Intelligence Quotient Of Children Research Articles

Association between Maternal Metal Exposure during Early Pregnancy and Intelligence in Children Aged 3 to 6 years: Results from a Chinese Birth Cohort

ObjectiveMaternal environmental metal exposure is common, but long-term prospective epidemiological evidence of its impact on children's intellectual development is still insufficient. MethodsData on maternal plasma metal levels and child intelligence were obtained for 211 3–6-year-old children from Guangxi Zhuang Birth Cohort. ICP-MS was employed to detect 17 metals, including 7 essential metals (Mn, Fe, Co, Ni, Cu, Zn, Mo) and 10 non-essential metals (As, Rb, Sr, Cd, Sb, Cs, Ba, W, Pb, U), in maternal plasma samples obtained before 13 weeks of gestation during the initial maternity checkup. Child intelligence was assessed using the Wechsler Intelligence Scale for Children-Fourth Edition. The GLM, RCS and mixture models were used to assess the associations of maternal plasma metal levels with child intelligence quotient (IQ) scores. ResultsThe GLM analysis revealed that U had a significant adverse effect on child IQ scores in high-dose exposure groups (-9.236 [-18.644, -4.936], p = 0.006) after adjusting for covariates, while Sb showed a linear adverse effect on children's intelligence in the adjusted model (-4.028 [-7.432, -0.626], p = 0.021). BKMR modeling indicated that overall IQ scores decreased as concentrations of non-essential metals mixtures increased after adjusting for essential metal mixtures, consistent with findings from the WQS (β [95% CI], -8.463 [-14.449, -2.476], p = 0.007) and Qgcomp models (-7.003 [-12.928, -1.078], p = 0.022). Among the non-essential metals, U had the highest negative weight at 37.96%, followed by Pb (23.35%) and Sb (16.91%). Furthermore, potential interactions were observed between metals (Pb and U) and Sb in the study findings. ConclusionReducing exposure to non-essential metal mixtures, especially U, Sb and Pb, during early pregnancy and ensuring adequate intake of specific essential metal elements could be a critical intervention in addressing childhood intellectual impairment.

Experiencing anesthesia and surgery early in life impairs cognitive and behavioral development.

The impact of anesthesia and surgery on neurocognitive and behavioral development in infants and children remains inadequately understood. To investigate the impact of early-life exposure to general anesthesia and surgery on cognitive and behavioral development. Children aged 0-3 years who underwent general anesthesia and surgical procedures between 2012 and 2015 were included. The cognitive and behavioral development of these children at ages 4-6 years was assessed. Age-, race-, and gender-matched children from the same geographic region, who did not undergo general anesthesia or surgery, served as the control group. The Wechsler Preschool Primary Scale of Intelligence, Fourth Edition (WPPSI-IV) was used to evaluate children's total intelligence quotient (FSIQ) and specific cognitive domains. The Gesell Development Schedules (GSCH) and Child Behavior Checklist (CBCL) were employed to assess behavioral and personality development. Additionally, the study analyzed the effects of various factors including anesthesia drugs, surgery duration, number of surgeries, age, weight, ethnicity, and gender on postoperative neurocognitive and behavioral outcomes. The study included 447 children with anesthesia/surgical exposure (AS) and 459 children in the control group. Analysis of cognitive and behavioral development showed a significant difference in the working memory index (WMI) between the AS and control groups (p < 0.05). Exploratory findings indicated that children administered remifentanil exhibited lower developmental quotient (DQ) values, whereas those given fentanyl showed higher (worse) Child Behavior Checklist (CBCL) total scores. Moreover, increased anesthesia/surgical exposures, younger age and lower body weight at exposure, and longer surgery durations were associated with cognitive and behavioral developmental challenges. This study examined the impact of early-life exposure to surgery and anesthesia on postoperative cognitive and behavioral development. Findings indicate that higher frequency of exposure to surgery and anesthesia, younger age, and lower body weight at exposure could negatively influence cognitive and behavioral development. Furthermore, variations in the effects of different anesthetics on behavior and cognition were observed. Caution is advised regarding the use of opioid analgesics such as remifentanil and fentanyl for more rigorous clinical applications.

