinct anatomical, network, and response-timing profiles. The first group, located primarily in subcortical and temporal regions, tended to produce larger early oddball responses among infants with lower subsequent BI. The second group, located primarily in prefrontal cortex, produced larger early oddball responses among infants with higher subsequent BI. These results provide preliminary insights into brain regions engaged by novelty in infants that may relate to later BI. The findings may inform understanding of anxiety disorders and guide future research. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

The Association Between Maternal Cortisol and Infant Amygdala Volume Is Moderated by Socioeconomic Status.

Background: It has been well established that socioeconomic status is associated with mental and physical health as well as brain development, with emerging data suggesting that these relationships begin in utero. However, less is known about how prenatal socioeconomic environments interact with the gestational environment to affect neonatal brain volume. Methods: Maternal cortisol output measured at each trimester of pregnancy and neonatal brain structure were assessed in 241 mother-infant dyads. We examined associations between the trajectory of maternal cortisol output across pregnancy and volumes of cortisol receptor-rich regions of the brain, including the amygdala, hippocampus, medial prefrontal cortex, and caudate. Given the known effects of poverty on infant brain structure, socioeconomic disadvantage was included as a moderating variable. Results: Neonatal amygdala volume was predicted by an interaction between maternal cortisol output across pregnancy and socioeconomic disadvantage (standardized ß = -0.31, p < .001), controlling for postmenstrual age at scan, infant sex, and total gray matter volume. Notably, amygdala volumes were positively associated with maternal cortisol for infants with maternal disadvantage scores 1 standard deviation below the mean (i.e., less disadvantage) (simple slope = 123.36, p < .01), while the association was negative in infants with maternal disadvantage 1 standard deviation above the mean (i.e., more disadvantage) (simple slope = -82.70, p = .02). Individuals with disadvantage scores at the mean showed no association, and there were no significant interactions in the other brain regions examined. Conclusions: These data suggest that fetal development of the amygdala is differentially affected by maternal cortisol production at varying levels of socioeconomic advantage.

Infants exposed in utero to Hurricane Maria have gut microbiomes with reduced diversity and altered metabolic capacity.

The gut microbiome is a potentially important mechanism that links prenatal disaster exposures with increased disease risks. However, whether prenatal disaster exposures are associated with alterations in the infant's gut microbiome remains unknown. We established a birth cohort study named Hurricane as the Origin of Later Alterations in Microbiome (HOLA) after Hurricane Maria struck Puerto Rico in 2017. We enrolled vaginally born Latino term infants aged 2 to 6 months, including n = 29 infants who were exposed in utero to Hurricane Maria in Puerto Rico and n = 34 infants who were conceived at least 5 months after the hurricane as controls. Shotgun metagenomic sequencing was performed on infant stool swabs. Infants exposed in utero to Hurricane Maria had a reduced diversity in their gut microbiome compared to the control infants, which was mainly seen in the exclusively formula-fed group (P = 0.02). Four bacterial species, including Bacteroides vulgatus, Clostridium innocuum, Bifidobacterium pseudocatenulatum, and Clostridium neonatale, were depleted in the exposure group compared to the control group. Compositional differences in the microbial community and metabolic genes between the exposure and control groups were significant, which were driven by the formula feeding group (P = 0.02 for the microbial community and P = 0.008 for the metabolic genes). Metabolic modules involved in carbohydrate metabolism were reduced in the exposure group. Prenatal maternal exposure to Hurricane Maria was associated with a reduced gut commensal and an altered microbial composition and metabolic potential in the offspring's gut. Breastfeeding can adjust the composition of the gut microbiomes of exposed infants. IMPORTANCE Climate change is a serious issue that is affecting human health. With more frequent and intense weather disasters due to climate change, there is an urgent need to evaluate and understand the impacts of prenatal disaster exposures on the offspring. The prenatal stage is a particularly vulnerable stage for disease origination. However, the impact of prenatal weather disaster exposures on the offspring's gut microbiome has not been evaluated. Our HOLA study starts to fill this knowledge gap and provides novel insights into the microbiome as a mechanism that links prenatal disaster exposures with elevated disease risks. Our major finding that reduced microbial diversity and altered metabolic capacity are associated with prenatal hurricane exposures warrants further studies to evaluate the impact of weather disasters on the unborn.

