Harmonized data describing simultaneous exposure to a large number of environmental contaminants in-utero and during childhood is currently very limited.
To characterize concentrations of a large ...number of environmental contaminants in pregnant women from Europe and their children, based on chemical analysis of biological samples from mother-child pairs.
We relied on the Early-Life Exposome project, HELIX, a collaborative project across six established population-based birth cohort studies in Europe. In 1301 subjects, biomarkers of exposure to 45 contaminants (i.e. organochlorine compounds, polybrominated diphenyl ethers, per- and polyfluoroalkyl substances, toxic and essential elements, phthalate metabolites, environmental phenols, organophosphate pesticide metabolites and cotinine) were measured in biological samples from children (6–12 years) and their mothers during pregnancy, using highly sensitive biomonitoring methods.
Most of the exposure biomarkers had high detection frequencies in mothers (35 out of 45 biomarkers with >90% detected) and children (33 out of 45 biomarkers with >90% detected). Concentrations were significantly different between cohorts for all compounds, and were generally higher in maternal compared to children samples. For most of the persistent compounds the correlations between maternal and child concentrations were moderate to high (Spearman Rho > 0.35), while for most non-persistent compounds correlations were considerably lower (Spearman Rho < 0.15). For mercury, PFOS and PFOA a considerable proportion of the samples of both mothers and their children exceeded the HBM I value established by The Human Biomonitoring Commission of the German Federal Environment Agency.
Although not based on a representative sample, our study suggests that children across Europe are exposed to a wide range of environmental contaminants in fetal life and childhood including many with potential adverse effects. For values exceeding the HBM I value identification of specific sources of exposure and reducing exposure in an adequate way is recommended. Considerable variability in this “chemical exposome” was seen between cohorts, showing that place of residence is a strong determinant of one's personal exposome. This extensive dataset comprising >100,000 concentrations of environmental contaminants in mother-child pairs forms a unique possibility for conducting epidemiological studies using an exposome approach.
•Children across Europe are exposed to a wide range of environmental contaminants.•Considerable variability in the “chemical exposome” was seen between cohorts.•Significant differences in concentrations between mothers and children were found.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
Objective The purpose of this study was to investigate the association of trimester-specific gestational weight gain with offspring fetal growth, obesity risk, and cardiometabolic health outcomes ...from birth to 4 years of age. Study Design We conducted the present study with 977 mother-child pairs of the pregnancy cohort “Rhea” study in Crete, Greece. We measured birthweight, body mass index from 6 months to 4 years of age, waist circumference, skinfold thickness, blood pressure, and blood levels of lipids, C-reactive protein, and adipose tissue hormones at 4 years of age. We used multiple linear and log Poisson regression models to examine the association of exposure with continuous or binary outcomes, respectively. Results Greater rate of gestational weight gain in the first trimester of pregnancy (per 200 g/wk) was associated with increased risk of overweight/obesity from 2 years (relative risk RR, 1.25; 95% confidence interval CI, 1.09–1.42) to 4 years of age (RR, 1.15; 95% CI, 1.05–1.25), but not with birth size. Each 200 g/wk of weight gain in the first trimester of pregnancy was also associated with greater risk of high waist circumference (RR, 1.13; 95% CI, 1.04–1.23), high sum of skinfold thickness (RR, 1.15; 95% CI, 1.02–1.29), and higher diastolic blood pressure at 4 years of age (β, 0.43 mm Hg; 95% CI, 0.00–0.86). Greater rate of gestational weight gain during the second and third trimesters of pregnancy (per 200 g/wk) was associated with greater risk of large-for-gestational-age neonates (RR, 1.22; 95% CI, 1.02, 1.45) and higher levels of cord blood leptin (ratio of geometric means, 1.08; 95% CI, 1.00–1.17), but not with child anthropometry at later ages. Conclusion Timing of gestational weight gain may influence childhood cardiometabolic outcomes differentially.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