A Cross-Sectional Study on the Impact of Children's Intelligence Quotient on Their Behavior and Anxiety in a Dental Setting

A Cross-Sectional Study on the Impact of Children's Intelligence Quotient on Their Behavior and Anxiety in a Dental Setting

Patterns of Adverse Childhood Experiences and Neurocognitive Development

Early life adversity is associated with higher risk of many adult health problems, including mental illness, substance abuse, suicide attempt, and chronic diseases. Many previous studies investigated adversities one at a time or investigated the health toll associated with the cumulative number of adversities. To examine the co-occurrence of adversities among children and how specific patterns of adversities are associated with neurocognitive development. This cohort study used data from the Collaborative Perinatal Project (CPP), which enrolled a national sample of women during pregnancy and followed their offspring to ages 7 to 8 years, between 1959 and 1974. The CPP was a community-based study conducted in 12 US medical centers. The CPP sample was ascertained through prenatal clinics and is diverse with respect to race and socioeconomic status. Data analysis was performed from August 2023 to March 2024. A latent class analysis was conducted of 12 adverse childhood experiences that occurred between birth and 7 years to identify common patterns of childhood adversities. Five neurocognitive tests were used to measure children's visual-motor, sensory-motor, auditory-vocal, intelligence quotient, and academic skills. The analysis sample included 49 853 offspring (25 226 boys [50.6%]); 24 436 children (49.0%) had low probability of experiencing any adversity, whereas the remaining half were classified into 5 groups reflecting distinct patterns of childhood adversities: parental harshness and neglect, 1625 children (3.3%); parental separation and poverty, 8731 children (17.5%); family instability, 3655 children (7.3%); family loss, instability, and poverty, 1505 children (3.0%); and crowded housing and poverty, 9901 children (19.9%). Children in 4 of these groups had lower neurocognitive scores than children with a low probability of experiencing adversity, with standardized mean differences ranging from -0.07 (95% CI, -0.11 to -0.03) to -0.86 (95% CI, -1.06 to -0.65). These findings suggest that adverse childhood experiences are associated with deficits in children's neurocognitive functions. It is important to understand the complexity in children's exposure to adversity and the resulting developmental consequences, as well as the underlying mechanisms, to help support children exposed to adversity and foster healthier and resilient trajectories of development.

Maternal cortisol levels in pregnancy and intelligence quotient in children at 7 years of age. odense child cohort

Maternal cortisol levels in pregnancy and intelligence quotient in children at 7 years of age. odense child cohort

Family screening for neurodevelopmental problems and its associations with child cognitive function enable tailored treatment for childhood obesity.

To identify neurodevelopmental disorders in children with obesity, and investigate associations to cognitive functions as well as parents' self-reported neurodevelopmental problems. Eighty children were included at two outpatient obesity clinics in Sweden 2018-2019. Of these, 50 children without previously diagnosed neurodevelopmental disorders were screened, and so were their parents. Children who screened positive for neurodevelopmental problems were referred to a specialised psychiatry unit for further diagnosis. Test results of cognitive functioning were compared with the norm and between study groups by neurodevelopmental diagnoses. Of the screened families, 17/50 children were diagnosed by the psychiatric unit with attention deficit-hyperactivity disorder (ADHD) and 15/82 parents screened positive for neurodevelopmental problems. Having a mother who screened positive for neurodevelopmental problems was associated with child ADHD (p < 0.05). The children's full-scale intelligence quotient (92.86 ± 12.01, p < 0.001) and working memory index (90.62 ± 12.17, p < 0.001) were lower than the norm. Working memory index was lower in children with ADHD compared to without ADHD: 84.76 ± 9.58 versus 94.09 ± 12.29 (p ≤ 0.01). Executive constraints were associated with verbal deviances. Increased awareness is needed about the overlap between neurodevelopmental problems and obesity in obesity clinics.

