Prenatal dangers

Research using data from a population-based birth cohort from Rotterdam, in The Netherlands, has found that children exposed to higher levels of air pollution when they were in womb had significantly thinner cortex in several brain regions. Some of this appeared to be related to impaired inhibitory control.

The study involved 783 children aged 6 to 10, who were given brain imaging and cognitive tests. Levels of air pollution in the mother’s environment during pregnancy were estimated using a standardized procedure. Mean fine particle levels were 20.2 μg/m3, and nitrogen dioxide levels were 39.3μg/m3. Note that the EU limit for mean fine particles is actually above that (25μg/m3), while the NO2 level is at the EU limit (40μg/m3), with 45% of the Dutch population experiencing higher levels. The World Health Organization sets a much lower level for fine particles: 10 μg/m3.

Children whose mothers were smokers were excluded from the study, as were children from areas where pollution measures weren’t available. Children included tended to be from a higher socio-economic position compared to those not included. Moreover, children with ADHD, or developmental or behavioral problems, were also excluded.

Global brain volume was not affected by fetal exposure. However, several brain regions showed significantly thinner cortex — in particular, the precuneus and rostral middle frontal regions, which partially accounted for the observed association between fetal exposure to fine particles and impaired inhibitory control (the ability to control your own behavior, especially impulsive behavior). This sort of cognitive impairment at early ages could have significant long-term consequences in academic achievement, later career success, and even in risk of mental disorders.

The findings are consistent with other studies linking acceptable air pollution levels with problems including cognitive impairment and child development.

https://www.eurekalert.org/pub_releases/2018-03/e-apl030818.php

Following a previous study linking higher maternal levels of two common chemicals with slower mental and motor development in preschoolers, a new study has found that this effect continues into school age.

The study involved 328 inner-city mothers and their children. The mothers' levels of prenatal urinary metabolites of di-n-butyl phthalate (DnBP), butylbenzyl phthalate (BBzP), di-isobutyl phthalate (DiBP), di-2-ethylhexyl phthalate and diethyl phthalate were measured in late pregnancy. IQ tests were given to the children at age 7.

Children's IQ scores were negatively associated with higher maternal phthalate levels. Among children of mothers with the highest versus lowest levels of DnBP and DiBP metabolite concentrations (the top 25% vs the bottom 25%), IQ was 6.7 and 7.6 points lower, respectively. There were similar associations with processing speed, perceptual reasoning and working memory; DiBP and verbal comprehension; BBzP and perceptual reasoning.

DnBP and DiBP are found in a wide variety of consumer products, from dryer sheets to vinyl fabrics to personal care products like lipstick, hairspray, and nail polish, even some soaps. Since 2009, several phthalates have been banned from children's toys and other childcare articles in the United States.

Although the results are correlational, and don't prove that phthalates are responsible, the researchers recommend that pregnant women avoid storing or microwaving food in plastic containers, and avoid scented cleaning and personal care products (phthalates hold scent). They are also advised not to use plastics labeled 3, 6, or 7.

Factors such as maternal IQ, maternal education, and quality of the home environment, were controlled for in the analysis. The range of phthalate metabolite levels measured in the mothers was not unusual.

http://www.eurekalert.org/pub_releases/2014-12/cums-pet120414.php

http://www.theguardian.com/lifeandstyle/2014/dec/10/phthalates-damage-childrens-iqs-womb-plastic-chemicals

[3841] Factor-Litvak, P., Insel B., Calafat A. M., Liu X., Perera F., Rauh V. A., et al.
(2014).  Persistent Associations between Maternal Prenatal Exposure to Phthalates on Child IQ at Age 7 Years.
PLoS ONE. 9(12), 

It’s always difficult in human studies to disentangle the effects of lifestyle factors. Alcohol is a case in point, and in particular the vexed question of whether any alcohol is safe during pregnancy. A new study, however, has avoided the complication of co-occurring lifestyle and environment factors by looking directly at genetic variants.

This study, believed to be the first substantial one of its kind, used genetic variation to investigate the effects of moderate (<6 units of alcohol per week) drinking during pregnancy among a large group of women and their children. Since the individual variations that people have in their DNA are not connected to lifestyle and social factors, the approach removes that potential complication.

The study, involving 4,167 children, found that four genetic variants in alcohol-metabolizing genes were strongly related to lower IQ at age eight. But this effect was only seen among the children of women who were moderate drinkers (heavy drinkers were not included in the study), pointing to the effect requiring exposure to alcohol in the womb.

Ten SNPs from four genes previously implicated in alcohol metabolism, intake, or dependency, were analyzed. Four SNPs (particular variants) were related to children’s scores on the cognitive test (WISC), of which three are rare and one quite common. There was an additive effect, with carriers of multiple ‘bad’ alleles being more affected.

There was some evidence that only drinking one or two drinks a week was not harmful to the fetus, but because the numbers of women were relatively small, and individual variability was high, this can’t be assessed with any great certainty.

The critical factor appears to be metabolism of alcohol, with mothers who are ‘fast' metabolizers being safer for their fetus than mothers who metabolize alcohol more slowly.

Mothers' alcohol intake was based on questionnaires completed when they were 18 weeks and 32 weeks pregnant. ‘Moderate’ was defined as between one and six drinks a week. All participants were of white-European origin.

Like us, guinea pigs can’t make vitamin C, but must obtain it from their diet. This makes them a good model for examining the effects of vitamin C deficiency.

In a recent study looking specifically at the effects of prenatal vitamin C deficiency, 80 pregnant guinea pigs were fed a diet that was either high or low in vitamin C. Subsequently, 157 of the newborn pups were randomly allocated to either a low or high vitamin C diet (after weaning), creating four conditions: high/high (controls); high/low (postnatal depletion); low/high (postnatal repletion); low/low (pre/postnatal deficiency). Only males experienced the high/low condition (postnatal depletion).