Phthalate esters (PEs), bisphenol A (BPA), and parabens (PBs), which are used in numerous consumer products, are known for their endocrine disrupting properties. Organophosphate chemicals (OPs), ...which form the basis of the majority of pesticides, are known for their neurotoxic activity in humans. All of these chemicals are associated with health problems to which children are more susceptible. Once they enter the human body, PEs, BPA, PBs, and OPs are metabolized and/or conjugated and finally excreted via urine. Hence, human exposure to these substances is examined through a determination of the urinary concentrations of their metabolites. This study assessed the exposure of Greek preschool-age children to PEs, BPA, PBs, and OPs by investigating the urinary levels of seven PEs metabolites, six PBs, BPA, and six dialkyl phosphate metabolites in five-hundred samples collected from 4-year-old children, subjects of the “RHEA” mother-child cohort in Crete, Greece. Daily intake of endocrine disruptors, calculated for 4 year old children, was lower than the corresponding daily intake for 2.5 year old children, which were determined in an earlier study of the same cohort. In some cases the daily intake levels exceeded the U.S. Environmental Protection Agency Tolerable Daily Intake (TDI) values and the EFSA Reference Doses (RfD) (e.g., for di-2-ethyl-hexyl phthalate, 3.6% and 1% of the children exceeded RfD and TDi, respectively). Exposure was linked to three main sources: PEs-BPA to plastic, PBs-diethyl phthalate to personal hygiene products, and OPs to food.
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IJS, KILJ, NUK, PNG, UL, UM
Maternal pre-pregnancy obesity may increase the risk of childhood obesity but it is unknown whether other metabolic factors in early pregnancy such as lipid profile and hypertension are associated ...with offspring cardiometabolic traits.
Our objective was to investigate whether fasting lipid, glucose, and insulin levels during early pregnancy and maternal pre-pregnancy weight status, are associated with offspring adiposity measures, lipid levels and blood pressure at preschool age.
The study included 618 mother-child pairs of the pregnancy cohort "Rhea" study in Crete, Greece. Pregnant women were recruited at the first prenatal visit (mean: 12 weeks, SD: 0.7). A subset of 348 women provided fasting serum samples for glucose and lipid measurements. Outcomes measures were body mass index, abdominal circumference, sum of skinfold thickness, and blood pressure measurements at 4 years of age. A subsample of 525 children provided non-fasting blood samples for lipid measurements.
Pre-pregnancy overweight/obesity was associated with greater risk of offspring overweight/obesity (RR: 1.83, 95%CI: 1.19, 2.81), central adiposity (RR: 1.97, 95%CI: 1.11, 3.49), and greater fat mass by 5.10 mm (95%CI: 2.49, 7.71) at 4 years of age. These associations were more pronounced in girls. An increase of 40 mg/dl in fasting serum cholesterol levels in early pregnancy was associated with greater skinfold thickness by 3.30 mm (95%CI: 1.41, 5.20) at 4 years of age after adjusting for pre-pregnancy BMI and several other confounders. An increase of 10 mmHg in diastolic blood pressure in early pregnancy was associated with increased risk of offspring overweight/obesity (RR: 1.22, 95%CI: 1.03, 1.45), and greater skinfold thickness by 1.71 mm (95% CI: 0.57, 2.86) at 4 years of age.
Metabolic dysregulation in early pregnancy may increase the risk of obesity at preschool age.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Persistent organic pollutants (POPs), including polychlorinated biphenyls (PCBs) and pesticides bioaccumulate through the food chain and cross the placenta. POPs are developmental toxicants in ...animals but the epidemiological evidence on pregnancy outcomes is inconsistent. Maternal gestational weight gain has been recently suggested as a key factor explaining the association between PCBs with lower birth weight.
We examined whether in utero exposure to current low levels of different POPs is associated with fetal growth and gestational age in a mother–child cohort in Crete, Greece (Rhea study), and evaluated specifically whether maternal gestational weight gain may affect this association.
