Humans are exposed to complex mixtures of phthalates. Gestational exposure to phthalates has been linked to preeclampsia and preterm birth through potential pathways such as endocrine disruption, oxidative stress, and inflammation. Eicosanoids are bioactive signaling lipids that are related to a variety of homeostatic and inflammatory processes. We investigated associations between urinary phthalates and their mixtures with plasma eicosanoid levels during pregnancy using the PROTECT cohort in Puerto Rico (N = 655). After adjusting for covariates, we estimated pair-wise associations between the geometric mean of individual phthalate metabolite concentrations across pregnancy and eicosanoid biomarkers using multivariable linear regression. We used bootstrapping of adaptive elastic net regression (adENET) to evaluate phthalate mixtures associated with eicosanoids and subsequently create environmental risk scores (ERS) to represent weighted sums of phthalate exposure for each individual. After adjusting for false-discovery, in single-pollutant analysis, 14 of 20 phthalate metabolites or parent compound indices showed significant and primarily negative associations with multiple eicosanoids. In our mixture analysis, associations with several metabolites of low molecular weight phthalates - DEP, DBP, and DIBP - became prominent. Additionally, MEHHTP and MECPTP, metabolites of a new phthalate replacement, DEHTP, were selected as important predictors for determining the concentrations of multiple eicosanoids from different pathway groups. A unit increase in phthalate ERS derived from bootstrapping of adENET was positively associated with several eicosanoids mainly from Cytochrome P450 pathway. For example, an increase in ERS was associated with 11(S)-HETE (β = 1.6, 95% CI: 0.020, 3.180), (±)11,12-DHET (β = 2.045, 95% CI: 0.250, 3.840), 20(S)-HETE (β = 0.813, 95% CI: 0.147, 1.479), and 9 s-HODE (β = 2.381, 95% CI: 0.657, 4.104). Gestational exposure to phthalates and phthalate mixtures were associated with eicosanoid levels during pregnancy. Results from the mixture analyses underscore the complexity of physiological impacts of phthalate exposure and call for further in-depth studies to examine these relationships.

Phthalates have been linked to changes in child neurodevelopment. However, sex-specificity has been reported inconsistently, and little is known about the impact of recent phthalate replacement chemicals. Our analysis included mother–child pairs (N = 274) from the PROTECT birth cohort in Puerto Rico. Phthalate metabolites were measured in multiple maternal urine collected during pregnancy. Neurodevelopment was measured at 6, 12, and 24 months of age using the Battelle Developmental Inventory-2nd edition (BDI), which provides scores for adaptive, personal-social, communication, motor, and cognitive domains. Multivariable linear regression was used to examine associations between phthalate metabolite concentrations and BDI scores, adjusting for maternal age, maternal education, child age, and specific gravity. Sex-specificity was assessed with sex X exposure interaction terms and stratified models. Results show that all five domains were significantly associated with mono-3-carboxypropyl phthalate (MCPP) at age 24 months, suggesting a holistic developmental delay related to this metabolite. Sex-specificity existed for all timepoints (p-interaction < 0.2), in general, showing stronger associations among boys. For example, metabolites of a recent phthalate replacement, di-2-ethylhexyl terephthalate (DEHTP), were differentially associated with the adaptive domain (boys −7.53%/IQR, 95% CI: −14.58, −0.48 vs. girls −0.85%/IQR, 95% CI: −5.08, 3.37), and the cognitive domain (boys −6.05%/IQR, 95% CI: −10.88, −1.22 vs. girls −1.93%/IQR, 95%CI: −4.14, 0.28) at 6 months. To conclude, gestational exposure to phthalates and phthalate replacements was associated with neurodevelopmental delay across multiple domains, with differences by sex and child age.

Phthalates are widely used plasticizers and solvents in a variety of consumer and personal care products, resulting in ubiquitous exposure across the general population. Pregnancy represents a particularly critical window of vulnerability, as prenatal phthalate exposures have been linked to adverse health outcomes, including preterm birth and child developmental problems. While growing evidence highlights potential neurotoxic effects in children, few studies have examined the combined impact of multiple phthalates and newly introduced replacement chemicals. In this study, we included 199 mother-child dyads from the PROTECT birth cohort in Puerto Rico. We assessed prenatal exposure to multiple phthalates and a replacement chemical, di(2-ethylhexyl) terephthalate (DEHTP), by measuring biomarkers in maternal urine samples. Neurodevelopmental outcomes were then evaluated in early childhood (ages 1-3 years) across multiple domains - adaptive, cognitive, communication, motor, and personal-social. We employed a range of mixture modeling approaches-adaptive elastic net (adENET), Bayesian kernel machine regression (BKMR), and quantile g-computation (Q-gcomp). We identified mono(carboxyisononyl) phthalate (MCOP) as a key contributor to poorer neurodevelopmental outcomes and observed an overall adverse trend for the combined mixture. These results provide evidence of additive and mixture effects among multiple phthalates and replacement chemicals, underscoring the need for further research to elucidate the biological mechanisms by which these exposures may collectively influence child neurodevelopment.

Phthalates are widely used in consumer products and are recognized as endocrine disruptors. Prenatal exposure to phthalates has been associated with various adverse health outcomes, including preterm birth and impaired fetal growth, and growing attention is being paid to their potential impact on child neurodevelopment. However, previous epidemiological studies examining prenatal phthalate exposure and child neurodevelopment have produced inconsistent or inconclusive findings, and evidence on phthalate mixtures remains limited. In this study, we utilized data from the Environmental influences on Child Health Outcomes (ECHO) Cohort to investigate associations between urinary biomarkers of prenatal phthalate exposure, both individually and as a mixture, and likelihood of neurodevelopmental delay (NDD) in offspring at ages 1 to 3 years. This study included 2378 pregnant person-child dyads from 10 ECHO cohorts who had measurements of NDD odds assessed using the Ages and Stages Questionnaire, Third Edition (ASQ-3). Our single-pollutant analyses revealed mixed findings. Higher prenatal exposure to certain phthalates was associated with higher odds of NDD across multiple domains, including motor and problem-solving skills, with evidence of effect modification by child sex. Conversely, we observed negative associations between specific prenatal phthalate concentrations and lower odds of NDD, particularly in communication domain. From mixture analyses, however, no significant associations were observed between the overall phthalate mixture and NDD odds in most domains, except for negative association for the personal-social domain. Further investigation into the biological mechanisms underlying these relationships, as well as more detailed evaluations of phthalate mixtures, will help advance our understanding of how prenatal phthalate exposure may influence early childhood neurodevelopment.