BACKGROUND:The relationship between prenatal exposure to low-level air pollution and child autism spectrum disorder (ASD) is unclear. OBJECTIVE:To examine associations of prenatal air pollution exposure with autism. METHODS:We analyzed data from 8,035 mother-child pairs from 44 United States cohorts in the Environmental influences on Child Health Outcomes (ECHO) Cohort. Fine particulate matter (PM2.5), nitrogen dioxide (NO2), and 8-h-max ozone (O3) levels were estimated at residential addresses during pregnancy. Parents rated children's autism-related traits using the Social Responsiveness Scale (SRS) (mean age 9.4 years, SD = 3.6) and reported physician-diagnosed ASD. We examined associations of the three air pollutants with SRS scores (10th, 50th, and 90th quantiles) using quantile regression and with ASD diagnosis using logistic regression. Models were run within census divisions, and coefficients were pooled in a meta-analysis. RESULTS:Average (SD) pregnancy exposures were 9.3 μg/m3 (2.7) for PM2.5, 21.8 ppb (8.8) for NO2, and 40.3 ppb (5.5) for O3, with variations across census divisions. The median SRS T-score was 46 (IQR = 41 to 52), and 444 children (5.5%) had an ASD diagnosis. Higher PM2.5 was associated with higher SRS scores at the 10th quantile (β = 0.74, 95% CI: 0.09, 1.40) but not at the median or highest quantile. The association between PM2.5 and ASD diagnosis was highly heterogeneous, with associations present in the South Central, Mountain, and Pacific census divisions. Heterogeneity was also high in the association between NO2 and SRS at the median and only in the mid-Atlantic, West North Central, and South Atlantic census divisions. Higher O3 was associated with higher SRS scores at the median (β per IQR increment = 0.83, 95% CI: 0.05, 1.61) and highest quantile (β = 2.19, 95% CI: 0.06, 4.32) in the meta-analysis. Higher O3 also was associated with ASD. DISCUSSION:Associations with ASD outcomes were present even at low levels of air pollutants.

BACKGROUND: Organophosphate ester flame retardants and plasticizers (OPEs) have myriad uses in industry and consumer products. Increasing human exposure to OPEs has raised concerns about their potential effects on child neurodevelopment during the pregnancy. Objective: We investigated whether OPE urinary concentrations during pregnancy were associated with child's autism-related outcomes. METHODS: We included 4159 mother-child pairs from 15 cohorts in the NIH Environmental influences on Child Health Outcomes (ECHO) Consortium, with children born from 2006-2020 (median age [interquartile range]: 6 [4,10] years). Nine OPE biomarkers were measured in urine samples collected mid- to late pregnancy. Dilution-adjusted biomarkers were modeled continuously, categorically (high [>median], moderate [≤median], nondetect), or as detect/nondetect depending on their detection frequency. We assessed child autism-related traits via a) parent report on the Social Responsiveness Scale (SRS) and b) clinical autism diagnosis. We examined associations of OPEs with child outcomes, including modification by child sex, using generalized estimating equations to account for clustering by ECHO cohort. RESULTS: Compared with nondetectable concentrations, high exposure to bis-(butoxyethyl) phosphate (BBOEP) was associated with higher autistic trait scores (adj-β 0.97, 95% confidence interval [CI]: 0.42, 1.52) and greater odds of autism diagnosis (adjusted odds ratio [adj-OR]: 1.27, 95% CI: 1.07, 1.50). Bis-(1-chloro-2-propyl) phosphate (BCPP) showed associations with autistic trait scores (BCPP adj-β for high exposure vs nondetect: 0.34, 95% CI: -0.46, 1.13; BCPP adj-β for moderate exposure vs nondetect: 0.72, 95% CI: 0.24, 1.20). High exposure to bis-(2-chloroethyl) phosphate (BCETP) was associated with lower odds of autism diagnosis (adj-OR: 0.76, 95% CI: 0.60, 0.95). Other OPEs showed no associations in adjusted models. Associations between BBOEP and higher autistic trait scores were stronger in males than females. DISCUSSION: Prenatal exposure to OPEs, specifically BCPP and BBOEP, may be associated with a higher risk of autism diagnosis and related traits in childhood.