We included 1117 mothers and their newborns from the Rhea study. Mothers were interviewed and blood samples collected during the first trimester of pregnancy. Information on birth outcomes was retrieved from medical records. Concentrations of several PCBs, other organochlorine compounds (dichlorodiphenyl dichloroethene DDE, dichlorodiphenyl trichloroethane DDT and hexachlorobenzene HCB) and one polybrominated diphenyl ether congener (tetra-bromodiphenyl ether BDE-47), were determined in maternal serum by triple quadrupole mass spectrometry. Multiple linear regression models were used to investigate the associations of birth weight, gestational age, and head circumference with each compound individually on the log10 scale, and with combined exposures through the development of an exposure score.
In multivariate models, birth weight was negatively associated with increasing levels of HCB (β=−161.1g; 95% CI: −296.6, −25.7) and PCBs (β=−174.1g; 95% CI: −332.4, −15.9); after further adjustment for gestational weight gain these estimates were slightly reduced (β=−154.3g; 95% CI: −300.8, −7.9 for HCB and β=−135.7g; 95% CI: −315.4, 43.9 for PCBs). Furthermore, in stratified analysis, the association between POPs and birth weight was only observed in women with inadequate or excessive gestational weight gain. Small, negative associations were observed with head circumference while no association was observed with gestational age.
The findings suggest that prenatal exposure to PCBs and HCB impairs fetal growth and adds to the growing literature that demonstrates an association between low-level environmental pollutant exposure and fetal growth. Furthermore our results suggest that the association of POPs, maternal gestational weight gain and birth weight is probably more complex than that previously hypothesized.
•Concentrations of several POPs were determined in 1st trimester maternal serum.•We examined whether in utero exposure to POPs is associated with birth outcomes.•Birth weight was lowered by PCBs and HCB.•Weight gain slightly influenced the association of POPs and birth weight.•Prenatal exposure to PCBs and HCB seems to impair fetal growth.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
The evidence regarding a potential link of low-to-moderate iodine deficiency, selenium status, and cadmium exposure during pregnancy with neurodevelopment is either contradicting or limited. We aimed ...to assess the prenatal impact of cadmium, selenium, and iodine on children's neurodevelopment at 4 years of age. The study included 575 mother—child pairs from the prospective "Rhea" cohort on Crete, Greece. Exposure to cadmium, selenium and iodine was assessed by concentrations in the mother's urine during pregnancy (median 13 weeks), measured by ICPMS. The McCarthy Scales of Children's Abilities was used to assess children's general cognitive score and seven different sub-scales. In multivariable-adjusted regression analysis, elevated urinary cadmium concentrations (≥0.8 μg/L) were inversely associated with children's general cognitive score mean change: —6.1 points (95 % CI — 12; —0.33) per doubling of urinary cadmium; corresponding to ~0.4 SD. Stratifying by smoking status (p for interaction 0.014), the association was restricted to smokers. Urinary selenium was positively associated with children's general cognitive score mean change: 2.2 points (95 % CI —0.38; 4.8) per doubling of urinary selenium; ~0.1 SD, although the association was not statistically significant. Urinary iodine (median 172 μg/L) was not associated with children's general cognitive score. In conclusion, elevated cadmium exposure in pregnancy of smoking women was inversely associated with the children's cognitive function at pre-school age. The results indicate that cadmium may adversely affect neurodevelopment at doses commonly found in smokers, or that there is an interaction with other toxicants in tobacco smoke. Additionally, possible residual confounding cannot be ruled out.