Prenatal exposure to per- and polyfluoroalkyl substances, fetal thyroid function, and intelligence quotient at 7 years of age: Findings from the Sheyang Mini Birth Cohort Study

BackgroundPrenatal exposure to per- and polyfluoroalkyl substances (PFASs) influences neurodevelopment. Thyroid homeostasis disruption is thought to be a possible underlying mechanism. However, current epidemiological evidence remains inconclusive. ObjectivesThis study aimed to explore the effects of prenatal PFAS exposure on the intelligence quotient (IQ) of school-aged children and assess the potential mediating role of fetal thyroid function. MethodsThe study included 327 7-year-old children from the Sheyang Mini Birth Cohort Study (SMBCS). Cord serum samples were analyzed for 12 PFAS concentrations and 5 thyroid hormone (TH) levels. IQ was assessed using the Wechsler Intelligence Scale for Children-Chinese Revised (WISC-CR). Generalized linear models (GLM) and Bayesian Kernel Machine Regression (BKMR) were used to evaluate the individual and combined effects of prenatal PFAS exposure on IQ. Additionally, the impact on fetal thyroid function was examined using a GLM, and a mediation analysis was conducted to explore the potential mediating roles of this function. ResultsThe molar sum concentration of perfluorinated carboxylic acids (ΣPFCA) in cord serum was significantly negatively associated with the performance IQ (PIQ) of 7-year-old children (β = -6.21, 95 % confidence interval [CI]: −12.21, −0.21), with more pronounced associations observed among girls (β = -9.57, 95 % CI: −18.33, −0.81) than in boys. Negative, albeit non-significant, cumulative effects were noted when considering PFAS mixture exposure. Prenatal exposure to perfluorooctanoic acid, perfluorononanoic acid, and perfluorooctanesulfonic acid was positively associated with the total thyroxine/triiodothyronine ratio. However, no evidence supported the mediating role of thyroid function in the link between PFAS exposure and IQ. ConclusionsIncreased prenatal exposure to PFASs negatively affected the IQ of school-aged children, whereas fetal thyroid function did not serve as a mediator in this relationship.

Prenatal exposure to pyrethroids and chlorpyrifos and IQ in 7-year-old children from the Odense Child Cohort

BackgroundOrganophosphates and pyrethroids are two major groups of insecticides used for crop protection worldwide. They are neurotoxicants and exposure during vulnerable windows of brain development may have long-term impact on human neurodevelopment. Only few longitudinal studies have investigated associations between prenatal exposure to these substances and intelligence quotient (IQ) at school age in populations with low, mainly dietary, exposure. ObjectiveTo investigate associations between maternal urinary concentrations of insecticide metabolites at gestational week 28 and IQ in offspring at 7-years of age. Materials and methodsData was derived from the Odense Child Cohort (OCC). Metabolites of chlorpyrifos (TCPy) and pyrethroids (3-PBA, cis- and trans-DCCA, 4-F-3PBA, cis-DBCA) were measured in maternal urine collected at gestational week (GW) 28. An abbreviated version of the Danish Wechsler Intelligence Scale for Children fifth edition (WISC-V) consisting of four subtests to estimate full scale IQ (FSIQ) was administered by trained psychologists. Data were analyzed by use of multiple linear regression and adjusted for confounders. Results812 mother/child-pairs were included. Median concentrations were 0.21 μg/L for 3-PBA, 1.67 μg/L for TCPy and the mean IQ for children were 99.4. Null association between maternal 3-PBA and child IQ at 7 years was seen, but with trends suggesting an inverse association. There was a significant association for maternal TCPy and child IQ at mid-level exposure. Trans-DCCA above the level of detection (LOD) was also associated with slightly lower child IQ, but the association was also not statistically significant. ConclusionsWe found no significant associations between maternal 3-PBA metabolites and child IQ at 7 years, but with trends suggesting an inverse association. A non-significant trend between maternal TCPy exposure and child IQ in 7-year-children was seen even in this low exposed population. Given the widespread exposure and increasing use of insecticides, this should be elaborated in future studies.

