Prenatal exposure to polychlorinated biphenyls: effects on birth size and gestational age

Polychlorinated biphenyls (PCBs), environmental pollutants that concentrate in the fatty tissue of predatory sports fish, cross the placenta in women exposed to ordinary dietary levels. Two hundred forty-two newborn infants whose mothers consumed moderate quantities of contaminated lake fish and 71 infants whose mothers did not each such fish were examined during the immediate postpartum period. PCB exposure, measured by both contaminated fish consumption and cord serum PCB levels, predicted lower birth weight and smaller head circumference. Exposed infants were 160 to 190 gm lighter than controls, and their heads were 0.6 to 0.7 cm smaller. Head circumference was disproportionately small in relation to both birth weight and gestational age. Control analyses showed that none of these effects was attributable to any of 37 potential confounding variables, including socioeconomic status, maternal age, smoking during pregnancy, and exposure to polybrominated biphenyls. These findings are consistent with earlier reports from studies in laboratory animals.     

Childhood growth and exposure to dichlorodiphenyl dichloroethene and polychlorinated biphenyls

OBJECTIVES: Dichlorodiphenyl dichloroethene (DDE) and polychlorinated biphenyls (PCB), toxic contaminants known to be persistent in the environment, may affect growth. We investigated whether growth from birth to 10 years of age is associated with blood concentrations of DDE and PCB taken at 8 years of age. STUDY DESIGN: We ambispectively followed up a cohort of 343 German children. DDE and PCB blood concentrations were determined in 1995. Height measurements were conducted prospectively between 1994 and 1997 and obtained retrospectively from each Child's Health Card. Linear regression models for repeated measurements, controlling for confounding factors, were applied. RESULTS: Growth was significantly reduced by an average of 1.8 cm (P <.0275) for girls in the highest DDE concentration quartile (>.44 microg/L in whole blood) compared with girls in the lowest quartile (0.08-0.2 microg/L). There was no observed growth effect of DDE in boys. PCB blood concentrations were not related to growth reduction in either girls or boys. CONCLUSIONS: Background level concentrations to DDE, but not PCB, during childhood are associated with a small reduction in growth for girls evident through the age of 8 years. The observed differences narrow at the year 9 examination and disappear at the year 10 examination. No effects on boys' heights were observed.     

Development after exposure to polychlorinated biphenyls and dichlorodiphenyl dichloroethene transplacentally and through human milk

Objective: To determine whether exposure to polychlorinated biphenyls (PCBs) or dichlorodiphenyl dichloroethene (DDE), either transplacentally or through breast feeding, affected scores on the Bayley Scales of Infant Development at 6 or 12 months of age. DESIGN: Cohort followed from birth to 1 year of age. SETTING: General community. PARTICIPANTS: Volunteer sample of 858 infants, of whom 802 had Bayley scores available at either 6 months or 12 months or both. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Bayley scales and chemical measurements were done independently. Higher transplacental exposure to PCBs was associated with lower psychomotor scores at both 6 and 12 months of age; the difference between the mean scores in the lowest and highest PCB groups was 7 points at 6 months and 8 points at 12 months. Higher transplacental exposure to DDE was associated with higher mental scores at 6 months of age (the difference between the mean scores in the lowest and highest DDE groups was 6 points), but no relationship was seen at 12 months. Exposure to either chemical through breast feeding was apparently unrelated to Bayley scores. Conclusions: Transplacental exposure to PCBs was associated with lower psychomotor scores. No deleterious effects were associated with breast feeding.     

Prenatal paracetamol exposure and risk of wheeze at preschool age*

Aim: To analyse the association between prenatal paracetamol exposure and preschool wheeze. Methods: Data were obtained from a prospective, longitudinal study of a cohort of children born in the region of western Sweden in 2003; 8176 families were randomly selected. The parents answered questionnaires at 6 and 12 months and at 4.5 years of age. The response rate was 55%, i.e. 4496 of the 5398 questionnaires distributed at 4.5 years (83%). Inhaled corticosteroid (ICS) treated wheeze during the last year was regarded as a proxy for doctor‐diagnosed asthma. Episodic viral wheeze was defined as wheezing only with viral infections and multiple‐trigger wheeze as wheezing also in between infections. Results: In the multivariate analysis, the risk of ICS‐treated wheeze was increased by paracetamol (OR 1.6; 95% CI 1.01–2.6). Within the ICS‐treated group, the effect was significant for multiple‐trigger wheeze (OR 2.4; 1.2–4.8) but not for episodic viral wheeze (OR 1.1; 0.5–2.3). Conclusion: Prenatal paracetamol exposure was an independent risk factor for ICS‐treated wheeze at preschool age, especially among children with ICS‐treated multiple‐trigger wheeze. Although the analysis adjusted for e.g. maternal asthma and antibiotic use, the possibility of residual confounding by maternal indication (respiratory illness) should be acknowledged.     

