Meconium Concentrations of Pesticides and Risk of Hypospadias: A Case-Control Study in Brittany, France.

BACKGROUND: Hypospadias is a male genital tract defect for which an increase in prevalence has been documented over the last few decades. A role for environmental risk factors is suspected, including prenatal exposure to pesticides. OBJECTIVES: To study the risk of hypospadias in association with multiple pesticide measurements in meconium samples. METHODS: The Brittany Registry of Congenital Anomalies (France) conducted a case-control study between 2012 and 2018. Cases were hypospadias, ascertained by a pediatrician and a pediatric surgeon, excluding genetic conditions, following European Surveillance of Congenital Anomalies guidelines (N = 69). Controls (N = 135) were two male infants without congenital anomaly born after each case in the same maternity unit. Mothers in the maternity units completed a self-administered questionnaire, we collected medical data from hospital records, and medical staff collected meconium samples. We performed chemical analysis of 38 pesticides (parent compound and/or metabolite) by UHPLC/MS/MS following strict quality assurance/quality control criteria and blind to case-control status. We carried out logistic regression accounting for frequency-matching variables and major risk factors. RESULTS: Among the 38 pesticides measured, 16 (42%) were never detected in the meconium samples, 18 (47%) were in <5% of samples, and 4 (11%) in ≥5% of the samples. We observed an association between the detection of fenitrothion in meconium and the risk of hypospadias (OR = 2.6 [1.0-6.3] with n cases = 13, n controls = 21), but not the other pesticides. CONCLUSIONS: Our small study provides a robust assessment of fetal exposure. Fenitrothion's established antiandrogenic activities provide biologic plausibility for our observations. Further studies are needed to confirm this hypothesis.

Early exposure to mercury and cardiovascular function of seven-year old children in Guadeloupe (French West Indies).

BACKGROUND: The cardiotoxicity of prenatal exposure to mercury has been suggested in populations having regular contaminated seafood intake, though replications in the literature are inconsistent. METHODS: The Timoun Mother-Child Cohort Study was set up in Guadeloupe, an island in the Caribbean Sea where seafood consumption is regular. At seven years of age, 592 children underwent a medical examination, including cardiac function assessment. Blood pressure (BP) was taken using an automated blood pressure monitor, heart rate variability (HRV, 9 parameters) and electrocardiogram (ECG) characteristics (QT, T-wave parameters) were measured using Holter cardiac monitoring during the examination. Total mercury concentrations were measured in cord blood at birth (median = 6.6 µg/L, N = 399) and in the children's blood at age 7 (median = 1.7 µg/L, N = 310). Adjusted linear and non-linear modelling was used to study the association of each cardiac parameter with prenatal and childhood exposures. Sensitivity analyses included co-exposures to lead and cadmium, adjustment for maternal seafood consumption, selenium and polyunsaturated fatty acids (n3-PUFAs), and for sporting activity. RESULTS: Higher prenatal mercury was associated with higher systolic BP at 7 years of age (ßlog2 = 1.02; 95% Confidence Interval (CI) = 0.10, 1.19). In boys, intermediate prenatal exposure was associated with reduced overall HRV and parasympathetic activity, and longer QT was observed with increasing prenatal mercury (ßlog2 = 4.02; CI = 0.48, 7.56). In girls, HRV tended to increase linearly with prenatal exposure, and no association was observed with QT-wave related parameters. Mercury exposure at 7 years was associated with decreased BP in girls (ßlog2 = -1.13; CI = -2.22, -0.004 for diastolic BP). In boys, the low/high-frequency (LF/HF) ratio increased for intermediate levels of exposure. CONCLUSION: Our study suggests sex-specific and non-monotonic modifications in some cardiac health parameters following prenatal exposure to mercury in pre-pubertal children from an insular fish-consuming population.

Prenatal exposure to persistent organic pollutants and its impact on the ovarian reserve at 12 years old in the PELAGIE mother-child cohort.