Overt hypothyroidism in pregnancy and language development in offspring: is there an association?

Overt hypothyroidism during pregnancy is linked to various obstetric complications, such as premature birth and fetal death. While some studies have shown that maternal hypothyroidism can impact a child's Intelligence Quotient (IQ) and language development, findings are controversial. The aim of this study was to explore the connection between treated maternal hypothyroidism during pregnancy and offspring neurodevelopment, focusing on learning and language and examining related maternal obstetric complications. Group 1 included 31 hypothyroid women with elevated thyroid stimulating hormone (TSH) (> 10mU/L, > 10µIU/mL) during pregnancy, and Group 2 had 21 euthyroid women with normal TSH levels (0.5-2.5mU/L, 0.5-2.5µIU/mL). Children underwent neuropsycological assessments using the Griffiths-II scale. Pregnancy outcome showed an average gestational age at delivery of 38.2weeks for hypothyroid women, compared to 40weeks for controls, and average birth weight of 2855.6g versus 3285g for controls, with hypothyroid women having children with higher intrauterine growth restriction (IUGR) prevalence and more caesarean sections. The 1-min APGAR score was lower for the hypothyroid group's children, at 8.85 versus 9.52. Neuropsychological outcomes showed children of hypothyroid mothers scored lower in neurocognitive development, particularly in the learning and language subscale (subscale C), with a notable correlation between higher maternal TSH levels and lower subscale scores. Fetuses born to hypothyroid mothers appeared to be at higher risk of IUGR and reduced APGAR score at birth. Neurocognitive development seemed to affect language performance more than the developmental quotient. This alteration appeared to correlate with the severity of hypothyroidism and its duration.

A REVIEW ON FACTORS AFFECTING MEDHA (INTELLIGENCE) IN CHILDREN

Intelligence encompasses the capacity for critical thinking, learning from experiences, problem-solving, and adapting to new situations. The Intelligence Quotient (IQ) serves as a metric to gauge human intelligence derived from standardised tests or subtests designed for this purpose. In Ayurveda, this cognitive ability aligns with the concept of Medha (intelligence), involving a comprehensive understanding of existing knowledge, combining elements such as buddhi (intellective faculty), smriti (recollecting memory), and dhriti (grasping power). In contemporary scientific terms, these components collectively represent IQ. It is crucial to recognise that achieving a high IQ is influenced by various factors, including prenatal conditions (maternal nutrition and health), events during birth, postnatal circumstances, environment, and daily routines. Optimal IQ in children requires consistent attention to the mother's nutrition from the perinatal period up to early childhood, considering the prenatal, natal, and postnatal environments. Proper monitoring, coupled with adequate food and healthcare for the mother, can contribute to achieving optimal IQ in the child. Nutrition plays a vital role in cognitive development during early childhood, influencing brain growth and intellect. Unfortunately, parents often overlook this critical factor. Certain elements, such as nimitta (cause and effect knowledge), rupa grahanat (form recognition), sadrishyat (similarity understanding), saviparyaat (contrast comprehension), sattvaanubhandha (mind concentration), abhyasat (practice), gyanayogaat (metaphysical knowledge attainment), and punah srutaat (sequential partial communication), contribute to good memory. The impairment of indriya (sensory organs) can lead to a deficiency in knowledge. Therefore, a holistic approach that considers prenatal, natal, and postnatal factors, coupled with proper nutrition and healthcare, is crucial for fostering optimal intelligence and cognitive development in children.

