Polish mother and child cohort study--defining the problem, the aim of the study and methodological assumption

The Effect of Environmental Factors on Immunological Pathways of Asthma in Children of the Polish Mother and Child Cohort Study

The FOXP3 transcription factor is a marker of regulatory T cells (Tregs), and is essential in the process of their activation and proper expression by promoting immune homeostasis. To assess the influence of the environment on the development of asthma, we hypothesized that in our cohort, exposure to environmental factors is associated with asthma risk in children, and that FOXP3 levels vary with their incidence and are negatively correlated with developing asthma. This prospective study conducted in Poland uses a cohort of 85 children (42 with and 43 without asthma diagnosis) aged 9 to 12 years recruited for the Polish Mother and Child Cohort Study. We collected questionnaires and organized visits to assess patients' clinical condition (skin prick tests, lung function assessments). Blood samples were taken to determine immune parameters. Breastfed children had lower risk of asthma. Asthma risk was higher in children who live in the city, with antibiotic course before the age of 2 and antibiotic therapy more than twice a year. Environmental factors were associated with childhood asthma. Breastfeeding, the coexistence of other allergic diseases, and the frequency of housekeeping affect FOXP3 levels, which are negatively correlated with the risk of asthma.

REPRO_PL-Polish Mother and Child Cohort-Exposure, Health Status, and Neurobehavioral Assessments in Adolescents-Design and Cohort Update

Early life is a crucial window of opportunity to improve health across the life course. The prospective cohort study design is the most adequate to evaluate the longitudinal effects of exposure, the notification of changes in the exposure level and evaluation of the simultaneous impact of various exposures, as well as the assessment of several health effects and trajectories throughout childhood and adolescence. This paper provides an overview of the Polish Mother and Child cohort (REPRO_PL), with particular emphasis on Phase IV of this study. REPRO_PL is conducted in central Europe, where such longitudinal studies are less frequently implemented. In this population-based prospective cohort, which was established in 2007, three phases covering pregnancy (I), early childhood (II), and early school age (III) periods have already been completed. Phase IV gives a uniform opportunity to follow-up children during adolescence in order to evaluate if the consequences of prenatal and early postnatal exposures still persist at the age of 14. Moreover, we will be able to investigate the associations between simultaneous exposures to a broad spectrum of environmental factors, adolescents' health and neurobehavioral outcomes, and their trajectories within life, which is a novel framework of high scientific, public health and clinical priority.

Home Environment in Early-Life and Lifestyle Factors Associated with Asthma and Allergic Diseases among Inner-City Children from the REPRO_PL Birth Cohort

OBJECTIVE

We hypothesized that, in our REPRO_PL cohort, exposure to indoor allergens and lifestyle factors in early life are associated with risk of asthma, atopic dermatitis, and allergic rhinitis at ten years of age.

METHODS

We only examined children who had lived in the same house from birth. Children's exposure to tobacco smoke was assessed based on cotinine levels in urine. House dust samples were collected.

RESULTS

Higher Fel d1 concentration in house dust was associated with significantly higher risk of developing asthma at age 10 years (95% CI,10.87 to 20.93; p < 0.001). Frequent house cleaning was associated with development of atopic dermatitis (odds ratio 0.61; 95% CI 0.37 to 0.99; p = 0.045). Clustering of exposure to HDM revealed two types of environment. Cluster 1, defined as lower HDM (dust), in contrast to Cluster 2, defined as higher HDM, was characterized by old-type windows, lower fungus and dampness levels, as well as more frequent house cleaning.

CONCLUSION

Exposure to cat allergens and new-type buildings that limit air flow while increasing the condensation of steam on the windows and thereby stimulating the growth of fungi are risk factors for the development of asthma.

Predictors of maternal dietary quality and dietary inflammation during pregnancy: An individual participant data meta-analysis of seven European cohorts from the ALPHABET consortium

BACKGROUND & AIMS

Maternal diet during pregnancy is a modifiable behaviour which plays an important role in maternal, neonatal and child health outcomes. Thus, knowledge of predictors of dietary quality and dietary inflammatory potential in European countries may contribute to developing maternal diet-related public health policies that target specific at-risk populations in Europe.

METHODS

We used harmonised data from >26,000 pregnant women enrolled in the ALSPAC, EDEN, Generation R, Lifeways, REPRO_PL, ROLO and SWS cohorts, as part of the ALPHABET consortium. Maternal dietary quality and inflammatory potential were assessed using the Dietary Approaches to Stop Hypertension (DASH) and the energy-adjusted Dietary Inflammatory Index (E-DII). We conducted an individual participant data meta-analysis to investigate the maternal sociodemographic, health and behavioural predictors of maternal diet before and during pregnancy.

RESULTS

DASH and E-DII scores were moderately correlated: from -0.63 (95% CI: -0.66, -0.59) to -0.48 (95% CI: -0.49, -0.47) across cohorts. Higher maternal age, education, household income, and physical activity during pregnancy were associated with a better dietary quality and a more anti-inflammatory diet. Conversely, multiparity and smoking during pregnancy were associated with a poorer dietary quality and a more proinflammatory diet. Women with obesity had a poorer pregnancy dietary quality than women with a normal body mass index range.

CONCLUSIONS

The results will help identify population subgroups who may benefit from targeted public health strategies and interventions aimed at improving women's dietary quality during pregnancy.

Maternal diet during pregnancy and risk of allergic diseases in children up to 7-9 years old from Polish Mother and Child Cohort study

BACKGROUND

The impact of maternal diet during pregnancy on the risk of allergic diseases in childhood is an increasing scientific and public health concern. We evaluated the associations of maternal type of diet and essential elements and vitamins intake during pregnancy with offspring allergic and respiratory outcomes.

METHODS

The study population included 557 mother-child pairs from Polish Mother and Child Cohort (REPRO_PL). Based on the Food Frequency Questionnaire filled in between the 20th-24th week of pregnancy, overall maternal diet was evaluated as the difference between the Prudent Dietary Pattern (PDP) score and Western Dietary Pattern (WDP) score ((PDP-WDP) score) and maternal achievement of dietary recommendations (estimated average requirement, EAR) for essential elements and vitamins was assessed. Children's health examination at age of 1, 2, and 7-9 years covered the following symptoms: infections, wheezing/asthma, food allergy, allergic rhinitis, and atopic dermatitis. At age of 7-9 years, children underwent spirometry and skin-prick tests.

RESULTS

Children of the mothers who were not achieving adequate intake of vitamin C during pregnancy had a higher risk of wheezing and having more than two infections within the first two years of life comparing to those who met EAR (OR = 2.6, p = 0.05, and OR = 2.3, p = 0.04, respectively). Inadequate intake of vitamin E during pregnancy was related to a higher risk of atopic dermatitis (OR = 2.7, p = 0.04), whereas inadequate intake of magnesium during pregnancy was associated with the risk of wheezing in the offspring at age of two years (OR = 3.7, p = 0.03). A lower (PDP-WDP) score during pregnancy (indicating unhealthier diet) was associated with a higher risk of infections (OR = 1.5, p = 0.007) but a lower risk of atopic dermatitis (OR = 0.7, p = 0.02) at age of 7-9 years.

CONCLUSIONS

These results may contribute to the body of evidence for the impact of maternal diet during pregnancy for children's optimal health, however further studies are needed before drawing conclusions and recommendations for clinical practice.