Although the ovarian reserve is constituted in utero, the literature on the effects of persistent organic pollutants (POPs) during this vulnerable period on the ovarian reserve later in life is limited. We investigated whether cord blood concentrations of POPs were associated with decreased anti-Müllerian hormone (AMH, a marker of the ovarian reserve) levels in girls at the age of 12. We included 239 girls from the French mother-child PELAGIE cohort. POP concentrations of 14 organochlorine pesticides, 17 polychlorinated biphenyls (PCBs), 5 polybrominated diphenyl ethers, and 9 per-polyfluoroalkyl substances were measured on cord blood sampled at birth. During a follow-up study at 12 years old, blood samples were collected to measure AMH levels. Single-exposure associations were examined with multivariable linear regression models adjusted a priori for potential confounders. Stratification on menarche status was also performed. Mixture effects were investigated using quantile g-computation and Bayesian kernel machine regression. Overall, 16 POPs were measured in at least 30% of samples. No significant associations were found in multivariable linear regressions, except for the third tercile of exposure to PCB 180 which was statistically significantly associated with an increase in AMH levels at 12 years old (Tercile 2 v. Tercile 1: 0.13 ng/mL, 95% CI = -0.29, 0.56; Tercile 3 v. Tercile 1: 0.51 ng/mL, 95% CI = 0.02, 0.99). Additionally, in post-menarcheal girls (N = 104) only, the second tercile of p,p'-DDE was statistically significantly associated with decreased AMH levels at 12 years old (Tercile 2 v. Tercile 1: -0.61 ng/mL, 95% CI = -1.16, -0.05, Tercile 3 v. Tercile 1: 0.02 ng/mL, 95% CI = -0.51, 0.54). Both mixture models returned null associations. Despite the limited associations observed in this study, we recommend exploring these associations in larger mother-child cohorts and at older ages.

Occupational exposure to organic solvents during pregnancy and child behavior from early childhood to adolescence.

BACKGROUND: Organic solvents are used in formulating an extensive range of products for professional use. Animal and human studies suggest that in utero solvent exposure may affect neurodevelopment. Our objective was to assess the association between occupational exposure to solvents during pregnancy and child behavior aged 2-12 years. METHODS: The French mother-child cohort PELAGIE (2002-2006) included 3,421 women recruited in early pregnancy. Occupational exposure to solvents was self-reported. For 459 children, parents used a questionnaire derived from the Child Behavior Checklist and the Preschool Social Behavior Questionnaire to assess their child's behavior, at age 2, and the Strengths and Difficulties Questionnaire at ages 6 and 12. A cross-lagged structural equation modeling approach was used to assess direct and indirect associations between exposure and child behavior. RESULTS: At age 2, an increased externalizing behavior score was suggested with prenatal exposure to solvents (mean change in standardized score (95%CI): 0.28 (-0.01, 0.57) for occasional exposure and 0.23 (-0.05, 0.51) for regular exposure). At ages 6 and 12, distinct sex-specific patterns were observed: among boys, no association with externalizing behavior was observed, while among girls, an association was seen for both occasional and regular exposure (total effect at age 12: 0.45 (0.06,0.83) and 0.40 (0.03, 0.76), respectively). For both sexes, occasional exposure may be associated with internalizing behavior at ages 6 and 12 (total effect at age 6: 0.37 (0.06, 0.68) and at age 12: 0.27 (-0.08, 0.62)). CONCLUSIONS: Occupational exposure to solvents during pregnancy may impact child behavior through either direct or cumulative effects during childhood; these associations may persist until early adolescence, especially among girls.

Persistent Organic Pollutant Exposure and Thyroid Function among 12-Year-Old Children.

INTRODUCTION: Polychlorobiphenyls (PCBs), organochlorine pesticides (OCPs), and per- and polyfluoroalkyl substances (PFASs) are persistent organic pollutants (POPs) having numerous toxicological properties, including thyroid endocrine disruption. Our aim was to assess the impact of POPs on thyroid hormones among 12-year-old children, while taking puberty into consideration. METHODS: Exposure to 7 PCBs, 4 OCPs, and 6 PFASs (in µg/L), and free tri-iodothyronine (fT3, pg/mL), free thyroxine (fT4, ng/dL), and thyroid-stimulating hormones (TSH, mIU/L) were assessed through blood-serum measurements at age 12 years in 249 boys and 227 girls of the PELAGIE mother-child cohort (France). Pubertal status was clinically rated using the Tanner stages. For each POP, associations were estimated using linear regression, adjusted for potential confounders. RESULTS: Among boys, hexachlorobenzene and perfluorodecanoic acid were associated with decreased fT3 (log-scale; ß [95% confidence interval] = -0.07 [-0.12,-0.02] and ß = -0.03 [-0.06,-0.00], respectively). Intermediate levels of perfluorohexanesulfonic acid (PFHxS) and PCB180 were associated, respectively, with increased and decreased fT4. After stratification on pubertal status, PCBs and OCPs were associated with decreased TSH only in the more advanced Tanner stages (3-5) and with decreased fT3 among early Tanner stages (1-2). Among girls, PFHxS was associated with decreased TSH (log-scale; ß = -0.15 [-0.29,-0.00]), and perfluorooctanoic acid was associated with decreased fT3 (ß2nd_tercile = -0.06 [-0.10,-0.03] and ß3rd_tercile = -0.04 [-0.08,-0.00], versus. 1st tercile). DISCUSSION: This cross-sectional study highlights associations between some POPs and thyroid function disruption, which appears consistent with the literature. Considering that the associations were sex-specific and moderated by pubertal status in boys, complex endocrine interactions are likely involved.

