Phthalate Exposures and Placental Health in Animal Models and Humans: A Systematic Review

Prenatal exposure to phthalates and phthalate replacements in relation to chorionic plate surface vasculature at delivery

Pregnant people are ubiquitously exposed to endocrine-disrupting phthalates through consumer products and food. The placenta may be particularly vulnerable to the adverse effects of phthalates, with evidence from animal models suggesting impacts on placental development and vascularization. We translate this research to humans, examining gestational exposure to phthalates and phthalate replacements in relation to novel markers of chorionic plate surface vascularization. Phthalate and phthalate replacement metabolites were measured in first trimester urine from pregnant participants in the Understanding Pregnancy Signals and Infant Development (UPSIDE) cohort (n = 154). At delivery, placentae underwent specialized 2D and 3D digital imaging to quantify chorionic plate surface vasculature. Using weighted quantile g-computation mixtures methods as well as multivariable linear regression models examining individual metabolites, we evaluated associations with overall chorionic plate surface area and five chorionic plate surface vascular measures, adjusting for covariates. We additionally examined interactions with placental sex. Exposure to a phthalate mixture was associated with longer total arterial arc length (β = 9.64 cm; 95%CI: 1.68, 17.59), shorter mean arterial arc length (β = -0.07 cm; 95%CI: -0.14, -0.01), and more arterial branch points (β = 5.77; 95%CI: 1.56, 9.98), but not chorionic plate surface area. In models considering individual metabolites and their molar sums, results were strongest for the metabolites of Di-isobutyl phthalate (DiBP), Di-isononyl phthalate (DiNP), and Di(2-ethylhexyl) phthalate (DEHP). Associations with metabolites of phthalate replacements tended to be in the same direction but weaker. Few sex differences were observed. Gestational phthalate exposure may be associated with alterations in placental chorionic plate surface vasculature characterized by more branching and shorter segments. These alterations may have implications for placental perfusion and suggest a placental mechanism by which phthalates may impact fetal development.

Toxic effects of dibutyl phthalate on trophoblast through mitochondria mediated cellular dysfunction

Dibutyl phthalate is a chemical commonly used as a plasticizer in the production of daily necessaries, such as cosmetics and toys. Although several toxic effects of dibutyl phthalate have been confirmed, those related to pregnancy are unknown. Trophoblasts are critical for fetal and placental development, and trophoblast damage may cause preeclampsia. This study aimed to confirm the toxic effect of dibutyl phthalate on trophoblasts. We used the human trophoblast cell line HTR-8/SVneo and human choriocarcinoma JEG-3 cells as a placental trophoblast model to investigate the toxic effects of dibutyl phthalate. Both cell lines were treated with dibutyl phthalate (0-20 μg/mL) to verify the mechanisms regulating trophoblast function. Dibutyl phthalate treatment significantly reduced trophoblast viability, reduced invasion ability, and induced mitochondrial depolarization. Ultimately, dibutyl phthalate regulated the PI3K and MAPK signaling pathways and the expression of autophagy-related proteins ATG5, LC3B, and SQSTM1/p62. We concluded that dibutyl phthalate induced autophagy and effectively weakened trophoblast function. Additionally, we conducted experiments to assess the potential effects of monobutyl phthalate, a metabolite of dibutyl phthalate, on cellular mobility, penetration, and autophagy induction. Our results demonstrated that monobutyl phthalate impaired these functions and weakened the trophoblast barrier, after dibutyl phthalate metabolized. Thus, exposure to dibutyl phthalate and its metabolite monobutyl phthalate can damage trophoblast function, highlighting their potential as hazardous substances that impair trophoblast barrier integrity.

Prenatal exposure to phthalates and childhood wheeze and asthma in the PROGRESS cohort

INTRODUCTION

Prenatal phthalate exposure may influence lung development and lead to wheezing and asthma in childhood, and these associations may vary by sex. Despite ubiquity of exposure, there is limited epidemiologic data on these associations in Latin America.