Prenatal environment is associated with the pace of cortical network development over the first three years of life.

Environmental influences on brain structure and function during early development have been well-characterized. In pre-registered analyses, we test the theory that socioeconomic status (SES) is associated with differences in trajectories of intrinsic brain network development from birth to three years (n = 261). Prenatal SES is associated with developmental increases in cortical network segregation, with neonates and toddlers from lower-SES backgrounds showing a steeper increase in cortical network segregation with age, consistent with accelerated network development. Associations between SES and cortical network segregation occur at the local scale and conform to a sensorimotor-association hierarchy of cortical organization. SES-associated differences in cortical network segregation are associated with language abilities at two years, such that lower segregation is associated with improved language abilities. These results yield key insight into the timing and directionality of associations between the early environment and trajectories of cortical development.

Social and psychological adversity are associated with distinct mother and infant gut microbiome variations.

Health disparities are driven by underlying social disadvantage and psychosocial stressors. However, how social disadvantage and psychosocial stressors lead to adverse health outcomes is unclear, particularly when exposure begins prenatally. Variations in the gut microbiome and circulating proinflammatory cytokines offer potential mechanistic pathways. Here, we interrogate the gut microbiome of mother-child dyads to compare high-versus-low prenatal social disadvantage, psychosocial stressors and maternal circulating cytokine cohorts (prospective case-control study design using gut microbiomes from 121 dyads profiled with 16 S rRNA sequencing and 89 dyads with shotgun metagenomic sequencing). Gut microbiome characteristics significantly predictive of social disadvantage and psychosocial stressors in the mothers and children indicate that different discriminatory taxa and related pathways are involved, including many species of Bifidobacterium and related pathways across several comparisons. The lowest inter-individual gut microbiome similarity was observed among high-social disadvantage/high-psychosocial stressors mothers, suggesting distinct environmental exposures driving a diverging gut microbiome assembly compared to low-social disadvantage/low-psychosocial stressors controls (P = 3.5 × 10-5 for social disadvantage, P = 2.7 × 10-15 for psychosocial stressors). Children's gut metagenome profiles at 4 months also significantly predicted high/low maternal prenatal IL-6 (P = 0.029), with many bacterial species overlapping those identified by social disadvantage and psychosocial stressors. These differences, based on maternal social and psychological status during a critical developmental window early in life, offer potentially modifiable targets to mitigate health inequities.

Microbiome-targeting therapies in the neonatal intensive care unit: safety and efficacy.

Microbiome-targeting therapies have received great attention as approaches to prevent disease in infants born preterm, but their safety and efficacy remain uncertain. Here we summarize the existing literature, focusing on recent meta-analyses and systematic reviews that evaluate the performance of probiotics, prebiotics, and/or synbiotics in clinical trials and studies, emphasizing interventions for which the primary or secondary outcomes were prevention of necrotizing enterocolitis, late-onset sepsis, feeding intolerance, and/or reduction in hospitalization length or all-cause mortality. Current evidence suggests that probiotics and prebiotics are largely safe but conclusions regarding their effectiveness in the neonatal intensive care unit have been mixed. To address this ambiguity, we evaluated publications that collectively support benefits of probiotics with moderate to high certainty evidence in a recent comprehensive network meta-analysis, highlighting limitations in these trials that make it difficult to support with confidence the routine, universal administration of probiotics to preterm infants.

Gut pathogen colonization precedes bloodstream infection in the neonatal intensive care unit.