Heavy metals and diminished ovarian reserve: single-exposure and mixture analyses amongst women consulting in French fertility centres.

RESEARCH QUESTION: Do heavy metals affect the risk of diminished ovarian reserve (DOR) in women of reproductive age? DESIGN: A total of 139 cases and 153 controls were included between 2016 and 2020. The participants were aged between 18 and 40 years and attended consultations for couple infertility in one of four fertility centres in western France. Cases of DOR were defined as women with an antral follicle count less than 7, anti-Müllerian hormone levels 1.1 ng/ml or less, or both. Controls were frequency matched on age groups and centres, and were women with normal ovarian reserve evaluations, no malformations and menstrual cycles between 26 and 35 days. Heavy metals (lead, mercury, cadmium and chromium) were measured in whole blood at inclusion. Single-exposure associations were examined with multivariable logistic regressions adjusted on potential confounders. Mixture effects were investigated with quantile g-computation and Bayesian kernel machine regression (BKMR). RESULTS: Chromium as a continuous exposure was significantly associated with DOR in unadjusted models (OR 2.07, 95% CI 1.04 to 4.13) but the association was no longer significant when confounders were controlled for (adjusted OR 2.75, 95% CI 0.88 to 8.60). Similarly, a statistically significant association was observed for the unadjusted second tercile of cadmium exposure (OR 1.87, 95% CI 1.06 to 3.30); however, this association was no longer statistically significant after adjustment. None of the other associations tested were statistically significant. Quantile g-computation and BKMR both yielded no significant change of risk of DOR for the mixture of metals, with no evidence of interaction. CONCLUSIONS: Weak signals that some heavy metals could be associated with DOR were detected. These findings should be replicated in other studies.

Prenatal exposure to persistent organic pollutants and molar-incisor hypomineralization among 12-year-old children in the French mother-child cohort PELAGIE.

BACKGROUND: Exceptional episodes of exposure to high levels of persistent organic pollutants have already been associated with developmental defects of enamel among children, but knowledge is still scarce concerning the contribution of background levels of environmental contamination. METHODS: Children of the French PELAGIE mother-child cohort were followed from birth, with collection of medical data and cord blood samples that were used to measure polychlorinated biphenyls (PCBs), organochlorine pesticides (OCs), and perfluorinated alkyl substances (PFASs). At 12 years of age, molar-incisor hypomineralization (MIH) and other enamel defects (EDs) were recorded for 498 children. Associations were studied using logistic regression models adjusted for potential prenatal confounders. RESULTS: An increasing log-concentration of ß-HCH was associated with a reduced risk of MIH and EDs (OR = 0.55; 95% CI, 0.32-0.95, and OR = 0.65; 95% CI, 0.43-0.98, respectively). Among girls, intermediate levels of p,p'-DDE were associated with a reduced risk of MIH. Among boys, we observed an increased risk of EDs in association with intermediate levels of PCB 138, PCB 153, PCB 187, and an increased risk of MIH with intermediate levels of PFOA and PFOS. CONCLUSIONS: Two OCs were associated with a reduced risk of dental defects, whereas the associations between PCBs and PFASs and EDs or MIH were generally close to null or sex-specific, with an increased risk of dental defects in boys. These results suggest that POPs could impact amelogenesis. Replication of this study is required and the possible underlying mechanisms need to be explored.