Early asymptomatic lead exposure and development at school age.

Sixty-seven 7-year-old children, who had asymptomatic lead exposure between 1 and 3 years of age, were compared in their performance on a series of psychologic tests to 70 children of the same age and socioeconomic background who presumably did not have significant exposure to lead. Exposed children had deficits in global IQ and associative abilities, in visual and fine motor coordination, and in behavior. School failure due to learning and behavior problems was more frequent in the lead exposed than in the control group.     

Pubertal growth and development and prenatal and lactational exposure to polychlorinated biphenyls and dichlorodiphenyl dichloroethene

OBJECTIVES: Polychlorinated biphenyls (PCBs) and dichlorodiphenyl dichloroethene (DDE) are ubiquitous toxic environmental contaminants. Prenatal and early life exposures affect pubertal events in experimental animals. We studied whether prenatal or lactational exposures to background levels of PCBs or DDE were associated with altered pubertal growth and development in humans.Study design: Follow-up of 594 children from an existing North Carolina cohort whose prenatal and lactational exposures had previously been measured. Height, weight, and stage of pubertal development were assessed through annual mail questionnaires. RESULTS: Height of boys at puberty increased with transplacental exposure to DDE, as did weight adjusted for height; adjusted means for those with the highest exposures (maternal concentration 4+ ppm fat) were 6.3 cm taller and 6.9 kg larger than those with the lowest (0 to 1 ppm). There was no effect on the ages at which pubertal stages were attained. Lactational exposures to DDE had no apparent effects; neither did transplacental or lactational exposure to PCBs. Girls with the highest transplacental PCB exposures were heavier for their heights than other girls by 5.4 kg, but differences were significant only if the analysis was restricted to white girls. CONCLUSIONS: Prenatal exposures at background levels may affect body size at puberty.     

Effects of in utero exposure to polychlorinated biphenyls and related contaminants on cognitive functioning in young children

Because prenatal exposure to polychlorinated biphenyls (PCBs) and related contaminants has been associated with reduced birth weight, neonatal behavioral anomalies, and poorer recognition memory in infants born to women who have consumed Lake Michigan sports fish, 236 children, previously evaluated for PCB-related deficits in infancy, were assessed at 4 years of age. Prenatal exposure (indicated by umbilical cord serum PCB level) predicted poorer short-term memory function on both verbal and quantitative tests in a dose-dependent fashion. These effects cannot be attributed to a broad range of potential confounding variables, the impact of which was evaluated statistically. Although much larger quantities of PCBs are transferred postnatally via lactation than prenatally across the placenta, exposure from nursing was unrelated to cognitive performance. The data demonstrate the continuation of a toxic impact received in utero and observed initially during infancy on a dimension of cognitive functioning fundamental to learning.     

Neurological condition in 42-month-old children in relation to pre- and postnatal exposure to polychlorinated biphenyls and dioxins.

Adverse neurological effects of exposure to PCBs have been found up to 18 months of age. Now we report on the effect of pre- and postnatal exposure to PCBs and dioxins on the neurological condition at 42 months of age. For this purpose, PCB levels were determined in cord and maternal plasma, and used as a measure of prenatal exposure. Breast milk was analyzed for PCBs and dioxins. In addition, PCBs were determined in plasma sampled from the child at 42 months of age. We evaluated the neurological condition of 394 children using the Touwen/Hempel method. After adjustment for covariates, neither prenatal PCB exposure nor postnatal exposure to PCBs and dioxins was found to be related to the neurological condition at 42 months of age.     