Bacterial bloodstream infections (BSIs) resulting in late-onset sepsis affect up to half of extremely preterm infants and have substantial morbidity and mortality. Bacterial species associated with BSIs in neonatal intensive care units (NICUs) commonly colonize the preterm infant gut microbiome. Accordingly, we hypothesized that the gut microbiome is a reservoir of BSI-causing pathogenic strains that increase in abundance before BSI onset. We analyzed 550 previously published fecal metagenomes from 115 hospitalized neonates and found that recent ampicillin, gentamicin, or vancomycin exposure was associated with increased abundance of Enterobacteriaceae and Enterococcaceae in infant guts. We then performed shotgun metagenomic sequencing on 462 longitudinal fecal samples from 19 preterm infants (cases) with BSI and 37 non-BSI controls, along with whole-genome sequencing of the BSI isolates. Infants with BSI caused by Enterobacteriaceae were more likely than infants with BSI caused by other organisms to have had ampicillin, gentamicin, or vancomycin exposure in the 10 days before BSI. Relative to controls, gut microbiomes of cases had increased relative abundance of the BSI-causing species and clustered by Bray-Curtis dissimilarity according to BSI pathogen. We demonstrated that 11 of 19 (58%) of gut microbiomes before BSI, and 15 of 19 (79%) of gut microbiomes at any time, harbored the BSI isolate with fewer than 20 genomic substitutions. Last, BSI strains from the Enterobacteriaceae and Enterococcaceae families were detected in multiple infants, indicating BSI-strain transmission. Our findings support future studies to evaluate BSI risk prediction strategies based on gut microbiome abundance in hospitalized preterm infants.

Pregnancy and neonatal outcomes among women with early-onset colorectal cancer: a nationwide case-control study.

Background: Early-onset colorectal cancer has risen worldwide, leaving more women with colorectal cancer at reproductive ages. We aimed to investigate the risk of adverse pregnancy and neonatal outcomes among women with early-onset colorectal cancer. Methods: We conducted a nationwide, matched case-control study of maternal/pregnancy outcomes including pre-eclampsia and Cesarean delivery (C-section) as well as neonatal outcomes including preterm birth among 207 births in women with early-onset colorectal cancer (ages 18-49) and 1019 births in women without colorectal cancer in Sweden (1992-2019). Early-onset colorectal cancer cases were identified through the Cancer Register, and outcome data were retrieved through linkage to Medical Birth Register and National Patient Register. Using conditional logistic regression, we estimated multivariable-adjusted odds ratios (ORs) and 95% confidence intervals (CIs). Findings: Between Jan 1, 1992, and Dec 31, 2019, women with early-onset colorectal cancer who gave birth had increased odds of pre-eclampsia (7.2% vs 3.2%; OR = 2.52, 95%CI = 1.25-5.08), any C-section (24.6% vs 19.4%; OR = 1.43, 95%CI = 1.00-2.06), particularly emergency C-section (17.4% vs 10.5%; OR = 1.79, 95%CI = 1.17-2.75), after adjustment for maternal education level, country of birth, body mass index and smoking in early pregnancy, and comorbidities. Maternal history of early-onset colorectal cancer was also associated with offspring preterm birth (12.1% vs 5.2%; OR = 2.31, 95%CI = 1.34-3.99), delineated as spontaneous (OR = 1.06, 95%CI = 0.47-2.39) or medically-indicated preterm birth (OR = 4.48, 95%CI = 2.05-9.79). There was no increased risk of congenital malformation or small for gestational age birth. Interpretation: In this population-based study, maternal history of early-onset colorectal cancer was associated with risk of both adverse pregnancy (pre-eclampsia, C-section) and neonatal outcomes (preterm birth). Funding: US National Institutes of Health, Swedish Society of Medicine, Swedish Cancer Foundation.

Evaluation of Birth by Cesarean Delivery and Development of Early-Onset Colorectal Cancer.