BACKGROUND: Exposure to metals and metalloids (hereafter referred to as 'metals') during gestation and early childhood may affect children's neurodevelopment. However, few studies have simultaneously evaluated the impact of exposure to both essential and nonessential metals across specific windows of exposure on children's neurodevelopmental outcomes. OBJECTIVE: To investigate whether levels of metals during gestation and the early postnatal period, individually and as a mixture, are related to child cognition at 5 years of age among participants in the New Hampshire Birth Cohort Study (NHBCS). METHODS: We followed 278 NHBCS pregnancy-offspring dyads for up to approximately 5 years of age. Total arsenic (As), copper (Cu), manganese (Mn), lead (Pb), selenium (Se), and zinc (Zn) were measured in toenail samples collected from pregnant persons at ∼24 to 28 weeks of gestation (representing periconception and early pregnancy) and at ∼6 weeks postpartum (representing midpregnancy), and their infants at ∼6 weeks of age (representing early infancy). Cognitive development at 5 years was assessed using the Wechsler Preschool and Primary Scale of Intelligence (WPPSI-IV), which includes measures of the full-scale intelligence quotient (FSIQ) and five composite indices. Associations between ln-metal toenail concentrations across multiple exposure windows and the six WPPSI-IV scores were estimated through mean field variational Bayes for lagged kernel machine regression (MFVB-LKMR). Potential effect modification by other elements in the mixture as well as sex was further explored. RESULTS: Biomarkers of As exposures of periconception and early pregnancy, midpregnancy, and early infancy were associated with lower cognitive scores at 5 years of age (e.g., FSIQ: -0.16 (95% Credible Interval (CrI): -0.24, -0.08) SD change). Periconception and early pregnancy exposures to Mn and Cu were associated with higher child cognitive scores. Sex differences were observed, especially with Mn exposure, with stronger positive associations among males during periconception and early pregnancy and among females during midpregnancy. For Pb and Zn exposures, associations with cognitive scores differed across exposure windows, exhibiting both positive and negative associations. DISCUSSION: By evaluating multiple essential and nonessential elements across the three previously mentioned exposure windows, we found evidence of sensitive periods of susceptibility to child cognitive measures. While results for As indicated detrimental effects, those for Cu and Mn suggested beneficial trends across all exposure windows.

Despite growing interest in profiling microRNAs (miRNAs) in infant and toddler stool, no studies have compared protocols for preserving and extracting miRNAs from this specimen type. Three commercially available kits and four preservation methods were compared for their ability to yield high quality RNA from children <2 years of age (infant/toddler). Of the three RNA extraction kits compared, Zymo BIOMICs yielded the highest RNA Quality Number (RQN) (median (range) RQN 9.4 (5.7-10.0)). Of the four preservation methods tested, RNAlater and Zymo DNA/RNA Shield Faecal Collection Tubes yielded the highest two RQNs (median (range) RQN 9.8 (5.7-10.0) and 9.4 (5.4-10.0), respectively), which did not differ from each other (p = 0.47). Subsequently, miRNA-seq was used to compare miRNA profiles for RNA extracted using the Zymo BIOMICs kit from paired aliquots of the same stool sample (n = 4 infant donors) collected into RNAlater and Zymo DNA/RNA Shield Faecal Collection Tubes. The percentage of reads classified as human and the percentage of human reads aligning to miRBase did not differ for samples collected in RNAlater versus Zymo Shield (p = 0.12 and p = 0.86, respectively). Furthermore, after multiple testing correction, normalized miRNA counts did not differ between the two preservatives for any of the 42 human miRNAs detected across the eight samples (pFDR ≥ 0.05). Collecting stool from infants and toddlers <2 years of age in either RNAlater or Zymo DNA/RNA Shield Faecal Collection Tubes, when paired with RNA extraction using the Zymo BIOMICs extraction kit, yielded high-quality RNA with similar human miRNA profiles.