METHODS

We assessed 593 mother-child dyads enrolled in the Programming Research in Obesity, Growth, Environment, and Social Stressors birth cohort in Mexico City. We quantified 15 phthalate metabolites in 2nd and 3rd trimester maternal urine. Report of ever wheeze, wheeze in the past 12 months (current wheeze) and ever asthma were obtained using a validated survey when children were 4 and 6 years of age. We examined individual associations with modified Poisson models. Mixture effects were assessed using Bayesian Weighted Quantile Sum (BWQS) regression. All models were adjusted for child's sex, maternal age and education at enrollment, and parity.

RESULTS

In Poisson models, a doubling of mono (carboxy-isononyl) phthalate (MCNP) during the 2nd trimester was associated with higher risk of wheeze (RR: 1.14, 95 % CI: 1.01, 1.29), and asthma (RR: 1.44, 95 % CI: 1.05, 1.97) at 4 years of age. Higher concentrations of the sum of di-isononyl phthalate metabolites (∑DiNP) during the 2nd trimester were also associated with asthma at 4 years of age (RR: 1.30, 95 % CI: 1.04, 1.61). Mixture associations of phthalate metabolite concentrations during the 2nd trimester and asthma at 4 years of age were stronger in males (BWQS, OR: 1.94, 95 % CI: 0.90, 4.60; 90 % CrI: 1.04, 3.73) compared to females (BWQS, OR: 1.23, 95 % CI: 0.56, 2.88; 90 % CrI: 0.61, 2.55). Additionally, we observed stronger inverse associations between prenatal phthalate mixtures during the 3rd trimester and current wheeze at 4 and 6 years of age in females (BWQS, OR: 0.54, 90 % CrI: 0.35, 0.82; OR: 0.45, 90 % CrI: 0.22, 0.84) compared to males (BWQS, OR: 0.95, 90 % Cri: 0.68, 1.35; OR: 0.97, 90 % CrI: 0.59, 1.54).

CONCLUSIONS

Prenatal phthalate metabolite concentrations were associated with respiratory outcomes in childhood, with some evidence of sex specific effects. Future work investigating phthalate exposure and wheeze trajectories/lung function will be important for understanding how these may predict later disease.

Exploring the link between the pediatric exposome, respiratory health, and executive function in children: a narrative review

Asthma is a highly prevalent inflammatory condition, significantly affecting nearly six million U.S. children and impacting various facets of their developmental trajectories including neurodevelopment. Evidence supports a link between pediatric environmental exposures in two key areas: asthma and executive function (E.F.). E.F.s are a collective of higher-order cognitive processes facilitating goal-oriented behaviors. Studies also identify asthma-associated E.F. impairments in children. However, limited research has evaluated the inter-relationships among environmental exposures, asthma, and E.F. in children. This review explored relevant research to identify and connect the potential mechanisms and pathways underlying these dynamic associations. The review suggests that the role of the pediatric exposome may function through (1) several underlying biological pathways (i.e., the lung-brain axis, neuroendocrine system, and hypoxia), which could drive asthma and maladaptive E.F. in children and (2) the relationships between the exposome, asthma, and E.F. is a bidirectional linkage. The review reveals essential synergistic links between asthma and E.F. deficits, highlighting the potential role of the pediatric exposome.

Short-Half-Life Chemicals: Maternal Exposure and Offspring Health Consequences-The Case of Synthetic Phenols, Parabens, and Phthalates

Phenols, parabens, and phthalates (PPPs) are suspected or known endocrine disruptors. They are used in consumer products that pregnant women and their progeny are exposed to daily through the placenta, which could affect offspring health. This review aims to compile data from cohort studies and in vitro and in vivo models to provide a summary regarding placental transfer, fetoplacental development, and the predisposition to adult diseases resulting from maternal exposure to PPPs during the gestational period. In humans, using the concentration of pollutants in maternal urine, and taking the offspring sex into account, positive or negative associations have been observed concerning placental or newborn weight, children's BMI, blood pressure, gonadal function, or age at puberty. In animal models, without taking sex into account, alterations of placental structure and gene expression linked to hormones or DNA methylation were related to phenol exposure. At the postnatal stage, pollutants affect the bodyweight, the carbohydrate metabolism, the cardiovascular system, gonadal development, the age of puberty, sex/thyroid hormones, and gamete quality, but these effects depend on the age and sex. Future challenges will be to explore the effects of pollutants in mixtures using models and to identify the early signatures of in utero exposure capable of predicting the health trajectory of the offspring.

