Faculty Bibliography

OBJECTIVES/OBJECTIVE:To evaluate whether parents who assess their infants as more developmentally advanced are more likely to begin feeding their infants complementary foods before 6 months, and whether developmental readiness explains racial and ethnic differences in complementary food introduction. STUDY DESIGN/METHODS:In a cohort of mothers of 5475 infants from New York state, 9 markers of infant development and timing of initiating complementary feeding were assessed. Mixed effect models assessed associations between developmental markers and initiation of complementary feeding before 6 months term-corrected age. Direct and indirect effects of racial and ethnic differences in complementary feeding through a total development score were computed. RESULTS:In a fully adjusted model, infant sitting (adjusted odds ratio [aOR]:1.60, 95% CI:1.32, 1.93), head control (aOR:1.51, 95% CI:1.26, 1.81), reaching (aOR:1.19, 95% CI:1.04, 1.37), mouthing (aOR:1.26, 95%CI:1.08, 1.46), and having a good appetite (aOR:1.61, 95%CI:1.15, 2.24) were uniquely associated with complementary feeding before age 6 months. A 1-point increase in a total development score was also associated with higher odds of complementary feeding (aOR:1.26, 95% CI:1.19, 1.33). The development score explained some racial and ethnic differences in the odds of complementary feeding before 6 months. CONCLUSIONS:Results suggest that parents are using their children's developmental markers to decide when to begin complementary feeding. Furthermore, observations of racial and ethnic differences in the timing of complementary feeding may be explained by perceptions of developmental readiness, in line with recommendations. Future research on complementary feeding should incorporate assessments of infant developmental readiness.

BACKGROUND:Maternal thyroid dysfunction and maternal depression during pregnancy may increase the risk of child behavioral and emotional problems. We sought to investigate the independent and interactive associations of these two risk factors with child behavior problems. METHODS:We combined data from four cohorts in the Environmental influences on Child Health Outcomes (ECHO) program (N = 949). Maternal thyroid function (thyroid-stimulating hormone [TSH], free thyroxine [fT4], thyroid peroxidase autoantibodies [TPO-Ab], fT4/TSH ratio) was measured predominantly during the first half of pregnancy. We harmonized maternal depression into a continuous measure of antepartum depressive symptomatology and a dichotomous measure reflecting (history of) clinical depression. Child internalizing and externalizing problems were harmonized to the T-score metric of the Child Behavior Checklist. We used multiple linear regression and random effects meta-analysis to assess the average relationship between each predictor and outcome, and the variability in these relationships across cohorts. RESULTS:Across cohorts, antepartum depressive symptomatology was positively associated with both internalizing (meta B = 2.879, 95 % CI 1.87-3.89, p < .001) and externalizing problems (meta B = 1.683, 95 % CI 0.67-2.69, p = .001). None of the indicators of maternal thyroid function was associated with child behavior problems across cohorts. TPO-Ab concentrations were positively associated with child externalizing problems only in offspring of depressed mothers (meta B = 3.063, 95 % CI 0.73-5.40, p = .010). CONCLUSIONS:This study supports the importance of maternal antepartum mental health for child behavior across diverse populations. However, we found little empirical evidence for an association between maternal thyroid function within the normal range during pregnancy and child behavioral problems.

Polycystic ovarian syndrome (PCOS) is a common female endocrinologic condition that affects both the metabolic and reproductive systems and is the most frequent cause of anovulatory infertility. It is also associated with a range of psychiatric outcomes in individuals, including bulimia nervosa, schizophrenia, bipolar disorder, depression, anxiety, and personality disorders. At the same time, evidence suggests that hyperandrogenism, the characteristic trait of PCOS, may impair fetal neurodevelopment. Epidemiological studies have linked maternal PCOS with a variety of behavioral and psychiatric conditions in offspring including autism spectrum disorder and attention deficit hyperactivity disorder. In this review, we explore evidence for potential underlying biological mechanisms that might explain these observed associations, discuss the complex interplay between genetics and various environmental factors across generations, and highlight avenues for future research.

BACKGROUND:Neighborhood quality may contribute to child mental health, but families with young children often move, and residential instability has also been tied to adverse mental health. This study's primary goal was to disentangle the effects of neighborhood quality from those of residential instability on mental health in middle childhood. METHODS:1,946 children from 1,652 families in the Upstate KIDS cohort from New York state, US, were followed prospectively from birth to age 10. Residential addresses were linked at the census tract level to the Child Opportunity Index 2.0, a multidimensional indicator of neighborhood quality. The number of different addresses reported from birth to age 10 was counted to indicate residential instability, and the change in COI quintile indicated social mobility. Parents completed three assessments of attention-deficit/hyperactivity disorder, problematic behavior, and internalizing psychopathology symptoms at ages 7, 8, and 10. Child and family covariates were selected a priori to adjust sample characteristics, increase estimate precision, and account for potential confounding. RESULTS:In unadjusted models, higher neighborhood quality at birth was associated with fewer psychopathology symptoms in middle childhood, but associations were largely mediated by residential instability. In adjusted models, residential instability was associated with more psychopathology symptoms, even accounting for social mobility. Neighborhood quality at birth had indirect effects on child mental health symptoms through residential instability. CONCLUSIONS:Children born into lower-quality neighborhoods moved more, and moving more was associated with higher psychopathology symptoms. Findings were similar across different timings of residential moves, for girls and boys, and for children who did not experience a major life event. Additional research is needed to better understand which aspects of moving are most disruptive to young children.

In the original publication [...].