Only the postnatal depletion group showed any effect on body weight; no group showed an effect on brain weight.

Nevertheless, although the brain as a whole grew normally, those who had experienced a prenatal vitamin C deficiency showed a significantly smaller hippocampus (about 10-15% smaller). This reduction was not reversed by later repletion.

This reduction appeared to be related to a significant reduction in the migration of new neurons into the dentate gyrus. There was no difference in the creation or survival of new neurons in the hippocampus.

This finding suggests that marginal deficiency in vitamin C during pregnancy (a not uncommon occurrence) may have long-term effects on offspring.

The first study to look at the effects of the drug ecstasy on infant development has shown that infants exposed to ecstasy before they were born tend to be behind, especially in motor and coordination skills, at four months.

The study involved 96 women who were questioned about their substance use prior to and during pregnancy. Most of the women surveyed had taken a variety of illegal drugs. 28 women had taken MDMA (ecstasy) during pregnancy. The infants of these women had poorer motor development and lower milestone attainment at 4 months, with a dose–response relationship to the amount of MDMA exposure.

The study is continuing, to see whether these children experience long-term problems.

Participants were primarily middle class with some university education and in stable partner relationships.

For more about the effects of ecstasy on cognition

A study in which mice were exposed to polluted air for three 5-hour sessions a week for 10 weeks, has revealed that such exposure damaged neurons in the hippocampus and caused inflammation in the brain. The polluted air was laden with particles collected from an urban freeway.

Another recent study found that, of 215 children, those whose cord blood showed high levels of combustion-related pollutants such as polycyclic aromatic hydrocarbons (PAH), had more attention (and anxiety) problems at ages 5 and 7. The children were born to nonsmoking African-American and Dominican women residing in New York City.

A study of 265 New York City minority children has found that those born with higher amounts of the insecticide chlorpyrifos had lower IQ scores at age 7. Those most exposed (top 25%) scored an average 5.3 points lower on the working memory part of the IQ test (WISC-IV), and 2.7 points lower on the full IQ test, compared to those in the lowest quartile.

The children were born prior to the 2001 ban on indoor residential use of the common household pesticide in the US. The babies' umbilical cord blood was used to measure exposure to the insecticide.

Previous research had found that, prior to the ban, chlorpyrifos was detected in all personal and indoor air samples in New York, and 70% of umbilical cord blood collected from babies. The amount of chlorpyrifos in babies' blood was associated with neurodevelopmental problems at age three. The new findings indicate that these problems persist.

While exposure to the organophosphate has measurably declined, agricultural use is still permitted in the U.S.

Similarly, another study, involving 329 7-year-old children in a farming community in California, has found that those with the highest prenatal exposure to the pesticide dialkyl phosphate (DAP) had an average IQ 7 points lower than children whose exposure was in the lowest quintile. Prenatal pesticide exposure was linked to poorer scores for working memory, processing speed, verbal comprehension, and perceptual reasoning, as well as overall IQ.

Prenatal exposure was measured by DAP concentration in the mother’s urine. Urine was also collected from the children at age 6 months and 1, 2, 3½ and 5 years. However, there was no consistent link between children’s postnatal exposure and cognition.

While this was a farming community where pesticide exposure would be expected to be high, the levels were within the range found in the general population.

It’s recommended that people wash fruit and vegetables thoroughly, and limit their use of pesticides at home.

A study involving 725 black and Dominican pregnant women living in New York and, later, their 3-year-old children, has found that children who were more highly exposed to PBO in personal air samples taken during the third trimester of pregnancy scored 3.9 points lower on the Bayley Mental Developmental Index than those with lower exposures. This is a similar effect size to that of lead exposure.

PBO is a marker for the insecticide permethrin, which is one of the most common pyrethroid insecticides used in U.S. homes since the EPA phased out the widespread residential use of organophosphorus insecticides in 2000-2001 because of risks to child neurodevelopment.

PBO was detected in the majority of personal air samples (75%).

As this is the first study of these compounds, the results should be considered preliminary.

Increased awareness and changes in diagnostic criteria can’t entirely explain the massive increase in autism — the U.S. Centers for Disease Control reported a 57% increase between 2002 and 2006. Another factor may involve environmental pollutants.

A Californian study involving 304 autism cases and 259 typically developing controls has found that living within 309 meters of a freeway at birth or during the third trimester was associated with a two-fold increase in autism risk. This association held after adjustment for gender, ethnicity, parental education, maternal age, or prenatal smoking. The researchers found no consistent pattern of association of autism with proximity to a major road.

The finding is consistent with other evidence that oxidative stress and inflammation are involved in the pathogenesis of autism. This is likely to be only one of many environmental factors that are involved.

A study involving 676 children (7-9) in rural Nepal has found that those whose mothers received iron, folic acid and vitamin A supplementation during their pregnancies and for three months after the birth performed better on some measures of intellectual and motor functioning compared to offspring of mothers who received vitamin A alone. However, there was no significant benefit for those whose mothers received iron, folic acid and zinc (plus vitamin A), or multiple micronutrients.

A negative effect of adding zinc is consistent with other research indicating that zinc inhibits iron absorption. Interestingly, new “ground-breaking” research demonstrates further the complexity of iron’s effects on the body. The researcher argues that many neurodegenerative diseases (such as Alzheimer’s) are partly caused by poorly bound iron, and it is vital to consume nutrients which bind iron and prevent the production of the toxins it will otherwise produce.

Such nutrients include brightly-colored fruits (especially purple) and vegetables, and green tea.

It’s also argued that Vitamin C is only beneficial if iron is safely bound, and if it’s not, excess Vitamin C might be harmful.

