Implications of prenatal steroid perturbations for neurodevelopment, behavior, and autism

Regrettable Substitutes and the Brain: What Animal Models and Human Studies Tell Us about the Neurodevelopmental Effects of Bisphenol, Per- and Polyfluoroalkyl Substances, and Phthalate Replacements

In recent decades, emerging evidence has identified endocrine and neurologic health concerns related to exposure to endocrine-disrupting chemicals (EDCs), including bisphenol A (BPA), certain per- and polyfluoroalkyl compounds (PFASs), and phthalates. This has resulted in consumer pressure to remove these chemicals from the market, especially in food-contact materials and personal care products, driving their replacement with structurally or functionally similar substitutes. However, these "new-generation" chemicals may be just as or more harmful than their predecessors and some have not received adequate testing. This review discusses the research on early-life exposures to new-generation bisphenols, PFASs, and phthalates and their links to neurodevelopmental and behavioral alterations in zebrafish, rodents, and humans. As a whole, the evidence suggests that BPA alternatives, especially BPAF, and newer PFASs, such as GenX, can have significant effects on neurodevelopment. The need for further research, especially regarding phthalate replacements and bio-based alternatives, is briefly discussed.

Correlations of the CNR1 Gene with Personality Traits in Women with Alcohol Use Disorder

Alcohol use disorder (AUD) is a significant issue affecting women, with severe consequences for society, the economy, and most importantly, health. Both personality and alcohol use disorders are phenotypically very complex, and elucidating their shared heritability is a challenge for medical genetics. Therefore, our study investigated the correlations between the microsatellite polymorphism (AAT)n of the Cannabinoid Receptor 1 (CNR1) gene and personality traits in women with AUD. The study group included 187 female subjects. Of these, 93 were diagnosed with alcohol use disorder, and 94 were controls. Repeat length polymorphism of microsatellite regions (AAT)n in the CNR1 gene was identified with PCR. All participants were assessed with the Mini-International Neuropsychiatric Interview and completed the NEO Five-Factor and State-Trait Anxiety Inventories. In the group of AUD subjects, significantly fewer (AAT)n repeats were present when compared with controls (p = 0.0380). While comparing the alcohol use disorder subjects (AUD) and the controls, we observed significantly higher scores on the STAI trait (p < 0.00001) and state scales (p = 0.0001) and on the NEO Five-Factor Inventory Neuroticism (p < 0.00001) and Openness (p = 0.0237; insignificant after Bonferroni correction) scales. Significantly lower results were obtained on the NEO-FFI Extraversion (p = 0.00003), Agreeability (p < 0.00001) and Conscientiousness (p < 0.00001) scales by the AUD subjects when compared to controls. There was no statistically significant Pearson's linear correlation between the number of (AAT)n repeats in the CNR1 gene and the STAI and NEO Five-Factor Inventory scores in the group of AUD subjects. In contrast, Pearson's linear correlation analysis in controls showed a positive correlation between the number of the (AAT)n repeats and the STAI state scale (r = 0.184; p = 0.011; insignificant after Bonferroni correction) and a negative correlation with the NEO-FFI Openness scale (r = -0.241; p = 0.001). Interestingly, our study provided data on two separate complex issues, i.e., (1) the association of (AAT)n CNR1 repeats with the AUD in females; (2) the correlation of (AAT)n CNR1 repeats with anxiety as a state and Openness in non-alcohol dependent subjects. In conclusion, our study provided a plethora of valuable data for improving our understanding of alcohol use disorder and anxiety.

Maternal use of hormonal contraception and risk of childhood autism spectrum disorders: A Parental Exposures and Child Health (PECH) cohort study

A recent hypothesis suggests that maternal hormonal contraception use has contributed to the increasing incidence of autism spectrum disorders (ASD). We used a nationwide population-based cohort (the PECH cohort) including 1,056,149 Danish children born in the period January 1, 1998, to December 31, 2014, to assess associations between maternal hormonal contraception use and childhood ASD (end of follow-up: December 31, 2017). Maternal hormonal contraception use was grouped as "recent use" (≤ 3 months before pregnancy start or during pregnancy), "previous use" (>3 months before pregnancy start) and "never use", except for few products. Incidence rate ratios (IRRs) were estimated using Poisson regression. During follow-up of nearly 12 million person-years, 19,996 children were diagnosed with ASD. A slightly higher IRR was observed for maternal recent use of any hormonal contraception, compared to previous use. This association was largely driven by the non-oral progestin-only products, and associations were especially seen for infantile autism and other/unspecified ASD. An increased IRR of infantile autism was also observed for recent use of the oral progestin-only products, compared to previous use. Our results suggest that maternal use of hormonal contraception may be associated with ASD risk in children, especially for the progestin-only products.

Association between prenatal exposure to per- and polyfluoroalkyl substances and neurodevelopment in children: Evidence based on birth cohort

BACKGROUND

Although numerous studies have examined the effect of prenatal per- and polyfluoroalkyl substances (PFAS) exposure on neurodevelopment in children, findings have been inconsistent.

OBJECTIVE

To better understand the effects of PFAS exposure during pregnancy on offspring neurodevelopment, we conducted a systematic review of prenatal exposure to different types of PFAS and neurodevelopment in children.

METHODS

A comprehensive search was conducted in the PubMed, Web of Science, and EMBASE electronic databases up to March 2023. Only birth cohort studies that report a specific association between PFAS exposure during pregnancy and neurodevelopment were included in this review.

RESULTS

31 birth cohort studies that met the inclusion criteria were qualitatively integrated. Among these, 14 studies investigated the impact of PFAS exposure during pregnancy on cognition, 13 on neurobehavior, and 4 on both cognition and neurobehavior. Additionally, 4 studies explored the influence of PFAS on children's comprehensive development.

CONCLUSION

Prenatal PFAS exposure was associated with poor neurodevelopment in children, including psychomotor development, externalizing behavior, and comprehensive development. However, conclusive evidence regarding its effects on other neurological outcomes remains limited. In addition, sex-specific effects on social behavior and sleep problems were identified.

Regulation of sexually dimorphic placental adaptation in LPS exposure-induced intrauterine growth restriction

BACKGROUND

Sexual dimorphism in placental physiology affects the functionality of placental adaptation during adverse pregnancy. Defects of placental function compromise fetal programming, affecting the offspring's adult life. However, studies focusing on the relationship between sex-specific placental adaptation and consequent fetal maldevelopment under sub-optimal uterus milieu are still elusive.

METHODS

Here, we investigated the effects of maternal lipopolysaccharide (LPS) exposure between placental sex. Pregnant ICR mice received intraperitoneal injection of phosphate-buffered saline or 100, 200, and 400 µg/kg LPS on the gestational day (GD) 15.5. To determine whether prenatal maternal LPS exposure resulted in complicated pregnancy outcomes, survival rate of embryos was calculated and the growth of embryos and placentas was examined. To elucidate global transcriptomic changes occurring in the placenta, total RNA-sequencing (RNA-seq) was performed in female and male placentas.

RESULTS

LPS administration induced placental inflammation in both sexes at GD 17.5. Prenatal infection resulted in growth retardation in both sexes of embryos, and especially more prevalently in male. Impaired placental development was observed in a sex-specific manner. LPS 400 µg/kg reduced the percentage area of the labyrinth in females and junctional zone in males, respectively. RNA-sequencing revealed widespread sexually dimorphic transcriptional changes in placenta. In particular, representative changes were involved in biological processes such as trophoblast differentiation, nutrient/ion transporter, pregnancy, and immune system.

CONCLUSIONS

Our results present the sexually dimorphic responses of placental physiology in intrauterine growth restriction model and provide tentative relationship further to be elucidated between sex-biased placental functional change and long-term effects on the offspring's later life.

Organophosphate Flame Retardants in Pregnant Women: Sources, Occurrence, and Potential Risks to Pregnancy Outcomes

Organophosphate flame retardants (OPFRs) are found in various environmental matrixes and human samples. Exposure to OPFRs during gestation may interfere with pregnancy, for example, inducing maternal oxidative stress and maternal hypertension during pregnancy, interfering maternal and fetal thyroid hormone secretion and fetal neurodevelopment, and causing fetal metabolic abnormalities. However, the consequences of OPFR exposure on pregnant women, impact on mother-to-child transmission of OPFRs, and harmful effects on fetal and pregnancy outcomes have not been evaluated. This review describes the exposure to OPFRs in pregnant women worldwide, based on metabolites of OPFRs (mOPs) in urine for prenatal exposure and OPFRs in breast milk for postnatal exposure. Predictors of maternal exposure to OPFRs and variability of mOPs in urine have been discussed. Mother-to-child transmission pathways of OPFRs have been scrutinized, considering the levels of OPFRs and their metabolites in amniotic fluid, placenta, deciduae, chorionic villi, and cord blood. The results showed that bis(1,3-dichloro-2-propyl) phosphate (BDCIPP) and diphenyl phosphate (DPHP) were the two predominant mOPs in urine, with detection frequencies of >90%. The estimated daily intake (EDI_M) indicates low risk when infants are exposed to OPFRs from breast milk. Furthermore, higher exposure levels of OPFRs in pregnant women may increase the risk of adverse pregnancy outcomes and influence the developmental behavior of infants. This review summarizes the knowledge gaps of OPFRs in pregnant women and highlights the crucial steps for assessing health risks in susceptible populations, such as pregnant women and fetuses.

Impact of Adverse Gestational Milieu on Maternal Cardiovascular Health

Cardiovascular disease affects 1% to 4% of the nearly 4 million pregnancies in the United States each year and is the primary cause of pregnancy-related mortality. Adverse pregnancy outcomes are associated with cardiovascular complications during pregnancy persisting into the postpartum period. Recently, investigations have identified an altered sex hormone milieu, such as in the case of hyperandrogenism, as a causative factor in the development of gestational cardiovascular dysfunction. The mechanisms involved in the development of cardiovascular disease in postpartum women are largely unknown. Animal studies have attempted to recapitulate adverse pregnancy outcomes to investigate causal relationships and molecular underpinnings of adverse gestational cardiac events and progression to the development of cardiovascular disease postpartum. This review will focus on summarizing clinical and animal studies detailing the impact of adverse pregnancy outcomes, including preeclampsia, gestational diabetes mellitus, and maternal obesity, on gestational cardiometabolic dysfunction and postpartum cardiovascular disease. Specifically, we will highlight the adverse impact of gestational hyperandrogenism and its potential to serve as a biomarker for maternal gestational and postpartum cardiovascular dysfunctions.

