Early-Life Temperamental Differences as Longitudinal Predictors of Unintentional Injuries.

OBJECTIVE: Unintentional injuries are the leading cause of hospitalization and death among children. Compared to environmental factors, less attention in injury preventive efforts has been paid to how individual characteristics relate to the risk of injury. Using a large prospective cohort, the current study assessed the longitudinal impact of early-life temperament on the cumulative number of injuries until mid-adolescence. METHODS: The data came from the European Longitudinal Study of Pregnancy and Childhood (ELSPAC-CZ). Temperament was evaluated by mothers when children were 3 years old (N = 3,545). The main outcome was the pediatrician-reported sum of child's injuries from age 3 to 15 (seven timepoints). Latent profile analysis (LPA) was used to determine classes based on temperamental dimensions and then extended to a mixture model with a distal count outcome. The covariates included maternal conflict and attachment, sex, family structure, and maternal education. RESULTS: The LPA determined the existence of three classes: shy children (8.1% of the sample; lowest activity/highest shyness), outgoing children (50.8%; highest activity/lowest shyness), and average: children (41.1%; middle values). Results from a mixture model showed that the outgoing temperament was associated with the highest longitudinal risk for injuries, as both average children (IRR = 0.89 [0.80, 0.99]), and the shy children (IRR = 0.80 [0.68, 0.95]) had lower risk. CONCLUSIONS: Early childhood temperamental differences can have long-term effects on injury risk. Highly active children showed the highest risk for future injuries, suggesting that these characteristics make them more likely to be involved in novel and potentially dangerous situations.

Association of the CD14 -260C/T polymorphism with plaque-induced gingivitis depends on the presence of Porphyromonas gingivalis.

BACKGROUND: Plaque-induced gingivitis is the most prevalent periodontal disease associated with pathogenic biofilms. The host immune system responds to pathogens through pattern recognition receptors (PRRs), such as Toll-like receptors (TLRs) and their co-receptor cluster of differentiation 14 (CD14). AIM: This study investigated the association between the functional polymorphism in the CD14 gene and the dental plaque microbiota in children with gingivitis. DESIGN: A total of 590 unrelated children (307 with plaque-induced gingivitis and 283 controls, aged 13-15 years) were enrolled in this case-control study. Dental plaque was processed using a ParoCheck® 20 detection kit. The CD14 -260C/T (rs2569190) polymorphism was determined with the PCR-RFLP method. RESULTS: Gingivitis was detected in 64.2% of boys and 35.8% of girls (P < .001). Children with gingivitis had a significantly higher occurrence of dental caries (P < .001). No significant differences in the CD14 -260C/T allele and genotype distribution among individuals with or without gingivitis in the whole cohort were found. Children with gingivitis and P gingivalis, however, were significantly more frequent carriers of the CT and TT genotypes than children with gingivitis without P gingivalis or healthy controls (P < .05). CONCLUSIONS: The CD14 -260C/T polymorphism acts in cooperation with P gingivalis to trigger plaque-induced gingivitis in Czech children.

Sibling relatedness rather than father absence predicts earlier age at menarche in ELSPAC cohort.

Many studies during the past 50 years have found an association between father absence and earlier menarche. In connection with these findings, several evolutionary theories assume that father absence is a causal factor accelerating reproductive development. However, a recent study analysing data from the Avon Longitudinal Study of Parents and Children (ALSPAC) found that father absence does not predict age at menarche when adjusted for sibling relatedness. In this study, we have replicated these results in the Czech section of the European Longitudinal Study of Pregnancy and Childhood (ELSPAC), which used the same questionnaires as ALSPAC to study a geographically distinct population. Our results support the conclusion that sibling relatedness rather than father absence predicts age at menarche. Furthermore, our results show that age at menarche in 1990s UK and Czech cohorts is very similar despite socioeconomic differences between the two countries.

Lack of association between ENAM gene polymorphism and dental caries in primary and permanent teeth in Czech children.

