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BackgroundPhthalate exposures are ubiquitous during pregnancy and may contribute to racial and ethnic disparities in preterm birth.ObjectivesWe investigated race and ethnicity in the relationship between biomarkers of phthalate exposure and preterm birth by examining: a) how hypothetical reductions in racial and ethnic disparities in phthalate metabolites might reduce the probability of preterm birth; and b) exposure-response models stratified by race and ethnicity.MethodsWe pooled individual-level data on 6,045 pregnancies from 16 U.S. cohorts. We investigated covariate-adjusted differences in nine urinary phthalate metabolite concentrations by race and ethnicity [non-Hispanic White (White, 43%), non-Hispanic Black (Black, 13%), Hispanic/Latina (38%), and Asian/Pacific Islander (3%)]. Using g-computation, we estimated changes in the probability of preterm birth under hypothetical interventions to eliminate disparities in levels of urinary phthalate metabolites by proportionally lowering average concentrations in Black and Hispanic/Latina participants to be approximately equal to the averages in White participants. We also used race and ethnicity-stratified logistic regression to characterize associations between phthalate metabolites and preterm birth.ResultsIn comparison with concentrations among White participants, adjusted mean phthalate metabolite concentrations were consistently higher among Black and Hispanic/Latina participants by 23%-148% and 4%-94%, respectively. Asian/Pacific Islander participants had metabolite levels that were similar to those of White participants. Hypothetical interventions to reduce disparities in metabolite mixtures were associated with lower probabilities of preterm birth for Black [13% relative reduction; 95% confidence interval (CI): -34%, 8.6%] and Hispanic/Latina (9% relative reduction; 95% CI: -19%, 0.8%) participants. Odds ratios for preterm birth in association with phthalate metabolites demonstrated heterogeneity by race and ethnicity for two individual metabolites (mono-n-butyl and monoisobutyl phthalate), with positive associations that were larger in magnitude observed among Black or Hispanic/Latina participants.ConclusionsPhthalate metabolite concentrations differed substantially by race and ethnicity. Our results show hypothetical interventions to reduce population-level racial and ethnic disparities in biomarkers of phthalate exposure could potentially reduce the probability of preterm birth. https://doi.org/10.1289/EHP12831.

STUDY QUESTION What is the longitudinal association between gestational phthalate exposure and in vivo placental outcomes? SUMMARY ANSWER Phthalates were adversely associated with placental microvasculature, stiffness, and presence of calcification, with different metabolites associated with different outcomes. WHAT IS KNOWN ALREADY Phthalate exposure is ubiquitous and implicated as a contributor to adverse pregnancy outcomes, possibly through impacts on the placenta. STUDY DESIGN, SIZE, DURATION A total of 303 women were recruited in early pregnancy and prospectively followed for up to eight visits across gestation in the Human Placenta and Phthalates study. PARTICIPANTS/MATERIALS, SETTING, METHODS At each visit, women provided urine samples and underwent placental ultrasounds. Urine was analyzed for 18 metabolites of phthalates and replacements. We took the geometric mean of repeated measurements to reflect pregnancy-averaged phthalate or replacement exposure for each participant (n = 303). Placental microvasculature, stiffness, and microcalcification presence were quantified from ultrasounds at each visit. Higher scores reflected worse placental function for all measures. Generalized linear mixed models were created to estimate the association between pregnancy-averaged exposure biomarker concentrations and repeated outcome measurements for microvasculature and stiffness. Gestational age at the time of calcification detection was modeled using Cox proportional hazards models. MAIN RESULTS AND THE ROLE OF CHANCE Monocarboxyisononyl phthalate and summed di(2-ethylhexyl) phthalate metabolites were associated with impaired microvasculature development, such that an interquartile range increase in concentration was associated with 0.11 standard deviation increase in the microvasculature ratio, indicating poorer vascularization (95% CI: 0.00, 0.22); 0.11 [95% CI: −0.01, 0.22], respectively. Monoethyl phthalate was associated with increased placental stiffness (0.09 [95% CI: −0.01, 0.19]) while summed di-iso-butyl phthalate metabolites and monobenzyl phthalate were associated with increased hazard of calcification detection (hazard ratios: 1.18 [95% CI: 0.98, 1.42]; 1.13 [95% CI: 0.96, 1.34]). LIMITATIONS, REASONS FOR CAUTION Outcomes used in this study are novel and further investigation is needed to provide clinical context and relevance. WIDER IMPLICATIONS OF THE FINDINGS We found evidence of associations between select phthalate biomarkers and various aspects of in vivo placental health, although we did not observe consistency across placental outcomes. These findings could illustrate heterogeneous effects of phthalate exposure on placental function. STUDY FUNDING/COMPETING INTEREST(S) This research was supported in part by the Intramural Research Program of the NIH, National Institute of Environmental Health Sciences (ZIA ES103344), and NIEHS T32ES007018. The authors declare that they have no competing interests to disclose. The findings and conclusions in this report are those of the authors and do not necessarily represent the official position of the Centers for Disease Control and Prevention. Use of trade names is for identification only and does not imply endorsement by the CDC, the Public Health Service, or the US Department of Health and Human Services. TRIAL REGISTRATION NUMBER N/A. [ABSTRACT FROM AUTHOR]