Contaminants of Emerging Concern (CECs) and Male Reproductive Health: Challenging the Future with a Double-Edged Sword

Approximately 9% of couples are infertile, with half of these cases relating to male factors. While many cases of male infertility are associated with genetic and lifestyle factors, approximately 30% of cases are still idiopathic. Contaminants of emerging concern (CECs) denote substances identified in the environment for the first time or detected at low concentrations during water quality analysis. Since CEC production and use have increased in recent decades, CECs are now ubiquitous in surface and groundwater. CECs are increasingly observed in human tissues, and parallel reports indicate that semen quality is continuously declining, supporting the notion that CECs may play a role in infertility. This narrative review focuses on several CECs (including pesticides and pharmaceuticals) detected in the nearshore marine environment of False Bay, Cape Town, South Africa, and deliberates their potential effects on male fertility and the offspring of exposed parents, as well as the use of spermatozoa in toxicological studies. Collective findings report that chronic in vivo exposure to pesticides, including atrazine, simazine, and chlorpyrifos, is likely to be detrimental to the reproduction of many organisms, as well as to sperm performance in vitro. Similarly, exposure to pharmaceuticals such as diclofenac and naproxen impairs sperm motility both in vivo and in vitro. These contaminants are also likely to play a key role in health and disease in offspring sired by parents exposed to CECs. On the other side of the double-edged sword, we propose that due to its sensitivity to environmental conditions, spermatozoa could be used as a bioindicator in eco- and repro-toxicology studies.

Prenatal Sex Hormone Exposure Is Associated with the Development of Autism Spectrum Disorder

Sexual differentiation is a major developmental process. Sex differences resulting from sexual differentiation have attracted the attention of researchers. Unraveling what contributes to and underlies sex differences will provide valuable insights into the development of neurodevelopmental disorders that exhibit sex biases. Autism spectrum disorder (ASD) is a neurodevelopmental disorder that affects an individual's social interaction and communication abilities, and its male preponderance has been consistently reported in clinical studies. The etiology of male preponderance remains unclear, but progress has been made in studying prenatal sex hormone exposure. The present review examined studies that focused on the association between prenatal testosterone exposure and ASD development, as well as sex-specific behaviors in individuals with ASD. This review also included studies on maternal immune activation-induced developmental abnormalities that also showed striking sex differences in offspring and discussed its possible interacting roles in ASD so as to present a potential approach for future studies on sex biases in ASD.

Brief postnatal exposure to bisphenol A affects apoptosis and gene expression in the medial prefrontal cortex and social behavior in rats with sex specificity

Bisphenol A (BPA) is an endocrine disruptor found in polycarbonate plastics and exposure in humans is nearly ubiquitous and it has widespread effects on cognitive, emotional, and reproductive behaviors in both humans and animal models. In our laboratory we previously found that perinatal BPA exposure results in a higher number of neurons in the adult male rat prefrontal cortex (PFC) and less play in adolescents of both sexes. Here we examine changes in the rate of postnatal apoptosis in the rat prefrontal cortex and its timing with brief BPA exposure. Because an increased number of neurons in the PFC is a characteristic of a subtype of autism spectrum disorder, we tested social preference following brief BPA exposure and also expression of a small group of genes. Males and females were exposed to BPA from postnatal days (P) 6 through 8 or from P10 through 12. Both exposures significantly decreased indicators of cell death in the developing medial prefrontal cortex in male subjects only. Additionally, males exposed to BPA from P6 - 8 showed decreased social preference and decreased cortical expression of Shank3 and Homer1, two synaptic scaffolding genes that have been implicated in social deficits. There were no significant effects of BPA in the female subjects. These results draw attention to the negative consequences following brief exposure to BPA during early development.

Effects of prenatal testosterone exposure on the development of autism-like behaviours in offspring of Wistar rats

BACKGROUND

A neurodevelopmental disease, autism spectrum disorder (ASD) occurs in males three times more commonly than girls. Higher prenatal testosterone exposure may result in autistic-like behaviour in boys, according to earlier research. It is unclear how fetal testosterone affects the development of autism. In this study, we tested the hypothesis that prenatal testosterone exposure in an animal model may result in autistic behaviours by modifying serotonin, dopamine, IGF-1 and oxytocin levels.

MATERIALS AND METHODS

Group 1 (control, n = 6) and Group 2 (testosterone undecanoate, n = 6) of female rats were randomly assigned. For 2-3 days during the oestrus cycle, female rats were housed with a reproductive male (three females/one male). On the 10th day of gestation, rats in Group 1 received 1 ml/kg% 0.9 NaCl saline, whereas rats in Group 2 received 250 mg/kg testosterone undecanoate. Until weaning on postnatal day 21 (P21), the mothers were permitted to care for their pups. On P21, 40 littermates-10 male and female for control and 10 male and female from mothers that exposed to testosterone-were arbitrarily split up and housed. On P50, these mature rats were tested for their behaviour. The rats were then sacrificed. The brain tissue was subjected to histological examinations as well as biochemical tests for homovanillic acid (HVA), 5-Hydroxyindoleacetic acid (5-HIAA), oxytocin and insulin-like growth factor-1 (IGF-1).

RESULTS

The groups differed significantly in the behavioural examinations (three-chamber social test, passive avoidance learning analysis, open field test), with the testosterone-exposed groups exhibiting autistic symptoms to a higher extent. When compared with the control groups, testosterone exposure caused significant histological changes in the hippocampus CA1 and CA3 areas, including gliosis and cell death of neurons. In the testosterone-exposed groups, HVA, 5-HIAA and IGF-1 tissue expressions in the brain elevated, whereas oxytocin levels reduced. These findings point to a potential connection between neurodevelopmental disorders like ASD and exposure to testosterone during gestation.

CONCLUSION

Overall, we revealed that prenatal testosterone exposure led to autistic traits by elevating serotonin, dopamine and IGF-1 levels while lowering oxytocin levels.

Fetal neurosonography and infant neurobehavior following conception by assisted reproductive technology with fresh or frozen embryo transfer

OBJECTIVE

We aimed to explore fetal cortical brain development by neurosonography in fetuses conceived by assisted reproductive technology (ART), including frozen and fresh embryo transfer (ET), compared with those conceived spontaneously (SC), and to investigate its association with infant neurobehavior at 12 months of age.

METHODS

This was a prospective cohort study of 210 singleton pregnancies, including 70 SC pregnancies, 70 conceived by in-vitro fertilization (IVF) following frozen ET and 70 conceived by IVF after fresh ET. Fetal neurosonography was performed at 32 ± 2 gestational weeks to assess cortical development. Sulci depths were measured offline and normalized by biparietal diameter (BPD). Ages and Stages Questionnaires (ASQ) were completed postnatally, at 12 ± 1 months of corrected age. Neurosonographic findings were adjusted by regression analysis for maternal age, ethnicity, parity, fetal sex and fetal-weight centile and gestational age at scan, and ASQ scores were adjusted for maternal age, ethnicity, parity, educational level and employment status, gestational age at birth, breastfeeding, infant sex and infant age at the ASQ evaluation.

RESULTS

Overall, in comparison to the SC fetuses, fetuses conceived by ART showed statistically significant differences in cortical development, with reduced parieto-occipital sulci depth adjusted for BPD (mean ± SD: fresh ET, 12.5 ± 2.5 vs frozen ET, 13.4 ± 2.6 vs SC, 13.4 ± 2.6, P < 0.001), cingulate sulci depth adjusted for BPD (median (interquartile range (IQR)): fresh ET, 5.8 (4.2-7.4) vs frozen ET, 5.8 (4.1-7.5) vs SC, 6.5 (4.8-7.8), P = 0.001) and calcarine sulci depth adjusted for BPD (median (IQR): fresh ET, 13.5 (10.1-16.1) vs frozen ET, 14.5 (12.1-15.8) vs SC, 16.4 (14.3-17.9), P < 0.001), together with lower Sylvian fissure grading score. Changes in cortical development were more pronounced in the fresh ET than in the frozen ET group. ART infants showed lower ASQ scores as compared to SC infants, particularly in the fresh ET group (mean ± SD global ASQ Z-score: fresh ET, -0.3 ± 0.4 vs frozen ET, -0.2 ± 0.4 vs SC, 0 ± 0.4, P < 0.001).

CONCLUSIONS

Fetuses conceived by ART show a distinctive pattern of cortical development and suboptimal infant neurodevelopment, with more pronounced changes in those conceived following fresh ET. These findings support the existence of in-utero brain reorganization associated with ART and warrant follow-up studies to assess its long-term persistence. © 2022 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

The associations between prenatal phthalate exposure measured in child meconium and cognitive functioning of 12-month-old children in two cohorts at elevated risk for adverse neurodevelopment

BACKGROUND

Phthalate metabolites in gestational-maternal urine represents short-term maternal exposure, but meconium, the newborn's first stool may better capture cumulative fetal exposure. We quantified phthalate metabolites in meconium from two cohorts of children at higher risk of adverse neurodevelopment and evaluated associations with their cognitive function at 12 months.

METHODS

Meconium phthalate metabolites were quantified in the Safe Passage Study (SPS), N = 720, a pregnancy cohort with high community-levels of prenatal alcohol use, and the Early Autism Risk Longitudinal Investigation (EARLI), N = 236, a high familial autism risk pregnancy cohort. EARLI also had second and third trimester (T2/T3) maternal urine for exposure assessment. Molar sum of di (2-ethylhexyl) (∑DEHP) metabolites and an anti-androgenic score (AAS) using mono-isobutyl, mono-n-butyl, monobenzyl (MBZP), and DEHP metabolites were computed. Cognitive function was assessed at 12 months using the Mullen Scales of Early Learning-Composite (ELC). Multivariable linear regression assessed associations between loge-transformed metabolites and ELC. Quadratic terms explored nonlinearity and interaction terms of metabolite by child's sex examined effect modification.

RESULTS

In SPS, MBzP (βLinear = -6.73; 95% CI: 12.04, -1.42; βquadratic = 1.95; 0.27, 3.62) and mono (2-ethyl-5-carboxypentyl), (βLinear = -3.81; -7.53, -0.27; βquadratic = 0.93; 0.09, 1.77) had U-shaped associations with ELC. In EARLI, T2 urine mono-carboxyisononyl was associated with linear decrease in ELC, indicating lower cognitive function. Interaction with sex was suggested (P < 0.2) for several urine metabolites, mostly indicating negative association between phthalates and ELC among girls but reversed among boys. Only mono-isononyl phthalate and ∑DEHP had consistent main effect associations across matrixes and cohorts, but similar interaction with sex was observed for meconium-measured ∑DEHP, AAS, MBzP, and mono (2-ethylhexyl) in both cohorts.