The relationship between food habits and physical activity and the IQ of primary school children

BackgroundChildren's intelligence quotient (IQ) is influenced by various environmental and genetic variables. The current study aimed to determine how children's dietary choices and physical activity levels correlated with their IQ.MethodsA total of 190 students (111 girls and 79 boys) between the ages of 8 and 10 were chosen randomly for this cross-sectional research. For all children, questionnaires were utilized to gather information on their anthropometry, socio-economic position, food habits, and 24-h memory. Children's physical activity questionnaire (CPAQ) was also used to gauge their level of physical activity. Raven's color progressive intelligence test was also used to gauge children's IQ. All the questions may be filled out online with the assistance of parents. SPSS software was used to gather and evaluate the generated data.ResultsOf 190 respondents, 79 (41.6%) are males, and 111 (58.4%) are girls. The results of the study showed that, a positive correlation between children's IQ and physical activity (P = 0.017, r = 0.17), if this relationship was not seen by gender. In addition, a positive correlation was observed between the IQ and food habits scores in all children (P = 0.001, r = 0.24), as well as by gender, that is, male (P = 0.04, r = 0.23) and female (P = 0.006, r = 0.26), which indicates that children with better food habits were associated with higher IQ.ConclusionIt was shown that elementary school children's IQ, food habits, and degree of physical activity are all positively correlated.

Association between prenatal exposure to alkylphenols and intelligence quotient among preschool children: sex-specific effects

BackgroundWhile prenatal exposure to alkylphenols (APs) has been demonstrated to be associated with neurodevelopmental impairments in animals, the evidence from epidemiological studies remains limited and inconclusive. This study aimed to explore the link between AP exposure during pregnancy and the intelligence quotient (IQ) of preschool children.MethodsA total of 221 mother-child pairs from the Guangxi Zhuang Birth Cohort were recruited. Nonylphenol (NP), 4-tert-octylphenol (4-T-OP), 4-n-nonylphenol (4-N-NP), and 4-n-octylphenol were measured in maternal serum in early pregnancy. Childhood IQ was evaluated by the Fourth Edition of Wechsler Preschool and Primary Scale of the Intelligence at 3 to 6 years of age. The impact of APs on childhood IQ were evaluated by generalized linear models (GLMs), restricted cubic spline (RCS), and Bayesian kernel machine regression (BKMR).ResultsIn GLMs, prenatal exposure to NP and the second tertile of 4-T-OP exhibited an inverse association with full-scale IQ (FSIQ) (β = -2.38; 95% CI: -4.59, -0.16) and working memory index (WMI) (β = -5.24; 95% CI: -9.58, -0.89), respectively. Prenatal exposure to the third tertile of 4-N-NP showed a positive association with the fluid reasoning index (β = 4.95; 95% CI: 1.14, 8.77) in total children, as well as in girls when stratified by sex. A U-shaped relationship between maternal 4-T-OP and WMI was noted in total children and girls by RCS (all P nonlinear < 0.05). The combined effect primarily driven by NP, of maternal AP mixtures at concentrations above the 50th percentile exhibited an inverse trend on FSIQ in total children and girls in BKMR.ConclusionsPrenatal exposure to various APs affects IQ in preschool children, and there may be nonmonotonic and sex-specific effects. Further investigation across the population is required to elucidate the potential neurotoxic effects of APs.

Influence of parental education on the intelligence quotient profiles and socially adaptive behavior of school-age children with autism spectrum disorder in eastern China.

Intelligence quotient (IQ) and adaptive behavior are the influencing factors of autism spectrum disorder (ASD) in children entering mainstream schools. This study explored the association between parental education level, IQ, and adaptive behavior in ASD groups. A total of 257 school-age ASD children were enrolled in our study from January 2017 to June 2021. Their parents completed a standard demographic form, including age at autism diagnosis, gender, school placement, and parents' educational background. The Chinese version of the Wechsler Intelligence Scale for Children, Fourth Edition (WISC-IV) was completed by a certified assessor for each enrolled child. Parents were interviewed on adaptive behavior using the Chinese version of the Adaptive Behavior Assessment System, Second Edition (ABAS-II). The average IQ of school-age ASD children was 76.88 (standard deviation (SD)=22.62) and boys had higher IQ levels than girls. The IQ was positively correlated with age. The General Adaptive Composite (GAC) score was 82.47 (SD=15.86) and adaptive behavior did not increase with age. ASD children who attended mainstream schools had better adaptive behavior profiles than other children. The mother's education level showed a significant correlation with the IQ and adaptive behavior of autistic children, while the father's education level did not. Consequently, better training and support for parents may help autistic children enter mainstream schools, with adaptive training being the most urgently required skill for parents.