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BFBNIB, EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
Animal studies suggest that prenatal vitamin D status may affect fetal brain growth. However, human studies are scarce with conflicting results. We aimed to investigate the association of maternal ...25-hydroxyvitamin D 25(OH) D levels with multiple neurodevelopmental outcomes at 4 years of age. We included 487 mother–child pairs from the prospective pregnancy cohort, “Rhea” in Crete, Greece. Maternal serum 25(OH) D concentrations were measured at the first prenatal visit (13 ± 2.4 weeks). Cognitive functions at 4 years were assessed by means of the McCarthy Scales of Children’s Abilities. Behavioral difficulties were assessed by means of Strengths and Difficulties Questionnaire and Attention Deficit Hyperactivity Disorder Test. Children of women in the high 25(OH) D tertile (>50.7 nmol/l) had 37% decreased number of hyperactivity–impulsivity symptoms (IRR 0.63, 95% CI 0.39, 0.99,
p
trend
= 0.05) and 40% decreased number of total ADHD-like symptoms (IRR 0.60, 95% CI 0.37, 0.95,
p
trend
= 0.03) at 4 years of age, compared to children of women in the low 25(OH) D tertile (<38.4 nmol/l), after adjustment for several confounders. Similar associations were found with the hyperactivity/inattention score of the SDQ questionnaire. Children of mothers with high 25(OH) D levels had also fewer total behavioral difficulties (beta-coeff: −1.25, 95% CI −2.32, −0.19) and externalizing symptoms (beta-coeff: −0.87, 95% CI −1.58, −0.15) at preschool age. The observed associations were stronger in girls than in boys (
p
for interaction
< 0.1). No association was observed between maternal 25(OH) D concentrations and cognitive function in preschoolers. Our results suggest that high maternal vitamin D levels in early pregnancy may protect against behavioral difficulties, especially ADHD-like symptoms at preschool age.
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DOBA, EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, IZUM, KILJ, KISLJ, MFDPS, NLZOH, NUK, OBVAL, ODKLJ, OILJ, PILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, SIK, UILJ, UKNU, UL, UM, UPUK, VKSCE, VSZLJ, ZAGLJ
Few studies have investigated longitudinal associations between early life phthalate exposure and subsequent obesity and cardiovascular risks in children with inconsistent results. We aimed to ...evaluate the associations between phthalate exposure during gestation and childhood with offspring obesity and cardiometabolic risk factors in 500 mother-child pairs from the Rhea pregnancy cohort in Crete, Greece. Seven phthalate metabolites monoethyl phthalate (MEP), mono-n-butyl phthalate (MnBP), mono-isobutyl phthalate (MiBP), monobenzyl phthalate (MBzP), mono(2-ethylhexyl) phthalate (MEHP), mono(2-ethyl-5-hydroxyhexyl) phthalate (MEHHP), and mono(2-ethyl-5-oxohexyl) phthalate (MEOHP) were quantified in spot urine samples collected from mothers (1st trimester) and their children at 4 years of age. We calculated the molar sum of DEHP metabolites (MEHP, MEHHP, MEOHP). We measured child weight, height, waist circumference, skinfold thicknesses, blood pressure (BP), and lipids at 4 and 6 years and leptin, adiponectin, and C-reactive protein at 4 years. We used generalized estimating equations to examine associations at each age and tested for interaction by sex. Child exposure to phthalate metabolites was associated with lower BMI z-scores in boys and higher BMI z-scores in girls. Each 10-fold increase in ΣDEHP was associated with a change in waist circumference of -2.6 cm (95% CI: -4.72, -0.48) in boys vs. 2.14 cm (95% CI: -0.14, 4.43) in girls (
-sex interaction = 0.003) and a change in waist-to-height ratio of -0.01 (95% CI: -0.03, 0.01) in boys vs. 0.02 (95% CI: 0.01, 0.04) in girls (
-sex interaction = 0.006). Phthalate metabolite concentrations at age 4 were negatively associated with systolic and diastolic blood pressure. MEP was associated with lower systolic BP z-scores (adj. β = -0.22; 95% CI: -0.36, -0.08) at 4 years. MnBP and MBzP were associated with lower diastolic BP z-scores (adj. β = -0.13; 95%CI: -0.23, -0.04, and adj. β = -0.11; 95% CI: -0.21, -0.01, respectively). A 10-fold increase in MiBP was associated with 4.4% higher total cholesterol levels (95% CI: 0.2, 8.7). Prenatal phthalate exposure was not consistently associated with child adiposity and cardiometabolic measures. Our findings suggest that early life phthalate exposure may affect child growth and adiposity in a sex-specific manner and depends on the timing of exposure.