Data from 217 children from Inuit communities in Arctic Quebec (average age 11), of whom some had mothers that reported binge drinking during pregnancy, has revealed that the alcohol-exposed group, while similar to the control in accuracy and reaction time, showed a significant differences in their brains’ electrical activity while doing those tasks (a Go/No-go response inhibition task and a continuous recognition memory task). The differences suggest that fetal alcohol exposure is associated with reduced efficiency in the initial extracting of the meaning of a stimulus, reduced allocation of attention to the task, and poorer conscious recognition memory processing.

A study following over 300 Mexican-American children living in an agricultural community has found that their prenatal exposure to organophosphate pesticides (measured by metabolites in the mother’s urine during pregnancy) was significantly associated with attention problems at age 5. This association was stronger among boys, and stronger with age (at 3 ½ the association, although present, did not reach statistical significance — perhaps because attention disorders are much harder to recognize in toddlers). Based on maternal report, performance on attention tests, and a psychometrician’s report, 8.5% of 5-year-olds were classified as having ADHD symptoms. Each tenfold increase in prenatal pesticide metabolites was linked to having five times the odds of scoring high on the computerized tests at age 5. The child’s own level of phosphate metabolites was not linked with attention problems.

Organophosphate pesticides disrupt acetylcholine, which is important for attention and short-term memory. While the exposure of these children to pesticides is presumably higher and more chronic than that of the general U.S. population, food is a significant source of pesticide exposure among the general population.

Marks AR, Harley K, Bradman A, Kogut K, Barr DB, Johnson C, et al. 2010. Organophosphate Pesticide Exposure and Attention in Young Mexican-American Children. Environ Health Perspect :-. doi:10.1289/ehp.1002056
Full text available at http://ehp03.niehs.nih.gov/article/fetchArticle.action?articleURI=info%3...

A study involving 125 women has found the first, direct human evidence that fetuses exposed to elevated levels of the stress hormone cortisol may have trouble paying attention or solving problems at 17 months. But more hopefully, the association only occurred among children showing insecure attachment to their mothers, independent of socioeconomic factors. The findings suggest that a stressful prenatal environment may be effectively counteracted by good parental care. The children will be followed up when they turn 6.

[1114] [Anonymous]
(2010).  Maternal Prenatal Cortisol and Infant Cognitive Development: Moderation by Infant-Mother Attachment.
Biological Psychiatry. In Press, Corrected Proof,

An imaging study has revealed that children (aged 5-15) whose mothers abused methamphetamine and alcohol during pregnancy had structural abnormalities in the brain that were more severe than those seen in children whose mothers abused alcohol alone. In particular, the striatal region was significantly smaller, and within the group, size of the caudate correlated negatively with IQ. Limbic structures, in particularly the cingulate cortex and the right inferior frontal gyrus, were significantly bigger. The striatal and limbic structures are also known to be particularly affected in adult methamphetamine abusers.

When a pregnant woman uses cocaine, it can interrupt the flow of nutrients and oxygen to the baby, putting such children at risk for premature birth, low birth weight and many other problems. However a new review of 32 major studies of school-age children reveals that the consequences for the brain are less sweeping than feared. Although many of the children did have low IQ and poor academic and language achievement, this seems to be related more to the home environment. But direct effects of cocaine exposure significantly affected children in specific areas such as sustained attention and self-regulated behavior — areas which could lead to serious problems later in life.

A five-year study involving 214 children born to healthy, non-smoking Caucasian women in Krakow, Poland, has found that those prenatally exposed to high levels of polycyclic aromatic hydrocarbons (PAHs) had a significant reduction in scores on a standardized test of reasoning ability and intelligence at age 5 (an estimated average decrease of 3.8 IQ points). The mothers wore small backpack personal air monitors for 48 hours during pregnancy to estimate their babies' PAH exposure. The finding persisted after mother’s intelligence, secondhand smoke exposure, lead and dietary PAH were taken into account. Previously, prenatal exposure to PAHs was found to adversely affect children's IQ at age 5 in children of nonsmoking African American and Dominican American women in New York City. PAHs are released into the air from the burning of fossil fuels.

The nutrient choline is known to play a critical role in memory and brain function by positively affecting the brain's physical development through increased production of stem cells (the parents of brain cells). New research demonstrates that this occurs through the effect of choline on the expression of particular genes. The important finding is that diet during pregnancy turns on or turns off division of stem cells that form the memory areas of the brain. Developing babies get choline from their mothers during pregnancy and from breast milk after they are born. Other foods rich in choline include eggs, meat, peanuts and dietary supplements. Breast milk contains much more of this nutrient than many infant formulas. Choline is a vitamin-like substance that is sometimes treated like B vitamins and folic acid in dietary recommendations.A choline food database is available at: www.nal.usda.gov/fnic/foodcomp.

A mouse study has found that the diet of a pregnant mother, especially in regards to choline, can change the epigenetic switches that control brain development in the fetus. Pregnant mice received different diets during the period when a fetus develops its hippocampus. The genetic changes affected neurogenesis. The findings add to other research pointing to the effects of maternal diet on fetal development. Top sources of choline are eggs and meat. Fish and soy are also good sources.

Older news items (pre-2010) brought over from the old website

Too much licorice in pregnancy may affect child's IQ and behavior

A Finnish study involving 321 eight year old children has found that those whose mothers ate more than 500mg of glycyrrhizin per week (found in the equivalent of 100g of pure licorice) had significant decrements in verbal and visuospatial abilities and in narrative memory, compared to those whose mothers consumed less licorice. They were also more likely to have poor attention spans and show disruptive behaviour such as ADHD. The effects on cognitive performance appeared dose related (that is, higher consumption correlated with greater impairment). Glycyrrhizin may impair the placenta, allowing stress hormones to cross from the mother to the baby. These hormones (glucocorticoids) are thought to affect fetal brain development and have been linked to behavioural disorders in children. Consumption of licorice among young women is common in Finland.