CONCLUSIONS

Few phthalate metabolites were consistently associated with children's cognitive function, but a similar set of meconium metabolites from both cohorts displayed sex-specific associations. Gestational phthalate exposure may have sexually-dimorphic associations with early cognitive function in children at higher risk for adverse neurodevelopment.

Maternal androgens and autism spectrum disorder in the MARBLES prospective cohort study

Background

Maternal hormonal risk factors for autism spectrum disorder (ASD) in offspring could intersect genetic and environmental risk factors.

Objectives

This analysis explored ASD risk in association with maternal testosterone, androstenedione, and dehydroepiandrosterone (DHEA) measured in first, second, and third trimesters of pregnancy.

Methods

MARBLES is a prospective pregnancy cohort study based at the MIND Institute in Northern California that enrolls mothers who have at least one child previously diagnosed with ASD and are expecting, or planning to have another child. At 36 months the younger sibling is clinically classified as having ASD, or as non-typically developing (Non-TD), or typically developing (TD). Maternal androgens during pregnancy were measured in serum samples from 196 mothers. Multivariable logistic regression models estimated risk of ASD and Non-TD in offspring compared to TD, in relation to the log-transformed maternal androgen concentrations, at each trimester.

Results

Non-significant associations were observed, and borderline significant associations were only observed in some stratified unadjusted models. Second trimester maternal testosterone was non-significantly associated with ASD in female offspring, although not after adjustment, aRR 1.54 (95% CI 0.71, 3.33), and second trimester maternal DHEA was non-significantly associated with non-TD in male offspring, again not after adjustment, aRR 0.50 (95% CI 0.21, 1.21). Secondary analysis suggested that third trimester androgen concentrations in mothers with male offspring had significant or near significant associations with their child's Social Responsiveness Scale score.

Conclusion

No significant associations were found between maternal androgen concentrations and risk of ASD or Non-TD in the child.

Maternal Obesity and Gut Microbiota Are Associated with Fetal Brain Development

Obesity in pregnancy induces metabolic syndrome, low-grade inflammation, altered endocrine factors, placental function, and the maternal gut microbiome. All these factors impact fetal growth and development, including brain development. The lipid metabolic transporters of the maternal-fetal-placental unit are dysregulated in obesity. Consequently, the transport of essential long-chain PUFAs for fetal brain development is disturbed. The mother’s gut microbiota is vital in maintaining postnatal energy homeostasis and maternal-fetal immune competence. Obesity during pregnancy changes the gut microbiota, affecting fetal brain development. Obesity in pregnancy can induce placental and intrauterine inflammation and thus influence the neurodevelopmental outcomes of the offspring. Several epidemiological studies observed an association between maternal obesity and adverse neurodevelopment. This review discusses the effects of maternal obesity and gut microbiota on fetal neurodevelopment outcomes. In addition, the possible mechanisms of the impacts of obesity and gut microbiota on fetal brain development are discussed.

Differential proteomics analysis of JEG-3 and JAR placental cell models and the effect of androgen treatment

The placenta is a vital fetal organ that plays an important role in maintaining fetal sex hormone homeostasis. Xenobiotics can alter placental sex-steroidogenic enzymes and transporters, including enzymes such as aromatase (CYP19A1) and the hydroxysteroid dehydrogenases (HSDs) but studying how compounds disrupt in vivo placental metabolism is complex. Utilizing high-throughput in vitro models is critical to predict the disruption of placental sex-steroidogenic enzymes and transporters, particularly by drug candidates in the early stages of drug discovery. JAR and JEG-3 cells are the most common, simple, and cost-effective placental cell models that are capable of high-throughput screening, but how well they express the sex-steroidogenic enzymes and transporters is not well known. Here, we compared the proteomes of JAR and JEG-3 cells in the presence and absence of physiologically relevant concentrations of dehydroepiandrosterone (DHEA, 8 µM) and testosterone (15 nM) to aid the characterization of sex-steroidogenic enzymes and transporters in these cell models. Global proteomics analysis detected 2931 and 3449 proteins in JAR cells and JEG-3 cells, respectively. However, dramatic differences in sex-steroidogenic enzymes and transporters were observed between these cells. In particular, the basal expression of steroid sulfatase (STS), HSD17B1, and HSD17B7 were unique to JEG-3 cells. JEG-3 cells also showed significantly higher protein levels of aldo-keto reductase (AKR) 1A1 and AKR1B1, while JAR cells showed significantly higher levels of HSD17B4 and HSDB12. Aldehyde dehydrogenase (ALDH) 3A2 and HSD17B11 enzymes as well as the transporters sterol O-acyltransferase (SOAT) 1 and ATP binding cassette subfamily G2 (ABCG2) were comparable between the cell lines, whereas sulfotransferases (SULTs) were uniquely present within JAR cells. Androgen treatments significantly lowered HSD17B11, HSD17B4, HSD17B12, and ALDH3A2 levels in JAR cells. DHEA treatment significantly raised the level of HSD17B1 by 51 % in JEG-3 cells, whereas CYP19A1 was increased to significant levels in both JAR and JEG-3 cells after androgen treatments. The proteomics data were supported by a complementary targeted metabolomics analysis of culture media in the DHEA (8 µM) and testosterone (15 nM) treated groups. This study has indicated that untreated JEG-3 cells express more sex-steroidogenic enzymes and transporters. Nevertheless, JEG-3 and JAR cells are unique and their respective proteomics data can be used to select the best model depending on the hypothesis.

Elevated exposures to persistent endocrine disrupting compounds impact the sperm methylome in regions associated with autism spectrum disorder

Environmental exposures to endocrine disrupting compounds (EDCs) such as the organochlorines have been linked with various diseases including neurodevelopmental disorders. Autism spectrum disorder (ASD) is a highly complex neurodevelopmental disorder that is considered strongly genetic in origin due to its high heritability. However, the rapidly rising prevalence of ASD suggests that environmental factors may also influence risk for ASD. In the present study, whole genome bisulfite sequencing was used to identify genome-wide differentially methylated regions (DMRs) in a total of 52 sperm samples from a cohort of men from the Faroe Islands (Denmark) who were equally divided into high and low exposure groups based on their serum levels of the long-lived organochlorine 1,1-dichloro-2,2-bis(p-chlorophenyl)ethylene (DDE), a primary breakdown product of the now banned insecticide dichlorodiphenyltrichloroethane (DDT). Aside from being considered a genetic isolate, inhabitants of the Faroe Islands have a native diet that potentially exposes them to a wide range of seafood neurotoxicants in the form of persistent organic pollutants (POPs). The DMRs were mapped to the human genome using Bismark, a 3-letter aligner used for methyl-seq analyses. Gene ontology, functional, and pathway analyses of the DMR-associated genes showed significant enrichment for genes involved in neurological functions and neurodevelopmental processes frequently impacted by ASD. Notably, these genes also significantly overlap with autism risk genes as well as those previously identified in sperm from fathers of children with ASD in comparison to that of fathers of neurotypical children. These results collectively suggest a possible mechanism involving altered methylation of a significant number of neurologically relevant ASD risk genes for introducing epigenetic changes associated with environmental exposures into the sperm methylome. Such changes may provide the potential for transgenerational inheritance of ASD as well as other disorders.

The associations of prenatal exposure to dioxins and polychlorinated biphenyls with neurodevelopment at 6 Months of age: Multi-pollutant approaches

BACKGROUND

Prenatal exposure to persistent organic pollutants, including polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), dioxin-like polychlorinated biphenyls (DL-PCBs), and nondioxin-like PCBs (NDL-PCBs), has been hypothesized to have a detrimental impact on neurodevelopment. However, the association of prenatal exposure to a dioxin and PCB mixture with neurodevelopment remains largely inconclusive partly because these chemical levels are correlated.

OBJECTIVES

We aimed to elucidate the association of in utero exposure to a mixture of dioxins and PCBs with neurodevelopment measured at 6 months of age by applying multipollutant methods.

METHODS

A total of 514 pregnant women were recruited between July 2002 and October 2005 in the Sapporo cohort, Hokkaido Study on Environment and Children's Health. The concentrations of individual dioxin and PCB isomers were assessed in maternal peripheral blood during pregnancy. The mental and psychomotor development of the study participants' infants was evaluated using the Bayley Scales of Infant Development-2nd Edition (n = 259). To determine both the joint and individual associations of prenatal exposure to a dioxin and PCB mixture with infant neurodevelopment, Bayesian kernel machine regression (BKMR) and quantile-based g-computation were employed.

RESULTS

Suggestive inverse associations were observed between in utero exposure to a dioxin and PCB mixture and infant psychomotor development in both the BKMR and quantile g-computation models. In contrast, we found no association of a dioxin and PCB mixture with mental development. When group-specific posterior inclusion probabilities were estimated, BKMR suggested prenatal exposure to mono-ortho PCBs as the more important contributing factors to early psychomotor development compared with the other dioxin or PCB groups. No evidence of nonlinear exposure-outcome relationships or interactions among the chemical mixtures was detected.

CONCLUSIONS

Applying the two complementary statistical methods for chemical mixture analysis, we demonstrated limited evidence of inverse associations of prenatal exposure to dioxins and PCBs with infant psychomotor development.

Elevated prenatal maternal sex hormones, but not placental aromatase, are associated with child neurodevelopment

Fetal exposure to testosterone may contribute to vulnerability for autism spectrum disorder (ASD). It is hypothesized that placental aromatase prevents fetal exposure to maternal testosterone, however, this pathway and the implications for child neurodevelopment have not been fully explored. We examined the relationships between prenatal maternal testosterone and estradiol at 19.2 ± 1.3 weeks, cord blood testosterone and estradiol at birth, placental aromatase mRNA expression, and neurodevelopment using the Social Communication Questionnaire (SCQ), the Behavioral Assessment System for Children, 3rd Edition (BASC-3), and the Empathizing Quotient for Children (EQ-C) at 4.5-6.5 years of age in a sample of 270 Nulliparous-Mothers-to-be (nuMoM2b) study participants. Maternal testosterone levels were positively associated with SCQ scores, but the association was not significant after adjusting for maternal age at delivery, nor was there a significant interaction with sex. Maternal estradiol levels were negatively associated with BASC-3 Clinical Probability scores among males (n = 139). We report a significant interaction effect of cord blood testosterone and fetal sex on both total SCQ scores and t-scores on the Developmental Social Disorders subscale. Placental aromatase was not associated with any neurodevelopmental or hormone measure, but under conditions of low placental aromatase expression, high maternal testosterone was positively associated with SCQ scores in males (n = 46). No other associations between hormone levels and neurodevelopment were significant. Our findings provide a foundation for further investigation of the mechanisms through which maternal sex hormones and placental steroidogenesis may affect fetal hormone production and neurobehavior.