OBJECTIVES: The enamelin gene (ENAM) polymorphism (rs12640848) was recently associated with dental caries in primary teeth in Polish children. The aims of the present study were to prove this association in primary dentition and to find a possible effect of this variant on caries development in permanent dentition in Czech children. MATERIALS AND METHODS: This study comprised 905 Czech children. Totally, 187 children aged 2-6 years with primary dentition [78 healthy subjects (with decayed/missing/filled teeth, dmft = 0) and 109 patients with early childhood caries (ECC; dmft ≥ 1)] were included in this case-control study. In addition, 177 subjects aged 13-15 years without caries (DMFT = 0) and 541 children with dental caries (DMFT ≥ 1) in permanent dentition were selected from the ELSPAC study. Genotype determination of the ENAM polymorphism (rs12640848) was based on the TaqMan method. RESULTS: No significant differences in the allele or genotype frequencies between the caries-free children and those affected by dental caries were observed in both primary and permanent dentitions. CONCLUSIONS: Lack of association between the ENAM polymorphism (rs12640848) and dental caries in Czech children was detected. CLINICAL RELEVANCE: Although ENAM is considered as a candidate gene for dental caries, the presence of the ENAM variant (rs12640848) cannot be used as a risk factor of this multifactorial disease in the Czech population.

Vitamin D Receptor TaqI Gene Polymorphism and Dental Caries in Czech Children.

AIM: We analyzed the VDR TaqI (rs731236) gene polymorphism in children with and those without dental caries. METHODS: A total of 388 subjects, 153 caries-free (with decayed/missing/filled teeth [DMFT] = 0) and 235 children with dental caries (DMFT ≥1), were genotyped by the TaqMan method. RESULTS: Although no significant differences in VDR TaqI allele and genotype frequencies between caries-free and caries-affected children were detected, a significant association between this polymorphism and gingivitis was found (p < 0.05). CONCLUSIONS: In contrast to previous studies from China and Turkey, the VDR TaqI gene variant cannot be used as a marker for identification of Czech children with increased dental caries risk.

Lack of Association between BMP2/DLX3 Gene Polymorphisms and Dental Caries in Primary and Permanent Dentitions.

The aim of this study was to analyze the association between BMP2 (rs1884302) and DLX3 (rs2278163) gene polymorphisms and dental caries in primary and permanent dentitions. A total of 914 subjects were genotyped by the TaqMan methods: 176 caries-free children (with Decayed/Missing/Filled Teeth, DMFT = 0), 542 patients with dental caries in permanent dentition (DMFT ≥1), 83 caries-free children with primary teeth (with decayed/missing/filled teeth, dmft = 0), and 113 children with early childhood caries (ECC, dmft ≥1). There were no significant differences in allele/genotype frequencies between patients with caries in permanent dentition/ECC and caries-free children or between patients with very low (DMFT = 0-2), low (DMFT = 3-5), moderate (DMFT = 6-8), or high (DMFT ≥9) caries experience. Variability in BMP2 and DLX3 was not associated with caries in the Czech population.

Is Perceived Discrimination in Pregnancy Prospectively Linked to Postpartum Depression? Exploring the Role of Education.

Objectives The role of perceived discrimination in postpartum depression is largely unknown. We investigate whether perceived discrimination reported in pregnancy contributes to postpartum depression, and whether its impact varies by education level. Methods Prospective data are a part of European Longitudinal Study of Pregnancy and Childhood, the Czech Republic. Surveys were collected in mid-pregnancy and at 6 months after delivery. Depression was measured using Edinburgh Postnatal Depression Scale. Generalized linear models were estimated to test the effects of perceived discrimination on postpartum depression. Results Multivariate models revealed that among women with low education, discrimination in pregnancy was prospectively associated with 2.43 times higher odds of postpartum depression (p < .01), after adjusting for antenatal depression, history of earlier depression, and socio-demographic background. In contrast, perceived discrimination was not linked to postpartum depression among women with high education. Conclusions Perceived discrimination is a risk factor for postpartum depression among women with low education. Screening for discrimination and socio-economic disadvantage during pregnancy could benefit women who are at risk for mental health problems.

ACE Insertion/Deletion Polymorphism Associated with Caries in Permanent but Not Primary Dentition in Czech Children.

OBJECTIVE: Dental caries is a multifactorial, infectious disease where genetic predisposition plays an important role. Insertion/deletion (I/D) polymorphism of angiotensin-converting enzyme (ACE) has very recently been associated with caries in Polish children. The aim of this study was to analyze ACE I/D polymorphism in a group of caries-free children versus subjects affected by dental caries in the Czech population. MATERIALS AND METHODS: In this case-control study, 182 caries-free children (with decayed/missing/filled teeth, DMFT = 0), 561 subjects with dental caries (DMFT ≥1) aged 13-15 years and 220 children aged 2-6 years with early childhood caries (ECC, dmft ≥1) were included. Genotype determination of ACE I/D polymorphism in intron 16 was based on the TaqMan method. RESULTS: Although no significant differences in the allele or genotype frequencies between the caries-free children and those affected by dental caries were observed, statistically significant differences between the children with DMFT = 0 and the subgroup of 179 patients with high caries experience (DMFT ≥4; p < 0.01 and p < 0.05, respectively) were detected. The comparison of DD versus II+ID genotype frequencies between the patients with DMFT ≥1 or DMFT ≥4 and healthy children also showed significant differences (31.5% or 35.6% vs. 23.6%, p < 0.05 or p < 0.01, respectively). A gender-based analysis identified a significant difference in the DD versus II+ID genotype frequencies only in girls (p < 0.05). In contrast, no significant association of ACE I/D polymorphism with ECC in young children was found (p > 0.05). CONCLUSIONS: ACE I/D polymorphism may be associated with caries in permanent but not primary dentition, especially in girls in the Czech population.