Raikkonen, K., Pesonen, A., Heinonen, K., Lahti, J., Komsi, N., Eriksson, J. G., et al. (2009). Maternal Licorice Consumption and Detrimental Cognitive and Psychiatric Outcomes in Children. Am. J. Epidemiol., 170(9), 1137-1146. doi: 10.1093/aje/kwp272.

http://www.eurekalert.org/pub_releases/2009-10/uoe-eli100609.php

Vitamin C deficiency impairs early brain development

A guinea pig study has found that newborn guinea pigs subjected to moderate vitamin C deficiency had 30% fewer hippocampal neurons and markedly worse spatial memory than guinea pigs given a normal diet. For several reasons the neonatal brain is thought to be particularly vulnerable to even a slight lowering of the vitamin C level. Vitamin C deficiency is very common in some parts of the world, and even in wealthy nations occurs in an estimated 5-10% of the adult population.

Tveden-Nyborg, P. et al. 2009. Vitamin C deficiency in early postnatal life impairs spatial memory and reduces the number of hippocampal neurons in guinea pigs. American Journal of Clinical Nutrition, 90 (3), 540-546.

http://www.eurekalert.org/pub_releases/2009-09/uoc-vcd090209.php

Children of older fathers perform less well in intelligence tests during infancy

Reanalysis of a dataset of over 33,000 children born between 1959 and 1965 and tested at 8 months, 4 years, and 7 years, has revealed that the older the father, the more likely the child was to have lower scores on the various tests used to measure the ability to think and reason, including concentration, learning, memory, speaking and reading skills. In contrast, the older the mother, the higher the scores of the child in the cognitive tests.

Saha, S. et al. 2009. Advanced paternal age is associated with impaired neurocognitive outcomes during infancy and childhood. PLoS Medicine 6(3), e1000040. doi:10.1371/journal.pmed.1000040 
Full text available at http://medicine.plosjournals.org/perlserv/?request=get-document&doi=10.1371/journal.pmed.1000040

http://www.eurekalert.org/pub_releases/2009-03/plos-coo030309.php

Early maternal experience can affect memory in her offspring

A study of pre-adolescent mice with a genetically-created defect in memory has found that a mere two weeks exposure to a stimulating environment resulted in a reversal of the memory defect. But most surprisingly, it was also found that this effect was passed on to the next generation, even though they had the same genetic defect and even though they had no such experience themselves, and even when they were reared by other mice (not their mothers). It’s worth emphasising that the enrichment occurs for the mother long before she’s fertile, yet still benefits her offspring. The finding adds to many recent studies showing that genes are more malleable than we thought.

Arai, J., Li, S., Hartley, D.M. & Feig, L.A. 2009. Transgenerational Rescue of a Genetic Defect in Long-Term Potentiation and Memory Formation by Juvenile Enrichment. Journal of Neuroscience, 29(5), 1496-1502.

http://www.physorg.com/news152905156.html
http://www.eurekalert.org/pub_releases/2009-02/rumc-wym020209.php
http://www.eurekalert.org/pub_releases/2009-02/tuhs-dyk012909.php

Breaking fish advice during pregnancy may benefit babies

Fears of the effects of mercury have led to government warnings to pregnant women to limit their consumption of seafood. However, a study involving nearly 12,000 women has found that children whose mothers ate the least amount of seafood during pregnancy showed the worst performance on tests of social development and verbal IQ, and beneficial effects were evident among children of women who ate more than the recommended guidelines.

Hibbeln, J.R. et al. 2007. Maternal seafood consumption in pregnancy and neurodevelopmental outcomes in childhood (ALSPAC study): an observational cohort study. The Lancet,369 (9561), 578-585.

http://www.newscientist.com/article/dn11193-breaking-fish-advice-during-pregnancy-might-benefit-babies.html

Ingredient commonly found in shampoos may inhibit brain development

An ingredient found in many shampoos and other personal care products (Diethanolamine (DEA)) appears to interfere with normal brain development in baby mice when applied to the skin of their pregnant mothers. DEA appears to block the body's ability to absorb the nutrient choline, which is essential for normal development of the brain. Whether the amounts most people absorb from personal care products would cause harm remains unclear. A list of some products that contain DEA can be found at http://householdproducts.nlm.nih.gov/index.htm.

Craciunescu, C.N., Wu, R. & Zeisel, S.H. 2006. Diethanolamine alters neurogenesis and induces apoptosis in fetal mouse hippocampus. FASEB Journal, 20, 1635-1640.

http://www.eurekalert.org/pub_releases/2006-08/uonc-uss080306.php

Lead exposure leads to brain cell loss and damage years later

A study of 532 former employees of a chemical manufacturing plant who had not been exposed to lead for an average of 18 years has found that the higher their lead levels were, the more likely they were to have smaller brain volumes and greater amounts of brain damage. 36% had white matter lesions. The results confirm earlier findings in this same population that people with occupational lead exposure experience declines in their thinking and memory skills years after their exposure.

Stewart, W.F. et al. 2006. Past adult lead exposure is linked to neurodegeneration measured by brain MRI. Neurology, 66, 1476-1484.

http://www.eurekalert.org/pub_releases/2006-05/aaon-lel051806.php

Prenatal exposure to urban air pollutants affects cognitive development

A study of 183 three-year-old children of non-smoking African-American and Dominican women residing in New York City has found that exposure during pregnancy to combustion-related urban air pollutants (specifically, polycyclic aromatic hydrocarbons) was linked to significantly lower scores on mental development tests and more than double the risk of developmental delay at age three.