BACKGROUND:Evidence suggests prenatal phthalate exposure adversely affects children's behavior. However, epidemiological studies on alternative plasticizers remain scarce. This study investigated associations of gestational exposure to phthalates and alternative plasticizers with internalizing and externalizing behaviors in children aged 1.5-5 years. METHODS:The study included 2617 mother-child dyads from 13 Environmental influences on Child Health Outcomes (ECHO) cohorts. Maternal urine samples, primarily collected mid- to late-pregnancy, were analyzed for 27 phthalate metabolites and 6 alternative plasticizer metabolites. Based on detection frequency, metabolite concentrations were modeled either continuously or categorically (Group 1: non-detectable, 2: lower detectable, 3: higher detectable). Covariate-adjusted associations between individual metabolite concentrations and internalizing and externalizing T-scores on the Child Behavior Checklist for Ages 1½-5 were estimated using linear mixed-effects models. Effect modification by child sex was also examined. RESULTS:for MHxP Group 3 = 1.23, 95% CI: 0.35, 2.12). We observed no robust associations between phthalate metabolites and internalizing T-scores, nor between cyclohexane-1,2-dicarboxylic acid mono carboxyisooctyl ester (DINCH) metabolites and any behavioral outcomes. Child sex modified associations between several metabolites and externalizing T-scores, although the direction of effect varied by metabolite. CONCLUSION/CONCLUSIONS:This large-scale study suggests that prenatal exposure to several phthalates, but not to the alternative plasticizer DINCH, may be associated with a small-to-modest increase in externalizing behaviors in young children.

BACKGROUND:Prenatal exposure to organophosphate esters (OPEs) has been linked to neurotoxic effects in children; however, epidemiological evidence remains inconclusive. We investigated associations of prenatal OPE exposure with child behaviors. METHODS:We analyzed data of 2948 mother-child dyads from 12 prospective cohorts of the Environmental influences on Child Health Outcomes (ECHO) Cohort. Nine OPE biomarkers quantified in prenatal maternal urine were modeled based on detection frequency. Child behaviors were assessed using the Child Behavior Checklist for Ages 1½-5. We used linear mixed effects models to examine associations between each OPE biomarker and composite T-scores. We evaluated child sex and social vulnerability as potential effect modifiers. RESULTS: = -0.89, 95% CI: -1.74, -0.04). Associations between high BCPP exposure and higher externalizing and total problem T-scores were stronger among children from highly vulnerable neighborhoods compared to those from less vulnerable neighborhoods (p-interaction < 0.1). Child sex modified associations for bis(1,3-dichloro-2-propyl) phosphate and high BCPP exposure, with males exhibiting greater adverse behaviors for all associations. DISCUSSION/CONCLUSIONS:Gestational exposure to several OPEs may be adversely associated with early behavioral development.

BACKGROUND/UNASSIGNED: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 pregnancy. OBJECTIVE/UNASSIGNED:We investigated whether OPE urinary concentrations during pregnancy were associated with child autism-related outcomes. METHODS/UNASSIGNED: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], non-detect), or as detect/non-detect 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/UNASSIGNED:Compared with non-detectable 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. non-detect: 0.34, 95% CI: -0.46, 1.13; BCPP adj-β for moderate exposure vs. non-detect: 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/UNASSIGNED:Prenatal exposure to OPEs, specifically BCPP and BBOEP, may be associated with higher risk of autism diagnosis and related traits in childhood. https://doi.org/10.1289/EHP16177.

BACKGROUND/UNASSIGNED:The relationship between prenatal exposure to low-level air pollution and child autism spectrum disorder (ASD) is unclear. OBJECTIVE/UNASSIGNED:To examine associations of prenatal air pollution exposure with autism. METHODS/UNASSIGNED: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/UNASSIGNED:also was associated with ASD. DISCUSSION/UNASSIGNED:Associations with ASD outcomes were present even at low levels of air pollutants. https://doi.org/10.1289/EHP16675.

BACKGROUND/UNASSIGNED:Maternal sustained smoking during pregnancy is associated with thousands of differentially methylated CpGs in newborns, but impacts of other prenatal tobacco smoking exposures remain unclear. OBJECTIVE/UNASSIGNED:To identify differential DNA methylation in newborns from maternal sustained smoking and less studied prenatal smoking exposures (i.e., maternal exposure to secondhand smoke [SHS] exposure during pregnancy, maternal quitting before pregnancy, paternal smoking around conception, paternal quitting before pregnancy). METHODS/UNASSIGNED:We conducted a large meta-analysis of prenatal tobacco smoking exposures and epigenome-wide newborn blood DNA methylation through the Pregnancy And Childhood Epigenetics Consortium (PACE). Across 19 cohorts, 11,175 parent-newborn pairs contributed information on at least one prenatal smoking exposure, mostly from questionnaires. Maternal blood or urine cotinine measurements, available in a few studies, provided objective data on maternal SHS and smoking during pregnancy. Primary analyses used Illumina450K methylation data; secondary analyses in 5 cohorts examined CpGs unique to the EPIC array. RESULTS/UNASSIGNED:) was associated with paternal former smoking. Forty-one novel genes were identified using maternal cotinine measurements compared to questionnaire. In EPIC unique analyses (n=3,415), differential methylation was observed with maternal sustained smoking (211 CpGs), maternal SHS (5 CpGs), and paternal former smoking (4 CpGs). Smoking-associated CpGs in blood were strongly enriched for functional elements across multiple tissues. CONCLUSIONS/UNASSIGNED:Maternal sustained smoking has the largest impact on newborn DNA methylation, suggesting a strong influence of the intrauterine environment. We observed minimal impacts for less studied exposures including SHS, maternal former smoking and paternal smoking. https://doi.org/10.1289/EHP16303.