Background: An infant's presentation at delivery may be an early indicator of developmental differences. Non‐vertex presentation (malpresentation) complicates delivery and often leads to caesarean section, which has been associated with neurodevelopmental delays, including autism spectrum disorder (ASD). However, malpresentation could be an early sign of an existing developmental problem that is also an upstream factor from caesarean delivery. Little research has been done to investigate the association between malpresentation and ASD. Objectives: We examine the association between malpresentation at delivery and ASD and whether this association differs by gestational age. Methods: We used data from the Study to Explore Early Development (SEED), a multi‐site, case–control study of children with ASD compared to population controls. The foetal presentation was determined using medical records, birth records and maternal interviews. We defined malpresentation as a non‐vertex presentation at delivery, then further categorised into breech and other malpresentation. We used multivariable logistic regression to estimate the adjusted odds ratio (aOR) for the association between malpresentation and ASD. Results: We included 4047 SEED participants, 1873 children with ASD and 2174 controls. At delivery, most infants presented vertex (n = 3760, 92.9%). Malpresentation was associated with higher odds of ASD (aOR 1.31, 95% confidence interval [CI] 1.02, 1.68) after adjustment for maternal age, poverty level, hypertensive disorder and smoking. The association was similar for breech and other types of malpresentation (aOR 1.28, 95% CI 0.97, 1.70 and aOR 1.40, 95% CI 0.87, 2.26, respectively) and did not differ markedly by gestational age. Conclusions: Malpresentation at delivery was modestly associated with ASD. Early monitoring of the neurodevelopment of children born with malpresentation could identify children with ASD sooner and enhance opportunities to provide support to optimise developmental outcomes. [ABSTRACT FROM AUTHOR]