Sex/gender differences in children with autism spectrum disorder: A brief overview on epidemiology, symptom profile, and neuroanatomy

Autism spectrum disorders (ASD) are a heterogeneous group of neurodevelopmental conditions whose shared core features are impairments in social interaction and communication as well as restricted patterns of behavior, interests, and activities. The significant and consistent male preponderance in ASD prevalence has historically affected the scientific knowledge of autism in females as regards, inter alia, the clinical presentation, the genetic architecture, and the structural brain underpinnings. Indeed, females with ASD are under-investigated as samples recruited for clinical research typically reflect the strong male bias of the disorder. In the last years, the study of the various aspects of sex/gender (s/g) differences in ASD is gaining increased clinical and research interest resulting in a growing number of investigations on this topic. Here, I review and discuss evidence emerged from epidemiological, clinical, and neuroimaging studies in the last decade focusing on s/g differences in children with ASD. These studies are the prerequisites for the development of assessment and treatment practices which take into consideration s/g differences in ASD. Ultimately, a better understanding of s/g differences aims at improving healthcare for both ASD males and females.

In utero exposure to 17α-hydroxyprogesterone caproate and risk of cancer in offspring

BACKGROUND

17α-hydroxyprogesterone caproate is a synthetic progestogen initially approved in the 1950s to treat gynecologic and obstetrical conditions. Despite continued concerns about safety and short-term efficacy regarding the use of 17α-hydroxyprogesterone caproate for the prevention of preterm birth in pregnant women, little is known about the long-term effects of 17α-hydroxyprogesterone caproate on the health of the offsprings.

OBJECTIVE

To examine the association between in utero exposure to 17α-hydroxyprogesterone caproate and the risk of cancer in the offspring.

STUDY DESIGN

The Child Health and Development Studies was a population-based cohort of >18,000 mother-child dyads receiving prenatal care in the Kaiser Foundation Health Plan (Oakland, CA) between 1959 and 1966. Clinical information was abstracted from the mothers' medical records beginning 6 months before pregnancy through delivery. We identified the number and timing of 17α-hydroxyprogesterone caproate injections during pregnancy. Incident cancers diagnosed in the offspring were ascertained through 2019 by linkage to the California Cancer Registry. We used the Cox proportional hazard models to estimate the adjusted hazard ratios and their 95% confidence intervals, with the follow-up time accrued from the date of birth through the date of cancer diagnosis, death, or last contact.

RESULTS

A total of 1008 offspring were diagnosed with cancer over 730,817 person-years of follow-up. Approximately 1.0% of the offspring (n=234) were exposed in utero to 17α-hydroxyprogesterone caproate. Exposure in the first trimester was associated with an increased risk of any cancer (adjusted hazard ratio, 2.57; 95% confidence interval, 1.59-4.15), and the risk increased with the number of injections (1-2 injections: adjusted hazard ratio, 1.80; 95% confidence interval, 1.12-2.90; ≥3 injections: adjusted hazard ratio, 3.07; 95% confidence interval, 1.34-7.05). Exposure in the second or third trimester conferred an additional risk for the male (adjusted hazard ratio, 2.59; 95% confidence interval, 1.07-6.28) but not for the female (adjusted hazard ratio, 0.30; 95% confidence interval, 0.04-1.11) offspring. The risk of colorectal (adjusted hazard ratio, 5.51; 95% confidence interval, 1.73-17.59), prostate (adjusted hazard ratio, 5.10; 95% confidence interval, 1.24-21.00), and pediatric brain (adjusted hazard ratio, 34.72; 95% confidence interval, 7.29-164.33) cancer was higher in the offspring first exposed to 17α-hydroxyprogesterone caproate in the first trimester than the offspring not exposed.

CONCLUSION

Caution using 17α-hydroxyprogesterone caproate in early pregnancy is warranted, given the possible link with cancer in the offspring.

Hypertensive disorders during pregnancy and polycystic ovary syndrome are associated with child communication and social skills in a sex-specific and androgen-dependent manner

Prenatal exposure to testosterone is implicated in the etiology of autism spectrum disorder (ASD). Hypertensive disorders of pregnancy and polycystic ovary syndrome are associated with both hyperandrogenism and increased risk for ASD. We examined whether increased maternal testosterone mediates the relationship between these hyperandrogenic disorders (HDs) during pregnancy and child communication and social skills. Maternal plasma was collected during the second trimester and parent-report measures of child communication and social skills were obtained at 4.5-6.5 years of age from 270 participants enrolled in the Nulliparous Pregnancy Outcomes Study: Monitoring Mothers-to-be (nuMoM2b). Our retrospective frequency-matched cohort study design identified 58 mothers with one or both of the HDs and 58 matched controls. Women diagnosed with an HD who carried a female had higher testosterone levels compared to those carrying a male (t(56) = -2.70, p = 0.01). Compared to females controls, females born to women with an HD had significantly higher scores on the Social Communication Questionnaire (t(114) = -2.82, p =0.01). Maternal testosterone partially mediated the relationship between a diagnosis of an HD and SCQ scores among females. These findings point to sex-specific associations of two HDs - hypertensive disorders of pregnancy and polycystic ovary syndrome - on child communication and social skills and a mediating effect of maternal testosterone during pregnancy. Further research is needed to understand placental-mediated effects of maternal testosterone on child brain development and neurodevelopmental outcomes.

A systematic review and meta-analysis of the association between maternal polycystic ovary syndrome and neuropsychiatric disorders in children

There is emerging evidence demonstrating an association between maternal polycystic ovary syndrome (PCOS) and autism spectrum disorder (ASD) in children, however, the cumulative effect of maternal PCOS on the development of ASD or other neuropsychiatry disorders (NPD) in children and separately for males and females has not been examined. We sought to systematically evaluate the influence of maternal PCOS on a wide range of NPD including ASD, attention deficit hyperactivity disorder (ADHD), chronic tic disorder (CDT), other behavior disorders, anxiety, depression, bipolar disorder, schizophrenia in children as well as in women of reproductive age only. We queried electronic databases including PubMed, EMBASE, and Google Scholar, until March 2021. We used DerSimonian and Laird (D-L) random effects method to compute pooled effect size in terms of odds ratio (OR). Nineteen studies (1667851 mothers, 2260622 children) were included in this study. Mothers with PCOS had an increased odds of children diagnosed with ASD (OR = 1.40, p < 0.001), ADHD (OR = 1.42, p < 0.001), CTD (OR = 1.44, p = 0.001), anxiety (OR = 1.33, p < 0.001), as well as other behavioral symptoms (OR = 1.45, p < 0.001) in the adjusted analysis. The association between maternal PCOS and ASD (OR: 1.43 vs. 1.66), ADHD (OR: 1.39 vs. 1.54), and CTD (OR: 1.42 vs. 1.51) was found to be significantly consistent between males and females, respectively. Our data do not suggest increased fetal testosterone exposure is associated with increased autistic traits in children. However, PCOS was significantly associated with increased odds of a wide range of NPD in women themselves. Maternal PCOS is a risk factor for various NPD with a similar extent in their children regardless of their underlying comorbidities. Managing PCOS is essential for women's health as well as for their children's health. More research is needed to determine the mechanisms and links between maternal PCOS and NPD in children.

Beyond Cholinesterase Inhibition: Developmental Neurotoxicity of Organophosphate Ester Flame Retardants and Plasticizers

BACKGROUND

To date, the toxicity of organophosphate esters has primarily been studied regarding their use as pesticides and their effects on the neurotransmitter acetylcholinesterase (AChE). Currently, flame retardants and plasticizers are the two largest market segments for organophosphate esters and they are found in a wide variety of products, including electronics, building materials, vehicles, furniture, car seats, plastics, and textiles. As a result, organophosphate esters and their metabolites are routinely found in human urine, blood, placental tissue, and breast milk across the globe. It has been asserted that their neurological effects are minimal given that they do not act on AChE in precisely the same way as organophosphate ester pesticides.

OBJECTIVES

This commentary describes research on the non-AChE neurodevelopmental toxicity of organophosphate esters used as flame retardants and plasticizers (OPEs). Studies in humans, mammalian, nonmammalian, and in vitro models are presented, and relevant neurodevelopmental pathways, including adverse outcome pathways, are described. By highlighting this scientific evidence, we hope to elevate the level of concern for widespread human exposure to these OPEs and to provide recommendations for how to better protect public health.

DISCUSSION

Collectively, the findings presented demonstrate that OPEs can alter neurodevelopmental processes by interfering with noncholinergic pathways at environmentally relevant doses. Application of a pathways framework indicates several specific mechanisms of action, including perturbation of glutamate and gamma-aminobutyric acid and disruption of the endocrine system. The effects may have implications for the development of cognitive and social skills in children. Our conclusion is that concern is warranted for the developmental neurotoxicity of OPE exposure. We thus describe important considerations for reducing harm and to provide recommendations for government and industry decision makers. https://doi.org/10.1289/EHP9285.

Is Psychopathy a Mental Disorder or an Adaptation? Evidence From a Meta-Analysis of the Association Between Psychopathy and Handedness

Psychopathy has historically been conceptualized as a mental disorder, but there is growing evidence that it may instead be an alternative, adaptive life history strategy designed by natural selection. Although the etiology of mental disorders is not fully understood, one likely contributor is perturbations affecting neurodevelopment. Nonright-handedness is a sign of such perturbations, and therefore can be used to test these competing models. If psychopathy is a mental disorder, psychopaths should show elevated rates of nonright-handedness. However, an adaptive strategy perspective expects psychopaths to be neurologically healthy and therefore predicts typical rates of nonright-handedness. We meta-analyzed 16 studies that investigated the association between psychopathy and handedness in various populations. There was no difference in the rates of nonright-handedness between community participants high and low in psychopathy. Furthermore, there was no difference between psychopathic and nonpsychopathic offenders in rates of nonright-handedness, though there was a tendency for offenders scoring higher on the Interpersonal/Affective dimension of psychopathy to have lower rates of nonright-handedness, and for offenders scoring higher on the Behavioral dimension of psychopathy to have higher rates of nonright-handedness. Lastly, there was no difference in rates of nonright-handedness between psychopathic and nonpsychopathic mental health patients. Thus, our results fail to support the mental disorder model and partly support the adaptive strategy model. We discuss limitations of the meta-analysis and implications for theories of the origins of psychopathy.