Disrupted Prenatal Metabolism May Explain the Etiology of Suboptimal Neurodevelopment: A Focus on Phthalates and Micronutrients and their Relationship to Autism Spectrum Disorder

Pregnancy is a time of high metabolic coordination, as maternal metabolism adapts to support the growing fetus. Many of these changes are coordinated by the placenta, a critical fetal endocrine organ and the site of maternal-fetal crosstalk. Dysregulation in maternal and placental metabolism during pregnancy has been linked to adverse outcomes, including altered neurodevelopment. Autism spectrum disorder (ASD) is a neurodevelopmental disorder linked to metabolic alterations in both children and their mothers. Prenatal environmental exposures have been linked to risk of ASD through dysregulated maternal, placental, and fetal metabolism. In this review, we focus on recent studies investigating the associations between prenatal metabolism in the maternal-placental-fetal unit and the impact of prenatal environmental exposures to phthalates and micronutrients on ASD risk. By identifying the mechanisms through which phthalates and other ubiquitous endocrine disrupting chemicals influence development, and how nutritional interventions can impact those mechanisms, we can identify promising ways to prevent suboptimal neurodevelopment.

Epigenetic footprints: Investigating placental DNA methylation in the context of prenatal exposure to phenols and phthalates

BACKGROUND

Endocrine disrupting compounds (EDCs) such as phthalates and phenols can affect placental functioning and fetal health, potentially via epigenetic modifications. We investigated the associations between pregnancy exposure to synthetic phenols and phthalates estimated from repeated urine sampling and genome wide placental DNA methylation.

METHODS

The study is based on 387 women with placental DNA methylation assessed with Infinium MethylationEPIC arrays and with 7 phenols, 13 phthalates, and two non-phthalate plasticizer metabolites measured in pools of urine samples collected twice during pregnancy. We conducted an exploratory analysis on individual CpGs (EWAS) and differentially methylated regions (DMRs) as well as a candidate analysis focusing on 20 previously identified CpGs. Sex-stratified analyses were also performed.

RESULTS

In the exploratory analysis, when both sexes were studied together no association was observed in the EWAS. In the sex-stratified analysis, 114 individual CpGs (68 in males, 46 in females) were differentially methylated, encompassing 74 genes (36 for males and 38 for females). We additionally identified 28 DMRs in the entire cohort, 40 for females and 42 for males. Associations were mostly positive (for DMRs: 93% positive associations in the entire cohort, 60% in the sex-stratified analysis), with the exception of several associations for bisphenols and DINCH metabolites that were negative. Biomarkers associated with most DMRs were parabens, DEHP, and DiNP metabolite concentrations. Some DMRs encompassed imprinted genes including APC (associated with parabens and DiNP metabolites), GNAS (bisphenols), ZIM2;PEG3;MIMT1 (parabens, monoethyl phthalate), and SGCE;PEG10 (parabens, DINCH metabolites). Terms related to adiposity, lipid and glucose metabolism, and cardiovascular function were among the enriched phenotypes associated with differentially methylated CpGs. The candidate analysis identified one CpG mapping to imprinted LGALS8 gene, negatively associated with ethylparaben.

CONCLUSIONS

By combining improved exposure assessment and extensive placental epigenome coverage, we identified several novel genes associated with the exposure, possibly in a sex-specific manner.

Disposables used cumulatively in routine IVF procedures could display toxicity

STUDY QUESTION

Is there a cumulative toxicity of disposables used in IVF procedures?