Perera, F.P. et al. 2006. Effect of Prenatal Exposure to Airborne Polycyclic Aromatic Hydrocarbons on Neurodevelopment in the First Three Years of Life Among Inner-City Children. Environmental Health Perspectives, published online ahead of print.
Full text is available at http://www.ehponline.org/members/2006/9084/9084.pdf

http://www.eurekalert.org/pub_releases/2006-04/cums-iue042506.php

Prenatal exposure to marine toxin causes lasting damage

A rat study has found that a single dose of the naturally occurring marine toxin domoic acid caused subtle but permanent cognitive damage in rats exposed to the chemical before birth. The effect occurred at levels below those generally deemed safe, and suggest that the toxin might negatively affect unborn children at levels that do not cause symptoms in expectant mothers. It was already known that toxic doses of domoic acid can damage the hippocampus.

Levin, E.D., Pizarro, K., Pang, W.G., Harrison, J. & Ramsdell, J.S. 2005. Persisting behavioral consequences of prenatal domoic acid exposure in rats. Neurotoxicology and Teratology, in press.

http://www.eurekalert.org/pub_releases/2005-09/dumc-pet090605.php

Rats infected as newborns vulnerable to memory problems when infected in adulthood

Underscoring the value of good prenatal care, a new rat study has found that rats who experienced a one-time infection as newborns didn't learn as well as adult rats who were not infected as pups, after their immunity was challenged. The findings fit into a growing body of evidence that even a one-time infection can potentially permanently change physiological systems, a phenomenon called "perinatal programming." The findings implicate prenatal infections, as the rats were infected on their 4th day, a time that corresponds, in terms of brain development, with the 3rd trimester in humans. It should be noted that adult rats who were not infected as pups did not suffer memory impairment as the result of adult infection, and those who were infected as newborns were completely normal until they received the second immune system challenge in adulthood. It’s suggested that this phenomenon may help explain some of the individual variability in disease susceptibility.

Bilbo, S.D., Levkoff, L.H., Mahoney, J.H., Watkins, L.R., Rudy, J.W. & Maier, S.F. 2005. Neonatal Infection Induces Memory Impairments Following an Immune Challenge in Adulthood. Behavioral Neuroscience, 119 (1)

http://www.eurekalert.org/pub_releases/2005-02/apa-ria020105.php

Prenatal exposure to solvents associated with negative cognitive effects

A study of 64 children aged 3 to 9 found that those children whose mothers were exposed to organic solvents during their pregnancies had lower scores on certain tests of language, behavior, and cognitive functioning. Organic solvents (used for example in dry cleaning, manufacturing, jobs involving paints and plastic adhesives, nail salons and medical laboratories) are some of the most common sources of workplace chemical exposure reported by pregnant women.

Laslo-Baker, D., Barrera, M., Knittel-Keren, D., Kozer, E., Wolpin, J., Khattak, S., Hackman, R., Rovet, J. & Koren, G. 2004. Child Neurodevelopmental Outcome and Maternal Occupational Exposure to Solvents. Archives of Pediatrics & Adolescent Medicine, 158, 956-961.

http://www.eurekalert.org/pub_releases/2004-10/jaaj-met093004.php

Environmental damage to brains of children

A new report suggests that the brains of children in many parts of Europe are suffering greater damage from environmental risks than previously recognized. A meeting in Malta of European delegates preparing for a ministerial conference on environment and health, being held in Budapest in June, were given preliminary results from a comprehensive study on environmental threats to children's health, being conducted by the WHO and the University of Udine, Italy. The full report is to be published at the Budapest conference. The findings suggest lead is the single most important damaging chemical for children. In 2001, the estimated percentage of European children in urban areas with elevated blood levels (above 10 micrograms per decilitre) ranged from 0.1% to 30.2%.

http://news.bbc.co.uk/1/hi/sci/tech/3568939.stm

Vital role in brain development for the nutrient choline

The nutrient choline is known to play a critical role in memory and brain function by positively affecting the brain's physical development through increased production of stem cells (the parents of brain cells). New research demonstrates that this occurs through the effect of choline on the expression of particular genes. The important finding is that diet during pregnancy turns on or turns off division of stem cells that form the memory areas of the brain. Developing babies get choline from their mothers during pregnancy and from breast milk after they are born. Other foods rich in choline include eggs, meat, peanuts and dietary supplements. Breast milk contains much more of this nutrient than many infant formulas. Choline is a vitamin-like substance that is sometimes treated like B vitamins and folic acid in dietary recommendations.
A choline food database is available at: www.nal.usda.gov/fnic/foodcomp.

Niculescu, M.D., Yamamuro, Y. & Zeisel, S.H. 2004. Choline availability modulates human neuroblastoma cell proliferation and alters the methylation of the promoter region of the cyclin-dependent kinase inhibitor 3 gene. Journal of Neurochemistry, 89 (5), 1252-1259.

http://www.eurekalert.org/pub_releases/2004-03/uonc-sdw031604.php

Prenatal exposure to secondhand smoke associated with greater risk of developmental delay

A new study funded by the National Institute of Environmental Health Sciences has found that children whose mothers are exposed during pregnancy to second-hand smoke have reduced scores on tests of cognitive development at age two, when compared to children from smoke-free homes. In addition, the children exposed to second-hand smoke during pregnancy are approximately twice as likely to have developmental scores below 80, which is indicative of developmental delay. These differences were magnified for children whose mothers lived in inadequate housing or had insufficient food or clothing during pregnancy. The combined effect results in a developmental deficit of about seven points in tests of cognitive performance.