Background: PFAS are widespread, persistent chemicals that cross the placenta and may affect fetal development. Animal studies suggest prenatal PFAS exposure increases offspring blood pressure (BP); however, epidemiologic evidence is limited and inconsistent. Hypothesis: We hypothesized that prenatal PFAS exposure is associated with higher childhood BP. Methods: We included children aged 3-13 years in the U.S. ECHO Cohort with data on gestational plasma or serum concentrations of PFOA, PFOS, PFHxS, PFNA, PFDA, and MeFOSAA. Children’s BP was obtained from study visits or medical records. We derived age-, sex-, and height-specific BP percentiles according to the 2017 American Academy of Pediatrics Guidelines and defined elevated BP as systolic BP (SBP) or diastolic BP (DBP) ≥90 th percentile. We used multivariable linear and modified Poisson models with generalized estimating equations and repeated BP measures clustered by participant (adjustment variables shown in Figure 1 footnotes ) and addressed missing data using multiple imputation by chained equations. We conducted subgroup analyses by child sex, ethnicity, and race, and we examined trimester-specific associations. Results: Among 2,435 children (50% female, 21% Hispanic, 25% Black), 22% had elevated BP at their last visit at a median age of 7.3 years ( Table 1 ). In adjusted analyses ( Figure 1 ), each doubling of PFOA was associated with a 1.23 (95% CI: 0.02, 2.45) higher SBP percentile, a 0.95 (0.10, 1.79) higher DBP percentile, and 1.07 (1.00, 1.15) times the risk of elevated BP. Each doubling of PFOS and PFNA was associated with a 1.14 (0.01, 2.27) and 0.85 (0.09, 1.61) higher DBP percentile, respectively. The PFOA-SBP association was stronger in males, and associations of PFOA, PFOS, and PFNA with DBP were stronger in females and non-Hispanic children. In trimester-specific analyses ( Figure 2 ), first-trimester PFOA, PFOS, and PFDA were associated with elevated BP; second-trimester PFOA and PFNA were associated with higher SBP percentiles; and third-trimester PFOS and MeFOSAA were associated with higher DBP percentiles. Conclusions: Prenatal exposure to PFOA, PFOS, and PFNA was associated with higher childhood BP. The trimester-specific associations should be interpreted with caution as they may also reflect cohort differences in PFAS profiles. PFAS may contribute to early-life programming of elevated lifelong cardiovascular risk, reinforcing the importance of population-level prevention.

Background:Children living in artisanal and small-scale gold mining (ASGM) communities are exposed to numerous metals with possible ototoxic and neurotoxic effects. Tests of peripheral and central auditory function can reflect toxicity to the ear and brain, respectively. This study investigated the link between metal exposure and peripheral and central auditory processing (CAP) in children exposed to metals in ASGM settings. Methods:In a cross-sectional study, 211 children aged 6-18 in ASGM communities performed audiometric (pure-tone audiometry, PTA) and CAP assessments (dichotic digits test, DDT). Toenail samples were analysed for 21 metals. Data on noise exposure and other covariates were collected via questionnaire. Linear and Elastic Net regression models were used to identify predictors of auditory impairment. Results:Median metal concentrations except chromium (Cr) and selenium (Se) exceeded published reference values. For CAP assessments, several metals were identified by Elastic Net (lead (Pb), antimony (Sb), uranium (U), vanadium (V)) and linear regression (aluminium (Al), cadmium (Cd), cobalt (Co), Cr, copper (Cu), iron (Fe), mercury (Hg), manganese (Mn), strontium (Sr), thallium (Tl), U, V), respectively. Both methods identified U and V as potential predictors. For peripheral auditory function, Elastic Net selected silver (Ag), Cd, Cr, Hg, and molybdenum (Mo), while linear regression identified Ag, arsenic (As), Co, Cr, Cu, Hg, Mn, Mo, Pb, Sr, and Tl. Silver (Ag), Cr, Hg, and Mo were consistently selected by both methods. At high-frequency peripheral thresholds, Elastic Net identified As, nickel (Ni), Pb, and tin (Sn), and linear regression identified Ag, Al, As, Cd, Co, Cu, Fe, Hg, Mn, Mo, Pb, and V. Both analyses selected As and Pb as potential predictors. Conclusions:CAP and peripheral auditory test performance correlated with metals known to have ototoxic and neurotoxic effects, as well as metals with previously unrecognised neurotoxic potential. These findings support measuring multiple metals in future epidemiologic studies to examine potential metal toxicities beyond those with known neurotoxicity.