SUMMARY ANSWER

A toxicity may be detected when consumables are used cumulatively, while no toxicity is detected when the same consumables are used and tested individually.

WHAT IS KNOWN ALREADY

Many components of items used in IVF laboratories may impair human embryonic development. Consequently, it is necessary to screen all reagents and materials which could be in contact with gametes and embryos. Toxicity tests, such as the mouse embryo assay and the human sperm motility assay (HSMA), are used by manufacturers as quality control tools to demonstrate the safety of their products. This evaluation is currently individually performed for each single consumable. However, during an IVF cycle, several devices are used sequentially, potentially creating a cumulative exposure to chemical contaminants, which could not be detected for individually tested consumables.

STUDY DESIGN, SIZE, DURATION

The objective of this observational study conducted from March 2021 to October 2022 was to evaluate with the HSMA methodology if there was a cumulative toxicity when several disposables are sequentially used. Fourteen categories of consumables currently used in routine IVF procedures were studied, which included devices used for sperm and oocyte collection (cups, condoms, and oocyte aspiration needles), manipulation (flasks, tubes, tips, pipettes, embryo transfer catheters, syringes, and gloves), culture (dishes), and storage (straws).

PARTICIPANTS/MATERIALS, SETTING, METHODS

After obtaining patient consent, the surplus semen assessed as having normal parameters according to the World Health Organization 2010 criteria were used to perform the HSMAs. First, each consumable was tested individually. Then, associations of three, four, and five consumables, previously validated as non-toxic when tested individually, were analyzed. HSMAs were conducted three times to ensure reproducibility, with a defined toxicity threshold of a sperm motility index (SMI) below 0.85 in at least two of three tests.

MAIN RESULTS AND THE ROLE OF CHANCE

Thirty-six references of disposables were first individually tested across 53 lots. Forty-nine (92%) demonstrated compliance. However, four (8%) devices revealed toxicity: one lot of 1 ml syringes, two lots of sperm cups, and one lot of 25 cm2 flasks. These four references were excluded from the IVF routine procedures. A total of 48 combinations of consumables were assessed, involving 41 lots from 32 references that were previously individually tested. Among the evaluated combinations, 17 out of 48 (35%) associations exhibited toxicity with a SMI below 0.85 for two of the three tests (n = 8) or all the three tests (n = 9). Notably, three out of 17 (18%) of the three-consumable associations, five out of 16 (31%) of the four-consumable associations, and nine out of 15 (60%) of the five-consumable associations were found not compliant. The toxicity did not originate from a single consumable, because only consumables that were individually pre-validated as non-toxic were included in the combinations, but the toxicity had a cumulative origin. The risk of cumulative toxicity increased with the number of consumables included in the association (Cochran-Mantel-Haenszel statistic, P = 0.013).

LIMITATIONS, REASONS FOR CAUTION

The high proportion of non-compliant combinations of disposables can be attributed directly to the extreme rigorous extraction conditions employed during the tests, which could deviate from the conditions encountered in routine clinical use. Also, the methodology employed in the HSMAs (e.g. toxicity extraction duration, sperm concentrations, and protein supplementation of the medium) can influence the sensitivity of the tests.

WIDER IMPLICATIONS OF THE FINDINGS

This study highlights the significance of performing toxicity testing on devices before introducing them into clinical practice. Disposables should be tested individually to detect immediate toxicities and also in combination. Our results advocate rationalizing the number of consumables used in each IVF procedure and re-evaluating the use of glass consumables.

STUDY FUNDING/COMPETING INTEREST(S)

This study received fundings from GCS Ramsay Santé pour l'Enseignement et la Recherche (Paris, France) and the Centre de Biologie Médicale BIOGROUP (Le Chesnay-Rocquencourt, France). The authors declare that they have no conflict of interest that could be perceived as prejudicing the impartiality of the reported research.

TRIAL REGISTRATION NUMBER

N/A.