Comparison of intelligent development (IQ &amp; EQ) of children with cleft lip and palate

Background: Attention to the issue of intelligence and its promotion in children with cleft lip and cleft palate (CL and CP) is necessary to reduce their injuries in life. This study aimed to determine the intelligence quotient (IQ) and emotional intelligence (EQ) in children with CL and CP in comparison to healthy children. Materials and Methods: In this descriptive study, 140 children, including 70 children with CL and CP, were selected from the Children treated in Craniofacial and Cleft Research Center, Spearman correlation, ANOVA and 70 healthy children were selected from the Pediatric Dentistry Department of Isfahan University, in the age range of 5–9 years. After obtaining the consent of the children's parents, the Raven IQ questionnaire and the Mayer and Salovey EQ questionnaire were given to the children. Data were analyzed by the Pearson correlation coefficient tests (α =0.05). Results: EQ score in healthy children was significantly higher than in children with CL and CP (P &lt; 0.001). The percentage of IQ cognitive intelligence in healthy children and children with CL and CP was not significantly different (P = 0.641). In healthy children, no significant relationship was observed between cognitive intelligence IQ and EQ (r = 0.018, P = 0.882). However, among children with CL and CP, there was a significant inverse relationship between cognitive intelligence IQ and EQ (P &lt; 0.001, r = −0.526). Conclusion: CL and CP have no effect on IQ in children, but it does affect EQ.

Developmental predictors of mathematics achievement at the end of Year 1

Abstract: This study examined the predictive role of child cognitive, social, emotional, and behavioural dimensions assessed at the age of 4½, as well as of the traditional variables related to academic school readiness before the entry to primary school, on mathematics achievement at the end of Year 1. A sample of 58 Portuguese children and their parents participated in this longitudinal study. Initial correlations indicated significant associations between child intelligence quotient (IQ), inhibitory control, set-shifting, dysregulation profile, academic school readiness, and their subsequent performance in mathematics. A hierarchical regression analysis showed that inhibitory control at 4½ years significantly predicted mathematics achievement at the end of Year 1 over and above the effect of academic school readiness before entering primary school. These results add to the existing literature by highlighting the impact of child executive functioning assessed during the preschool years on subsequent mathematics performance in early school years.

Children's cognitive impairment associated with cassava cyanide in Democratic Republic of the Congo: Burden of disease.

Worldwide, tens of millions of children rely on cassava as a dietary staple throughout their formative years of brain and behavioral development. Recently, it was discovered that cassava cyanide can impair children's neurocognitive development at relatively low exposures. We revisited the World Health Organization's foodborne disease burden estimate of cassava cyanide, focusing on the new health endpoint of children's cognitive impairment in Democratic Republic of the Congo (DRC). The loss of Intelligence Quotient (IQ) scores was used to measure the endpoint of cognitive impairment caused by cassava cyanide exposure, which was estimated based on the concentration-effect relationship between children's IQ scores and cyanide concentrations in flour. We estimated the burden of intellectual disability (ID) associated with cassava cyanide exposure in terms of disability-adjusted life years (DALYs). The median content of cyanide in cassava samples collected from DRC was 12.5 mg/kg, causing a median decrement to children's IQ of 2.37 points. The estimated number of children with ID associated with cassava cyanide exposure was 1,643 cases, although 1,567 of these cases (95%) were mild ID. The burden of cognitive impairment attributable to cassava cyanide in DRC alone was 13,862 DALYs per 100,000 children, or 3.01 million for all children under age 5. The results of the study, showing a significant burden of cassava cyanide-related cognitive impairment in children even at relatively low doses, can contribute to the implementation of cost-effective interventions to make cassava consumption safer for children in high-risk rural areas of DRC.