Prenatal exposure to neurotoxic metals and micronutrients and neurodevelopmental outcomes in early school age children from Poland

Exposure to environmental factors, such as neurotoxic metals and micronutrients, during critical periods of development can contribute to long-term consequences in offspring's health, including neurodevelopmental outcomes. The aim of this study was to evaluate the association between simultaneous prenatal exposure to metals [lead (Pb), cadmium (Cd), mercury (Hg)] and micronutrients [selenium (Se), zinc (Zn), copper (Cu)] and neurodevelopmental outcomes in school-age children from the Polish Mother and Child Cohort (REPRO_PL). Metals and micronutrients concentrations were measured in cord blood (Pb, Cd, Se, Zn, Cu) and in maternal hair (Hg) collected during the 3rd trimester of pregnancy. Behavioral and emotional problems, as well as children's cognitive and psychomotor development, were assessed in 436 school-age children using the Strengths and Difficulties Questionnaire (SDQ, filled in by the mothers) and the Polish adaptation of the Intelligence and Development Scales (IDS, administered by trained psychologists). Multivariate regression models were applied after imputation of missing values, using two approaches: (i) a joint analysis taking into account all metals and micronutrients simultaneously, and (ii) an ExWAS study (single-exposure model). In the SDQ, Hyperactivity/Inattention problems and Total difficulties were associated with higher Hg concentrations in maternal hair (0.18, 95% CI: 0.05; 0.3; and 0.14, 95% CI: 0.01; 0.3, respectively), whereas Emotional symptoms were inversely associated with Se and Zn levels in cord blood (-0.13, 95% CI: -0.3; 0.004; and -0.10, 95% CI: -0.2; 0.02, respectively). In the IDS, cord blood Pb levels were found to be negatively associated with Fluid and Crystallized IQ (-0.12, 95% CI: -0.3; 0.02; and -0.14, 95% CI: -0.3; 0.007, respectively) as well as Mathematical skills (-0.15, 95% CI: -0.3; 0.01). The current research has been able to simultaneously assess the exposure to various interacting chemicals during the prenatal period. We demonstrate that prenatal co-exposures to Pb, Hg, Zn and Se have long-term influences on the neuropsychological outcome of school-age children.

Human-Biomonitoring derived exposure and Daily Intakes of Bisphenol A and their associations with neurodevelopmental outcomes among children of the Polish Mother and Child Cohort Study

BACKGROUND

Bisphenol A (BPA) is an industrial chemical mostly used in the manufacture of plastics, resins and thermal paper. Several studies have reported adverse health effects with BPA exposures, namely metabolic disorders and altered neurodevelopment in children, among others. The aim of this study was to explore BPA exposure, its socio-demographic and life-style related determinants, and its association with neurodevelopmental outcomes in early school age children from Poland.

METHODS

A total of 250 urine samples of 7 year-old children from the Polish Mother and Child Cohort Study (REPRO_PL) were analyzed for BPA concentrations using high performance liquid chromatography with online sample clean-up coupled to tandem mass spectrometry (online-SPE-LC-MS/MS). Socio-demographic and lifestyle-related data was collected by questionnaires or additional biomarker measurements. Emotional and behavioral symptoms in children were assessed using mother-reported Strengths and Difficulties Questionnaire (SDQ). Cognitive and psychomotor development was evaluated by Polish adaptation of the Intelligence and Development Scales (IDS) performed by trained psychologists.

RESULTS

Urinary BPA concentrations and back-calculated daily intakes (medians of 1.8 μg/l and 46.3 ng/kg bw/day, respectively) were similar to other European studies. Urinary cotinine levels and body mass index, together with maternal educational level and socio-economic status, were the main determinants of BPA levels in Polish children. After adjusting for confounding factors, BPA has been found to be positively associated with emotional symptoms (β: 0.14, 95% CI: 0.022; 0.27). Cognitive and psychomotor development were not found to be related to BPA levels.

CONCLUSIONS

This study represents the first report of BPA levels and their determinants in school age children in Poland. The exposure level was found to be related to child emotional condition, which can have long-term consequences including social functioning and scholastic achievements. Further monitoring of this population in terms of overall chemical exposure is required.

Neurodevelopmental exposome: The effect of in utero co-exposure to heavy metals and phthalates on child neurodevelopment

In this study, the exposome paradigm has been applied on a mother-child cohort adopting an optimised untargeted metabolomics approach for human urine followed by advanced bioinformatics analysis. Exposome-wide association algorithms were used to draw links between in utero co-exposure to metals and phthalates, metabolic pathways deregulation, and clinically observed phenotypes of neurodevelopmental disorders such as problems in linguistic, motor development and cognitive capacity. Children (n = 148) were tested at the first and second year of their life using the Bayley Scales of Infant and Toddler Development, Third Edition (Bayley-III). Their mothers had been exposed to metals and phthalates during the pregnancy, according to human biomonitoring results from previously performed studies. Untargeted metabolomics analysis of biobanked urine samples from the mothers was performed using a combination of the high throughput analytical methods liquid chromatography-high resolution mass spectrometry (LC-HRMS) and nuclear magnetic resonance (NMR). Most perturbed metabolic pathways from co-exposure heavy metals and phthalates were pathways related to the tricarboxylic acid cycle (TCA cycle) and oxidative phosphorylation, indicating the possibility of disruption of mitochondrial respiration. Overproduction of reactive oxygen species (ROS); the presence of glutathione peroxidase 3 (GPx3) during pregnancy and presence of glutathione peroxidase 1 (GPx1) in the umbilical cord were linked to verbal development problems. Another finding of the study is that in real life, adverse outcomes occur as a combination of environmental and social factors, all of them acting synergistically towards the deployment of an observed phenotype. Finally, the two-steps association process (exposure to pathways and pathways to adverse outcomes) was able to (a) provide associations that are not evident by directly associating exposure to outcomes and (b) provides additional insides on the mechanisms of environmental disease.

Determinants of the Essential Elements and Vitamins Intake and Status during Pregnancy: A Descriptive Study in Polish Mother and Child Cohort

The study objective was to identify determinants of essential elements and vitamins intake, and microelements and vitamins concentration in blood among pregnant women from Poland. Based on the data from food frequency questionnaires and information about supplements taken (n = 1252), daily supply of six elements (calcium, magnesium, iron, zinc, copper, selenium) and nine vitamins (folate, vitamins A, E, C, B1, B2, B3, B6, B12) was calculated. Zinc, copper, selenium (n = 340), vitamin A and E (n = 358) concentration was determined in blood collected during pregnancy. Most of the women did not meet the demand for essential elements and vitamins with a diet. About 94% of the respondents declared supplements use. The women with higher education, indicating leisure-time, physical activity and multiparity had a higher chance of meeting the average demand for the majority of the analyzed nutrients. On the other hand, factors such as BMI < 18.5kg/m², a higher level of stress, and late first medical-care visit were associated with a lower chance of meeting the recommendations. Higher socio-economic status was a determinant of a higher selenium concentration in plasma (β = 3.1; 95%CI: 0.2–5.9), whereas BMI ≥ 25 kg/m², and multiparity of a higher copper concentration in plasma (β = 0.2; 95%CI: 0.03-0.4; β = 0.2; 95%CI: 0.1–0.4). Higher plasma concentration of vitamin E was noted among women older than 30 years of age comparing to those who were 30 or younger (β = 1.5; 95%CI: 0.6–2.4). Although more studies are required, especially such based on laboratory measures, our results indicate target groups for dietary interventions during pregnancy for children’s optimal health and development.

Associations of maternal dietary inflammatory potential and quality with offspring birth outcomes: An individual participant data pooled analysis of 7 European cohorts in the ALPHABET consortium

BACKGROUND

Adverse birth outcomes are major causes of morbidity and mortality during childhood and associate with a higher risk of noncommunicable diseases in adult life. Maternal periconception and antenatal nutrition, mostly focusing on single nutrients or foods, has been shown to influence infant birth outcomes. However, evidence on whole diet that considers complex nutrient and food interaction is rare and conflicting. We aim to elucidate the influence of whole-diet maternal dietary inflammatory potential and quality during periconceptional and antenatal periods on birth outcomes.