Prenatal drug exposure: effects on cognitive functioning at 5 years of age

The goal of this cross-sectional study was to compare cognitive functioning at age 5 years in prenatal drug-exposed children with nondrug-exposed children from a comparable inner-city environment. Children with prenatal drug exposure scored significantly lower on measures of language, school readiness skills, impulse control, and visual attention span/sequencing than controls matched for age and socioeconomic status. Intelligence, visual-motor, manual dexterity, and sustained attention scores were not significantly different between groups. The total sample scored significantly below the normative mean on standardized measures of intelligence, language, school readiness, visual-motor skills, impulse control, and sustained attention, with 40% scoring at least 1 standard deviation below the mean (IQ < 85) on a measure of intelligence. Findings suggest that children with prenatal drug exposure are at increased risk for learning and attention problems and are in need of close developmental surveillance and possible intervention to support school success and improve behavioral outcome.     

Early exposure to paracetamol or to antibiotics and eczema at school age: Modification by asthma and rhinoconjunctivitis

Garcia‐Marcos L, González‐Díaz C, Garvajal‐Urueña I, Pac‐Sa MR, Busquets‐Monge RM, Suárez‐Varela MM, Batlles‐Garrido J, Blanco‐Quirós A, Varela ÁL.‐S., García‐Hernández G, Aguinaga‐Ontoso I. Early exposure to paracetamol or to antibiotics and eczema at school age: modification by asthma and rhinoconjunctivitis.
Pediatr Allergy Immunol 2010.
© 2010 John Wiley & Sons A/S The association between early exposure to paracetamol or to antibiotics and eczema is conflicting. This study aims to know whether the early exposure to those drugs is associated with eczema at school age, and whether the strength of the association is modified by the presence of asthma or rhinoconjunctivitis. Children aged 6–7 (n = 13908) from the International Study of Asthma and Allergies in Childhood in Spain provided data about current asthma, rhinoconjunctivitis and eczema. Parent‐reported information was also obtained on paracetamol and antibiotic consumption during the first year of life. Logistic regression analysis with eczema as outcome and including exposure to paracetamol or to antibiotics, together with possible confounders, was carried out in the whole sample of children and in five different strata: no respiratory symptom and any respiratory symptom further subdivided into: asthma with rhinoconjunctivitis, asthma without rhinoconjunctivitis and rhinoconjunctivitis without asthma. In the whole sample, exposure to paracetamol was associated with eczema (aOR 1.56 [1.36–1.80]) as was antibiotic consumption (aOR 1.66 [1.43–1.92]). These associations did not substantially change after additionally adjusting for the other drug. A similar pattern was found among children without respiratory symptoms. In children with symptoms, adjusting for the other drug modified the association with paracetamol (aOR from 1.32 [1.03–1.71] to 1.09 [0.83–1.43]) but did not change that with antibiotics (aOR from 1.80 [1.38–2.35] to 1.81 [1.37–2.39]). Early exposure to paracetamol or to antibiotics is associated with an increased prevalence of eczema at school age. Asthma and/or rhinoconjunctivitis substantially modifies this association.     

Prenatal alcohol exposure and attention, learning and intellectual ability at 14 years: a prospective longitudinal study

BACKGROUND: A range of adverse birth outcomes is associated with heavy prenatal alcohol exposure. AIM: To examine the effects of moderate levels of alcohol consumption during pregnancy on children's intellectual ability, learning and attention at 14 years of age. STUDY DESIGN AND SUBJECTS: The Mater-University of Queensland Study of Pregnancy involves a prospective birth cohort of 7223 singletons whose mothers were enrolled at the first antenatal visit. At 14 years, 5139 mothers and adolescents completed attentional and learning questionnaires, and 3731 adolescents completed psychometric assessments. OUTCOME MEASURES: For adolescents, the Wide Range Achievement Test--Revised (WRAT-R) and Raven's Standard Progressive Matrices Test (Raven's) were administered. Mothers completed the Child Behaviour Checklist (CBCL) and adolescents completed the Youth Self Report (YSR). Learning was assessed by a series of questions in the mother and adolescent questionnaires. Maternal measures included the quantity and frequency of alcohol consumption, and the extent of binge drinking. RESULTS: For consumption of <1 glass/day in early or late pregnancy, there was no association with any attention, learning or cognitive outcomes. The strongest estimates of effect were found among those consuming > or =1 glasses/day. Exposure in late pregnancy was associated with increased prevalence of overall learning difficulty in the unadjusted, although not the adjusted analysis. Binge drinking was associated with a higher prevalence of Raven's score <85 (1 standard deviation). CONCLUSIONS: Although a number of study limitations need to be considered, the results suggest that consumption at the level of <1 drink/day does not lead to adverse outcomes in relation to attention, learning and cognitive abilities, as measured in the current research.     