GLUT2 and TAS1R2 Polymorphisms and Susceptibility to Dental Caries.

OBJECTIVE: Dental caries is one of the most frequent multifactorial diseases. Among the numerous factors influencing the risk of caries, genetics plays a substantial role, with heritability ranging from 40 to 60%. Gene variants affecting taste preference and glucose transport were recently associated with caries risk. The aim of this study was to analyze two common polymorphisms in the sweet taste receptor (TAS1R2) and glucose transporter (GLUT2) genes in children with dental caries and healthy controls in the Czech population. METHODS: A total of 637 unrelated Caucasian children, aged 11-13 years, were included in this case-control study. One hundred and fifty-five subjects were caries-free (with decayed/missing/filled teeth, DMFT = 0) and 482 children were caries-affected (DMFT ≥ 1). The TAS1R2 (Ile191Val, rs35874116) and GLUT2 (Thr110Ile, rs5400) genotypes were determined using the 5' nuclease TaqMan® assay for allelic discrimination. RESULTS: Compared with subjects with the common Thr allele, carriers of the Ile allele of GLUT2 had significantly more frequently dental caries (p < 0.05, OR = 1.639, 95% CI: 1.089-2.466). Similarly, children with the Val allele for the TAS1R2 Ile191Val polymorphism were more frequently affected by caries than children who carried the Ile allele (p < 0.05, OR = 1.413, 95% CI: 1.014-1.969). In contrast, no significant associations between GLUT2 and/or TAS1R2 polymorphisms and fillings were found, but allele frequencies of the TAS1R2 variant were marginally significantly different between children with DMFT = 0 and DMFT ≥1 (p = 0.053, OR = 1.339, 95% CI: 0.996-1.799). However, no significant interaction between both genes and risk of dental caries was found. CONCLUSIONS: In conclusion, GLUT2 and TASR1 polymorphisms may influence the risk of caries in the Czech population.

[Ontogenetic conditions of unemployment]. / Ontogenetická podmínenost nezamestnanosti.

BACKGROUND: Previous unemployment studies mostly dealt with unemployments economic causes and consequences. Hidden causes of male unemployment, independent from socio-economic circumstances of a society, could consist, besides others, in natural biological factors - family experience during childhood. Theoretical background of our study included the concept of psychical deprivation, the concept of human ontogenesis developmental stages of E. Erikson and knowledge of biodromal psychology. Using data from the European Longitudinal Study of Parenthood and Childhood international project we compared groups of employed and unemployed men by means of a retrospective survey and we studied the following: 1. What differences there were in their childhood; 2. To what extent educational approaches transfer from parents to their children; 3. What influence has negative experience from childhood on the future assertion of men in the labour market. METHODS AND RESULTS: The survey set consisted of 3141 (88.7%) employed men and 399 (11.3%) unemployed men in 1991-1992. Basic research data were acquired by means of questionnaires. Relative risk was used to compare the groups of the employed and the unemployed. The employed men are more likely to be from complete families then the unemployed men. The unemployed men, in comparison to the employed men, 2.08 times more frequently spent their childhood in orphanages, children's villages or in foster families, 3.89 times more frequently attended special schools, 2.22 times more frequently lived away from home until the age of 18 and 2.51 times more frequently lived in detention centres or in diagnostic institutes until the age of 18 (p < 0.001). 66.6% of the employed men and 65.1% of the unemployed men were psychically and physically abused in their childhood. CONCLUSION: Consequences of negative experience from childhood decrease the chances of inclusion of young men into the labour market. Social roles of young men (future fathers) could be also distorted by such experience. Social integration and social success rate of the unemployed men group therefore develops in an unfavourable direction.