Prenatal and childhood chlordecone exposure, cognitive abilities and problem behaviors in 7-year-old children: the TIMOUN mother-child cohort in Guadeloupe.

BACKGROUND: Chlordecone is a highly persistent organochlorine insecticide that was intensively used in banana fields in the French West Indies, resulting in a widespread contamination. Neurotoxicity of acute exposures in adults is well recognized, and empirical data suggests that prenatal exposure affects visual and fine motor developments during infancy and childhood, with greater susceptibility in boys. OBJECTIVE: To assess the associations between pre- and postnatal exposures to chlordecone and cognitive and behavioral functions in school-aged children from Guadeloupe. METHODS: We examined 576 children from the TIMOUN mother-child cohort in Guadeloupe at 7 years of age. Concentrations of chlordecone and other environmental contaminants were measured in cord- and children's blood at age 7 years. Cognitive abilities of children were assessed with the Wechsler Intelligence Scale for Children-IV (WISC-IV), and externalizing and internalizing problem behaviors documented with the Strengths and Difficulties Questionnaire (SDQ) completed by the child's mother. We estimated covariate-adjusted associations between cord- and 7-years chlordecone concentrations and child outcomes using structural equations modeling, and tested effect modification by sex. RESULTS: Geometric means of blood chlordecone concentrations were 0.13 µg/L in cord blood and 0.06 µg/L in children's blood at age 7 years. A twofold increase in cord blood concentrations was associated with 0.05 standard deviation (SD) (95% Confidence Interval [CI]: 0.0, 0.10) higher internalizing problem scores, whereas 7-years chlordecone concentrations were associated with lower Full-Scale IQ scores (FSIQ) and greater externalized behavioral problem scores. A twofold increase in 7-year chlordecone concentrations was associated with a decrease of 0.67 point (95% CI: -1.13, -0.22) on FSIQ and an increase of 0.04 SD (95% CI: 0.0, 0.07) on externalizing problems. These associations with Cognitive abilities were driven by decreases in perceptive reasoning, working memory and verbal comprehension. Associations between 7-year exposure and perceptive reasoning, working memory, and the FSIQ were stronger in boys, whereas cord blood and child blood associations with internalizing problems were stronger in girls. CONCLUSIONS: These results suggests that cognitive abilities and externalizing behavior problems at school age are impaired by childhood, but not in utero, exposure to chlordecone, and that prenatal exposure is related to greater internalizing behavioral problems.

Prenatal and childhood exposure to chlordecone and adiposity of seven-year-old children in the Timoun mother-child cohort study in Guadeloupe (French West Indies).

BACKGROUND: Exposure to persistent environmental organic pollutants may contribute to the development of obesity among children. Chlordecone is a persistent organochlorine insecticide with estrogenic properties that was used in the French West Indies (1973-1993) and is still present in the soil and the water and food consumed by the local population. We studied the association between prenatal and childhood exposure to chlordecone and the adiposity of prepubertal children. METHODS: Within the Timoun Mother-Child Cohort Study in Guadeloupe (French West Indies), 575 children had a medical examination at seven years of age, including adiposity measurements. A Structural Equation Modeling approach was used to create a global adiposity score from four adiposity indicators: the BMI z-score, percentage of fat mass, sum of the tricipital and subscapular skinfold thickness, and waist-to-height ratio. Chlordecone concentrations were measured in cord blood at birth and in the children's blood at seven years of age. Models were adjusted for prenatal and postnatal covariates. Sensitivity analyses accounted for co-exposure to PCB-153 and pp'-DDE. Mediation analyses, including intermediate birth outcomes, were conducted. RESULTS: Prenatal chlordecone exposure tended to be associated with increased adiposity at seven years of age, particularly in boys. However, statistical significance was only reached in the third quartile of exposure and neither linear nor non-linear trends could be formally identified. Consideration of preterm birth or birth weight in mediation analyses did not modify the results, as adjustment for PCB-153 and pp'-DDE co-exposures. CONCLUSION: Globally, we found little evidence of an association between chlordecone exposure during the critical in utero or childhood periods of development and altered body-weight homeostasis in childhood. Nevertheless, some associations we observed at seven years of age, although non-significant, were consistent with those observed at earlier ages and would be worth investing during further follow-ups of children of the Timoun Mother-Child Cohort Study when they reach puberty.