Importance:Although fluoride exposure at high levels during the perinatal period has been associated with socioemotional problems among children, there is limited evidence regarding potential associations at lower levels of fluoride exposure, particularly in the US. Objective:To examine the association between prenatal exposure to public drinking water fluoride levels and children's socioemotional problems in a pooled US pediatric consortium. Design, Setting, and Participants:This cohort study used observational pregnancy cohort data from January 1, 2005, to December 31, 2019, on children aged 1.5 to 17 years from the Environmental Influences on Child Health Outcomes (ECHO) Cohort, which took place at 20 prenatal pediatric cohort sites across 34 US states. Statistical analysis was conducted from December 2024 to December 2025. Exposure:Area-level, time-weighted, mean fluoride concentrations in public water were estimated based on residential addresses during pregnancy. Main Outcomes and Measures:Children's socioemotional problems were assessed using caregiver reports of internalizing and externalizing problems via the Child Behavior Checklist. Generalized estimating equation models evaluated the adjusted mean difference in T scores (1) across the range of exposure values in cubic spline models, (2) per 500.0-µg/L higher fluoride level in linear models, (3) across quartiles of exposure, and (4) at the US Public Health Services recommended cutoff (≤700.0 µg/L; 3998 less than the cutoff). Results:The cohort comprised 5520 children (mean [SD] age, 5.8 [3.0] years; 2849 boys [51.6%]). The mean (SD) prenatal time-weighted water fluoride level was 407.9 (361.0) µg/L (range, <1.4-3272.5 µg/L). The adjusted mean difference in emotional and behavioral problem T scores per 500.0-μg/L higher exposure to prenatal public water fluoride was -0.15 (95% CI, -0.85 to 0.56) for internalizing problems and 0.06 (95% CI, -0.44 to 0.55) for externalizing problems, consistently showing no associations at the continuous level. However, some positive associations were observed only when using change point models for externalizing problems (adjusted mean difference, 1.59 [95% CI, 0.72-2.47] per 500.0-µg/L increase above the inflection point), and for some subgroups. Conclusions and Relevance:In this cohort study, prenatal exposure to fluoride levels in regulated public water was not associated with internalizing and externalizing problems among offspring. In change point models, positive associations were found for externalizing problems. The results contribute to growing evidence that could inform future policy decisions regarding fluoride in the US public water systems. Additional studies are needed to further investigate this association, especially examining other sources of fluoride that may have an association with children's emotional and behavioral problems.

Background Pregnant women are widely exposed to organophosphate esters (OPEs). Few studies have examined how gestational OPE exposures may influence child growth rates, which are important predictors of subsequent cardiometabolic health. Methods Among 4566 mother-child dyads from 14 sites within the Environmental influences on Child Health Outcomes (ECHO) Cohort, we evaluated associations of gestational urinary concentrations of nine OPE metabolites with early and mid-childhood rates of change in age- and sex-standardized weight (WAZ), height (HAZ), and body mass index (BMIZ). Using linear mixed models, we estimated associations between each OPE metabolite and each growth measure separately in early childhood (2-5 years; n = 4321) and mid-childhood (6-10 years; n = 2504). We evaluated effect modification by child sex and maternal pre-pregnancy BMI. Results Rates of change in WAZ and HAZ during early childhood were higher per doubling of gestational bis(1,3-dichloro-2-propyl) phosphate (BDCPP) (WAZ: 0.003 SD-units/year; 95% CI 0.001, 0.005; HAZ: 0.005 SD-units/year, 95% CI 0.002, 0.007). During mid-childhood, gestational diphenyl phosphate (DPHP) was positively associated with the rate of change in BMIZ (0.011 SD-units/year, 95% CI 0.004, 0.017) and WAZ (0.007 SD-units/year, 95% CI 0.002, 0.013). Bis(1-chloro-2-propyl) phosphate (BCPP) was associated with lower rates of growth in both periods. Some positive associations with rates of growth in early childhood were stronger among females, and children of mothers with BMI<25 kg/m2. Discussion In this large, diverse sample of U.S. children, gestational exposure to OPEs was associated with child growth rates, but the direction and magnitude differed by OPE biomarker and developmental period (early- or mid-childhood).