Co-exposure to phthalates and polycyclic aromatic hydrocarbons and the risk of gestational hypertension in Chinese women

Phthalates (PAEs) and polycyclic aromatic hydrocarbons (PAHs) are frequently detected in females of reproductive age. Many studies have found that environmental PAE and PAH levels are independent risk factors for gestational hypertension. However, exposure to both components is a more realistic scenario. To better assess the health effects of PAEs and PAHs in pregnant women, we explored the associations of exposure to both individual and combined PAEs and PAHs with gestational hypertension. This nested case-control study was a component of a prospective cohort study conducted in Beijing, China. We included 206 women with gestational hypertension and 214 pregnant controls. We used gas chromatography/tandem mass spectrometry (GC-MS/MS) to detect 8 PAEs and 13 PAHs in > 80 % of all collected hair samples. Multiple linear regression models were employed to test the individual associations between each component and gestational hypertension. A quantile-based g-computation (qgcomp) model and a weighted quantile sum (WQS) regression model were used to estimate whether exposure to both PAEs and PAHs increased the risk of gestational hypertension. The individual exposure analyses revealed that diethyl phthalate (DEP), diisobutyl phthalate (DIBP) (both PAEs), benzo(k)fluoranthene (BKF), anthracene, (ANT), and benzo(a)pyrene (BAP) (all PAHs) were positively associated with increased risk of gestational hypertension. In mixed-effect analyses, the qgcomp model indicated that co-exposure to PAEs and PAHs increased the risk of gestational hypertension (odds ratio = 2.01; 95 % confidence interval: 1.02, 3.94); this finding was verified by the WQS regression model. Our findings support earlier evidence that both PAEs and PAHs increase the risk of gestational hypertension, both individually and in combination. This suggests that reductions in exposure to endocrine system-disrupting chemicals such as PAEs and PAHs might reduce the risk of gestational hypertension.

Prenatal exposures to phthalates and life events stressors in relation to child behavior at age 4-6: A combined cohort analysis

Prenatal exposures to chemical and psychosocial stressors can impact the developing brain, but few studies have examined their joint effects. We examined associations between prenatal phthalate exposures and child behavior, hypothesizing that prenatal stressful life events (PSLEs) may exacerbate risks. To do so, we harmonized data from three U.S. pregnancy cohorts comprising the ECHO-PATHWAYS consortium. Phthalate metabolites were measured in single mid-pregnancy urine samples. When children were ages 4-6 years, mothers completed the Child Behavior Checklist (CBCL), from which a Total Problems score was calculated. Mothers additionally provided recall on their exposure to 14 PSLEs during pregnancy. Primary models examined problem behaviors in relation to: (1) phthalate mixtures calculated through weighted quantile sums regression with permutation test-derived p-values; and (2) joint exposure to phthalate mixtures and PSLEs (counts) using interaction terms. We subsequently refitted models stratified by child sex. Secondarily, we fit linear and logistic regression models examining individual phthalate metabolites. In our main, fully adjusted models (n = 1536 mother-child dyads), we observed some evidence of weak main effects of phthalate mixtures on problem behaviors in the full cohort and stratified by child sex. Interaction models revealed unexpected relationships whereby greater gestational exposure to PSLEs predicted reduced associations between some phthalates (e.g., the metabolites of di-2-ethylhexyl phthalate, di-n-octyl phthalate, di-iso-nonyl phthalate) and problem behaviors, particularly in males. Few associations were observed in females. Additional research is needed to replicate results and examine potential mechanisms.