BackgroundOrganophosphorous (OP) pesticides are associated with reduced fetal growth in animals, but human studies are inconsistent.ObjectivesWe pooled data from four cohorts to examine associations of prenatal OP exposure with birth weight (n = 1,169), length (n = 1,152), and head circumference (n = 1,143).MethodsData were from the CHAMACOS, HOME, Columbia, and Mount Sinai birth cohorts. Concentrations of three diethyl phosphate (ΣDEP) and three dimethyl phosphate (ΣDMP) metabolites of OP pesticides [summed to six dialkyl phosphates (ΣDAPs)] were measured in maternal urine. Linear regression and mixed-effects models were used to examine associations with birth outcomes.ResultsWe found no significant associations of ΣDEP, ΣDMP, or ΣDAPs with birth weight, length, or head circumference overall. However, among non-Hispanic black women, increasing urinary ΣDAP and ΣDMP concentrations were associated with decreased birth length (β = -0.4 cm; 95% CI: -0.9, 0.0 and β = -0.4 cm; 95% CI: -0.8, 0.0, respectively, for each 10-fold increase in metabolite concentration). Among infants with the PON1192RR genotype, ΣDAP and ΣDMP were negatively associated with length (β = -0.4 cm; 95% CI: -0.9, 0.0 and β = -0.5 cm; 95% CI: -0.9, -0.1).ConclusionsThis study confirms previously reported associations of prenatal OP exposure among black women with decreased infant size at birth, but finds no evidence of smaller birth weight, length, or head circumference among whites or Hispanics. Contrary to our hypothesis, we found stronger inverse associations of DAPs and birth outcome in infants with the less susceptible PON1192RR genotype. The large pooled data set facilitated exploration of interactions by race/ethnicity and PON1 genotype, but was limited by differences in study populations.CitationHarley KG, Engel SM, Vedar MG, Eskenazi B, Whyatt RM, Lanphear BP, Bradman A, Rauh VA, Yolton K, Hornung RW, Wetmur JG, Chen J, Holland NT, Barr DB, Perera FP, Wolff MS. 2016. Prenatal exposure to organophosphorous pesticides and fetal growth: pooled results from four longitudinal birth cohort studies. Environ Health Perspect 124:1084-1092; http://dx.doi.org/10.1289/ehp.1409362.

Summary: Children in America today are at an unacceptably high risk of developing neurodevelopmental disorders that affect the brain and nervous system including autism, attention deficit hyperactivity disorder, intellectual disabilities, and other learning and behavioral disabilities. These are complex disorders with multiple causes—genetic, social, and environmental. The contribution of toxic chemicals to these disorders can be prevented. Approach: Leading scientific and medical experts, along with children’s health advocates, came together in 2015 under the auspices of Project TENDR: Targeting Environmental Neuro-Developmental Risks to issue a call to action to reduce widespread exposures to chemicals that interfere with fetal and children’s brain development. Based on the available scientific evidence, the TENDR authors have identified prime examples of toxic chemicals and pollutants that increase children’s risks for neurodevelopmental disorders. These include chemicals that are used extensively in consumer products and that have become widespread in the environment. Some are chemicals to which children and pregnant women are regularly exposed, and they are detected in the bodies of virtually all Americans in national surveys conducted by the U.S. Centers for Disease Control and Prevention. The vast majority of chemicals in industrial and consumer products undergo almost no testing for developmental neurotoxicity or other health effects. Conclusion: Based on these findings, we assert that the current system in the United States for evaluating scientific evidence and making health-based decisions about environmental chemicals is fundamentally broken. To help reduce the unacceptably high prevalence of neurodevelopmental disorders in our children, we must eliminate or significantly reduce exposures to chemicals that contribute to these conditions. We must adopt a new framework for assessing chemicals that have the potential to disrupt brain development and prevent the use of those that may pose a risk. This consensus statement lays the foundation for developing recommendations to monitor, assess, and reduce exposures to neurotoxic chemicals. These measures are urgently needed if we are to protect healthy brain development so that current and future generations can reach their fullest potential.