Brain metabolic profile assessed by magnetic resonance spectroscopy in ‎‎children with Down syndrome: Relation to intelligence quotient.

Down syndrome (DS) is one of the most common causes of intellectual disability. Children with DS have varying intelligence quotient (IQ) that can predict their learning abilities. To assess the brain metabolic profiles of children with DS and compare them to standard controls, using magnetic resonance spectroscopy (MRS) and correlating the results with IQ. This case-control study included 40 children with DS aged 6-15 years and 40 age and sex-matched healthy children as controls. MRS was used to evaluate ratios of choline/creatine (Cho/Cr), N-acetyl aspartic acid/creatine (NAA/Cr), and myoinositol/creatine (MI/Cr (in the frontal, temporal, and occipital lobes and basal ganglia and compared to controls and correlated with IQ. Children with DS showed significant reductions in NAA/Cr and MI/Cr and a non-significant reduction in Cho/Cr in frontal lobes compared to controls. Additionally, we observed significant decreases in NAA/Cr, MI/Cr, and Cho/Cr in the temporal and occipital lobes and basal ganglia in children with DS compared to controls. Furthermore, there was a significant correlation between IQ and metabolic ratios in the brains of children with DS. Brain metabolic profile could be a good predictor of IQ in children with DS.

Long-term intellectual and developmental outcomes after pediatric epilepsy surgery: A systematic review and meta-analysis.

In addition to the primary aim of seizure freedom, a key secondary aim of pediatric epilepsy surgery is to stabilize and, potentially, optimize cognitive development. Although the efficacy of surgical treatment for seizure control has been established, the long-term intellectual and developmental trajectories are yet to be delineated. We conducted a systematic review and meta-analysis of studies reporting pre- and postsurgical intelligence or developmental quotients (IQ/DQ) of children with focal lesional epilepsy aged ≤18 years at epilepsy surgery and assessed at >2 years after surgery. We determined the IQ/DQ change and conducted a random-effects meta-analysis and meta-regression to assess its determinants. We included 15 studies reporting on 341 patients. The weighted mean age at surgery was 7.1 years (range = .3-13.8). The weighted mean postsurgical follow-up duration was 5.6 years (range = 2.7-12.8). The overall estimate of the mean presurgical IQ/DQ was 60 (95% confidence interval [CI] = 47-73), the postsurgical IQ/DQ was 61 (95% CI = 48-73), and the change was +.94 IQ/DQ (95% CI = -1.70 to 3.58, p = .486). Children with presurgical IQ/DQ ≥ 70 showed a tendency for higher gains than those with presurgical IQ/DQ < 70 (p = .059). Higher gains were determined by cessation of antiseizure medication (ASM; p = .041), not just seizure freedom. Our findings indicate, on average, stabilization of intellectual and developmental functioning at long-term follow-up after epilepsy surgery. Once seizure freedom has been achieved, ASM cessation enables the optimization of intellectual and developmental trajectories in affected children.

Integrative transcriptome and metabolome analysis of fluoride exposure induced developmental neurotoxicity in mouse brain

Fluoride could cause developmental neurotoxicity and significantly affect the intelligence quotient (IQ) of children. However, the systematic mechanism of neuronal damage caused by excessive fluoride administration in offspring is largely unknown. Here, we present a comprehensive integrative transcriptome and metabolome analysis to study the mechanism of developmental neurotoxicity caused by chronic fluoride exposure. Comparing the different doses of fluoride treatments in two generations revealed the exclusive signature of metabolism pathways and gene expression profiles. In particular, neuronal development and synaptic ion transport are significantly altered at the gene expression and metabolite accumulation levels for both generations, which could act as messengers and enhancers of fluoride-induced systemic neuronal injury. Choline and arachidonic acid metabolism, which highlighted in the integrative analysis, exhibited different regulatory patterns between the two generations, particularly for synaptic vesicle formation and inflammatory factor transport. It may suggest that choline and arachidonic acid metabolism play important roles in developmental neurotoxic responses for offspring mice. Our study provides comprehensive insights into the metabolomic and transcriptomic regulation of fluoride stress responses in the mechanistic explanation of fluoride-induced developmental neurotoxicity.