Associations between prenatal exposure to phthalates and birth weight: A meta-analysis study

Previous studies have suggested that phthalates are associated with birth weight. However, most phthalate metabolites have not been fully explored. Therefore, we conducted this meta-analysis to assess the relationship between phthalate exposure and birth weight. We identified original studies that measured phthalate exposure and reported its association with infant birth weight in relevant databases. Regression coefficients (β) with 95% confidence intervals (CIs) were extracted and analyzed for risk estimation. Fixed-effects (I² ≤ 50%) or random-effects (I² > 50%) models were adopted according to their heterogeneity. Overall summary estimates indicated negative associations of prenatal exposure to mono-n-butyl phthalate (pooled β = -11.34 g; 95% CI: -20.98 to -1.70 g) and mono-methyl phthalate (pooled β = -8.78 g; 95% CI: -16.30 to -1.27 g). No statistical association was found between the other less commonly used phthalate metabolites and birth weight. Subgroup analyses indicated that exposure to mono-n-butyl phthalate was associated with birth weight in females (β = -10.74 g; 95% CI: -18.70 to -2.79 g). Our findings indicate that phthalate exposure might be a risk factor for low birth weight and that this relationship may be sex specific. More research is needed to promote preventive policies regarding the potential health hazards of phthalates.

Long-term exposure to di(2-ethylhexyl) phthalate, diisononyl phthalate, and a mixture of phthalates alters estrous cyclicity and/or impairs gestational index and birth rate in mice

Phthalates are found in plastic food containers, medical plastics, and personal care products. However, the effects of long-term phthalate exposure on female reproduction are unknown. Thus, this study investigated the effects of long-term, dietary phthalate exposure on estrous cyclicity and fertility in female mice. Adult female CD-1 mice were fed chow containing vehicle control (corn oil) or 0.15-1500 ppm of di(2-ethylhexyl) phthalate (DEHP), diisononyl phthalate (DiNP), or a mixture of phthalates (Mix) containing DEHP, DiNP, benzyl butyl phthalate, di-n-butyl phthalate, diisobutyl phthalate, and diethyl phthalate. Measurements of urinary phthalate metabolites confirmed effective delivery of phthalates. Phthalate consumption for 11 months did not affect body weight compared to control. DEHP exposure at 0.15 ppm for 3 and 5 months increased the time that the mice spent in estrus and decreased the time the mice spent in metestrus/diestrus compared to control. DiNP exposure (0.15-1500 ppm) did not significantly affect time in estrus or metestrus/diestrus compared to control. Mix exposure at 0.15 and 1500 ppm for 3 months decreased the time the mice spent in metestrus/diestrus and increased the time the mice spent in estrus compared to control. DEHP (0.15-1500 ppm) or Mix (0.15-1500 ppm) exposure did not affect fertility-related indices compared to control. However, long-term DiNP exposure at 1500 ppm significantly reduced gestational index and birth rate compared to control. These data indicate that chronic dietary exposure to phthalates alters estrous cyclicity, and long-term exposure to DiNP reduces gestational index and birth rate in mice.

Single inhalation exposure to polyamide micro and nanoplastic particles impairs vascular dilation without generating pulmonary inflammation in virgin female Sprague Dawley rats

BACKGROUND

Exposure to micro- and nanoplastic particles (MNPs) in humans is being identified in both the indoor and outdoor environment. Detection of these materials in the air has made inhalation exposure to MNPs a major cause for concern. One type of plastic polymer found in indoor and outdoor settings is polyamide, often referred to as nylon. Inhalation of combustion-derived, metallic, and carbonaceous aerosols generate pulmonary inflammation, cardiovascular dysfunction, and systemic inflammation. Additionally, due to the additives present in plastics, MNPs may act as endocrine disruptors. Currently there is limited knowledge on potential health effects caused by polyamide or general MNP inhalation.

OBJECTIVE

The purpose of this study is to assess the toxicological consequences of a single inhalation exposure of female rats to polyamide MNP during estrus by means of aerosolization of MNP.

METHODS

Bulk polyamide powder (i.e., nylon) served as a representative MNP. Polyamide aerosolization was characterized using particle sizers, cascade impactors, and aerosol samplers. Multiple-Path Particle Dosimetry (MPPD) modeling was used to evaluate pulmonary deposition of MNPs. Pulmonary inflammation was assessed by bronchoalveolar lavage (BAL) cell content and H&E-stained tissue sections. Mean arterial pressure (MAP), wire myography of the aorta and uterine artery, and pressure myography of the radial artery was used to assess cardiovascular function. Systemic inflammation and endocrine disruption were quantified by measurement of proinflammatory cytokines and reproductive hormones.