BackgroundOrganophosphorus pesticides (OPs) are used in agriculture worldwide. Residential use was common in the United States before 2001.ObjectivesWe conducted a pooled analysis of four birth cohorts (children's centers; n = 936) to evaluate associations of prenatal exposure to OPs with child development at 24 months.MethodsUsing general linear models, we computed site-specific and pooled estimates of the association of total dialkyl (ΣDAP), diethyl (ΣDEP), and dimethylphosphate (ΣDMP) metabolite concentrations in maternal prenatal urine with mental and psychomotor development indices (MDI/PDI) and evaluated heterogeneity by children's center, race/ethnicity, and PON1 genotype.ResultsThere was significant heterogeneity in the center-specific estimates of association for ΣDAP and ΣDMP and the MDI (p = 0.09, and p = 0.05, respectively), as well as heterogeneity in the race/ethnicity-specific estimates for ΣDAP (p = 0.06) and ΣDMP (p = 0.02) and the MDI. Strong MDI associations in the CHAMACOS population per 10-fold increase in ΣDAP (β = -4.17; 95% CI: -7.00, -1.33) and ΣDMP (β = -3.64; 95% CI: -5.97, -1.32) were influential, as were associations among Hispanics (β per 10-fold increase in ΣDAP = -2.91; 95% CI: -4.71, -1.12). We generally found stronger negative associations of ΣDAP and ΣDEP with the 24-month MDI for carriers of the 192Q PON1 allele, particularly among blacks and Hispanics.ConclusionsData pooling was complicated by center-related differences in subject characteristics, eligibility, and changes in regulations governing residential use of OPs during the study periods. Pooled summary estimates of prenatal exposure to OPs and neurodevelopment should be interpreted with caution because of significant heterogeneity in associations by center, race/ethnicity, and PON1 genotype. Subgroups with unique exposure profiles or susceptibilities may be at higher risk for adverse neurodevelopment following prenatal exposure.CitationEngel SM, Bradman A, Wolff MS, Rauh VA, Harley KG, Yang JH, Hoepner LA, Barr DB, Yolton K, Vedar MG, Xu Y, Hornung RW, Wetmur JG, Chen J, Holland NT, Perera FP, Whyatt RM, Lanphear BP, Eskenazi B. 2016. Prenatal organophosphorus pesticide exposure and child neurodevelopment at 24 months: an analysis of four birth cohorts. Environ Health Perspect 124:822-830; http://dx.doi.org/10.1289/ehp.1409474.

Summary: Advances in technologies to measure a broad set of exposures have led to a range of exposome research efforts. Yet, these efforts have insufficiently integrated methods that incorporate genetic data to strengthen causal inference, despite evidence that many exposome-associated phenotypes are heritable. Objective: We demonstrate how integration of methods and study designs that incorporate genetic data can strengthen causal inference in exposomics research by helping address six challenges: reverse causation and unmeasured confounding, comprehensive examination of phenotypic effects, low efficiency, replication, multilevel data integration, and characterization of tissue-specific effects. Examples are drawn from studies of biomarkers and health behaviors, exposure domains where the causal inference methods we describe are most often applied. Discussion: Technological, computational, and statistical advances in genotyping, imputation, and analysis, combined with broad data sharing and cross-study collaborations, offer multiple opportunities to strengthen causal inference in exposomics research. Full application of these opportunities will require an expanded understanding of genetic variants that predict exposome phenotypes as well as an appreciation that the utility of genetic variants for causal inference will vary by exposure and may depend on large sample sizes. However, several of these challenges can be addressed through international scientific collaborations that prioritize data sharing. Ultimately, we anticipate that efforts to better integrate methods that incorporate genetic data will extend the reach of exposomics research by helping address the challenges of comprehensively measuring the exposome and its health effects across studies, the life course, and in varied contexts and diverse populations. https://doi.org/10.1289/EHP9098, Introduction The past decade has witnessed a paradigm shift in the environmental sciences as studies have shifted from examining specific exposures to attempting to comprehensively measure and characterize the broad [...]

INTRODUCTION: We examined midlife (1990–1992, mean age 57) and late‐life (2011–2013, mean age 75) nonalcoholic fatty liver disease (NAFLD) and aminotransferase with incident dementia risk through 2019 in the Atherosclerosis Risk in Communities (ARIC) Study. METHODS: We characterized NAFLD using the fatty liver index and fibrosis‐4, and we categorized aminotransferase using the optimal equal‐hazard ratio (HR) approach. We estimated HRs for incident dementia ascertained from multiple data sources. RESULTS: Adjusted for demographics, alcohol consumption, and kidney function, individuals with low, intermediate, and high liver fibrosis in midlife (HRs: 1.45, 1.40, and 2.25, respectively), but not at older age, had higher dementia risks than individuals without fatty liver. A U‐shaped association was observed for alanine aminotransferase with dementia risk, which was more pronounced in late‐life assessment. DISCUSSION: Our findings highlight dementia burden in high‐prevalent NAFLD and the important feature of late‐life aminotransaminase as a surrogate biomarker linking liver hypometabolism to dementia. Highlights: Although evidence of liver involvement in dementia development has been documented in animal studies, the evidence in humans is limited.Midlife NAFLD raised dementia risk proportionate to severity.Late‐life NAFLD was not associated with a high risk of dementia.Low alanine aminotransferase was associated with an elevated dementia risk, especially when measured in late life. [ABSTRACT FROM AUTHOR]