Rauh, V.A., Whyatt, R.M., Garfinkel, R., Andrews, H., Hoepner, L., Reyes, A., Diaz, D., Camann, D. & Perera, F.P. 2004. Developmental effects of exposure to environmental tobacco smoke and material hardship among inner-city children. Neurotoxicology and Teratology, 26 (3), 373-385.

http://www.eurekalert.org/pub_releases/2004-03/nioe-sse031504.php

Pre-term labor drug sensitizes brain to pesticide injury

A rat study has found that unborn rats exposed to terbutaline - a drug commonly prescribed to halt pre-term labor and stave off premature birth - suffered greater brain cell damage than those not given the drug upon secondary exposure to the common insecticide chlorpyrifos. This suggests that this drug might leave the brains of children susceptible to other chemicals ubiquitously present in the environment, and may help explain earlier suggestions that children whose mothers are administered terbutaline suffer cognitive deficits.

Rhodes, M.C., Seidler, F.J., Qiao, D., Tate, C.A., Cousins, M.M. & Slotkin, T.A. 2004. Does pharmacotherapy for preterm labor sensitize the developing brain to environmental neurotoxicants? Cellular and synaptic effects of sequential exposure to terbutaline and chlorpyrifos in neonatal rats. Toxicology and Applied Pharmacology, 195 (2), 203-217.

http://www.eurekalert.org/pub_releases/2004-03/dumc-pld033004.php

Impact of prenatal environment on learning abilities

In a fascinating study that points to the importance of environment (including prenatal environment) in determining behavioral and cognitive abilities, embryos from mice with a low response to stress were transferred to high-stress surrogate mice. The two strains of mice differed not only in their response to stress but also in their learning abilities. At birth, the mice were cross-fostered again and reared by either a low-stress mother or a high-stress mother. The mice were tested at three months, and researchers found that the low-stress mice that were transferred as embryos to and also later reared by high-stress females were less likely to explore new environments than those carried and reared by low-stress mothers. The low-stress mice reared by high-stress surrogates also performed more poorly on cognitive tests of their ability to navigate mazes.

Francis, D.D., Szegda, K., Campbell, G., Martin, W.D. & Insel, T.R. 2003. Epigenetic sources of behavioral differences in mice. Nature Neuroscience, 6 (5),445–446.

http://www.eurekalert.org/pub_releases/2003-05/euhs-ees051203.php

Fetuses recognize mother's voice in the womb

A study of 60 third-term fetuses found that they could distinguish between their mother’s voice and the voice of a stranger, as measured by changes in heart rate. Previous research has shown that newborns prefer their own mother's voice to that of a female stranger, but this demonstrates that this preference and recognition begins in the womb.

Kisilevsky, B.S., Hains, S.M.J., Lee, K., Xie, X., Huang, H., Ye, H.H., Zhang K. & Wang, Z. 2003. Effects of experience on fetal voice recognition. Psychological Science, 14 (3), 220-224(5).

Cognitive development affected in babies exposed prenatally to cocaine

In the first study to use measures of both the mothers’ self report of their prenatal drug use, and infant meconium, which provided a physical measure of the amount of drug exposure, 415 cocaine-exposed infants born in Cleveland were compared to non-exposed infants on cognitive and motor development until age 2. Infants were tested at 6.5, 12 and 24 months. Mental retardation in the cocaine-exposed children at age 2 was 4.89 times higher than would be expected in the general population. The percentage of children with mild delays requiring intervention was almost double the rate of the high risk, non-cocaine group. The study also found that tobacco exposure had significant negative effects on infant development.

Singe, L.T., Arendt, R., Minnes, S., Salvator, A., Kirchner, H.L., Farkas, K., & Kliegman, R. 2002. Cognitive and Motor Outcomes of Cocaine-Exposed Infants. Journal of the American Medical Association, 287,1952-1960.

http://www.eurekalert.org/pub_releases/2002-04/cwru-a2y041602.php

Use of ecstasy during pregnancy may produce learning and memory impairments in child

Researchers today reported the first evidence that a mother’s use of MDMA (ecstasy) during pregnancy may result in specific types of long-term learning and memory impairments in her offspring.
The research was conducted by scientists from Children’s Hospital Research Foundation and the University of Cincinnati College of Medicine, on rats. It appears the damage to offspring occurs only if the drug is taken during a particular critical period of pregnancy.

Broening, H.W., Morford, L.L., Inman-Wood, S.L., Fukumura, M. & Vorhees, C.V. 2001. 3,4-Methylenedioxymethamphetamine (Ecstasy)-Induced Learning and Memory Impairments Depend on the Age of Exposure during Early Development. Journal of Neuroscience, 21, 3228-3235.

http://www.eurekalert.org/pub_releases/2001-04/NIoD-Rfet-2904101.php

Prenatal exposure to Alcohol

Where math takes place normally and in children with fetal alcohol spectrum disorder

An imaging study involving 21 children with fetal alcohol spectrum disorder confirms the importance of the left parietal area for mathematical tasks. Children with FASD are particularly impaired in mathematical ability. Brain activity patterns also revealed that the involvement of regions in the left cerebellum and the brainstem in math processing may be specific to children with FASD.

[291] Lebel, C., Rasmussen C., Wyper K., Andrew G., & Beaulieu C.
(2010).  Brain Microstructure Is Related to Math Ability in Children With Fetal Alcohol Spectrum Disorder.
Alcoholism: Clinical and Experimental Research. 34(2), 354 - 363.

http://www.eurekalert.org/pub_releases/2009-11/ace-ema111209.php

Possible genetic risk for fetal alcohol disorders

In partial explanation of why children who are exposed to alcohol because their mothers drank during pregnancy are differently affected, new research with rhesus monkeys has found evidence of a gene variant that appears to make the carrier more susceptible to the effects of fetal alcohol exposure. The gene involved is the serotonin transporter gene promoter, and this variant has previously been implicated in increased depression risk.