Effects of polychlorinated biphenyls exposure on physical growth from birth to childhood and adolescence: A prospective cohort study.

BACKGROUND/AIMS: Given that their traditional lifestyle and diet still relies on fish and other marine species for sustenance, the Inuit are highly exposed to polychlorinated biphenyls (PCBs) and PCBs are increasingly linked to obesity. However, evidence is not consistent regarding which periods of exposure are most relevant. In this study, we examine whether in utero, childhood, and adolescent exposure to PCBs are related to physical growth at adolescence. METHOD: Inuit adolescents from Canada (N=212) enrolled in a prospective longitudinal cohort study since birth were assessed for height, weight, body mass index (BMI), fat mass index (FMI) and fat free mass index (FFMI) at 18 years of age. PCB 153 concentrations were quantified in blood samples obtained at birth (umbilical cord), 11, and 18 years of age. Maternal anthropometrics were measured and those for the newborns collected from medical records. Data on biological mothers and participants' sociodemographic characteristics and food security were collected using interviews. Multiple linear regression analyses were used to test associations between PCB 153 concentrations and adolescent anthropometric measures. RESULTS: Cord PCB 153 was not related to height or FFMI at adolescence. By contrast, analyses showed that cord PCB 153 was related to higher BMI, FMI and marginally to weight in girls but not boys. Child PCB 153 was not related to height, weight or FFMI in adolescence. Child PCB 153 was related to lower BMI and FMI at adolescence in both sexes, particularly among those considered overweight or obese during childhood. Adolescent PCB 153 was not associated with any outcome. CONCLUSION: This study suggests that prenatal exposure to PCBs may have a long-term effect on growth in early adulthood among girls and identifies the peri-pubertal period as another window of sensitivity for the action of PCBs. Our findings also suggest that exposure to PCBs and body size be documented in multiple time periods from infancy to adulthood.

Prenatal exposure to glycol ethers and response inhibition in 6-year-old children: The PELAGIE cohort study.

BACKGROUND: Exposure to glycol ethers (GEs) is suspected of impairing neurodevelopment in children, but the specific impact on their inhibitory capacity, a central deficit of ADHD, has never been studied. We aimed to assess the impact of prenatal exposure to GEs on the response inhibition of children aged six years. METHODS: In total, 169 mother-child pairs from the French cohort PELAGIE (2002-2006) were studied. Maternal urinary concentrations of six GE metabolites (alkoxycarboxylic acids) were measured during pregnancy. Multiple imputation by quantile regression was used to handle non-detected values and the data were then classified into quartiles. Inhibition of children was evaluated by the Rhythmic Continuous Performance Test 90 (R-CPT90). The inhibition score (percentage of correct responses to non-target stimuli) was corrected for compliance with the instructions (percentage of correct responses to target stimuli). The analysis used a multiple linear regression model, adjusting for confounding factors for each metabolite. RESULTS: Median concentrations of metabolites ranged from 0.02 mg/L (Ethoxyacetic acid, EAA) to 0.39 mg/L (Phenoxyacetic acid, PhAA). The median corrected inhibition score was 37.9% [first quartile: 29.8 - third quartile: 47.9]. We found a negative and statistically significant association between the inhibition score and prenatal urinary EAA concentration (p-trend = 0.03), with a significant ß coefficient for the third quartile (ß = -0.064; 95% confidence interval: -0.121, -0.007). There were no statistically significant associations for the other five metabolites. CONCLUSION: These results are consistent with the hypothesis of possible impact of prenatal environmental exposure on inhibitory capacity among children. Data about the GEs metabolized to EAA (history of exposure sources and toxicokinetics) should be gathered to further interpret these results and guide precautionary measures.

Association between early lead exposure and externalizing behaviors in adolescence: A developmental cascade.