'Pseudoneurological' symptoms, dissociation and stress-related psychopathology in healthy young adults.

BACKGROUND: Somatoform dissociation is a specific form of dissociation with somatic manifestations represented in the form of 'pseudoneurological' symptoms due to disturbances or alterations of normal integrated functions of consciousness, memory or identity mainly related to trauma and other psychological stressors. With respect to the distinction between psychological and somatoform manifestations of dissociation current data suggest a hypothesis to which extent mild manifestations of 'pseudoneurological' symptoms in healthy young population may be linked to stress-related psychopathological symptoms or whether these symptoms more likely could be attributed to unexplained somatic factors. METHODS: With this aim we have assessed the relationship between somatoform dissociation and stress-related psychopathology (i.e. anxiety, depression, symptoms of traumatic stress, alexithymia) in a group of 250 healthy non-psychiatric and non-clinical young adults. RESULTS: Results of this study show that the symptoms of somatoform dissociation are significantly linked to stress-related psychopathology. CONCLUSIONS: Findings of this study show that the 'pseudoneurological' symptoms may be linked to stress-related psychopathological processes which indicate that also mild levels of stress may influence somatic feelings and may lead to various somatoform dissociative symptoms.

Epileptic-like symptoms and stress conditions in adolescents.

According to recent clinical data, epileptiform changes in temporolimbic structures may be related to psychopathological symptoms known to be related to stress. These data are also consistent with findings that temporal lobe epileptiform activity may provoke various somatic, sensory, behavioral, and memory disturbances similar to temporolimbic seizures and may lead to complex partial seizure-like symptoms which may also occur in nonepileptic conditions. Together, these findings suggest a hypothesis concerning the extent to which psychopathological changes usually related to stress may be associated with complex partial seizure-like symptoms or whether these symptoms might more likely be explained by various somatic factors. To test the hypothesis in a sample particularly vulnerable to stress, these relations between stress-related psychopathology and complex partial seizure-like symptoms were examined in a sample of 340 adolescents. Complex partial seizure-like symptoms were significantly associated with stress-related psychopathology: even mild stress may cause symptoms similar to cognitive and affective disturbances observed in patients with complex partial seizures.

[Mistreated and non-mistreated girls - childhood, partnership, maternity - a longitudinal study]. / Týraná a netýraná devcata - detství, partnerství, materství: longitudinální studie.

BACKGROUND: The aim of the study is to find out whether women maltreated in childhood were different health-wise, psychologically and socially from the women who were not maltreated and whether they were violent toward their own children. MATERIAL AND METHODS: In the study sample of 3848 mothers-to-be included in the Brno part of the ELSPAC study, 48,3 % were maltreated in their youth, 51,7 % were not maltreated. The presented paper compares data provided in their questionnaires regarding these four periods: the period of time until the birth of their children, the period from 6 months till 18 months of age, period from 18 months till three years of age and last period from three till five years of age of their children. The acquired data characterize health, social and psychological situation of the women and their families. Girls from both compared groups came from families with similar socio-economical backgrounds and also their own families later in their lives were similar. However health of the maltreated girls parents was worse and their family relationships less stable with higher frequency of conflicts when compared to the situation of non-maltreated girls parents. RESULTS: Similarly, the maltreated girls health and psychological condition was worse, their partners and children health was also worse, their social support was weaker, frustrations and stresses more frequent, their partner relationships with higher level of conflicts and mutual violence. As mothers, they themselves acted towards their children with distinctively more frequent physical coarseness and psychological cruelty. These findings repeated consistently throughout all four timeline levels of the study. CONCLUSION: The relationships in the maltreated women own families were similar to the relationships in their original families, comparably worse than in the families of non-maltreated women. Women maltreated in their childhood repeated the same behavior toward their own children that their parents had towards them. Violence on children is transferred from one generation to the next and develops from their youngest age.

[Factors influencing the experimentation with smoking: observed in ELSPAC Study]. / Faktory ovlivnující experimentování s kourením: výsledky studie ELSPAC.