METHODS AND FINDINGS

We harmonized and pooled individual participant data (IPD) from up to 24,861 mother-child pairs in 7 European mother-offspring cohorts [cohort name, country (recruitment dates): ALSPAC, UK (1 April 1991 to 31 December 1992); EDEN, France (27 January 2003 to 6 March 2006); Generation R, the Netherlands (1 April 2002 to 31 January 2006); Lifeways, Ireland (2 October 2001 to 4 April 2003); REPRO_PL, Poland (18 September 2007 to 16 December 2011); ROLO, Ireland (1 January 2007 to 1 January 2011); SWS, United Kingdom (6 April 1998 to 17 December 2002)]. Maternal diets were assessed preconceptionally (n = 2 cohorts) and antenatally (n = 7 cohorts). Maternal dietary inflammatory potential and quality were ranked using the energy-adjusted Dietary Inflammatory Index (E-DII) and Dietary Approaches to Stop Hypertension (DASH) index, respectively. Primary outcomes were birth weight and gestational age at birth. Adverse birth outcomes, i.e., low birth weight (LBW), macrosomia, small-for-gestational-age (SGA), large-for-gestational-age (LGA), preterm and postterm births were defined according to standard clinical cutoffs. Associations of maternal E-DII and DASH scores with infant birth outcomes were assessed using cohort-specific multivariable regression analyses (adjusted for confounders including maternal education, ethnicity, prepregnancy body mass index (BMI), maternal height, parity, cigarettes smoking, and alcohol consumption), with subsequent random-effects meta-analyses. Overall, the study mothers had a mean ± SD age of 29.5 ± 4.9 y at delivery and a mean BMI of 23.3 ± 4.2 kg/m2. Higher pregnancy DASH score (higher dietary quality) was associated with higher birth weight [β(95% CI) = 18.5(5.7, 31.3) g per 1-SD higher DASH score; P value = 0.005] and head circumference [0.03(0.01, 0.06) cm; P value = 0.004], longer birth length [0.05(0.01, 0.10) cm; P value = 0.010], and lower risk of delivering LBW [odds ratio (OR) (95% CI) = 0.89(0.82, 0.95); P value = 0.001] and SGA [0.87(0.82, 0.94); P value < 0.001] infants. Higher maternal prepregnancy E-DII score (more pro-inflammatory diet) was associated with lower birth weight [β(95% CI) = -18.7(-34.8, -2.6) g per 1-SD higher E-DII score; P value = 0.023] and shorter birth length [-0.07(-0.14, -0.01) cm; P value = 0.031], whereas higher pregnancy E-DII score was associated with a shorter birth length [-0.06(-0.10, -0.01) cm; P value = 0.026] and higher risk of SGA [OR(95% CI) = 1.18(1.11, 1.26); P value < 0.001]. In male, but not female, infants higher maternal prepregnancy E-DII was associated with lower birth weight and head circumference, shorter birth length, and higher risk of SGA (P-for-sex-interaction = 0.029, 0.059, 0.104, and 0.075, respectively). No consistent associations were observed for maternal E-DII and DASH scores with gestational age, preterm and postterm birth, or macrosomia and LGA. Limitations of this study were that self-reported dietary data might have increased nondifferential measurement error and that causality cannot be claimed definitely with observational design.

CONCLUSIONS

In this cohort study, we observed that maternal diet that is of low quality and high inflammatory potential is associated with lower offspring birth size and higher risk of offspring being born SGA in this multicenter meta-analysis using harmonized IPD. Improving overall maternal dietary pattern based on predefined criteria may optimize fetal growth and avert substantial healthcare burden associated with adverse birth outcomes.

Environmental exposure to persistent organic pollutants measured in breast milk of lactating women from an urban area in central Poland

Mothers' milk is considered a channel by means of which new-borns are exposed to polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), and dioxin-like polychlorinated biphenyls (dl-PCBs), environmental pollutants entering food chain and accumulating in fat-rich tissues. In this study, the concentrations of selected PCDDs, PCDFs, and dl-PCBs (a total of 29 substances) in milk samples of 110 breast-feeding women from an urban area were analyzed using the high-resolution gas chromatography/high-resolution mass spectrometry method. Environmental exposure to these substances was expressed by means of the World Health Organization Toxicity Equivalent (WHO-TEQ₂₀₀₅) using the Toxicity Equivalent Factor values from van der Berg et al. (Toxicol. Sci. 93: 223-241, 2006). Concentrations and WHO-TEQ₂₀₀₅ values were then searched for plausible relationships with selected demographic and diet-related factors. The total WHO-TEQ₂₀₀₅ toxicity equivalent for all 29 substances was (mean ± SD) 10.57 ± 4.57 pg/g fat, while the WHO-TEQ₂₀₀₅ levels of PCDDs/PCDFs and dl-PCBs were 7.90 ± 4.17 pg/g fat and 2.67 ± 1.36 pg/g fat, respectively. The concentration and WHO-TEQ₂₀₀₅ toxicity equivalent of dl-PCBs correlated significantly with the mothers' age (r_P = 0.3814, p < 0.00005; r_P = 0.2817, p < 0.005, respectively). The total WHO-TEQ₂₀₀₅ toxicity equivalent for all analyzed substances was found to be positively associated with the frequency of consumption of fish and dairy products (p < 0.05 for both associations). These outcomes must, however, be interpreted cautiously due to limited size of the study. The results of this paper may provide a basis for further studies on the exposure to PCDDs, PCDFs, and dl-PCBs, and mechanisms underlying their action.

Dog keeping at home before and during pregnancy decreased the risk of food allergy in 1-year-old children

Introduction

The relationship between allergen exposure to animals in pregnancy and the development of allergic symptoms is not clear.

Aim

To evaluate the association between prenatal and postnatal exposure to pet ownership and development of atopic dermatitis, food allergy and wheezing in children at the age of 1 and 2.

Material and methods

The mother-child pairs included in this study were part of the Polish Mother and Child Cohort. Mothers in each trimester of pregnancy and 1 year after childbirth have completed a questionnaire on animal exposure. Children's health status was assessed at around one year and two years of age.

Results

Keeping a dog at home before and during pregnancy (every trimester) decreased the risk of food allergy in the first year of life. On the other hand, keeping any animal other than a dog (cat, hamster, guinea pig, rabbit) before pregnancy and during each trimester separately increased the risk of food allergy in the first year of life of children. Keeping a guinea pig in the first trimester of pregnancy increased the risk of wheezing in the first year of life. The analysis did not show any significant associations between keeping animals at home before and during pregnancy and the occurrence of atopic dermatitis in the second year of life.

Conclusions

Keeping a dog at home before and during pregnancy decreased the risk of food allergy in 1-year-old children. This effect was eliminated in case of having a cat, hamster, guinea pig, or rabbit.

Longitudinal effect of phthalates exposure on allergic diseases in children

BACKGROUND

Environmental chemicals, such as phthalates, phenols, and parabens, may affect children's immune development and contribute to the risk of atopic diseases and asthma.

OBJECTIVE

To evaluate the associations between prenatal and childhood phthalate exposure and atopic diseases in children at the age of 9 years.

METHODS

This analysis is restricted to 145 mother-child pairs from the prospective Polish Mother and Child Cohort Study. Phthalate metabolite levels were assessed in the urine samples collected from mothers during the third trimester of pregnancy and from children at age of 2 and 9 years. For the appropriate recognition of children's health status, a questionnaire was administered to the mothers and completed with information from the medical record of each child. The clinical examination was performed by a pediatrician/allergist in the presence of the mother or a relative.

RESULTS

A higher urine concentration of mono-2-ethyl-5-oxohexyl phthalate increased the risk of food allergy in children at the age of 9 years (odds ratio [OR], 1.75; 95% CI, 1.19-2.57; P = .004) and decreased the risk of atopic dermatitis (OR, 0.49; 95% CI, 0.27-0.87; P = .02). For mono-2-ethyl-5-hydroxyhexyl phthalate, an increased risk of atopic dermatitis was observed (OR, 1.90; 95% CI, 1.18-3.05; P = .008). A higher urine concentration of mono-benzyl phthalate increased the risk of asthma in children (OR, 1.67; 95% CI, 1.08-2.58; P = .02), but the risk of asthma decreased when the concentration of mono-2-ethylhexyl phthalate was higher (OR, 0.64; 95% CI, 10.43-0.97; P = .04).

CONCLUSION

Our study has not provided clear evidence of the negative effect of phthalate exposure during pregnancy and within the 9 years after birth on allergic diseases in children.