Endocrine-Disrupting Chemicals and Child Health

While definitions vary, endocrine-disrupting chemicals (EDCs) have two fundamental features: their disruption of hormone function and their contribution to disease and disability. The unique vulnerability of children to low-level EDC exposures has eroded the notion that only the dose makes the thing a poison, requiring a paradigm shift in scientific and policy practice. In this review, we discuss the unique vulnerability of children as early as fetal life and provide an overview of epidemiological studies on programming effects of EDCs on neuronal, metabolic, and immune pathways as well as on endocrine, reproductive, and renal systems. Building on this accumulating evidence, we dispel and address existing myths about the health effects of EDCs with examples from child health research. Finally, we provide a list of effective actions to reduce exposure, and subsequent harm that are applicable to individuals, communities, and policy-makers. Expected final online publication date for the Annual Review of Pharmacology and Toxicology, Volume 62 is January 2022. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

Gestational Phthalate Exposure and Preschool Attention Deficit Hyperactivity Disorder in Norway

Supplemental Digital Content is available in the text.

Prenatal phthalate exposure has been linked to altered neurobehavioral development in both animal models and epidemiologic studies, but whether or not these associations translate to increased risk of neurodevelopmental disorders is unclear. We used a nested case-cohort study design to assess whether maternal urinary concentrations of 12 phthalate metabolites at 17 weeks gestation were associated with criteria for Attention Deficit Hyperactivity Disorder (ADHD) classified among 3-year-old children in the Norwegian Mother, Father and Child Cohort Study (MoBa). Between 2007 and 2011, 260 children in this substudy were classified with ADHD using a standardized, on-site clinical assessment; they were compared with 549 population-based controls. We modeled phthalate levels both linearly and by quintiles in logistic regression models adjusted for relevant covariates and tested for interaction by child sex. Children of mothers in the highest quintile of di-iso-nonyl phthalate (∑DiNP) metabolite levels had 1.70 times the odds of being classified with ADHD compared with those in the lowest quintile (95% confidence interval [CI] = 1.03 to 2.82). In linear models, there was a trend with the sum of di-2-ethylhexyl phthalate metabolites (∑DEHP); each natural log-unit increase in concentration was associated with 1.22 times the odds of ADHD (95% CI = 0.99 to 1.52). In boys, but not girls, mono-n-butyl phthalate exposure was associated with increased odds of ADHD (odds ratio [OR] 1.42; 95% CI = 1.07 to 1.88). Additional adjustment for correlated phthalate metabolites attenuated estimates. These results suggest gestational phthalate exposure may impact the behavior of children as young as 3 years.

Maternal use of hormonal contraception and epilepsy in offspring

STUDY QUESTION

Is maternal use of hormonal contraception associated with the development of epilepsy in the offspring?

SUMMARY ANSWER

We found that maternal use of hormonal contraception was associated with a slightly increased risk of epilepsy in the offspring.

WHAT IS KNOWN ALREADY

Foetal exposure to exogenous hormones has been associated with changes in brain development. However, little is known about maternal hormonal contraception use and development of epilepsy in the offspring.

STUDY DESIGN, SIZE, DURATION

A nationwide cohort of all live born children born in Denmark between 1 January 1998 and 31 December 2014, was followed from day 29 after birth for epilepsy (first diagnosis of epilepsy or first redeemed prescription for anti-epileptic medication) to censoring (emigration, death) or 31 December 2015, whichever occurred first.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Diagnoses of epilepsy were obtained from the National Patient Registry. The Danish National Prescription Registry supplied information on redeemed prescriptions for hormonal contraception and anti-epileptic medication. Maternal hormonal contraception use was categorized as never use (reference group), previous use (prescriptions redeemed >3 months before pregnancy start) and recent use (prescriptions redeemed ≤3 months before or during pregnancy).

MAIN RESULTS AND THE ROLE OF CHANCE

The data show that 17 585 children developed epilepsy during a median follow-up of 9.2 years (9 732 635 person-years). The hazard ratio (HR) for epilepsy was 1.07 (95% CI 1.02-1.13) in children of mothers who had used any type of hormonal contraception recently, compared with children of mothers who had not used hormonal contraception. The HR was similar for recent use of oral combined products, while the HRs for recent or previous use of non-oral combined products were 1.32 (95% CI 0.98-1.77) and 1.16 (95% CI 1.02-1.32), respectively. For non-oral progestin-only products, the HRs were 1.19 (95% CI 1.04-1.38) and 1.53 (95% CI 1.31-1.80), respectively, for recent and previous use.

LIMITATIONS, REASONS FOR CAUTION

There may be some misclassification of maternal hormonal contraception use, as some women may not have used the redeemed prescriptions or used them at a different point in time; potentially leading to an attenuation of the estimates. In addition, although we were able to account for known risk factors for epilepsy, unknown or residual confounding cannot be ruled out.

WIDER IMPLICATIONS OF THE FINDINGS

Our findings are based on nationwide population-based data and can therefore be applied to other similar populations. However, as this is the first study in this field, further studies are needed to confirm our findings.

STUDY FUNDING/COMPETING INTEREST(S)

No specific funding was obtained for this study, which was supported by internal funding at the Unit of Virus, Lifestyle and Genes. All authors report no conflicts of interest.

TRIAL REGISTRATION NUMBER

N/A.

The Roles of Dietary, Nutritional and Lifestyle Interventions in Adipose Tissue Adaptation and Obesity

The obesity and the associated non-communicable diseases (NCDs) are globally increasing in their prevalence. While the modern-day lifestyle required less ventilation of metabolic energy through muscular activities, this lifestyle transition also provided the unlimited accession to foods around the clock, which prolong the daily eating period of foods that contained high calorie and high glycemic load. These situations promote the high continuous flux of carbon substrate availability in mitochondria and induce the indecisive bioenergetic switches. The disrupted bioenergetic milieu increases the uncoupling respiration due to the excess flow of the substrate-derived reducing equivalents and reduces ubiquinones into the respiratory chain. The diversion of the uncoupling proton gradient through adipocyte thermogenesis will then alleviate the damaging effects of free radicals to mitochondria and other organelles. The adaptive induction of white adipose tissues (WAT) to beige adipose tissues (beAT) has shown beneficial effects on glucose oxidation, ROS protection and mitochondrial function preservation through the uncoupling protein 1 (UCP1)-independent thermogenesis of beAT. However, the maladaptive stage can eventually initiate with the persistent unhealthy lifestyles. Under this metabolic gridlock, the low oxygen and pro-inflammatory environments promote the adipose breakdown with sequential metabolic dysregulation, including insulin resistance, systemic inflammation and clinical NCDs progression. It is unlikely that a single intervention can reverse all these complex interactions. A comprehensive protocol that includes dietary, nutritional and all modifiable lifestyle interventions, can be the preferable choice to decelerate, stop, or reverse the NCDs pathophysiologic processes.

Endocrine disrupting chemicals: strategies to protect present and future generations

Introduction: Endocrine-disrupting chemicals (EDCs) are chemicals that alter the actions of hormones. In the 21^st Century, numerous expert groups of clinicians, scientists, and environmental activists have called for action to protect present and future generations from the harm induced by EDC exposures. These demands for regulatory responses come because of the strong weight of the evidence from epidemiology, wildlife, and controlled laboratory studies.Areas covered: In this review, we examine the conclusions drawn by experts from different scientific and medical disciplines. We also address several areas where recent findings or work has changed the landscape of EDC work including new approaches to identify and evaluate the evidence for EDCs using a key characteristics approach, the need to expand our understanding of vulnerable periods of development, and the increasing concern that traditional methods used to evaluate toxicity of environmental chemicals are insufficient for EDCs and how collaborative science could help to address these gaps.Expert opinion: The science is clear: there is more than enough evidence to demonstrate that EDCs affect the health of humans and wildlife. Waiting to act is a decision that puts the health of current and future generations at risk.

Prenatal phthalate exposures and executive function in preschool children

BACKGROUND

Prenatal phthalate exposure has been linked with altered neurodevelopment, including externalizing behaviors and attention-deficit hyperactivity disorder (ADHD). However, the implicated metabolite, neurobehavioral endpoint, and child sex have not always been consistent across studies, possibly due to heterogeneity in neurodevelopmental instruments. The complex set of findings may be synthesized using executive function (EF), a construct of complex cognitive processes that facilitate ongoing goal-directed behaviors. Impaired EF can be presented with various phenotypes of poor neurodevelopment, differently across structured conditions, home/community, or preschool/school. We evaluated the relationship between prenatal phthalate exposure and comprehensive assessment of preschool EF.

METHODS

Our study comprised 262 children with clinically significant/subthreshold ADHD symptoms and 78 typically developing children who were born between 2003 and 2008 and participated in the Preschool ADHD Substudy, which is nested within a population-based prospective cohort study, the Norwegian Mother, Father, and Child Cohort (MoBa). Twelve phthalate metabolites were measured from urine samples that their mothers had provided during pregnancy, at 17 weeks' gestation. All children, at approximately 3.5-years, took part in a detailed clinical assessment that included parent-and teacher-rated inventories and administered tests. We used instruments that measured constructs related to EF, which include a parent-and teacher-reported Behavior Rating Inventory of Executive Function-Preschool (BRIEF-P) and three performance-based tests: A Developmental NEuroPSYchological Assessment (NEPSY), Stanford-Binet intelligence test V (SB5), and the cookie delay task (CDT). The standard deviation change in test score per interquartile range (IQR) increase in phthalate metabolite was estimated with multivariable linear regression. We applied weighting in all models to account for the oversampling of children with clinically significant or subthreshold symptoms of ADHD. Additionally, we assessed modification by child sex and potential co-pollutant confounding.

RESULTS

Elevated exposure to mono-benzyl phthalate (MBzP) during pregnancy was associated with poorer EF, across all domains and instruments, in both sex. For example, an IQR increase in MBzP was associated with poorer working memory rated by parent (1.23 [95% CI: 0.20, 2.26]) and teacher (1.13 [0.14, 2.13]) using BRIEF-P, and administered tests such as SB5 (no-verbal: 0.19 [0.09, 0.28]; verbal: 0.13 [0.01, 0.25]). Adverse associations were also observed for mono-n-butyl phthalate (MnBP) and mono-iso-butyl phthalate (MiBP), although results varied by instruments. EF domains reported by parents using BRIEF-P were most apparently implicated, with stronger associations among boys (e.g., MnBP and inhibition: 2.74 [1.77, 3.72]; MiBP and inhibition: 1.88 [0.84, 2.92]) than among girls (e.g., MnBP and inhibition: -0.63 [-2.08, 0.83], interaction p-value: 0.04; MiBP and inhibition: -0.15 [-1.04, 0.74], interaction p-value: 0.3). Differences by sex, however, were not found for the teacher-rated BRIEF-P or administered tests including NEPSY, SB5, and CDT.