Correlation between subject reproductive age (years) and estimated relative proportions of cells in solid breast tissue (n = 95). Component cell types include epithelial cells, endothelial cells, fibroblasts, adipocytes, B cells, CD4+ T cells, CD8+ T cells, monocytes, neutrophils, and NK cells.

Epigenome-wide association analysis identifying CpG sites that are significantly differentially methylated in women with a family history of breast cancer relative to women without a family history of breast cancer in (A) solid breast tissue and (B) breast milk, adjusted for estimated proportions of epithelial cells, endothelial cells, fibroblasts, adipocytes, monocytes, and neutrophils. (C) Overlap of identified hypermethylated and hypomethylated loci (P < 0.01) in solid breast tissue and breast milk.

Estimated relative proportions of component cell types in the breast-specific reference library among an independent data set of isolated adipocytes from abdominal subcutaneous fat samples (n = 30, GSE58622).

BACKGROUND:The 2020-2025 Dietary Guidelines for Americans (DGA) include, for the first time, tailored recommendations for pregnant females, and guidance on weight management. In the United States, nearly 50% of pregnant females exceed the recommended gestational weight gain (GWG), whereas only ∼30% gain weight within the established guidelines. Optimal nutrition during pregnancy is essential for maternal and fetal health, and for achieving appropriate GWG. OBJECTIVES:This study evaluated adherence to the 2020-2025 DGA during pregnancy and examined its association with GWG. METHODS:We included 1452 pregnant participants from the New Hampshire birth cohort study. Intake of specific food groups and nutrients was estimated by a validated food frequency questionnaire. The difference between prepregnancy weight and the last recorded weight prior to delivery was used to calculate GWG. Adherence to the food groups and nutrient intake was based on the 2020‒2025 DGA and the Food and Nutrition Board of the National Academies of Sciences, Engineering, and Medicine for pregnant people. The association between overall and individual adherence to food groups and nutrients in relation to GWG was evaluated by multinomial regression analysis. Models were adjusted for age, prepregnancy body mass index (in kg/m2), gestational smoking, educational level, parity, infant birth weight, gestational age, and energy intake. RESULTS:Only 3% of participants met the recommended intake for all 5 core 2020‒2025 DGA food groups, with particularly low adherence observed for fruits, grains, and dairy. Intake of several nutrients also fell below recommendations. Just 30% of females achieved GWG within the recommendations. Participants adherent to the 2020-2025 DGA had 19% and 4% higher odds of having GWG within the recommended range compared with under- and overrecommendations, respectively (odds ratio: 0.81; 95% confidence interval: 0.81, 0.81; and odds ratio: 0.96; 95% confidence interval: 0.95, 0.97). CONCLUSIONS:Adherence to the 2020‒2025 DGA and GWG guidelines was low in this rural cohort. Addressing inadequate dietary patterns and promoting balanced nutrient intake may improve pregnancy outcomes and support healthier GWG trajectories. However, because an adequate diet alone was associated with recommended GWG in only ∼19% of participants, additional strategies are likely needed to help more pregnant individuals meet GWG recommendations.

The microbiome of adolescents is poorly understood, as are factors influencing its composition. We aimed to describe the healthy adolescent microbiome and identify early-life and concurrent predictors of its composition. We performed metagenomic sequencing of 247 fecal specimens from 167 adolescents aged 11–14 years participating in the Health Outcomes and Measures of the Environment (HOME) Study, a longitudinal pregnancy and birth cohort (Cincinnati, OH). We described common features of the adolescent gut microbiome and applied self-organizing maps (SOMs)—a machine-learning approach—to identify distinct microbial profiles (n = 4). Using prospectively collected data on sociodemographic characteristics, lifestyle, diet, and sexual maturation, we identified early-life and concurrent factors associated with microbial diversity and phylum relative abundance with linear regression models and composition with Kruskal–Wallis and Fisher’s exact tests. We found that household income and other sociodemographic factors were consistent predictors of the microbiome, with higher income associated with lower diversity and differential relative abundances of Firmicutes (increased) and Actinobacteria (decreased). Sexual maturation, distinct from chronological age, was related to higher diversity in females and differences in phylum relative abundances and compositional profiles in both males and females. Our study suggests that adolescence is a unique window for gut microbial composition and that it may be shaped by both early-life and concurrent exposures, highlighting its potential in future epidemiologic research.