Phthalate exposure and neurodevelopmental outcomes in early school age children from Poland

Some phthalates are known endocrine disrupting chemicals (EDC). They are widely present in the environment thus their impact on children's health is of particular scientific interest. The aim of the study was to evaluate the association between phthalate exposure and neurodevelopmental outcomes, in particular behavioral, cognitive and psychomotor development, in 250 early school age children from the Polish Mother and Child Cohort (REPRO_PL). Urine samples were collected at the time of children's neurodevelopmental assessment and were analysed for 21 metabolites of 11 parent phthalates. Behavioral and emotional problems were assessed by the Strengths and Difficulties Questionnaire (SDQ) filled in by the mothers. To assess children's cognitive and psychomotor development, Polish adaptation of the Intelligence and Development Scales (IDS) was administered. The examination was performed by trained psychologists. Dimethyl phthalate (DMP) and di-n-butyl phthalate (DnBP) were the two phthalates showing the highest statistically significant associations, with higher total difficulties scores (β = 1.5, 95% CI 0.17; 2.7; β = 1.5, 95% CI 0.25; 2.8, respectively) as well as emotional symptoms and hyperactivity/inattention problems for DnBP (β = 0.46, 95% CI -0.024; 0.94; β = 0.72, 95% CI 0.065; 1.4, respectively), and peer relationships problems for DMP (β = 0.37, 95% CI -0.013; 0.76). In addition, DnBP and DMP have been found to be negatively associated with fluid IQ (β = -0.14, 95% CI -0.29; 0.0041) and crystallized IQ (β = -0.16, 95% CI -0.29; -0.025), respectively. In the case of mathematical skills, three phthalates, namely DMP (β = -0.17, 95% CI -0.31; -0.033), DEP (β = -0.16, 95% CI -0.29; -0.018) and DnBP (β = -0.14, 95% CI -0.28; 0.0012), have also shown statistically significant associations. This study indicates that exposure to some phthalates seems to be associated with adverse effects on behavioral and cognitive development of early school age children. Further action including legislation, educational and interventional activities to protect this vulnerable population is still needed.

Deriving the Dietary Approaches to Stop Hypertension (DASH) Score in Women from Seven Pregnancy Cohorts from the European ALPHABET Consortium

The ALPHABET consortium aims to examine the interplays between maternal diet quality, epigenetics and offspring health in seven pregnancy/birth cohorts from five European countries. We aimed to use the Dietary Approaches to Stop Hypertension (DASH) score to assess diet quality, but different versions have been published. To derive a single DASH score allowing cross-country, cross-cohort and cross-period comparison and limiting data heterogeneity within the ALPHABET consortium, we harmonised food frequency questionnaire (FFQ) data collected before and during pregnancy in ≥26,500 women. Although FFQs differed strongly in length and content, we derived a consortium DASH score composed of eight food components by combining the prescriptive original DASH and the DASH described by Fung et al. Statistical issues tied to the nature of the FFQs led us to re-classify two food groups (grains and dairy products). Most DASH food components exhibited pronounced between-cohort variability, including non-full-fat dairy products (median intake ranging from 0.1 to 2.2 servings/day), sugar-sweetened beverages/sweets/added sugars (0.3-1.7 servings/day), fruits (1.1-3.1 servings/day), and vegetables (1.5-3.6 servings/day). We successfully developed a harmonized DASH score adapted to all cohorts being part of the ALPHABET consortium. This methodological work may benefit other research teams in adapting the DASH to their study's specificities.

Determinants of phthalate exposure and risk assessment in children from Poland

Phthalates are a group of widely used chemicals and humans are exposed to them in their daily life. Some phthalates may affect the hormonal balance in both children and adults. The aim of this study was to assess the phthalate exposure and its determinants among children at age of 7 years from the Polish Mother and Child Cohort Study (REPRO_PL). 250 urine samples collected in 2014-2015 were analysed for 21 metabolites of 11 parent phthalates using on-line high performance liquid chromatography coupled to tandem mass spectrometry (HPLC-MS/MS). This represents the most extensive set of phthalate metabolites ever determined for Poland. Ten metabolites were quantifiable in 100% of the samples, another eight in >90%. The highest median concentrations were found for the primary monoester metabolites of di-iso-butyl (MiBP, 72.4 μg/l), di-n-butyl (MnBP, 56.3 μg/l) and diethyl (MEP, 42.0 μg/l) phthalate, followed by the sum of di-2-ethylhexyl (ΣDEHP, 89.3 μg/l) and di-iso-nonyl (ΣDiNP, 21.9 μg/l) phthalate metabolites. Metabolite concentrations were higher in children at 7 years than in the same children at age 2 or in their mothers during pregnancy. Generally, phthalate exposures in this study were much higher than exposures reported in other European populations. Multivariate regression models showed that body mass index, place of residence, breastfeeding duration, socio-economic status and parental education were associated with the metabolite levels in the 7-year old children. Daily intake and hazard index calculations revealed that a small percentage of children (around 3-10%) exceeded the tolerable daily intakes established by international institutions such as EFSA and U.S. EPA indicating that these children might be at risk of anti-androgenic effects from the individual and cumulative exposure to phthalates. Thus, further monitoring of this population, by educational programs and follow-up interventions, is required.

Sociodemographic, Lifestyle, Environmental and Pregnancy-Related Determinants of Dietary Patterns during Pregnancy

Background: Characterization of dietary patterns represents a valid and meaningful measure of overall diet quality and nutrient intake. The study aims at evaluating the sociodemographic, lifestyle, environmental, and pregnancy-related determinants of maternal dietary patterns during pregnancy. Methods: The analysis was conducted on a group of pregnant women from the Polish Mother and Child Cohort (REPRO_PL). During the second trimester of pregnancy, 1306 women filled in a modified version of the validated food frequency questionnaire (FFQ). Dietary patterns were estimated using an exploratory factor analysis. Potential dietary determinants were assessed via a questionnaire or biomarker measurements (saliva cotinine level). Results: Two dietary patterns were identified. The Prudent dietary pattern was characterized by high consumption of fruit, vegetables, legumes, whole grains, poultry, and low-fat dairy products, while the Western dietary pattern included high intake of refined grains, processed meat, potatoes, and very low intake of whole grains. Clear sociodemographic, environmental, lifestyle, and pregnancy-related determinants of diet quality were established. Older age (β = 0.2; p < 0.01), higher educational level (β = 0.3; p < 0.01), and socioeconomic status (SES) (β = 0.2; p < 0.01), overweight/obesity before (β = 0.3; p < 0.01), as well as physical activity during pregnancy (β = 0.2; p = 0.01) were positive determinants of a healthier diet (increasing Prudent–Western difference in dietary pattern scores). On the other hand, parity (β = −0.2; p = 0.04) and living in small cities (β = −0.3; p = 0.02) were significantly related to a rather Western dietary pattern. Conclusions: The current study presents evidence on specific factors influencing dietary patterns. They need to be accounted for in educational programs and interventions focused on healthy diet recommendations during pregnancy.

Associations between maternal physical activity in early and late pregnancy and offspring birth size: remote federated individual level meta-analysis from eight cohort studies

OBJECTIVE

Evidence on the impact of leisure time physical activity (LTPA) in pregnancy on birth size is inconsistent. We aimed to examine the association between LTPA during early and late pregnancy and newborn anthropometric outcomes.

DESIGN

Individual level meta-analysis, which reduces heterogeneity across studies.

SETTING

A consortium of eight population-based studies (seven European and one US) comprising 72 694 participants.

METHODS

Generalised linear models with consistent inclusion of confounders (gestational age, sex, parity, maternal age, education, ethnicity, BMI, smoking, and alcohol intake) were used to test associations between self-reported LTPA at either early (8-18 weeks gestation) or late pregnancy (30+ weeks) and the outcomes. Results were pooled using random effects meta-analyses.

MAIN OUTCOME MEASURES

Birth weight, large-for-gestational age (LGA), macrosomia, small-for-gestational age (SGA), % body fat, and ponderal index at birth.