CONCLUSION AND RELEVANCE

Elevated mid-pregnancy MBzP, MiBP, and MnBP were associated with more adverse profiles of EF among preschool-aged children across a range of instruments and raters, with some associations found only among boys. Given our findings and accumulating evidence of the prenatal period as a critical window for phthalate exposure, there is a timely need to expand the current phthalate regulations focused on baby products to include pregnancy exposures.

Estrogen receptor beta and neural development

The female sex hormone estradiol (E2, 17β-estradiol) has important functions in the developing brain. In addition to regulating sexual differentiation of the brain, E2 participates in the development of brain areas involved in functions unrelated to reproduction, such as cognition. E2 signals mainly thorough two estrogen receptors; estrogen receptor alpha (ERα) and beta (ERβ). While ERα has distinct functions for sexual imprinting of the developing brain, ERβ is considered to participate in the development of brain areas related to cognitive function. In this chapter we will focus on ERβ's role during neural development. We will discuss the contributions of sex chromosomal and sex hormonal effects in this process and place it in relation to recent data on ERβ obtained from stem cell models. Finally, we will discuss the lessons learned from mouse and stem cell models in understanding ERβ's role in neural development and how new stem cell models, by addressing the human relevance, may help to advance our progress in this field.

Testosterone and the Brain: From Cognition to Autism

Sex and gender matter in all aspects of life. Humans exhibit sexual dimorphism in anatomy, physiology, but also pathology. Many of the differences are due to sex chromosomes and, thus, genetics, other due to endocrine factors such as sex hormones, some are of social origin. Over the past decades, huge number of scientific studies have revealed striking sex differences of the human brain with remarkable behavioral and cognitive consequences. Prenatal and postnatal testosterone influence brain structures and functions, respectively. Cognitive sex differences include especially certain spatial and language tasks, but they also affect many other aspects of the neurotypical brain. Sex differences of the brain are also relevant for the pathogenesis of neuropsychiatric disorders such as autism spectrum disorders, which are much more prevalent in the male population. Structural dimorphism in the human brain was well-described, but recent controversies now question its importance. On the other hand, solid evidence exists regarding gender differences in several brain functions. This review tries to summarize the current understanding of the complexity of the effects of testosterone on brain with special focus on their role in the known sex differences in healthy individuals and people in the autism spectrum.

Vertical exposition to Luffa operculata extract deregulates behavior and hypothalamus neurotransmitters in juvenile rats

ETHNOPHARMACOLOGICAL RELEVANCE

Luffa operculata (L.) Cogn (Cucurbitaceae) is a traditional plant popularly used in the abortion induction, against sinusitis and is toxic.

AIM OF THE STUDY

To verify the influence of the aqueous extract obtained from the dry fruit of L. operculata (BNE) on the male rats vertically exposed to a subabortive dose of BNE, by evaluating alterations in behavior and neurochemical features in hypothalamus, striatum and frontal cortex, at a juvenile age, after receiving a stress challenge given by the use of the "New York subway stress" technique (NYS).

MATERIALS AND METHODS

Pregnant female rats (F0 generation) received 1.0 mg/kg BNE, or distilled water (100 mL/kg), by gavage, between gestation days GD17 and GD21. The pups were weaned at PND21 and were kept up to PND60 (juvenile age) in controlled environmental conditions. Four groups were obtained: control (CG), experimental (EG), stress control (SCG) and stress experimental (SEG) After being stressed, the animals were behavioral screened for in the open field (OF) and in light-dark box (LDB) apparatuses. They were euthanized, and the liver, kidneys and brain were removed for both macroscopic and microscopic analyses, and for quantification of vanillylmandelic acid (VMA), norepinephrine (NE), dopamine (DA) and its metabolite, 3,4-dihydroxyphenylacetic acid (DOPAC) and the serotonin (5-HT) and its metabolite 5-hydroxyindolylacetic acid (5-HIAA) were accessed in the hypothalamus, frontal cortex and striatum.

RESULTS AND DISCUSSION

although most of the behavior changes were due to the stress challenge, the rats spent more time in the dark side of the LDB and were less likely to explore the light side, indicating that the treatment with BNE induced to fear. Interferences of BNE over behavior were due to impairment of VMA, NE, 5-HT and DA and increasing of DOPAC in the hypothalamus, and an increase of 5-HIAA in the frontal cortex, indicating alterations in the hypothalamic-hypophysis-adrenal axis (HHAA). No macroscopic or histopathological changes were observed in the liver, kidneys, or brain, although GFAP was diminished in the SCG, as expected for stressed rats.

CONCLUSION

the vertical exposition of juvenile rats to BNE led to the manifestation of fear and to a down regulation of the hypothalamic-hypophysis-adrenal axis.

A Unifying Theory for Autism: The Pathogenetic Triad as a Theoretical Framework

This paper presents a unifying theory for autism by applying the framework of a pathogenetic triad to the scientific literature. It proposes a deconstruction of autism into three contributing features (an autistic personality dimension, cognitive compensation, and neuropathological risk factors), and delineates how they interact to cause a maladaptive behavioral phenotype that may require a clinical diagnosis. The autistic personality represents a common core condition, which induces a set of behavioral issues when pronounced. These issues are compensated for by cognitive mechanisms, allowing the individual to remain adaptive and functional. Risk factors, both exogenous and endogenous ones, show pathophysiological convergence through their negative effects on neurodevelopment. This secondarily affects cognitive compensation, which disinhibits a maladaptive behavioral phenotype. The triad is operationalized and methods for quantification are presented. With respect to the breadth of findings in the literature that it can incorporate, it is the most comprehensive model yet for autism. Its main implications are that (1) it presents the broader autism phenotype as a non-pathological core personality domain, which is shared across the population and uncoupled from associated features such as low cognitive ability and immune dysfunction, (2) it proposes that common genetic variants underly the personality domain, and that rare variants act as risk factors through negative effects on neurodevelopment, (3) it outlines a common pathophysiological mechanism, through inhibition of neurodevelopment and cognitive dysfunction, by which a wide range of endogenous and exogenous risk factors lead to autism, and (4) it suggests that contributing risk factors, and findings of immune and autonomic dysfunction are clinically ascertained rather than part of the core autism construct.

Associations Between Sex Hormone Levels and Autistic Traits in Infertile Patients With Polycystic Ovary Syndrome and Their Offspring

OBJECTIVES

1) To explore the associations between autistic traits and sex hormone changes in patients with polycystic ovary syndrome (PCOS); 2) To explore the influence of PCOS parental autistic traits and related sex hormone changes on autistic traits in their offspring.

METHOD

This is a case-control study that recruited two groups: polycystic ovarian syndrome-induced infertile subjects as the observation group and fallopian tube factor-induced infertility subjects as the control group. Both cohorts were patients undergoing infertility treatment in the Productive Medicine Center, Peking University People's Hospital. Two types of questionnaires were completed by patients between May 1^st, 2015, and May 1^st, 2016: 1. The autism-spectrum quotient (AQ) 2. Repetitive behavior scale-revised (RBS-r). Levels of sex hormones in serum were measured in patients. The correlations between the levels of these biochemical factors and scores of the autistic traits were analysed. From July 1^st, 2020 to September 1^st, 2021, these patients were followed up by telephone and asked to fill out a questionnaire online. The questionnaire included date of delivery, complications, medicine used and negative events during pregnancy (e.g., death of relatives, divorce, etc.), delivery condition, breastfeeding, AQ scale and Autism Behavior Checklist (ABC) of their children.

RESULTS

The patients in the PCOS group had significantly higher AQ scores than those in the control group. Levels of luteinizing hormone and testosterone were also higher in the PCOS group. No significant differences were found between the two groups in RBS-r levels, follicle-stimulating hormone, estradiol or progesterone. In the two combined groups, there were significantly positive correlations between the AQ scores and the luteinizing hormone concentration, as well as between scores of RBS-r and testosterone concentration. Moreover, there was a significantly negative correlation between the level of progesterone and the RBS-r score. According to the follow-up data, the AQ scores of offspring were positively correlated with the RBS-r scores of their mothers. The ABC scores of offspring were positively correlated with the RBS-r scores and the childbearing age of their mothers. No significant difference was found between the two groups in age of delivery, complications, special medication used, negative events during pregnancy, delivery situation, postpartum breastfeeding, age of children, or AQ scores or ABC scores of children. There were no significant correlations between the scale scores of children and the related sex hormone levels of mothers. This could indicate that the higher levels of luteinizing hormone and testosterone and the lower level of progesterone accompanied more pronounced autistic traits in PCOS. Furthermore, the higher delivery age and RBS-r score in mothers accompanied the higher AQ and ABC scores in children.

CONCLUSION

Compared with the control group, PCOS patients had more autistic traits (especially social dysfunction). The autistic traits in PCOS patients might be related to the elevation in testosterone concentration and luteinizing hormone levels and the decline in progesterone level. Moreover, the autistic traits in the offspring of PCOS patients might be related to the parental high delivery age and high tendency to autism traits.

Physical health of autistic girls and women: a scoping review

BACKGROUND

There is a growing recognition of sex and gender influences in autism. Increasingly, studies include comparisons between sexes or genders, but few have focused on clarifying the characteristics of autistic girls'/women's physical health.

METHODS

A scoping review was conducted to determine what is currently known about the physical health of autistic girls/women. We screened 1112 unique articles, with 40 studies meeting the inclusion criteria. We used a convergent iterative process to synthesize this content into broad thematic areas.

RESULTS

Autistic girls/women experience more overall physical health challenges compared to non-autistic girls/women and to autistic boys/men. Emerging evidence suggests increased prevalence of epilepsy in autistic girls/women compared to non-autistic girls/women and to autistic boys/men. The literature also suggests increased endocrine and reproductive health conditions in autistic girls/women compared to non-autistic girls/women. Findings regarding gastrointestinal, metabolic, nutritional, and immune-related conditions are preliminary and inconsistent.

LIMITATIONS

The literature has substantial heterogeneity in how physical health conditions were assessed and reported. Further, our explicit focus on physical health may have constrained the ability to examine interactions between mental and physical health. The widely differing research aims and methodologies make it difficult to reach definitive conclusions. Nevertheless, in keeping with the goals of a scoping review, we were able to identify key themes to guide future research.