BACKGROUND: Lead (Pb) exposure is associated with adverse neurological development. Most notably, it has been observed through externalizing behavior symptoms, as observed among Inuit children from northern Québec. Evidence for a persistent neurological impact of early Pb exposure later in life is however scarce. Pb exposure may initiate a developmental cascade that increases the risk of long-term behavior problems. OBJECTIVES: Testing for direct associations between childhood Pb concentrations and adolescent externalizing symptoms and substance use, as well as indirect associations through childhood behavior assessments. METHODS: The study sample is a longitudinal cohort of Inuit children (n = 212) followed since birth. Blood Pb concentrations were measured during childhood (median age = 11.4 years) and adolescence (median age = 18.5 years). Externalizing/inattentive behavior were teacher-assessed through the Teacher Report Form and the Disruptive Behavior Disorders Rating Scale for children. At the adolescence follow-up, behavior problems were self-reported by filling Achenbach's Youth Self-Report, the Barkley Adult ADHD-IV Rating Scale, and the Diagnostics Interview Schedule for Children. Adolescent substance use was also self-assessed through the DEP-ADO. Direct and indirect associations of child Pb concentrations with adolescent outcomes were tested through mediation models. RESULTS: Child blood Pb concentrations were not directly associated with any adolescent outcomes. On the contrary, childhood Pb exposure was indirectly associated, through childhood externalizing behavior assessments, with adolescent externalizing behaviors, binge drinking, and cannabis use. These indirect associations held after controlling for adolescents' concurrent Pb blood concentrations. DISCUSSION: Our results highlight the indirect but lasting effects of child Pb exposure on adolescent behavior problems, and the importance of childhood externalizing behavior in this relationship. Adverse early-life environment put children on a riskier developmental trajectory, increasing their likelihood of lifelong psychological, social and health problems.

Prenatal exposure to glycol ethers and cryptorchidism and hypospadias: a nested case-control study.

OBJECTIVES: Glycol ethers (GE) are oxygenated solvents frequently found in occupational and consumer products. Some of them are well-known testicular and developmental animal toxicants. This study aims to evaluate the risk of male genital anomalies in association with prenatal exposure to GE using urinary biomarkers of exposure. METHODS: We conducted a case-control study nested in two joint mother-child cohorts (5303 pregnant women). Cases of cryptorchidism and hypospadias were identified at birth and confirmed during a 2-year follow-up period (n=14 cryptorchidism and n=15 hypospadias). Each case was matched to three randomly selected controls within the cohorts for region of inclusion and gestational age at urine sampling. Concentrations of five GE acidic metabolites were measured in spot maternal urine samples collected during pregnancy. ORs were estimated with multivariate conditional logistic regressions including a Firth's penalisation. RESULTS: Detection rates of urinary GE metabolites ranged from 8% to 93% and only two were sufficiently detected (>33%) in each cohort to be studied: methoxyacetic acid (MAA) and phenoxyacetic acid (PhAA). A significantly higher risk of hypospadias was associated with the highest tertile of exposure to MAA: OR (95% CI) 4.5(1.4 to 23.4). No association were observed with urinary concentration of PhAA, nor with the risk of cryptorchidism. CONCLUSIONS: In view of the toxicological plausibility of our results, this study, despite its small sample size, raises concern about the potential developmental toxicity of MAA on the male genital system and calls for thorough identification of current sources of exposure to MAA.

Correction to: Occupational exposure to organic solvents during pregnancy and childhood behavior: findings from the PELAGIE birth cohort (France, 2002-2013).

Following publication of the original article [1], the author asked to replace Table 2 with the correct version.

Occupational exposure to organic solvents during pregnancy and childhood behavior: findings from the PELAGIE birth cohort (France, 2002-2013).

BACKGROUND: Numerous industries use organic solvents, and many workers from various occupational sectors are exposed to these known neurotoxicants, including pregnant women. Our objective is to explore whether occupational exposure of pregnant women to solvents may impair the neurodevelopment of their babies and consequently affect their behavior in childhood. METHODS: Within the French birth cohort PELAGIE, parents assessed their children's internalizing and externalizing behaviors using items from the Child Behavior Checklist and the Preschool Social Behavior Questionnaire at age 2, and the Strength and Difficulties Questionnaire at age 6. The occupational exposure to solvents of the pregnant women was self-reported prospectively at the beginning of their pregnancy (N = 715). We applied structural equation modeling to capture the longitudinal association of prenatal exposure to solvents with children's behavioral traits at 2 and 6 years. RESULTS: Increased externalizing behavior score at age 2 was associated with prenatal exposure to solvents (standardized score: 0.34 (95% CI = 0.11, 0.57) for occasional exposure and 0.26 (0.05, 0.48) for regular exposure). This association was attenuated at age 6 (0.22 (- 0.02, 0.47) for occasional exposure and 0.07 (- 0.14, 0.28) for regular exposure). No association was observed for internalizing behavior. CONCLUSIONS: Pregnant women's occupational exposure to solvents may affect their children's behavior in early childhood. This effect may be attenuated with aging or diluted by the effects of other postnatal predictors.