RESULTS

Late, but not early, gestation maternal moderate to vigorous physical activity (MVPA), vigorous activity, and LTPA energy expenditure were modestly inversely associated with BW, LGA, macrosomia, and ponderal index, without heterogeneity (all: I2  = 0%). For each extra hour/week of MVPA, RR for LGA and macrosomia were 0.97 (95% CI: 0.96, 0.98) and 0.96 (95% CI: 0.94, 0.98), respectively. Associations were only modestly reduced after additional adjustments for maternal BMI and gestational diabetes. No measure of LTPA was associated with risk for SGA.

CONCLUSIONS

Physical activity in late, but not early, pregnancy is consistently associated with modestly lower risk of LGA and macrosomia, but not SGA.

TWEETABLE ABSTRACT

In an individual participant meta-analysis, late pregnancy moderate to vigorous physical activity modestly reduced birth size outcomes.

Sex-Dependent Impact of Low-Level Lead Exposure during Prenatal Period on Child Psychomotor Functions

The impact of exposure to lead on child neurodevelopment has been well established. However, sex differences in vulnerability are still not fully explained. We aimed at evaluating the effect of a low-level lead exposure, as measured between 20 to 24 weeks of pregnancy and in cord blood, on developmental scores up to 24 months of age in 402 children from the Polish Mother and Child Cohort (REPRO_PL). Additionally, sex-dependent susceptibility to lead at this very early stage of psychomotor development was assessed. The blood lead levels were analyzed using inductively coupled plasma mass spectrometry (ICP-MS). In order to estimate the children’s neurodevelopment, the Bayley Scales of Infant and Toddler Development was applied. The geometric mean (GM) for blood lead level during 20–24 weeks of pregnancy was 0.99 ± 0.15 µg/dL and, in the cord blood, it was 0.96 ± 0.16 µg/dL. There was no statistically significant impact of lead exposure during prenatal period on the girls’ psychomotor abilities. Among the boys, we observed lower scores for cognitive functions, along with increasing cord blood lead levels (β = −2.07; p = 0.04), whereas the results for the language and motor abilities were not statistically significant (p > 0.05). Our findings show that fetal exposure to very low lead levels might affect early cognitive domain, with boys being more susceptible than girls. Education on health, higher public awareness, as well as intervention programs, along with relevant regulations, are still needed to reduce risks for the vulnerable population subgroups.

Vitamins A and E during Pregnancy and Allergy Symptoms in an Early Childhood-Lack of Association with Tobacco Smoke Exposure

Epidemiological studies have suggested an association between maternal antioxidant levels during pregnancy and development of allergic diseases in their offspring. The aim of the study was to determine plasma vitamins A and E concentration in the 1st trimester of pregnancy, at delivery and in cord blood and to search for a relationship with allergy in up to 2-year-old children who were prenatally exposed or not exposed to tobacco smoke. The study participants included 252 mother-child pairs from Polish Mother and Child Cohort. Vitamin concentrations were measured using the HPLC-UV method, smoking status&mdash;as saliva cotinine level using the HPLC-MS/MS technique. Children&rsquo;s health status was assessed using a questionnaire and pediatricians/allergists examination. Cord plasma vitamin concentrations were significantly lower than their levels in maternal plasma in the 1sttrimester and at delivery (p < 0.001). Significantly higher concentrations of vitamin E have been shown to occur during the 1st trimester of pregnancy in plasma of the women who have actively/passively smoked cigarettes compared to the non-smokers (p < 0.02). Multivariate analysis with inclusion of a variety of confounding factors have not indicated any statistically significant associations between &beta;-carotene, vitamins A and E and the risk of food allergy, atopic dermatitis and wheezing in their children up to 2 years of age. The interaction between smoking during pregnancy and vitamins levels on the risk of allergy was not statistically significant (p < 0.4). The relationship between plasma concentration of vitamins A and E, and the risk of allergy in their young children has not been demonstrated.

Micronutrients during pregnancy and child psychomotor development: Opposite effects of Zinc and Selenium

Studies on the impact of micronutrient levels during different pregnancy periods on child psychomotor functions are limited. The aim of this study was to evaluate the association between maternal plasma concentrations of selected micronutrients, such as: copper (Cu), zinc (Zn), selenium (Se), and child neuropsychological development. The study population consisted of 539 mother-child pairs from Polish Mother and Child Cohort (REPRO_PL). The micronutrient levels were measured in each trimester of pregnancy, at delivery and in the cord blood. Psychomotor development was assessed in children at the age of 1 and 2 years using the Bayley Scales of Infant and Toddler Development. The mean plasma Zn, Cu and Se concentrations in the 1st trimester of pregnancy were 0.91±0.27mg/l, 1.98±0.57mg/l and 48.35±10.54μg/l, respectively. There were no statistically significant associations between Cu levels and any of the analyzed domains of child development. A positive association was observed between Se level in the 1st trimester of pregnancy and child language and motor skills (β=0.18, p=0.03 and β=0.25, p=0.005, respectively) at one year of age. Motor score among one-year-old children decreased along with increasing Zn levels in the 1st trimester of pregnancy and in the cord blood (β=-12.07, p=0.003 and β=-6.51, p=0.03, respectively). A similar pattern was observed for the association between Zn level in the 1st trimester of pregnancy and language abilities at one year of age (β=-7.37, p=0.05). Prenatal Zn and Se status was associated with lower and higher child psychomotor abilities, respectively, within the first year of life. Further epidemiological and preclinical studies are necessary to confirm the associations between micronutrient levels and child development as well as to elucidate the underlying mechanisms of their effects.

Environmental Tobacco Smoke Exposure during Pregnancy and Child Neurodevelopment

The developing fetus is especially vulnerable to environmental toxicants, including tobacco constituents. The aim of this study was to assess the impact of environmental tobacco smoke (ETS) exposure during pregnancy on child neurodevelopment within the first two years of life. The study population consisted of 461 non-smoking pregnant women (saliva cotinine level <10 ng/mL). Maternal passive smoking was assessed based on the cotinine level in saliva analyzed by the use of high-performance liquid chromatography coupled with tandem mass spectrometry (HPLC-ESI + MS/MS) and by questionnaire data. The cotinine cut-off value for passive smoking was established at 1.5 ng/mL (sensitivity 63%, specificity 71%). Psychomotor development was assessed in children at the age of one- and two-years using the Bayley Scales of Infant and Toddler Development. Approximately 30% of the women were exposed to ETS during pregnancy. The multivariate linear regression model indicated that ETS exposure in the 1st and the 2nd trimesters of pregnancy were associated with decreasing child language functions at the age of one (β = −3.0, p = 0.03, and β = −4.1, p = 0.008, respectively), and two years (β = −3.8, p = 0.05, and β = −6.3, p = 0.005, respectively). A negative association was found for cotinine level ≥1.5 ng/mL in the 2nd trimester of pregnancy and child cognition at the age of 2 (β = −4.6, p = 0.05), as well as cotinine levels ≥1.5 ng/mL in all trimesters of pregnancy and child motor abilities at two years of age (β = −3.9, p = 0.06, β = −5.3, p = 0.02, and β = −4.2, p = 0.05, for the 1st, the 2nd, and the 3rd trimester of pregnancy, respectively; for the 1st trimester the effect was of borderline statistical significance). This study confirmed that ETS exposure during pregnancy can have a negative impact on child psychomotor development within the first two years of life and underscore the importance of public health interventions aiming at reducing this exposure.

Maternal stress during pregnancy and neurodevelopmental outcomes of children during the first 2 years of life

AIM

A growing body of literature documents associations between maternal stress in pregnancy and child development, but findings across studies are often inconsistent. The aim of this study was to estimate the association between exposure to different kinds of prenatal stress and child psychomotor development.

METHODS

The study population consisted of 372 mother-child pairs from Polish Mother and Child Cohort. The analysis was restricted to the women who worked at least 1 month during pregnancy period. Maternal psychological stress during pregnancy was assessed based on: the Subjective Work Characteristics Questionnaire, Perceived Stress Scale and Social Readjustment Rating Scale. The level of satisfaction with family functioning and support was evaluated by APGAR Family Scale. Child psychomotor development was assessed at the 12th and 24th months of age by Bayley Scales of Infant and Toddler Development.