CONCLUSIONS

The emerging literature suggests that autistic girls/women have heightened rates of physical health challenges compared to non-autistic girls/women and to autistic boys/men. Clinicians should seek to provide holistic care that includes a focus on physical health and develop a women's health lens when providing clinical care to autistic girls/women.

Maternal excessive gestational weight gain as a risk factor for autism spectrum disorder in offspring: a systematic review

Background

Abnormal gestational weight gain (GWG) is a prenatal complication that may contribute to long-term behavioral and neurodevelopmental differences in offspring. This systematic review summarizes research on the association between maternal GWG and risk of autism spectrum disorder (ASD) in offspring.

Methods

Google and electronic databases, including PubMed, SCOPUS, Embase, Cochrane Library and Google Scholar, were searched for original human studies published in English through June 2020. Articles that examined the association between GWG and risk of ASD in offspring were included. Duplicate and irrelevant studies were removed; and data were obtained through critical analysis.

Results

Of 96 articles searched, eight studies were included in the final review. All studies (n = 7) investigating the association of maternal excessive GWG with risk of ASD in offspring indicated that high GWG was independently associated with an increased risk of ASD. Of five studies investigating the association of inadequate GWG with the risk of ASD, four indicated that low GWG was not associated with an increased risk of ASD. Of seven studies examining the association of maternal pre-pregnancy BMI or weight with the risk of ASD, five reported that maternal pre-pregnancy BMI or weight did not appear to be independently associated with risk of ASD. The GWG-ASD association is independent of maternal BMI and child’s intellectual disability, but offspring’s genetic susceptibility connection to the GWG-ASD association remains a topic of debate.

Conclusions

The findings suggest that maternal excessive GWG may be associated with increased risk of ASD in offspring. However, insufficient GWG does not appear to have such association.

Thresholds and Endocrine Disruptors: An Endocrine Society Policy Perspective

The concept of a threshold of adversity in toxicology is neither provable nor disprovable. As such, it is not a scientific question but a theoretical one. Yet, the belief in thresholds has led to traditional ways of interpreting data derived from regulatory guideline studies of the toxicity of chemicals. This includes, for example, the use of standard "uncertainty factors" when a "No Adverse Effect Level" (or similar "benchmark dose") is either observed, or not observed. In the context of endocrine-disrupting chemicals (EDCs), this approach is demonstrably inappropriate. First, the efficacy of a hormone on different endpoints can vary by several orders of magnitude. This feature of hormone action also applies to EDCs that can interfere with that hormone. For this reason, we argue that the choice of endpoint for use in regulation is critical, but note that guideline studies were not designed with this in mind. Second, the biological events controlled by hormones in development not only change as development proceeds but are different from events controlled by hormones in the adult. Again, guideline endpoints were also not designed with this in mind, especially since the events controlled by hormones can be both temporally and spatially specific. The Endocrine Society has laid out this logic over several years and in several publications. Rather than being extreme views, they represent what is known about hormones and the chemicals that can interfere with them.

Assessment of Multipollutant Exposures During Pregnancy Using Silicone Wristbands

Silicone wristbands can assess multipollutant exposures in a non-invasive and minimally burdensome manner, which may be suitable for use among pregnant women. We investigated silicone wristbands as passive environmental samplers in the New Hampshire Birth Cohort Study, a prospective pregnancy cohort. We used wristbands to assess exposure to a broad range of organic chemicals, identified multipollutant exposure profiles using self-organizing maps (SOMs), and assessed temporal consistency and determinants of exposures during pregnancy. Participants (n = 255) wore wristbands for 1 week at 12 gestational weeks. Of 1,530 chemicals assayed, 199 were detected in at least one wristband and 16 were detected in >60% of wristbands. A median of 23 (range: 12,37) chemicals were detected in each wristband, and chemicals in commerce and personal care products were most frequently detected. A subset of participants (n=20) wore a second wristband at 24 gestational weeks, and concentrations of frequently detected chemicals were moderately correlated between time points (median intraclass correlation: 0.22; range: 0.00,0.69). Women with higher educational attainment had fewer chemicals detected in their wristbands and the total number of chemicals detected varied seasonally. Triphenyl phosphate concentrations were positively associated with nail polish use, and benzophenone concentrations were highest in summer. No clear associations were observed with other a priori relations, including certain behaviors, season, and socioeconomic factors. SOM analyses revealed 12 profiles, ranging from 2 to 149 participants, captured multipollutant exposure profiles observed in this cohort. The most common profile (n = 149) indicated that 58% of participants experienced relatively low exposures to frequently detected chemicals. Less common (n ≥ 10) and rare (n < 10) profiles were characterized by low to moderate exposures to most chemicals and very high and/or very low exposure to a subset of chemicals. Certain covariates varied across SOM profile membership; for example, relative to women in the most common profile who had low exposures to most chemicals, women in the profile with elevated exposure to galaxolide and benzyl benzoate were younger, more likely to be single, and more likely to report nail polish use. Our study illustrates the utility of silicone wristbands for measurement of multipollutant exposures in sensitive populations, including pregnant women.

Maternal use of hormonal contraception and risk of childhood ADHD: a nationwide population-based cohort study

Although maternal use of hormones has been suspected of increasing the risk for childhood attention-deficit/hyperactivity disorder (ADHD), no study has examined hormonal contraception use in this context. We examined the association between maternal hormonal contraception use before or during pregnancy and ADHD risk in children. This nationwide population-based cohort study included 1,056,846 children born in Denmark between 1998 and 2014. Prescriptions for hormonal contraceptives redeemed by the mother was categorized as: no use, previous use (> 3 months before pregnancy), and recent use (≤ 3 months before or during pregnancy). Children were followed for ADHD, from birth until 31 December 2015. Cox proportional hazard models were used to estimate hazard ratios (HRs) with 95% confidence intervals (CIs). During 9,819,565 person-years of follow-up (median: 9.2), ADHD was diagnosed or a prescription for ADHD medication redeemed for 23,380 children (2.2%). The adjusted HR for ADHD was higher in children of mothers who had previously (HR 1.23; 95% CI 1.18-1.28) or recently (HR 1.30; 95% CI 1.24-1.37) used hormonal contraception than in those of mothers with no use. The highest estimates were seen for use of non-oral progestin products with HRs of 1.90 (95% CI 1.59-2.26) for previous use, 2.23 (95% CI 1.96-2.54) for recent use, and 3.10 (95% CI 1.62-5.91) for use during pregnancy. Maternal use of hormonal contraception was associated with an increased risk for ADHD in the offspring; more pronounced for non-oral progestin-only than other products.

Progesterone and fetal-neonatal neuroprotection

The role of progesterone goes beyond the maintenance of pregnancy. The hormone, indeed, protects the developing fetal brain and influences its maturation. Metabolomes analyzed by mass spectrometric methods have revealed the great diversity of steroids in maternal plasma and fetal fluids, but their developmental significance remains to be investigated. Progesterone and its metabolites reach highest levels during the third trimester, when the brain growth spurt occurs: its volume triples, synaptogenesis is particularly active, and axons start to be myelinated. This developmental stage coincides with a period of great vulnerability. Studies in sheep have shown that progesterone and its metabolite allopregnanolone protect the vulnerable fetal brain. Work in rats and mice have demonstrated that progesterone plays an important role in myelin formation. These experimental studies are discussed in relation to preterm birth. Influences of progesterone on very early stages of neural development at the beginning of pregnancy are yet to be explored.

Diminished verbal ability among children conceived through ART with exposure to high serum estradiol in utero

Purpose

Higher serum estradiol levels occur in women undergoing assisted reproductive technology (ART) owing to ovarian stimulation. Here, we investigated the association between maternal serum estradiol levels and the intellectual development of offspring conceived with ART.

Methods

A total of 204 singletons born after fresh embryo transfer were recruited for this cohort study. Among them, 102 children were born from mothers with high serum estradiol levels (> 12,000 pmol/L) on the day that human chorionic gonadotropin was administered. Another 102 children, matched by gestational age and age of the children, were recruited as controls from mothers with low serum estradiol (≤ 12,000 pmol/L). The Wechsler Preschool and Primary Scale of Intelligence was used to evaluate the intellectual development of the children.

Results

Children from mothers with higher serum estradiol levels scored lower in the verbal intelligence quotient (IQ) tests and verbal comprehension than children whose mothers had lower estradiol levels. The main difference between the two groups was in verbal subtests including information, vocabulary, and sorting. Partial correlation analysis revealed that the logarithm of maternal serum estradiol level negatively correlated with verbal IQ, performance IQ, and full scale IQ.

Conclusion

Our data demonstrate that a high maternal serum estradiol level may negatively associate the verbal ability of children conceived via ART.

Prenatal exposure to a mixture of persistent organic pollutants (POPs) and child reading skills at school age

BACKGROUND

Prenatal exposure to persistent organic pollutants (POPs) may affect child neurobehavior; however, exposures to mixtures of POPs have rarely been examined.

METHODS

We estimated associations of prenatal serum concentrations of 17 POPs, namely 5 polybrominated diphenyl ethers (PBDEs), 6 polychlorinated biphenyls (PCBs), dichlorodiphenyldichloroethylene (DDE), dichlorodiphenyltrichloroethane (DDT), and 4 per- and polyfluoroalkyl substances (PFAS), with Wide Range Achievement Test-4 reading composite scores at age 8 years in 161 children from a pregnancy and birth cohort (Health Outcomes and Measures of the Environment [HOME] Study, 2003-present) in Cincinnati, OH. We applied 6 statistical methods: least absolute shrinkage and selection operator (LASSO), elastic net (ENET), Sparse Principal Component Analysis (SPCA), Weighted Quantile Sum (WQS) regression, Bayesian Kernel Machine Regression (BKMR), and Bayesian Additive Regression Trees (BART), to estimate covariate-adjusted associations with individual and their mixtures in multi-pollutant models.

RESULTS

Both LASSO and ENET models indicated inverse associations with reading scores for BDE-153 and BDE-28, and positive associations for CB-118, CB-180, perfluoroctanoate (PFOA), and perfluorononanoate (PFNA). The SPCA identified inverse associations for BDE-153 and BDE-100 and positive associations for perfluorooctane sulfonate (PFOS), PFOA, and PFNA, as parts of different principal component scores. The WQS regression showed the highest weights for BDE-100 (0.35) and BDE-28 (0.16) in the inverse association model and for PFNA (0.29) and CB-180 (0.21) in the positive association model. The BKMR model identified BDE-100 and BDE-153 for inverse associations and CB-118, CB-153, CB-180, PFOA, and PFNA for positive associations. The BART method found dose-response functions similar to the BKMR model. No interactions between POPs were identified.