Association of light-to-moderate alcohol drinking in pregnancy with preterm birth and birth weight: elucidating bias by pooling data from nine European cohorts.

Women who drink light-to-moderately during pregnancy have been observed to have lower risk of unfavourable pregnancy outcomes than abstainers. This has been suggested to be a result of bias. In a pooled sample, including 193 747 live-born singletons from nine European cohorts, we examined the associations between light-to-moderate drinking and preterm birth, birth weight, and small-for-gestational age in term born children (term SGA). To address potential sources of bias, we compared the associations from the total sample with a sub-sample restricted to first-time pregnant women who conceived within six months of trying, and examined whether the associations varied across calendar time. In the total sample, drinking up to around six drinks per week as compared to abstaining was associated with lower risk of preterm birth, whereas no significant associations were found for birth weight or term SGA. Drinking six or more drinks per week was associated with lower birth weight and higher risk of term SGA, but no increased risk of preterm birth. The analyses restricted to women without reproductive experience revealed similar results. Before 2000 approximately half of pregnant women drank alcohol. This decreased to 39% in 2000-2004, and 14% in 2005-2011. Before 2000, every additional drink was associated with reduced mean birth weight, whereas in 2005-2011, the mean birth weight increased with increasing intake. The period-specific associations between low-to-moderate drinking and birth weight, which also were observed for term SGA, are indicative of bias. It is impossible to distinguish if the bias is attributable to unmeasured confounding, which change over time or cohort heterogeneity.

Behavioural disorders in 6-year-old children and pyrethroid insecticide exposure: the PELAGIE mother-child cohort.

OBJECTIVE: The potential impact of environmental exposure to pyrethroid insecticides on child neurodevelopment has only just started to receive attention despite their widespread use. We investigated the associations between prenatal and childhood exposure to pyrethroid insecticides and behavioural skills in 6-year-olds. METHODS: The PELAGIE cohort enrolled 3421 pregnant women from Brittany, France between 2002 and 2006. 428 mothers were randomly selected for the study when their children turned 6, and 287 (67%) agreed to participate. Children's behaviour was assessed using the Strengths and Difficulties Questionnaire (SDQ). Three subscales (prosocial behaviour, internalising disorders and externalising disorders) were considered. Five pyrethroid metabolites were measured in maternal and child urine samples collected between 6 and 19 gestational weeks and at 6 years of age, respectively. Logistic regression and reverse-scale Cox regression models were used to estimate the associations between SDQ scores and urinary pyrethroid metabolite concentrations, adjusting for organophosphate metabolite concentrations and potential confounders. RESULTS: Increased prenatal cis-3-(2,2-dichlorovinyl)-2,2-dimethylcyclopropane carboxylic acid (DCCA) concentrations were associated with internalising difficulties (Cox p value=0.05). For childhood 3-phenoxybenzoic acid (PBA) concentrations, a positive association was observed with externalising difficulties (Cox p value=0.04) and high ORs were found for abnormal or borderline social behaviour (OR 2.93, 95% CI 1.27 to 6.78, and OR 1.91, 95% CI 0.80 to 4.57, for the intermediate and highest metabolite categories, respectively). High childhood trans-DCCA concentrations were associated with reduced externalising disorders (Cox p value=0.03). CONCLUSIONS: The present study suggests that exposure to certain pyrethroids, at environmental levels, may negatively affect neurobehavioral development by 6 years of age.

An update systematic review of fetal death, congenital anomalies, and fertility disorders among health care workers.