RESULTS

Negative impact on child cognitive development at the age of two was observed for the Perceived Stress Scale (β = -0.8; P = 0.01) and the Social Readjustment Rating Scale (β = -0.4; P = 0.03) after adjusting for the variety of confounders. Occupational stress, as well as satisfaction with family functioning, was not significantly associated with child psychomotor development (P > 0.05).

CONCLUSIONS

The study supports the findings that prenatal exposure to maternal stress is significantly associated with decreased child cognitive functions. In order to further understand and quantify the effects of prenatal stress on child neurodevelopment further studies are needed. This will be important for developing interventions that provide more assistance to pregnant women, including emotional support or help to manage psychological stress.

Prenatal and postnatal exposure to polycyclic aromatic hydrocarbons and allergy symptoms in city children

BACKGROUND

Studies indicate that exposure to polycyclic aromatic hydrocarbons (PAH) is associated with adverse respiratory and allergy outcomes. Exposure to PAH may impair the immune function of the foetus and, subsequently, be responsible for an increased susceptibility of children to allergic diseases.

OBJECTIVES

The aim of the present study was to assess the association between mother's exposure to PAH during pregnancy and allergy diseases in their infants. We also assessed the above associations using measured PAH exposure in children's urine during the first two years of life.

METHODS

The current analysis was restricted to 455 mothers and their children from Lodz district. The women were interviewed three times during the pregnancy in order to collect demographic, socio-economic and medical history data. Children's health status was assessed at the age of 10-18 months and repeated at two years of age. The associations between dependent dichotomous variables and urine concentrations of 1-hydroxypyrene (1-HP) were analysed using logistic regression.

RESULTS

We showed that higher urine concentrations of 1-HP in mothers at 20-24 weeks of pregnancy increased the risk of more frequent respiratory infections (p=0.02) in children during their first year of life. Higher 1-HP concentrations in children's urine increased the risk of food allergy (p=0.002) in children during their first two years of life.

CONCLUSIONS

This study suggests awareness of environmental factors, which may affect children's health since PAH showed to be a risk factor for airway infections and food allergy in children after adjustment for other risk factors.

Estimation of Saliva Cotinine Cut-Off Points for Active and Passive Smoking during Pregnancy-Polish Mother and Child Cohort (REPRO_PL)

A reliable assessment of smoking status has significant public health implications and is essential for research purposes. The aim of this study was to determine optimal saliva cotinine cut-off values for smoking during pregnancy. The analyses were based on data from 1771 women from the Polish Mother and Child Cohort. Saliva cotinine concentrations were assessed by high performance liquid chromatography coupled with tandem mass spectrometry (HPLC-ESI + MS/MS). The saliva cotinine cut-off value for active smoking was established at 10 ng/mL (sensitivity 96%, specificity 95%) and for passive smoking at 1.5 ng/mL (sensitivity 63%, specificity 71%). About 5% of the self-reported non-smoking women were classified as smokers based on the cotinine cut-off value. Significantly more younger, single, and less educated self-reported non-smokers had a cotinine concentration higher than 10 ng/mL compared to those who were older, married, and who had a university degree. Close to 30% of the non-smokers who indicated that smoking was not allowed in their home could be classified as exposed to passive smoking based on the cut-off value. The study suggests that self-reported smoking status is a valid measure of active smoking, whereas in the case of passive smoking, a combination of questionnaire data and biomarker verification may be required.

Selenium status during pregnancy and child psychomotor development-Polish Mother and Child Cohort study

BACKGROUND

The studies on the impact of selenium (Se) levels in different pregnancy periods on child psychomotor functions are limited. The aim of this study was to evaluate the impact of prenatal Se on child neurodevelopment.

METHODS

The study population consisted of 410 mother-child pairs from Polish Mother and Child Cohort. Se levels were measured in each trimester of pregnancy, at delivery, and in cord blood by graphite furnace atomic absorption spectrometry. Psychomotor development was assessed in children at the age of 1 and 2 y using the Bayley Scales of Infant and Toddler Development.

RESULTS

Plasma Se levels decreased through pregnancy (from 48.3 ± 10.6 µg/l in the first trimester to 38.4 ± 11.8 µg/l at delivery; P < 0.05). A statistically significant positive association between Se levels in the first trimester of pregnancy and motor development (β = 0.2, P = 0.002) at 1 y of age, and language development (β = 0.2, P = 0.03) at 2 y of age was observed. The positive effect of Se levels on cognitive score at 2 y of age was of borderline significance (β = 0.2, P = 0.05).

CONCLUSION

Prenatal selenium status was associated with child psychomotor abilities within the first years of life. Further epidemiological and preclinical studies are needed to confirm the association and elucidate the underlying mechanisms of these effects.

Maternal lifestyle during pregnancy and child psychomotor development - Polish Mother and Child Cohort study

BACKGROUND

Nowadays special attention is paid to prenatal exposures to maternal lifestyle factors and their impact on a child development.

AIM

The objective of this study was to evaluate the impact of modifiable maternal lifestyle factors on child neurodevelopment based on the Polish Mother and Child Cohort study.

MATERIAL AND METHODS

The current analysis included 538 mother-child pairs. The following factors related to maternal lifestyle were considered: smoking and environmental tobacco smoke (ETS) exposure (based on the cotinine level in maternal saliva measured using LC-ESI+MS/MS method), alcohol consumption and leisure-time physical activity (LTPA) in pregnancy, pre-pregnancy BMI, and folic acid supplementations before and during pregnancy based on questionnaire data. Psychomotor development was assessed in children at the ages of one and two by the Bayley Scales of Infant and Toddler Development.

RESULTS

Significant association was observed between prenatal exposure to tobacco constituents and a decreased child motor development in assessments performed at both ages (β=-0.8, p=0.01; β=-1.4, p<0.001). Maternal pre-pregnancy underweight was associated with decreased language abilities at 12 months of age (β=-5.2, p=0.01) and cognitive and motor development at 24 months of age, for which the associations were of borderline significance (p=0.06). The recommended level of LTPA during pregnancy was beneficial for child language development at two years of age (β=4.8, p=0.02). For alcohol and folic acid consumption there were no significant associations with any of the analyzed domains of child neurodevelopment.

CONCLUSIONS

Children prenatally exposed to tobacco compounds and those of underweight mothers had a decreased psychomotor development. The recommended level of LTPA during pregnancy had positive impact on child development. These results underscore the importance of policies and public health interventions promoting healthy lifestyle among women in reproductive age and during pregnancy.

Phthalate exposure and child development: the Polish Mother and Child Cohort Study

BACKGROUND

Widespread phthalate exposure has prompted investigations concerning their potential adverse health effects.

AIM

The objective of this study was to evaluate the impact of pre and early postnatal phthalate exposure on child psychomotor development based on the data from the prospective Polish Mother and Child Cohort Study (REPRO PL).

STUDY DESIGN, SUBJECTS AND OUTCOME MEASURES

Phthalate exposure was determined by measuring 11 phthalate metabolites (MEP, MiBP, MnBP, 3OH-MnBP, MBzP, MEHP, 5OH-MEHP, 5oxo-MEHP, OH-MiNP, oxo-MiNP, and MnOP) in the urine collected from mothers during the third trimester of pregnancy (prenatal exposure) and from their children at the 24th month of age (postnatal exposure). The analysis was performed by the HPLC-MS/MS method. Psychomotor development was assessed in children at the age of 2years by the Bayley Scales of Infant and Toddler Development.

RESULTS

Child motor development was inversely associated with natural log concentrations (μg/g creatinine) of 3OH-MnBP (β= -2.3; 95% CI -4.0 to -0.6), 5OH-MEHP (β= -1.2; 95% CI -2.2 to -0.3), 5oxo-MEHP (β= -1.8; 95% CI -3.3 to -0.2) and sum of DEHP metabolites (β= -2.2; 95% CI -3.6 to -0.8), DnBP metabolites (β= -1.9; 95% CI -3.4 to -0.4), and high molecular weight phthalates (β= -2.5; 95% CI -4.1 to -0.9) in the urine collected from mothers during pregnancy after adjustment for a variety of potential confounders. Additional adjustment for postnatal phthalate exposure did not change the results. Postnatal child exposure to phthalates was not associated with any of the measured scores of child psychomotor development.