CONCLUSIONS

Despite some inconsistency among biomarkers, these analyses revealed inverse associations between prenatal PBDE concentrations and children's reading scores. Positive associations of PCB congeners and PFAS with reading skills were also found.

Prenatal sex hormones and behavioral outcomes in children

Abnormal sex hormone levels in utero have been associated with child behavioral problems, but it is unclear if normal variation in prenatal sex hormones is associated with subsequent behavior in childhood. We assessed maternal sex hormones, including serum estrone (E1), estradiol (E2), estriol (E3), free testosterone (FT), and total testosterone (TT), during early pregnancy (gestational week 6-21 (mean = 11.1)) and evaluated child behavior at ages 4-5 using the Behavioral Assessment System for Children (BASC-2) and Social Responsiveness Scale (SRS-2) in 404 mother/child pairs (211 girls, 193 boys) within The Infant Development and Environment Study, a multi-site pregnancy cohort study. Associations between hormones and composite scores were evaluated using multiple linear regressions in both sexes combined, and separate models assessed effect modification by sex with the addition of interaction terms. A 10-fold increase in maternal FT or TT was associated in both sexes with a 4.3-point (95 % CI: 0.5, 8.2) or 4.4-point (0.8, 8.0) higher BASC-2 internalizing composite T score, respectively. In addition, a 10-fold increase in FT or TT was associated with a 3.8-point (0.04, 7.5) or 4.0-point (0.5, 7.5) higher behavioral symptoms index composite score. In models evaluating effect modification by sex, a 10-fold increase in E1 was associated with a 4.3-point (1.2, 7.4) decrease in adaptive skills composite score in girls only (interaction p = 0.04). We observed associations between testosterone and internalizing behaviors and behavioral symptoms index in both sexes, as well as a female-specific association between E1 and adaptive skills. Sex hormones during pregnancy may play a key role in influencing later-life behavior, and additional studies should further examine different periods of susceptibility to hormonal signals.

General anesthesia, germ cells and the missing heritability of autism: an urgent need for research

Agents of general anesthesia (GA) are commonly employed in surgical, dental and diagnostic procedures to effectuate global suppression of the nervous system, but in addition to somatic targets, the subject's germ cells-from the embryonic primordial stage to the mature gametes-may likewise be exposed. Although GA is generally considered safe for most patients, evidence has accumulated that various compounds, in particular the synthetic volatile anesthetic gases (SVAGs) such as sevoflurane, can exert neurotoxic, genotoxic and epigenotoxic effects, with adverse consequences for cellular and genomic function in both somatic and germline cells. The purpose of this paper is to review the evidence demonstrating that GA, and in particular, SVAGs, may in some circumstances adversely impact the molecular program of germ cells, resulting in brain and behavioral pathology in the progeny born of the exposed cells. Further, we exhort the medical and scientific communities to undertake comprehensive experimental and epidemiological research programs to address this critical gap in risk assessment.

Maternal polycystic ovarian syndrome in autism spectrum disorder: a systematic review and meta-analysis

There is evidence showing a positive correlation between prenatal androgens and their effect on the development of central nervous system and the autistic spectrum disorder (ASD) phenotype in offspring of mothers with polycystic ovary syndrome (PCOS). We applied a systematic review to investigate whether women with PCOS have increased odds of having a child with ASD, while, secondarily, if these women themselves are at high risk of having the disease. Major databases from inception until 14th October 2018 were searched. The primary outcome measure was the odds of an ASD diagnosis in children of mothers with diagnosed PCOS, while the secondary outcome was the odds of ASD diagnosis in women with PCOS. Scheduled subgroup analyses were according to the time of birth and maternal age. We assessed the odds ratio (OR), using a random-effects model; heterogeneity was assessed by I² and τ² statistics. The quality of the evidence was evaluated using the Newcastle-Ottawa Scale. Ten studies were eligible for inclusion, including a total of 33,887 ASD children and 321,661 non-ASD children. Diagnosed PCOS was associated with a 1.66 times increase in the odds of ASD in the offspring [95% CI: 1.51, 1.83, p = 1.99 × 10^-25, 7 studies, I² = 0%, τ² = 0]. Women with PCOS were 1.78 times more likely to be diagnosed with ASD (95% CI: 1.10, 2.87, p = 0.0179, 5 studies, I² = 85.4%, τ² = 0.2432). Additional analyses did not change the initial result. The overall quality of the evidence was high. The pooled effects size displayed low heterogeneity (I² = 0%) for the primary outcome. While the heterogeneity in the secondary outcome appears to attenuate when only high quality studies are synthesized, still the result exhibits significant heterogeneity. Τhe available data allowed a subgroup analysis only for classification system for PCOS diagnosis and showed a significant increase of ASD diagnosis in the offspring of women with Read Code and ICD diagnosed PCOS. In conclusion, the available evidence suggests that women with PCOS have increased odds of having a child with ASD, an effect size estimate based on a large number of patients from studies of good quality. Regarding the evidence on the prevalence of ASD in PCOS women, results suggest that women with PCOS are more likely to be diagnosed with ASD.

Sex-specific effects of perinatal FireMaster® 550 (FM 550) exposure on socioemotional behavior in prairie voles

The rapidly rising incidence of neurodevelopmental disorders with social deficits is raising concern that developmental exposure to environmental contaminants may be contributory. Firemaster 550 (FM 550) is one of the most prevalent flame-retardant (FR) mixtures used in foam-based furniture and baby products and contains both brominated and organophosphate components. We and others have published evidence of developmental neurotoxicity and sex specific effects of FM 550 on anxiety-like and exploratory behaviors. Using a prosocial animal model, we investigated the impact of perinatal FM 550 exposure on a range of socioemotional behaviors including anxiety, attachment, and memory. Virtually unknown to toxicologists, but widely used in the behavioral neurosciences, the prairie vole (Microtus ochrogaster) is a uniquely valuable model organism for examining environmental factors on sociality because this species is spontaneously prosocial, biparental, and displays attachment behaviors including pair bonding. Dams were exposed to 0, 500, 1000, or 2000 μg of FM 550 via subcutaneous (sc) injections throughout gestation, and pups were directly exposed beginning the day after birth until weaning. Adult offspring of both sexes were then subjected to multiple tasks including open field, novel object recognition, and partner preference. Effects were dose responsive and sex-specific, with females more greatly affected. Exposure-related outcomes in females included elevated anxiety, decreased social interaction, decreased exploratory motivation, and aversion to novelty. Exposed males also had social deficits, with males in all three dose groups failing to show a partner preference. Our studies demonstrate the utility of the prairie vole for investigating the impact of chemical exposures on social behavior and support the hypothesis that developmental FR exposure impacts the social brain. Future studies will probe the possible mechanisms by which these effects arise.

Prenatal exposure to phthalates and neurocognitive development in children at two years of age

BACKGROUND

Phthalates are a family of endocrine disruptors with short elimination half-lives in the human body. To date, few epidemiological studies have examined repeated measures of maternal urinary phthalates and the combined effects of prenatal exposure to multiple phthalates on children's neurocognitive development.

OBJECTIVES

We aimed to investigate the association between children's neurocognitive development at 2 years of age and prenatal phthalate exposure, as assessed by repeated measurements during pregnancy, and to further examine the effects of co-exposure to multiple phthalates using cumulative risk assessment.

METHOD

Within a prenatal cohort in Wuhan, China, we measured five high-molecular-weight (HMW) phthalates and three low-molecular-weight (LMW) phthalate metabolites' concentrations in three urine samples collected in the 1st, 2nd, and 3rd trimester of pregnancy from each mother. We assessed neurocognitive development by Bayley Scales of Infant and Toddler Development (BSID) at 2 years of age (n = 476) to obtain the children's mental development index (MDI) and psychomotor development index (PDI).

RESULTS

Higher exposure levels to LMW phthalates compared to HMW phthalates were observed in our population. Ln-transformed averaged concentration of mono-n-butyl phthalate (MnBP), a metabolite of the LMW phthalate di-n-butyl phthalate (DnBP) during pregnancy, was associated with decreased PDI scores in all children (β = -1.90, 95% CI: -3.43, -0.37). Similarly, the averaged sum concentration of ∑dibutyl phthalate (∑DBP) was associated with decreased PDI scores in all children (β = -1.89, 95% CI: -3.63, -0.15). A negative trend of association between exposure to HMW phthalates and PDI scores was observed in girls, while a positive association was found in boys. In cumulative risk assessment analyses, we consistently observed that the hazard quotient of DnBP (the parent compound of MnBP) was inversely associated with PDI scores in all children, whereas the hazard quotient of di-2-ethylhexyl phthalate (DEHP), an HMW phthalate, was positively associated with PDI scores in boys only.

CONCLUSIONS

This study is the first to use repeated measurement of maternal urinary phthalates in all three trimesters to assess prenatal exposure in relation to children's neurodevelopment. Our study suggested a negative association between prenatal exposure to MnBP and children's psychomotor development, and potentially sex-specific associations between HMW phthalates and neurocognitive development among boys and girls. These findings warrant further confirmation.

Lactational exposure to phthalates impaired the neurodevelopmental function of infants at 9 months in a pilot prospective study

Phthalates are widespread endocrine-disrupting chemicals (EDCs) that have been suggested to affect neurodevelopment. However, association between lactational exposure to phthalates and neurodevelopmental effects has rarely been reported in epidemiological studies. We conducted a pilot prospective study of 138 mother-infant pairs to evaluate whether lactational exposure to phthalates was associated with neurodevelopmental effects in infants. At baseline survey, the spot urine samples from both mothers and infants were collected for measuring ten metabolites of phthalates, and the food intake information of infants was assessed by the food-frequency questionnaire (FFQ). At the follow-up survey in 9 months of age, the neurodevelopmental Function of infants was assessed using the Ages and Stages Questionnaire Edition 3 (ASQ-3). Multivariate logistic regression models were used to calculate the odds ratio (OR) for delayed development according to the level of exposure to phthalates. Our results indicated that MnBP and MiBP were high in lactating infants and mothers. In the overall study population, most metabolites showed positive associations with delayed development of most ASQ-3 domains. In male, MMP, MEP, MiBP and MnBP but not DEHP metabolites were significantly associated with increased odds of delayed development of all domains. In female, most LMWP metabolites and the four oxidative metabolites of DEHP were significantly associated with increased odds of delayed development of most domains. In conclusion, we found a significant negative association between lactational exposure to phthalates and ASQ-3 domains. Some of the sex-specific observations warrant further investigation. The dietary source of lactational phthalates exposure may not the breast milk or infant formula but the complementary food.