BACKGROUND: Health care workers (HCWs) are occupationally exposed to various hazards, some associated with adverse pregnancy outcomes in previous reviews. This systematic review aims at synthesizing the recent literature on occupational exposures among HCWs related to fetal death, congenital anomalies, and fertility disorders. METHODS: We searched the Medline database from 2000 to 2015 for articles about all potential occupational exposures of women and men working in this sector. RESULTS: We retained 32 studies, most of them (n = 30) among women HCWs. Studies based on job title reported excess risks of some congenital anomalies (especially nervous and musculoskeletal systems) among HCWs compared to non-HCWs but no evidence about fetal death. Excess risks associated with specific exposures includes reports of some congenital anomalies for women exposed to anesthetic gases. Exposure to some sterilizing agents and, with less evidence, to antineoplastic drugs and to ionizing radiation, is associated with increased risks of miscarriage but not stillbirth. Strenuous work schedules appear to be associated with fertility disorders, but the evidence is limited. Only a few studies have been published since 2000 about non-ionizing radiation, or about fertility disorders related to chemical or physical agents, or about male HCWs. CONCLUSIONS: Despite the establishment of recommendations to limit exposures of HCWs, some excess risks of adverse pregnancy outcomes are still reported and need to be explained.

Drinking Water Disinfection By-products, Genetic Polymorphisms, and Birth Outcomes in a European Mother-Child Cohort Study.

BACKGROUND: We examined the association between exposure during pregnancy to trihalomethanes, the most common water disinfection by-products, and birth outcomes in a European cohort study (Health Impacts of Long-Term Exposure to Disinfection By-Products in Drinking Water). We took into account exposure through different water uses, measures of water toxicity, and genetic susceptibility. METHODS: We enrolled 14,005 mothers (2002-2010) and their children from France, Greece, Lithuania, Spain, and the UK. Information on lifestyle- and water-related activities was recorded. We ascertained residential concentrations of trihalomethanes through regulatory records and ad hoc sampling campaigns and estimated route-specific trihalomethane uptake by trimester and for whole pregnancy. We examined single nucleotide polymorphisms and copy number variants in disinfection by-product metabolizing genes in nested case-control studies. RESULTS: Average levels of trihalomethanes ranged from around 10 µg/L to above the regulatory limits in the EU of 100 µg/L between centers. There was no association between birth weight and total trihalomethane exposure during pregnancy (ß = 2.2 g in birth weight per 10 µg/L of trihalomethane, 95% confidence interval = 3.3, 7.6). Birth weight was not associated with exposure through different routes or with specific trihalomethane species. Exposure to trihalomethanes was not associated with low birth weight (odds ratio [OR] per 10 µg/L = 1.02, 95% confidence interval = 0.95, 1.10), small-for-gestational age (OR = 0.99, 0.94, 1.03) and preterm births (OR = 0.98, 0.9, 1.05). We found no gene-environment interactions for mother or child polymorphisms in relation to preterm birth or small-for-gestational age. CONCLUSIONS: In this large European study, we found no association between birth outcomes and trihalomethane exposures during pregnancy in the total population or in potentially genetically susceptible subgroups. (See video abstract at http://links.lww.com/EDE/B104.).

Prenatal exposure to chlordecone, gestational weight gain, and birth weight in a Guadeloupean birth cohort.

BACKGROUND: Chlordecone is a persistent organochlorine insecticide with well-defined estrogenic properties. It was intensively used in the French West Indies until 1993 to control the banana root borer. Because of the long-term contamination of soils and water, the population is currently exposed to chlordecone through food consumption. Chlordecone has been found in the blood of pregnant women and in cord blood. It has been shown to be an endocrine-disrupting chemical and exposure during pregnancy may affect fetal growth. OBJECTIVES: The objective of our study was to examine the association between prenatal exposure to chlordecone and fetal growth based on the TIMOUN birth cohort conducted in Guadeloupe, with a focus on the potential modification of this relationship by maternal body mass index (BMI) and gestational weight gain (GWG). METHODS: Chlordecone was determined in cord plasma at birth in 593 babies. Birth weight was the indicator of fetal growth. Maternal pre-pregnancy BMI and GWG were determined. Adherence to GWG recommendations of the US Institute of Medicine based on maternal pre-pregnancy BMI was assessed. Birth weight was analyzed relative to cord blood chlordecone levels using linear and non-linear regression models. RESULTS: Overall chlordecone in cord blood was not associated with birth weight, but we found an interaction between chlordecone exposure with GWG and adherence to GWG recommendations. After stratification by GWG, we found a significant U-shaped association between birth weight and chlordecone exposure, within the upper quartiles of GWG or excessive GWG. CONCLUSION: Chlordecone exposure may affect fetal growth, particularly when excessive GWG is present.