BACKGROUND: The causes of children' and adolescents' smoking, along with mechanisms which lead to addiction, include both genetic and environmental factors: individual, social and societal. The European Longitudinal Study of Pregnancy and Childhood (ELSPAC) collects data about the cohort of children from Brno and district Znojmo at scheduled stages from 18th week of prenatal to 19th year of age, using an international standardized questionnaire set. At the age of eleven the children first reported information on themselves. The aim of this study was to analyse different life conditions of 11-year-old children from Brno with different smoking behaviour. METHODS AND RESULTS: Respondents filled in at home a questionnaire; according which they could be personally identified, and their answers reviewed by parents. These conditions could influence the truthfulness of statements. The cohort of 2160 children was divided into the 3 groups: never smokers (79.8%), with one single attempt (15.3%) and repeatedly smoking children (4.9%). The differences were evaluated using standard statistical tests. An important part of the reviewed population experimented with legal drugs: cigarette smoking (20%) and alcohol drinking (one third of never smoking and three quarters of smoking children); there were also sporadic experiments with other psychotropic substances. The age of 9-10 years was critical for the majority of children in relation to their first experiments with addictive drugs. Smoking children were more often exposed to passive smoking, they lived in substitute or non-harmonic families, had the worse relations to school and poorer school results, their leisure time was useless. They had more health problems and some conduct disorders. CONCLUSIONS: Data obtained from 11-year-aged children from the ELSPAC study have confirmed that in the Czech Republic legal drugs are easily available for young-school aged children, and inadequate attention is addressed to realisation of some goals of the National Programme Health 21.

The socioeconomic gradient in child health and noncognitive skills: Evidence from the Czech Republic.

We investigate the presence of a socioeconomic status (SES) gradient in children's health and noncognitive skill development, and its evolution with child age using cohort data from the Czech Republic. We show that family SES are positively associated with better child health. These effects start to emerge at age 3 and are persistent for all subsequent ages. We find a modest strengthening of the gradient as the children grow older. Similarly, at the lowest distribution of average family income, children lag in their noncognitive skills. We find evidence that children enter school with substantial differences in noncognitive skill endowments based on family SES. This correlation persists when controlling for poor health at birth, the roles of specific and chronic health problems, housing conditions, and partner characteristics. Maternal health status explains some of the association between family income and child noncognitive skills. We account for the endogeniety of SES and non-linearities in measures.

Estimating Growth in Height from Limited Longitudinal Growth Data Using Full-Curves Training Dataset: A Comparison of Two Procedures of Curve Optimization-Functional Principal Component Analysis and SITAR.

A variety of models are available for the estimation of parameters of the human growth curve. Several have been widely and successfully used with longitudinal data that are reasonably complete. On the other hand, the modeling of data for a limited number of observation points is problematic and requires the interpolation of the interval between points and often an extrapolation of the growth trajectory beyond the range of empirical limits (prediction). This study tested a new approach for fitting a relatively limited number of longitudinal data using the normal variation of human empirical growth curves. First, functional principal components analysis was done for curve phase and amplitude using complete and dense data sets for a reference sample (Brno Growth Study). Subsequently, artificial curves were generated with a combination of 12 of the principal components and applied for fitting to the newly analyzed data with the Levenberg-Marquardt optimization algorithm. The approach was tested on seven 5-points/year longitudinal data samples of adolescents extracted from the reference sample. The samples differed in their distance from the mean age at peak velocity for the sample and were tested by a permutation leave-one-out approach. The results indicated the potential of this method for growth modeling as a user-friendly application for practical applications in pediatrics, auxology and youth sport.

Association between Stress Urinary Incontinence and Depressive Symptoms after Birth: the Czech ELSPAC Study.

The study objectives were to (1) identify risk factors related to stress urinary incontinence (SUI) and postnatal depression (PD) after birth, and (2) investigate both possible directions of association between SUI and PD in population-based sample of Czech mothers. 3,701 nulliparous and multiparous women completed the self-reported questionnaires at 6 weeks and 6 months after birth and were included into the analyses of this prospective cohort study. Unadjusted and adjusted logistic regressions examined relationship between SUI a PD accounting for range of other risk factors. During the first 6 months after birth, 650 mothers (17.6%) developed SUI and 641 (17.3%) displayed signs of PD. The mode of delivery, parity and higher BMI were associated with SUI. The rate of PD symptoms was higher in mothers with positive history of prenatal depression, and in divorced or widowed mothers. Both conditions were associated with worse self-reported health, back pain and stop-smoker status. Initially, SUI at 6 weeks was slightly, but significantly associated with onset of PD at 6 months (OR 1.51, 95% CI 1.02-2.23) while PD at 6 weeks was not significantly related to new cases of SUI at 6 months (OR 1.48, 95% CI 0.91-2.39). After full adjustment these OR reduced to 1.41 and 1.38 (both non-significant), respectively. SUI and PD are common conditions in women postpartum that share some risk factors. Our study suggests that both directions of their relationship are possible although a larger study is needed to confirm our findings.