Background Many women diagnosed with cancer as adolescents and young adults (AYAs, age 15-39 years) want biological children after cancer but lack information on the potential impact of their cancer history on future reproductive outcomes. We investigated the risk of adverse birth outcomes among AYA cancer survivors. Methods We identified insured women diagnosed with AYA breast cancer, thyroid cancer, gynecologic cancers, lymphoma, or melanoma from 2003 to 2016 in the state of North Carolina or the Kaiser Permanente health care systems in northern and southern California. Post-diagnosis births to cancer survivors were each matched with up to 5 births to women without cancer. Risk ratios for preterm birth (<37 completed weeks), very preterm birth (<34 completed weeks), low birth weight (<2500 g), and small for gestational age (SGA, <10th percentile of weight for gestational age) were estimated using modified Poisson regression. Results Analyses included 1648 births to 1268 AYA cancer survivors and 7879 births to 6066 women without cancer. Overall, risk of preterm birth, very preterm birth, low birth weight, and SGA did not significantly differ between births to women with and without cancer. However, births to women with gynecologic cancers had a significantly increased risk of low birth weight (risk ratio = 1.82; 95% confidence interval: 1.03 to 3.21) and suggested increased risk of preterm birth (risk ratio = 1.59; 95% confidence interval: 0.99 to 2.54). Chemotherapy exposure was not associated with increased risk of adverse birth outcomes. Conclusions Women with gynecologic cancers, but not other cancers, had an increased risk of adverse birth outcomes compared to women without cancer. [ABSTRACT FROM AUTHOR]

Objective Maternal smoking is associated with as much as a 50% reduced risk of preeclampsia, despite increasing risk of other poor pregnancy outcomes that often co-occur with preeclampsia, such as preterm birth and fetal growth restriction. Researchers have long sought to understand whether this perplexing association is biologically based, or a result of noncausal mechanisms. We examined whether smoking-response genes modify the smoking-preeclampsia association to investigate potential biological explanations. Study Design We conducted a nested case–control study within the Norwegian Mother, Father and Child Birth Cohort (1999–2008) of 2,596 mother–child dyads. We used family-based log-linear Poisson regression to examine modification of the maternal smoking-preeclampsia relationship by maternal and fetal single nucleotide polymorphisms involved in cellular processes related to components of cigarette smoke (n = 1,915 with minor allele frequency ≥10%). We further investigated the influence of smoking cessation during pregnancy. Results Three polymorphisms showed overall (p < 0.001) multiplicative interaction between smoking and maternal genotype. For rs3765692 (TP73) and rs10770343 (PIK3C2G), protection associated with smoking was reduced with two maternal copies of the risk allele and was stronger in continuers than quitters (interaction p = 0.02 for both loci, based on testing 3-level smoking by 3-level genotype). For rs2278361 (APAF1) the inverse smoking-preeclampsia association was eliminated by the presence of a single risk allele, and again the trend was stronger in continuers than in quitters (interaction p = 0.01). Conclusion Evidence for gene–smoking interaction was limited, but differences by smoking cessation warrant further investigation. We demonstrate the potential utility of expanded dyad methods and gene–environment interaction analyses for outcomes with complex relationships between maternal and fetal genotypes and exposures. Key Points Maternal and fetal genotype may differentially influence preeclampsia. Smoking-related genes did not strongly modify smoking–preeclampsia association. Smoking cessation reduced strength of gene by smoking interactions. [ABSTRACT FROM AUTHOR]