[499] Kraemer, G. W., Moore C. F., Newman T. K., Barr C. S., & Schneider M. L.
(2008).  Moderate Level Fetal Alcohol Exposure and Serotonin Transporter Gene Promoter Polymorphism Affect Neonatal Temperament and Limbic-Hypothalamic-Pituitary-Adrenal Axis Regulation in Monkeys.
Biological Psychiatry. 63(3), 317 - 324.

http://www.eurekalert.org/pub_releases/2007-09/uow-srp092107.php

Post-natal choline supplements may reduce cognitive effects associated with prenatal alcohol exposure

A rat study has found that giving choline to rat pups exposed to alcohol during the equivalent of the third trimester, when there’s a spurt in brain growth, significantly reduced the severity of alcohol-related over-activity and spatial learning deficits. The benefits lasted months after choline treatment, suggesting that choline’s effects are long-lasting. Further studies are needed to establish exactly how choline helps and how late in development it can reduce fetal alcohol effects, and then, whether the effects also apply to humans. However, although early postnatal choline may reduce learning deficits and hyperactivity following early alcohol exposure, it doesn’t help reduce motor coordination deficits.

Thomas, J.D. et al. 2007. Choline Supplementation Following Third-Trimester Equivalent Alcohol Exposure Attenuates Behavioral Alterations in Rats. Behavioral Neuroscience, 121 (1), 120-130.

http://www.eurekalert.org/pub_releases/2007-02/apa-csp022607.php

Eye movement tasks can be used to assess fetal alcohol spectrum disorders

Fetal alcohol spectrum disorders (FASD) cover a wide array of adverse developmental outcomes in children due to prenatal alcohol exposure and is harder to diagnose than the more severe Fetal Alcohol Syndrome. Now new research indicates than simple eye-movement tasks can be used to assess individuals with FASD.

Green, C.R. et al. 2007. Deficits in Eye Movement Control in Children With Fetal Alcohol Spectrum Disorders. Alcoholism: Clinical and Experimental Research, 31 (3), 500–511.

http://www.eurekalert.org/pub_releases/2007-02/ace-emt021507.php

Numbers, sequences pose problems for Fetal Alcohol Syndrome children

An assessment of 50 Canadian children aged six to 15 years, who had been diagnosed with Fetal Alcohol Spectrum Disorder, has revealed that they had specific deficits in memory for numbers and sequences, which may contribute to common math difficulties faced by these children. The study also found differences between Aboriginal children and Caucasian children with FASD.

[1041] Rasmussen, C., Horne K., & Witol A.
(2006).  Neurobehavioral Functioning in Children with Fetal Alcohol Spectrum Disorder.
Child Neuropsychology. 12(6), 453 - 453.

http://www.eurekalert.org/pub_releases/2006-12/uoa-nsp122006.php

Prenatal exposure to alcohol linked to lower I.Q.

Analysis of data from the Maternal Health Practices and Child Development Project, an examination of prenatal substance use among women who attended a prenatal clinic from 1983 to 1985, has found that even light to moderate drinking – especially during the second trimester – is associated with lower IQs in African-American offspring at 10 years of age, but not Caucasian children. The difference was not due to differences in the amount or pattern of alcohol use during pregnancy or by differences in socioeconomic status.

[364] Willford, J., Leech S., & Day N.
(2006).  Moderate prenatal alcohol exposure and cognitive status of children at age 10.
Alcoholism, Clinical and Experimental Research. 30(6), 1051 - 1059.

http://www.eurekalert.org/pub_releases/2006-05/ace-lpa051806.php

New 'eye movement' test may help treat fetal alcohol syndrome

At present there are no objective diagnostic tools that can be used to distinguish between children with Fetal Alcohol Spectrum Disorder (FASD) and those with other developmental disorders such as Attention-Deficit Hyperactivity Disorder (ADHD). Many of the behavioural tests used to assess children with FASD are geared to white, middle-class English-speaking people. Now a pilot study involving 25 children aged 8-12 has found that the specific brain abnormalities associated with FASD can be identified using a simple test that measures eye movement.

Reynolds, J. & Green, C. 2005. Presented at the annual meeting of the international Society for Neuroscience in Washington, D.C.

http://www.eurekalert.org/pub_releases/2005-11/qu-nm111105.php

Key neural system at risk from fetal alcohol exposure

A study of pregnant rhesus monkeys has found that prenatal exposure to alcohol has pronounced effects on the development and function later in life of the brain's dopamine system. Dopamine is a key chemical messenger in the brain. The study indicates there is no safe dose, nor safe time to drink, for pregnant women. The monkeys consumed the equivalent of one to two drinks a day. Abnormalities in dopamine functioning can contribute to addiction, memory, attention and problem solving, and more pronounced conditions such as schizophrenia. The nature of the damage is significantly different depending on the timing of the alcohol exposure.

[511] Kraemer, G. W., Schneider M. L., Moore C. F., Barnhart T. E., Larson J. A., DeJesus O. T., et al.
(2005).  Moderate-Level Prenatal Alcohol Exposure Alters Striatal Dopamine System Function in Rhesus Monkeys.
Alcoholism: Clinical and Experimental Research. 29(9), 1685 - 1697.

http://www.eurekalert.org/pub_releases/2005-09/uow-kns091305.php

Prenatal alcohol exposure can lead to lasting changes in cognitive processing

A study involving 337 African-American children, 7.5 years of age, selected from the Detroit Prenatal Alcohol Longitudinal Cohort, has found that although children known to have been prenatally exposed to moderate-to-heavy levels of alcohol were able to perform as well as other children when tasks were simple – such as naming colors within a timed period – when pressed to respond quickly while having to think about the response, their processing speed slowed down significantly. The observed deficits in working memory are thought to be partly a result of the slower processing speed. The study also confirmed earlier suggestions that number processing is particularly affected.