3 Fluoride Exposure and Hypothyroidism in Pregnant Women: A Potential Mechanism of Fluoride Neurotoxicity

Objective:Fluoride exposure has been associated with thyroid dysfunction, but fluoride's impact on thyroid function in pregnancy is unclear, especially during early gestation when the fetus is dependent on maternal thyroid hormone. We examined the potential thyroid-disrupting effects of maternal fluoride exposure in pregnancy and tested whether thyroid disruption in pregnancy mediates the association between maternal fluoride exposure and child intelligence quotient (IQ) among Canadian mother-child dyads living in areas with optimal fluoridation.Participants and Methods:We measured fluoride concentrations in drinking water and in spot urine samples collected in each trimester from pregnant women enrolled in the Maternal-Infant Research on Environmental Chemicals study. We also measured thyroid hormone (thyroid stimulating hormone [TSH], free thyroxine [FT4], and total thyroxine [TT4]) levels during the first trimester of pregnancy and categorized women as euthyroid (n=1301), subclinical hypothyroid (n=100), or primary hypothyroid (n=28). Those categorized as primary hypothyroid were combined with an additional 79 women who reported clinical diagnoses at time of study enrolment (total n=107). In a sample of 1508 women, we used logistic regression to estimate the association between fluoride exposure and risk of either subclinical or primary hypothyroidism, separately, and linear regression to estimate associations between fluoride exposure and women's thyroid hormone levels (TSH, FT4, TT4). We tested effect modification by child sex and thyroid peroxidase (TPO) antibody status. In a subsample of 439 mother-child pairs, we measured child Full-Scale IQ (FSIQ) at 3-4 years of age using the Wechsler Preschool and Primary Scale of Intelligence. We used linear regression to test associations between maternal hypothyroidism or thyroid hormone levels, and children's FSIQ scores. Finally, mediation analysis in the counterfactual framework was used to estimate the proportion of the effect of maternal fluoride exposure on child FSIQ mediated by maternal hypothyroidism, through evaluation of the natural direct (not through hypothyroidism) and indirect (through hypothyroidism) effects.Results:Using categorical measures of thyroid status, a 0.5 mg/L increase in water fluoride concentration was associated with a 1.64 (95% confidence interval [CI], 1.04 to 2.58) increased odds of primary hypothyroidism. This association was stronger among women with normal TPO antibody levels (&lt; 5.61 IU/mL) (odds ratio, 2.80; 95% CI, 1.24 to 6.36). In contrast, we did not find a significant association between maternal urinary fluoride and hypothyroidism. For continuous measures of thyroid hormone levels, a 1 mg/L increase in maternal urinary fluoride was associated with a 35% (p=0.01) increase in TSH among women pregnant with a female fetus. In our subsample analyses, children born to women with primary hypothyroidism had lower FSIQ than children of euthyroid women, especially among boys (B, 8.78; 95% CI, -16.78 to -0.79). In contrast, maternal TSH, FT4, and TT4 levels were not significantly associated with child FSIQ scores. Maternal primary hypothyroidism did not significantly mediate the relationship between maternal water fluoride concentration and child FSIQ (p natural indirect effect= .35).Conclusions:Fluoride in drinking water may increase the risk of hypothyroidism in pregnancy. Thyroid dysfunction in pregnancy may be one mechanism underlying developmental neurotoxicity of fluoride.