Cognitive development and attention performances at school age of "normal" prematurely born children]

OBJECTIVE: A preterm birth can exert an influence on cognitive development. The aim of this study was to determine whether preterm birth may impact on attention executive processes, at school age, in children without neurological sequelae. DESIGN AND METHODS: Prematurely born children admitted in the level III NICU of the Maternité régionale of Nancy between 1992 and 1994, underwent at 8 to 10 years 8 subtests of the mental processing scales of the K-ABC, which assess process categories involved in learning. The children were also submitted to 3 tests that evaluate attention mechanisms efficiency (category fluency task, backward digits span, Tower of London). The controls were children born at term recruted in schools of the same area. RESULTS: The 124 children were born with birth weight appropriate for gestational age, and were in the school grades expected for their ages, in 3rd, 4rth, and 5fth grades. Fifty-three children were born at term, 29 were prematurely born (33-36 w), and 42 were very prematurely born (28-32 w). Birth term was significantly correlated (P < 0.001) with scores at sequential processing scale, at simultaneous processing scale and at the mental processing composite scale. At this scale, the children born at term obtained a median score of 112, the children prematurely born of 101, and the children very prematurely born of 98.5. For 40 third grade children (18 born at term, 10 prematurely born, and 12 very prematurely born), birth term was significantly correlated with performances at the 3 tests of attention. In all cases, preterm was inversely correlated with performances. CONCLUSION: The results are consistent with a lower efficiency in attention executive processes which may be related to the higher frequency of learning disabilities associated with prematurity.     

Prenatal family adversity and maternal mental health and vulnerability to peer victimisation at school

Background: Prenatal stress has been shown to predict persistent behavioural abnormalities in offspring. Unknown is whether prenatal stress makes children more vulnerable to peer victimisation. Methods: The current study is based on the Avon Longitudinal Study of Parents and Children, a prospective community‐based study. Family adversity, maternal anxiety and depression were assessed at repeated intervals in pregnancy and the postnatal period. Parenting, partner conflict and temperament were measured at preschool age. Peer victimisation was assessed using multiple informants (child, parent, teacher) at primary school age (between ages 7 and 10). Results: Prenatal severe family adversity and maternal mental health directly increased the risk of victimisation at school even when controlled for postnatal family adversity and maternal mental health, parenting, partner conflict and temperament. Effects were found to be independent of sources of information of peer victimisation. Partner conflict and maladaptive parenting also independently increased the risk of peer victimisation. Conclusions: Experiences in pregnancy may affect the developing foetus and increase vulnerability to be victimised by peers. Conflict between parents and their parenting further increase the risk of being victimised by peers at school.     

Parental smoking and neonatal serum levels of polychlorinated biphenyls and hexachlorobenzene

Polychlorinated biphenyls (PCB) and hexachlorobenzene (HCB) are ubiquitous compounds that have tumor-promoting properties if applied together with tobacco-specific carcinogens. It was the purpose of the present study to investigate whether parental smoking by itself will increase the prenatal uptake of such organochloric compounds. With the informed consent of the parents, blood samples were taken from 80 full-term neonates before the first oral feeding. Six PCB congeners (PCB 28, 52, 101, 138, 153, and 180) and HCB were analyzed with capillary gas chromatography. Information about parental smoking behavior, the geographic origin of the parents, and their actual and previous working places was recorded. We composed three study groups for statistical analyses: active smoking mothers (n = 12), passive smoking mothers (n = 33), and nonsmoking families (n = 35). Neonates born to active smoking mothers had the highest PCB and HCB concentrations compared with children of passive or nonsmoking mothers. These differences were statistically significant (p < 0.01) in the cases of PCB 138, total PCB, and HCB. Newborns of passive smoking mothers had higher PCB and HCB concentrations than children of nonsmoking families but lower values than those of active smoking mothers. These differences were statistically significant for all compounds with the exception of PCB 180. It is concluded that active and passive maternal smoking increases the neonatal burden with PCB and HCB.