Background:Child-centred approaches represent a conceptual framework that emphasises the holistic characterisation of individual developmental patterns across cognitive, behavioural and social domains. As a complementary analytic tool, self-organising maps (SOMs), an artificial neural network, offer flexible, data-driven clustering capabilities that are well-suited to modeling complex, multidimensional and longitudinal developmental data. Despite their potential, few studies have applied such methods to profile early neurodevelopment, especially in rural populations. Methods:We applied SOM to longitudinal neurobehavioural data (n=235) from healthy participant children from 3 to 5 years of age in the New Hampshire Birth Cohort Study, a rural pregnancy cohort. Group profiles reflect measures of behaviour and social responsiveness, cognition and motor performance and were examined in relation to known predictors of maternal-child characteristics using multinomial logistic regression as a proof of concept. Results:In our cohort, most children had neurotypical neurobehavioural scores, and 51% were boys. Mothers predominantly had some college education (74%), were married (93%) and were 31 years of age on average with above-average IQs relative to US norms. We identified six distinct neurobehavioural profiles (18-57 children each). The six profiles included: highest overall scores (profile 5), worst overall scores (profile 4), greatest behavioural/social improvement (profile 1), slight improvement (profile 3), average scores (profile 2) and highest adaptability (profile 6) relative to the full sample. Regression models showed expected associations with child sex, maternal IQ and parent-child relationships (eg, higher maternal IQ correlated with better cognitive outcomes). Conclusions:Using a SOM, we identified distinct neurobehavioural profiles among rural children, reflecting variation across behaviour, social responsiveness, cognition and motor skills. These profiles varied by maternal and child characteristics and highlight the potential of neural network approaches to inform early risk or resilience identification in understudied populations.

Shared hypermethylated loci (P < 0.01) in solid breast tissue and breast milk with family history of disease

Correlation between subject BMI (kg/m2) and estimated relative proportions of cells in breast milk (n = 48). Component cell types include epithelial cells, endothelial cells, fibroblasts, adipocytes, B cells, CD4+ T cells, CD8+ T cells, monocytes, neutrophils, and NK cells.

PURPOSE:The Environmental influences on Child Health Outcomes (ECHO) Cohort has enrolled over 60,000 children to examine how early environmental factors (broadly defined) are associated with key child health outcomes. The ECHO Cohort may be well-positioned to contribute to our understanding of rural environments and contexts, which has implications for rural health disparities research. The present study examined the outcome of child obesity to not only illustrate the suitability of ECHO Cohort data for these purposes but also determine how various definitions of rural and urban populations impact the presentation of findings and their interpretation. METHODS:This analysis uses data from children in the ECHO Cohort study who had residential address information between January 2010 and October 2023, including a subset who also had height and weight data. Several rural-urban classification schemes were examined with and without collapsing into binary rural/urban groupings (ie, the Rural-Urban Continuum Codes, 2010 Rural-Urban Commuting Area [RUCA] Codes, and Urban Influence Codes). FINDINGS:Various rural/urban definitions and classification schemes produce similar obesity prevalence (17%) when collapsed into binary categories (rural vs urban) and for urban participants in general. When all categories within a classification scheme are examined, however, the rural child obesity prevalence ranges from 5.8% to 24%. CONCLUSIONS:Collapsing rural-urban classification schemes into binary groupings erases nuance and context needed for interpreting findings, ultimately impacting health disparities research. Future work should leverage both individual- and community-level datasets to provide context, and all categories of classification schemes should be used when examining rural populations.

Shared hypermethylated loci (P < 0.01) in solid breast tissue and breast milk with increasing BMI