CONCLUSIONS

The study findings add further support to the possibility that prenatal phthalate exposure may be detrimental to child neurodevelopment and underscore the importance of policies and public health interventions aiming at reduction of such exposure.

Effect of prenatal polycyclic aromatic hydrocarbons exposure on birth outcomes: the Polish mother and child cohort study

The aim of this study was to assess the impact of PAH exposure on various anthropometric measures of birth outcomes. The study population consisted of 210 nonsmoking pregnant women. Urine samples collected between 20th and 24th week of pregnancy were used for analysis of the following PAH metabolites: 1-, 2-, 3-, 4-, and 9-hydroxyphenanthrene (1-, 2-, 3-, 4-, and 9-OH-PHE), 1-hydroxypyrene (1-OH-PYR), 1,6 + 1,8-dihydroxypyrene (DI-OH-PYR), phenanthrene trans-1,2-dihydrodiol (PHE-1,2-diol), and phenanthrene trans-9,10-dihydrodiol (PHE-9,10-diol) by gas chromatography-mass spectrometry. Environmental tobacco smoke exposure (ETS) was assessed by cotinine level in saliva using a stable isotope dilution LC-ESI-MS/MS method. The mean PAH metabolite concentrations were in the range of 0.15 µg/g creatinine for 9-OH-PHE to 5.9 µg/g creatinine for PHE-9,10-diol. It was shown that none of the individual PAH exposure markers demonstrate a statistically significant influence on birth outcomes. Interestingly a statistically significant association was found between the sum of OH-PHE along with cotinine level and the cephalization index after adjusting for potential confounders (P = 0.04). This study provides evidence that combined exposure of pregnant women to common environmental pollutants such as PAH and ETS might adversely affect fetal development. Thus, reduction of human exposure to these mixtures of hazardous compounds would in particular result in substantial health benefits for newborns.

The determination of polycyclic aromatic hydrocarbons in the urine of non-smoking Polish pregnant women

The aim of this study was to characterize the PAH exposure level among the non-smoking Polish pregnant women and to identify the minimal set of PAH metabolites that specifically reflect environmental PAH exposure. The study population consisted of 210 non-smoking pregnant women. The urine sample was used for analysis of the following PAH metabolites: 1-, 2-, 3-, 4-, 9-hydroxyphenanthrene (1-, 2-, 3-, 4-, 9-OH-PHE), 1-hydroxypyrene (1-OH-PYR), 1,6+1,8-dihydroxypyrene (DI-OH-PYR), phenanthrene trans-1,2-dihydrodiol (PHE-1,2-diol) and phenanthrene trans-9,10-dihydrodiol (PHE-9,10-diol). The analysis of all the biomarkers was performed by gas chromatography-mass spectrometry after their derivatization. The mean PAH metabolite concentrations were in the range of 0.15 (± 0.2) μg/g creatinine for 9-OH-PHE to 5.9 (± 10.6) μg/g creatinine for PHE-9,10-diol. Women living in the city center had higher concentrations of 1-OH-PHE (β=0.6; p=0.04), 3-OH-PHE (β=0.8; p=0.02), 9-OH-PHE (β=0.9; p=0.02), and DI-OH-PYR (β=1.0; p=0.006) than those living outside the city center. The usage of coal for residential heating was a significant predictor of all PAH metabolites except for 9-OH-PHE (p=0.1) and PHE-9,10-diol (p=0.08). With the increasing cotinine levels we observed a significant increase in the concentrations of the following PAH metabolites: 3-OH-PHE (β=0.2; p=0.007), 4-OH-PHE (β=0.3; p=0.002), PHE-1,2-diol (β=0.3; p<0.001), 1-OH-PYR (β=0.2; p=0.01). High-density housing, usage of coal for residential heating, cotinine level in saliva, season of urine collection and distance from the place of residence to the main road explained 26% of the variance of 3-OH-PHE and 21% of the variance of 1-OH-PHE. 2-OH-PHE, 3-OH-PHE, 9-OH-PHE and PHE-9,10-diol are sufficient to predict environmental PAH exposure. The urinary PAH biomarker levels found in this study indicate that non-smoking Polish pregnant women suffer from a higher PAH exposure than those in other western countries. This higher PAH exposure level probably poses a significant health risk for the newborns and young children and will require further attention in the future.

Longitudinal follow-up of the relationship between dietary intake and growth and development in the Lifeways cross-generation cohort study 2001-2013

In this paper we will review evidence on the early life and familial influences on childhood growth and development, with particular reference to the Lifeways cross-generation cohort study in the Republic of Ireland. The Lifeways cross-generation cohort study was established in 2001-2013 through two maternity hospitals in the Republic of Ireland and was one of many new cohort studies established worldwide in the millennium period. Mothers were recruited at first booking visit, completing a self-administered questionnaire, which included a 147 item semi-quantitative FFQ. Longitudinal follow-up is ongoing in 2013, with linkage data to hospital and general practice records and examination of children when aged 5 and 9 years. The study is one of very few containing data on grandparents of both lineages with at least one grandparent recruited at baseline. There have been consistent associations between parental and grandparental health status characteristics and children's outcomes, including infant birth-weight, BMI when child was aged 5 years and childhood wheeze or asthma when child was aged 3 and aged 5 years. In conclusion, empirical evidence to date shows consistent familial and cross-generational patterns, particularly in the maternal line.

Estimation of cutoff values of cotinine in urine and saliva for pregnant women in Poland

Setting appropriate cutoff values and the use of a highly sensitive analytical method allow for correct classification of the smoking status. Urine-saliva pairs samples of pregnant women in the second and third trimester, and saliva only in the first trimester were collected. Offline SPE and LC-ESI-MS/MS method was developed in the broad concentration range (saliva 0.4-1000 ng/mL, urine 0.8-4000 ng/mL). The mean recoveries were 3.7 ± 7.6% for urine and 99.1 ± 2.6% for saliva. LOD for saliva was 0.12 ng/mL and for urine 0.05 ng/mL; LOQ was 0.4 ng/mL and 0.8 ng/mL, respectively. Intraday and interday precision equaled, respectively, 1.2% and 3.4% for urine, and 2.3% and 6.4% for saliva. There was a strong correlation between salivary cotinine and the uncorrected cotinine concentration in urine in the second and third trimesters of pregnancy. The cutoff values were established for saliva 12.9 ng/mL and urine 42.3 ng/mL or 53.1 μg/g creatinine with the ROC curve analysis. The developed analytical method was successfully applied to quantify cotinine, and a significant correlation between the urinary and salivary cotinine levels was found. The presented cut-off values for salivary and urinary cotinine ensure a categorization of the smoking status among pregnant women that is more accurate than self-reporting.

Developmental effects of exposures to environmental factors: the Polish Mother and Child Cohort Study

This paper estimates the effects of exposure to environmental factors, including lead, mercury, environmental tobacco smoke (ETS), and polycyclic aromatic hydrocarbons (PAH), on child psychomotor development. The study population consists of mother-child pairs in the Polish Mother and Child Cohort Study. Prenatal and postnatal exposure to environmental factors was determined from biomarker measurements as follows: for lead exposure—cord blood lead level, for mercury—maternal hair mercury level, for ETS—cotinine level in saliva and urine, and for PAH—1-hydroxypyrene (1-HP) in urine. At the age of 12 (406 subjects) and 24 months (198 subjects) children were assessed using Bayley Scales of Infant and Toddler Development. There were no statistically significant effects of prenatal exposure to mercury or 1-HP on child psychomotor development. After adjusting for potential confounders, adverse effects of prenatal exposure to ETS on motor development (β = −2.6; P = 0.02) and postnatal exposure to ETS on cognitive (β = −0.2; P = 0.05) and motor functions (β = −0.5; P = 0.01) were found. The adverse effect of prenatal lead exposure on cognitive score was of borderline significance (β = −6.2; P = 0.06). The study underscores the importance of policies and public health interventions that aim to reduce prenatal and postnatal exposure to lead and ETS.

