Year: 2018
Type: article
Study design: Observational Study
Abstract: BACKGROUND: Evidence from experimental and observational studies suggests that prenatal phthalate exposures may be associated with autism spectrum disorder (ASD). We examined whether prenatal phthalate exposures were associated with an increased risk of ASD. METHODS: We quantified 14 metabolites of eight phthalates in 636 multiple maternal urine samples collected during 2nd and 3rd trimesters of pregnancy from 201 mother-child pairs in MARBLES (Markers of Autism Risk in Babies - Learning Early Signs), a high-risk ASD longitudinal cohort. At 3 years old, children were clinically assessed for ASD and classified into three diagnostic categories: ASD (n = 46), non-typical development (Non-TD, n = 55), and typical development (TD, n = 100). We used multinomial logistic regression to evaluate the association of phthalate metabolite concentrations with ASD and Non-TD. RESULTS: Most associations of phthalate biomarkers with both ASD and Non-TD were null, with the exception that monoethyl phthalate (MEP) was significantly associated with an increased risk of Non-TD (per 2.72-fold relative increase in concentration: Relative risk ratio (RRR) = 1.38; 95% confidence interval (CI): 1.01, 1.90). When stratified by prenatal vitamin use during the first month of pregnancy, among mothers who took vitamins, ASD risk was inversely associated with mono-isobutyl phthalate (MiBP, RRR = 0.44; 95% CI: 0.21, 0.88), mono(3-carboxypropyl) phthalate (MCPP, RRR = 0.41; 95% CI: 0.20, 0.83) and mono-carboxyisooctyl phthalate (MCOP, RRR = 0.49; 95% CI: 0.27, 0.88), but among mothers who did not take prenatal vitamins, Non-TD risk was positively associated with MCPP (RRR = 5.09; 95% CI: 2.05, 12.6), MCOP (RRR = 1.86; 95% CI: 1.01, 3.39), and mono-carboxyisononyl phthalate (MCNP, RRR = 3.67; 95% CI: 1.80, 7.48). When stratified by sex, among boys, MEP, monobenzyl phthalate, MCPP, MCNP, and sum of di(2-ethylhexyl) phthalate metabolites (ΣDEHP) were positively associated with Non-TD risk, but associations with ASD were null. Among girls, associations with both ASD and Non-TD were null. CONCLUSIONS: Our study showed that phthalate exposures in mid- to late pregnancy were not associated with ASD in children from this high-risk ASD cohort. Further studies should be conducted in the general population without high-risk genes to confirm our findings.
Source: Environmental Health
Language: English
Subfield: Health, Toxicology and Mutagenesis
Field: Environmental Science
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $3,490
Funders: Autism Speaks, U.S. Environmental Protection Agency, Autism Science Foundation, Université de Sherbrooke, MIND Institute, University of California, Davis, National Institutes of Health, Centers for Disease Control and Prevention, University of California, Davis, Intellectual and Developmental Disabilities Research Center, National Institute of Environmental Health Sciences, Eunice Kennedy Shriver National Institute of Child Health and Human Development
Awards: G1241784340, G1334584848, BUILDS MARBLES: Biorepository Upkeep and Infrastructure for Longitudinal Data Sharing for MARBLES, Folic Acid Prevention Pathways for ASD in High Risk Families, G281283810, G3073890309, G353256192, MIND Institute Intellectual and Developmental Disabilities Research Center, G4096623411, Autism Risk, Prenatal Environmental Exposures, and Pathophysiologic Markers, Prenatal Exposure to Phthalates in a High-Risk ASD Pregnancy Cohort, G4997004123, G5083323197, G5120299696, G5144221652, G53145986, G5489970504, The UC Davis Center for Children's Enviromental Health and Disease Prevention, G623652068, G6426333833, G713830352, G7461874501, Environmental Influence on Infant Microbiome Development and ASD Symptoms, G821961197, G8885467479, UC Davis Environmental Health Sciences Core Center
OpenAlex ID: W2902095901