Importance: The incidence of early-onset colorectal cancer (CRC), diagnosed younger than 50 years of age, has increased worldwide. Gut dysbiosis throughout the life course is hypothesized as a leading mechanism, yet epidemiologic data are limited. Objective: To prospectively examine the association between birth by cesarean delivery and early-onset CRC among offspring. Design, Setting, and Participants: In this population-based, nationwide case-control study in Sweden, adults diagnosed with CRC between 18 and 49 years of age from 1991 to 2017 were identified through the Epidemiology Strengthened by Histopathology Reports in Sweden (ESPRESSO) cohort. Up to 5 general population control individuals without CRC were matched with each case on age, sex, calendar year, and county of residence. Pathology-confirmed end points were linked with the Swedish Medical Birth Register and other national registers. Analyses were conducted from March 2022 through March 2023. Exposure: Birth by cesarean delivery. Main Outcomes and Measures: The primary outcome was development of early-onset CRC in the overall population and by sex. Results: We identified 564 case patients with incident early-onset CRC (mean [SD] age, 32.9 [6.2] years; 284 [50.4%] male) and 2180 matched controls (mean [SD] age, 32.7 [6.3] years; 1104 [50.6%] male). Compared with vaginal delivery, birth by cesarean delivery was not associated with early-onset CRC in the overall population (adjusted odds ratio [aOR], 1.28; 95% CI, 0.91-1.79) after multivariable adjustment for matching and maternal and pregnancy-related factors. A positive association was found for females (aOR, 1.62; 95% CI, 1.01-2.60), but there was no association for males (aOR, 1.05; 95% CI, 0.64-1.72). Conclusions and Relevance: In this nationwide, population-based case-control study, birth by cesarean delivery was not associated with early-onset CRC compared with birth by vaginal delivery in the overall population in Sweden. However, females born by cesarean delivery had greater odds of early-onset CRC compared with individuals born through vaginal delivery. This finding suggests that early-life gut dysbiosis may contribute to early-onset CRC in females.

Social disadvantage during pregnancy: effects on gestational age and birthweight.

OBJECTIVE: Whether psychosocial adversity during pregnancy impacts fetal health outcomes at birth remains underexplored. This is a critical issue given significant social disadvantage and psychosocial stress faced by pregnant women worldwide. STUDY DESIGN: Measures of social disadvantage and psychological factors, and medical/reproductive and nutritional health status in pregnant women were obtained at each trimester. Using Structural Equation Modeling (SEM), we investigated the relationship of forms of adversity to each other and to infant gestational age, and birthweight. RESULTS: Among 399 singletons, Social Disadvantage significantly predicted gestational age (p = 0.003), and residual birthweight (p = 0.006). There was a 0.4 week decrease in gestational age and a 3% decrease in birthweight for each standard deviation increase in Social Disadvantage. CONCLUSION: Significant negative effects of social adversity on the developing fetus were found. Notably, these effects emerged despite good prenatal care and after accounting for maternal age and medical reproductive risk factors.

Maturation of large-scale brain systems over the first month of life.

The period immediately after birth is a critical developmental window, capturing rapid maturation of brain structure and a child's earliest experiences. Large-scale brain systems are present at delivery, but how these brain systems mature during this narrow window (i.e. first weeks of life) marked by heightened neuroplasticity remains uncharted. Using multivariate pattern classification techniques and functional connectivity magnetic resonance imaging, we detected robust differences in brain systems related to age in newborns (n = 262; R2 = 0.51). Development over the first month of life occurred brain-wide, but differed and was more pronounced in brain systems previously characterized as developing early (i.e. sensorimotor networks) than in those characterized as developing late (i.e. association networks). The cingulo-opercular network was the only exception to this organizing principle, illuminating its early role in brain development. This study represents a step towards a normative brain "growth curve" that could be used to identify atypical brain maturation in infancy.

Network-specific selectivity of functional connections in the neonatal brain.

The adult human brain is organized into functional brain networks, groups of functionally connected segregated brain regions. A key feature of adult functional networks is long-range selectivity, the property that spatially distant regions from the same network have higher functional connectivity than spatially distant regions from different networks. Although it is critical to establish the status of functional networks and long-range selectivity during the neonatal period as a foundation for typical and atypical brain development, prior work in this area has been mixed. Although some studies report distributed adult-like networks, other studies suggest that neonatal networks are immature and consist primarily of spatially isolated regions. Using a large sample of neonates (n = 262), we demonstrate that neonates have long-range selective functional connections for the default mode, fronto-parietal, and dorsal attention networks. An adult-like pattern of functional brain networks is evident in neonates when network-detection algorithms are tuned to these long-range connections, when using surface-based registration (versus volume-based registration), and as per-subject data quantity increases. These results help clarify factors that have led to prior mixed results, establish that key adult-like functional network features are evident in neonates, and provide a foundation for studies of typical and atypical brain development.