RESULTS

Our aerosolization exposure platform was found to generate particles within the micro- and nano-size ranges (thereby constituting MNPs). Inhaled particles were predicted to deposit in all regions of the lung; no overt pulmonary inflammation was observed. Conversely, increased blood pressure and impaired dilation in the uterine vasculature was noted while aortic vascular reactivity was unaffected. Inhalation of MNPs resulted in systemic inflammation as measured by increased plasma levels of IL-6. Decreased levels of 17β-estradiol were also observed suggesting that MNPs have endocrine disrupting activity.

CONCLUSIONS

These data demonstrate aerosolization of MNPs in our inhalation exposure platform. Inhaled MNP aerosols were found to alter inflammatory, cardiovascular, and endocrine activity. These novel findings will contribute to a better understanding of inhaled plastic particle toxicity.

Effects of non-phthalate plasticizer bis(2-ethylhexyl) sebacate (DEHS) on the endocrine system in Japanese medaka (Oryzias latipes)

Water pollution due to plasticizers is one of the most severe environmental problems worldwide. Phthalate plasticizers can act as endocrine disruptors in vertebrates. In this study, we investigated whether the non-phthalate bis(2-ethylhexyl) sebacate (DEHS) plasticizer can act as an endocrine disruptor by evaluating changes in the expression levels of thyroid hormone-related, reproduction-related, and estrogen-responsive genes of Japanese medaka (Oryzias latipes) exposed to the plasticizer. Following the exposure, the gene expression levels of thyroid-stimulating hormone subunit beta (tshβ), deiodinase 1 (dio1), and thyroid hormone receptor alpha (trα) did not change. Meanwhile, DEHS suppressed dio2 expression, did not induce swim bladder inflation, and eventually reduced the swimming performance of Japanese medaka. These findings indicate that DEHS can potentially disrupt the thyroid hormone-related gene expression and metabolism of these fish. However, exposure to DEHS did not induce changes in the gene expression levels of kisspeptin 1 (kiss1), gonadotropin-releasing hormone (gnrh), follicle-stimulating hormone beta (fshβ), luteinizing hormone beta (lhβ), choriogenin H (chgH), and vitellogenin (vtg) in a dose-dependent manner. This is the first report providing evidence that DEHS can disrupt thyroid hormone-related metabolism in fish.

Maternal Serum and Placental Metabolomes in Association with Prenatal Phthalate Exposure and Neurodevelopmental Outcomes in the MARBLES Cohort

Prenatal exposure to phthalates, a family of endocrine-disrupting plasticizers, is associated with disruption of maternal metabolism and impaired neurodevelopment. We investigated associations between prenatal phthalate exposure and alterations of both the maternal third trimester serum metabolome and the placental metabolome at birth, and associations of these with child neurodevelopmental outcomes using data and samples from the Markers of Autism Risk in Babies Learning Early Signs (MARBLES) cohort. The third trimester serum (n = 106) and placental (n = 132) metabolomes were investigated using 1H nuclear magnetic resonance spectroscopy. Children were assessed clinically for autism spectrum disorder (ASD) and cognitive development. Although none of the urinary phthalate metabolite concentrations were associated with maternal serum metabolites after adjustment for covariates, mixture analysis using quantile g-computation revealed alterations in placental metabolites with increasing concentrations of phthalate metabolites that included reduced concentrations of 2-hydoxybutyrate, carnitine, O-acetylcarnitine, glucitol, and N-acetylneuraminate. Child neurodevelopmental outcome was not associated with the third trimester serum metabolome, but it was correlated with the placental metabolome in male children only. Maternal phthalate exposure during pregnancy is associated with differences in the placental metabolome at delivery, and the placental metabolome is associated with neurodevelopmental outcomes in males in a cohort with high familial ASD risk.