Pregnancy and birth cohort resources in europe: a large opportunity for aetiological child health research

BACKGROUND

During the past 25 years, many pregnancy and birth cohorts have been established. Each cohort provides unique opportunities for examining associations of early-life exposures with child development and health. However, to fully exploit the large amount of available resources and to facilitate cross-cohort collaboration, it is necessary to have accessible information on each cohort and its individual characteristics. The aim of this work was to provide an overview of European pregnancy and birth cohorts registered in a freely accessible database located at http://www.birthcohorts.net.

METHODS

European pregnancy and birth cohorts initiated in 1980 or later with at least 300 mother-child pairs enrolled during pregnancy or at birth, and with postnatal data, were eligible for inclusion. Eligible cohorts were invited to provide information on the data and biological samples collected, as well as the timing of data collection.

RESULTS

In total, 70 cohorts were identified. Of these, 56 fulfilled the inclusion criteria encompassing a total of more than 500,000 live-born European children. The cohorts represented 19 countries with the majority of cohorts located in Northern and Western Europe. Some cohorts were general with multiple aims, whilst others focused on specific health or exposure-related research questions.

CONCLUSION

This work demonstrates a great potential for cross-cohort collaboration addressing important aspects of child health. The web site, http://www.birthcohorts.net, proved to be a useful tool for accessing information on European pregnancy and birth cohorts and their characteristics.

European birth cohorts for environmental health research

BACKGROUND

Many pregnancy and birth cohort studies investigate the health effects of early-life environmental contaminant exposure. An overview of existing studies and their data is needed to improve collaboration, harmonization, and future project planning.

OBJECTIVES

Our goal was to create a comprehensive overview of European birth cohorts with environmental exposure data.

METHODS

Birth cohort studies were included if they a) collected data on at least one environmental exposure, b) started enrollment during pregnancy or at birth, c) included at least one follow-up point after birth, d) included at least 200 mother-child pairs, and e) were based in a European country. A questionnaire collected information on basic protocol details and exposure and health outcome assessments, including specific contaminants, methods and samples, timing, and number of subjects. A full inventory can be searched on www.birthcohortsenrieco.net.

RESULTS

Questionnaires were completed by 37 cohort studies of > 350,000 mother-child pairs in 19 European countries. Only three cohorts did not participate. All cohorts collected biological specimens of children or parents. Many cohorts collected information on passive smoking (n = 36), maternal occupation (n = 33), outdoor air pollution (n = 27), and allergens/biological organisms (n = 27). Fewer cohorts (n = 12-19) collected information on water contamination, ionizing or nonionizing radiation exposures, noise, metals, persistent organic pollutants, or other pollutants. All cohorts have information on birth outcomes; nearly all on asthma, allergies, childhood growth and obesity; and 26 collected information on child neurodevelopment.

CONCLUSION

Combining forces in this field will yield more efficient and conclusive studies and ultimately improve causal inference. This impressive resource of existing birth cohort data could form the basis for longer-term and worldwide coordination of research on environment and child health.

Polish mother and child cohort study (REPRO_PL)--methodology of follow-up of the children

BACKGROUND

A prospective cohort study design gives the opportunity for identification, update of different exposures and their verification by biomarker measurements. The aim of The Polish Mother and Child Cohort Study (REPRO_PL) is to evaluate the impact of exposure to different environmental factors during pregnancy and, after birth, on the pregnancy outcome, children's health and neurodevelopment.

MATERIALS AND METHODS

REPRO_PL cohort was established in 2007. From the cohort of 1300 mother-child pairs, 300 children are followed-up until they are two years old to asses the exposure, health status and neurodevelopment. Children are examined twice: at one and two years of age by a pediatrician and a psychologist/child development specialist. During each visit, detailed questionnaire is conducted with the mothers and supplemented with the information from the medical charts to have appropriate recognition of the child's health and development. Additionally, the current health status of the child is checked and his/her biometry is performed. A urine sample is collected from each child for the verification of environmental tobacco smoke (ETS) and polycyclic aromatic hydrocarbons (PAH) exposure. Some children have a blood sample collected for the assessment of the lead and cadmium levels. Child's neurodevelopment is assessed based on Bayley Scales for Infant and Toddler Development (Bayley-III).

RESULTS AND CONCLUSIONS

The results of the study will become available within the next few years and will help to determine the impact of the environmental exposures on children's health and neurodevelopment. REPRO_PL cohort is a middle-sized cohort, very much focused on specific research questions with the potential for future extension and cooperation.

Exposure to polycyclic aromatic hydrocarbons and newborn biometric indicators

OBJECTIVES

The aim of the study was to examine the impact of polycyclic aromatic hydrocarbons (PAH) on foetal growth.

MATERIALS AND METHODS

The prospective Polish Mother and Child Cohort study was performed in 8 regions of Poland. The study population consisted of 449 mother-child pairs All women were interviewed three times during pregnancy (once in each trimester). 1-hydroxypyrene (1-HP) concentration in urine was chosen as the biomarker of exposure to PAH. The urine sample collected from the participant women between 20-24 weeks of pregnancy was analysed using high performance liquid chromatography (HPLC). The active and passive smoking exposure was verified by determination of saliva cotinine level using high performance liquid chromatography coupled with tandem mass spectrometry/positive electrospray ionisation (LC-ESI+MS/MS) and isotope dilution method.

RESULTS

The exposure to PAH measured by 1-HP level in urine of pregnant women was significantly associated with child birth weight (β = -158.3; p = 0.01), chest circumference (β = -0.7; p = 0.02) and cephalisation index (β = 4.2; p = 0.01) after adjustment for gestational age, child gender, pregnant woman marital status, educational level, season of last menstruation period (LMP), prepregnancy body mass index (BMI), and weight gain in pregnancy. After inclusion salivary cotinine levels into the analysis, the results were not statistically significant.

CONCLUSIONS

Prenatal exposures to PAH adversely influence foetal development including child weight, length, head and chest circumference. Tobacco smoking is the important source of PAH. After controlling for active and passive smoking, the observed associations were not statistically significant.

Toxic and essential elements in blood from delivering women in selected areas of São Paulo State, Brazil

This study was designed to evaluate the degree of environmental contamination and possible exposure of pregnant women to toxic elements in seven selected areas of São Paulo State, Brazil. The overall median concentration of Mo in maternal blood was 0.53 μg L⁻¹, highly significant differences found between sites (p < 0.0001). Cd was found to be low overall - 0.09 μg L⁻¹ (0.01-0.58 μg L⁻¹) - with mothers from the Coastal and Rural 1 sites having the highest levels (p < 0.016).Median Hg concentration was 0.60 μg L⁻¹ (0.06 μg L⁻¹-4.35 μg L⁻¹); median Pb level was 16.2 μg L⁻¹ (3.5-57.7 μg L⁻¹) and no differences between sites were observed for both metals. Median Mn level was 16.7 μg L⁻¹ (7.0-39.7 μg L⁻¹), being highest in Urban 2 site (p < 0.016). Concentrations of maternal Co were found to range between 0.06 μg L⁻¹ and 1.1 μg L⁻¹ (median 0.25 μg L⁻¹) and As level was 0.60 μg L⁻¹ (0.10-3.8 μg L⁻¹) overall, with no statistical significance between sites for Co and As. Median Se concentrations were found to be 64 μg L⁻¹ (36-233 μg L⁻¹), with the highest median levels found in Urban 3 site; site differences were statistically significant (p < 0.0001). Correlation for each element (between paired maternal and cord blood) was measured only in Rural site 1; significant correlation was shown for Hg, Pb, Mn and Co (p < 0.05). These findings may be interpreted as indicating low environmental contamination in São Paulo State, Brazil. These findings could also indicate that pregnant women have little or no contact with pollutants, possibly due to awareness campaigns carried out by public health practitioners.