Perinatal Maternal Stress and Susceptibility to Infectious Diseases in Later Childhood: An Early Life Programming Perspective.

There is evidence of transmission of stress-related dysregulation from parents to offspring during early developmental stages, leading to adverse health outcomes. This study investigates whether perinatal stress is linked to the risk of infectious diseases in children aged 7-11 years. We hypothesize that stress exposure during pregnancy and the first 6 months after birth independently predict common infectious diseases. Data are obtained from ELSPAC-CZ, a prospective birth cohort. Maternal stress, operationalized as the number of life events, is examined for pregnancy and the first 6 months postpartum. Children's diseases include eye infection, ear infection, bronchitis/lung infection, laryngitis, strep throat, cold sores, and flu/flu-like infection. More prenatal and postnatal life events are both independently linked to a higher number of infectious diseases between the ages of 7-11 years. The effect is larger for postnatal vs. prenatal events, and the effect of prenatal events is attenuated after maternal health in pregnancy is controlled. The results suggest that perinatal stress is linked to susceptibility to infectious diseases in school-age children. Interventions to address stress in pregnant and postpartum women may benefit long-term children's health.

Association of interleukin-6 (IL-6) haplotypes with plaque-induced gingivitis in children.

OBJECTIVES: The proinflammatory cytokine interleukin-6 (IL-6) is a key regulator of the host response to microbial infection and major modulator of extracellular matrix catabolism and bone resorption. The aim of this case-control study was to test differences between children with and without gingivitis in the distribution of IL-6 alleles at positions -174, -572, and -597 and their haplotypes. MATERIAL AND METHODS: A total of 455 Caucasian children, aged 11 to 13 years, were enrolled in this study. According to gingival bleeding on probing indices, 183 were classified as healthy subjects and 272 as children with plaque-induced gingivitis. DNA for genetic analysis was obtained from buccal epithelial cells and PCR-RFLP methods were used for genotyping three selected IL-6 promoter polymorphisms. RESULTS: Complex analysis revealed significant differences in haplotype frequencies between patients and healthy subjects (p<0.01). The CGA haplotype was significantly more frequent in children with gingivitis than in healthy subjects (41.5% versus 34.1%). In subanalyses, we found that IL-6 -174C allele was more frequent in patients (44.3%) than in healthy children (36.1%, p=0.016, P(corr)<0.05). Multivariate logistic regression analysis showed that allele C remained a risk factor for gingivitis in children (p=0.03) regardless of plaque or gender. However, the proportions of the IL-6 -597 and -572 genotypes were comparable between the two groups. CONCLUSIONS. Our results indicate that the three promoter polymorphisms in the IL-6 gene act in a cooperative fashion and suggest that IL-6 haplotypes could play a role in the pathogenesis of gingivitis in Caucasian children.

Maternal smoking during pregnancy, behavioral problems and school performances of their school-aged children.

BACKGROUND: Child behavior and school performance is influenced by many genetic and environmental factors including prenatal exposure to chemical neurotoxins contained in cigarette smoke. The European Longitudinal Study of Pregnancy and Childhood (ELSPAC) prospective study which in the Czech Republic incorporates a cohort of children born in the years 1991/2 in Brno city and the Znojmo district also allows to analyze the relationships between prenatal cigarette smoke exposure and the occurrence of behavior and learning disorders. METHODS: Using questionnaires repeatedly filled in by teachers and investigation protocols performed by research team workers data for the Brno sample of children was collected on the occurrence of signs indicating more serious problems with school assignment fulfilling and behavior disorders in the childrens' 8, 11 and 13 years of age. According to mothers' statements about their smoking behavior during pregnancy, the children were divided into two groups: prenatally exposed and non-exposed. The frequency differences of individual traits were evaluated in the SPSS statistical program (Pearson's chi2 test and linear associations, probability relations). RESULTS: In the ELSPAC study set the occurrence of inferior schoolwork performance evaluated based on term-report grades was more frequent in children prenatally exposed to mothers' smoking, along with more frequently diagnosed disorders which to significant extent implicate these inferior results and also special care needs occurred more frequently when compared to their peers born to non-smoking mothers. In the prenatally exposed subset also more frequent occurrence of various signs characterizing behavior disorders including attention disorders, hyperactivity, aggressiveness and signs of delinquency behavior were recorded. CONCLUSIONS: The Czech ELSPAC cohort confirmed the results of other studies; within it was documented that children born to smoking mothers have more frequent behavioral problems and problems with fulfilling their school assignments in the school age period.