[946] Burden, M. J., Jacobson S. W., & Jacobson J. L.
(2005).  Relation of Prenatal Alcohol Exposure to Cognitive Processing Speed and Efficiency in Childhood.
Alcoholism: Clinical and Experimental Research. 29(8), 1473 - 1483.

http://www.eurekalert.org/pub_releases/2005-08/ace-pae080705.php

Prenatal alcohol exposure has effects far beyond fetal alcohol syndrome

Numerous studies have documented IQ deficits in children with fetal alcohol syndrome (FAS). Little research, however, has found IQ deficits in children with alcohol-related neurodevelopmental disorder (ARND), who generally exhibit less severe neurobehavioral deficits than children with FAS. A new study demonstrates that what was interpreted in prior studies as a lack of any IQ effects in nonsyndromal, alcohol-exposed children was really due to a differential effect of exposure related to several risk/protective factors. Specifically, children whose mothers are older than 30 years, those whose mothers have alcohol dependence, those whose parents provide a less stimulating environment, and those whose mothers reported drinking during the time of conception, are at greater risk from prenatal alcohol exposure.

Jacobson, S.W., Jacobson, J.L., Sokol, R.J., Chiodo, L.M. & Corobana, R. 2004. Maternal Age, Alcohol Abuse History, and Quality of Parenting as Moderators of the Effects of Prenatal Alcohol Exposure on 7.5-Year Intellectual Function. Alcoholism: Clinical & Experimental Research, 28(11), 1732-1745.

http://www.eurekalert.org/pub_releases/2004-11/ace-pae110804.php

New hope for children with fetal alcohol syndrome

A study of 415 people diagnosed with either fetal alcohol syndrome (FAS) or fetal alcohol effect (FAE) found two factors greatly increased the chances of escaping the negative experiences common to those with such problems - being diagnosed early in life and being raised in a stable and nurturing environment. These findings offer hope in a situation that many have regarded as hopeless.

[1051] Streissguth, A. P., Bookstein F. L., Barr H. M., Sampson P. D., O'Malley K., & Young J K.
(2004).  Risk factors for adverse life outcomes in fetal alcohol syndrome and fetal alcohol effects.
Journal of Developmental and Behavioral Pediatrics: JDBP. 25(4), 228 - 238.

http://www.eurekalert.org/pub_releases/2004-08/uow-nhf081004.php

Light drinking during pregnancy may lead to learning and memory deficits in adolescents

The dangers for the developing child of heavy drinking during pregnancy are well-known, but an ongoing longitudinal study of 580 children and their mothers has found that even light to moderate drinking may have significant effects on the cognitive development of the child – effects which show up in adolescents in subtle difficulties with learning and memory, specifically in the auditory/verbal domain.

Willford, J.A., Richardson, G.A., Leech, S.L. & Day, N.L. 2004. Verbal and Visuospatial Learning and Memory Function in Children With Moderate Prenatal Alcohol Exposure. Alcoholism: Clinical & Experimental Research, 28(3), 497-507.

http://www.eurekalert.org/pub_releases/2004-03/ace-ltm030804.php

Deficits associated with prenatal alcohol exposure can be seen as early as infancy

Most of the research on arousal and attention deficits caused by prenatal alcohol exposure has been conducted with children. A new study examined different components of attention through use of heart-rate data collected from six-month-old infants. The findings indicate that slower processing speeds and arousal-regulation problems exist as early as infancy.

Kable, J.A. & Coles, C.D. 2004. The Impact of Prenatal Alcohol Exposure on Neurophysiological Encoding of Environmental Events at Six Months. Alcoholism: Clinical & Experimental Research, 28(3), 489-496.

http://www.eurekalert.org/pub_releases/2004-03/ace-daw030804.php

Prenatal exposure to alcohol affects executive functioning in young children

A study of 316 four-year-old children whose mothers had used various combinations of cocaine, alcohol, and/or marijuana during pregnancy, found that children in the alcohol-exposed group performed significantly worse at an inhibition task than the children in the control group (no maternal use of such substances during pregnancy). This effect persisted even after controlling for prenatal drug exposure, postnatal environmental factors, and child verbal IQ, and suggests that children exposed prenatally to alcohol find it more difficult to inhibit inappropriate behaviors. This may partly explain why such children are at greater risk for social and academic problems. The subtle effect may not be noticeable in most children, but for those who operate at lower levels of functioning, the effect may make all the difference between coping and not. This effect occurred with prenatal alcohol exposure of less than one drink per day. In the United States, it is estimated that among women who know they are pregnant, 2% continue to drink at a moderate level and 5% continue to have at least two drinks per week.

[560] Noland, J. S., Singer L. T., Arendt R. E., Minnes S., Short E. J., & Bearer C. F.
(2003).  Executive Functioning in Preschool-Age Children Prenatally Exposed to Alcohol, Cocaine, and Marijuana.
Alcoholism: Clinical and Experimental Research. 27(4), 647 - 656.

http://www.eurekalert.org/pub_releases/2003-04/ace-efi040503.php

Motor skill training may help children with fetal alcohol exposure

The disorders associated with fetal exposure to alcohol are a leading cause of mental retardation and developmental delay.Research with rats has looked at the effect of motor skill training on the development of rats similarly exposed to alcohol at a critical stage of their prenatal development. Those rats trained in increasingly difficult challenges involving motor skills were found to develop 20% more synapses in the cerebellum than the rats that did not train, even though they had the expected 30% loss of Purkinje cells. The research brings hope that, despite the damage done to the motor function, it may be possible to rehabilitate these deficits if caught early enough.

[1369] Klintsova, A. Y., Scamra C., Hoffman M., Napper R. M. A., Goodlett C. R., & Greenough W. T.
(2002).  Therapeutic effects of complex motor training on motor performance deficits induced by neonatal binge-like alcohol exposure in rats: : II. A quantitative stereological study of synaptic plasticity in female rat cerebellum.
Brain Research. 937(1-2), 83 - 93.

http://www.eurekalert.org/pub_releases/2002-08/uoia-cpl080702.php

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