The interaction of genetic sex and prenatal alcohol exposure on health across the lifespan

Prenatal alcohol exposure (PAE) can reprogram the development of cells and tissues, resulting in a spectrum of physical and neurobehavioral teratology. PAE immediately impacts fetal growth, but its effects carry forward post-parturition, into adolescence and adulthood, and can result in a cluster of disabilities, collectively termed Fetal Alcohol Spectrum Disorders. Emerging preclinical and clinical research investigating neurological and behavioral outcomes in exposed offspring point to genetic sex as an important modifier of the effects of PAE. In this review, we discuss the literature on sex differences following PAE, with studies spanning the fetal period through adulthood, and highlight gaps in research where sex differences are likely, but currently under-investigated. Understanding how sex and PAE interact to affect offspring health outcomes across the lifespan is critical for identifying the full complement of PAE-associated secondary conditions, and for refining targeted interventions to improve the quality of life for individuals with PAE.

Fatty acid ethyl esters in meconium: A biomarker of fetal alcohol exposure and effect

To determine if meconium fatty acid ethyl esters (FAEE) in rat pups is a good biomarker of prenatal exposure and effect to alcohol, three groups of pregnant rats were studied: one control (pair fed) and two treatment groups given 25% alcohol at 2.2 or 5.5 g-1 kg-1 d-1. The pups were delivered on day 20 and, for each dam, were separated into a male and female group. The body, brain, intestines, and placenta of the pups were obtained, weighed, and stored at -20°C. The pups' intestines (as surrogate of meconium) from each group were pooled, and meconium was analyzed by gas chromatography/mass spectroscopy for FAEE. The meconium showed the following FAEE: ethyl palmitate, ethyl stearate, and ethyl linolenate and were only found in the alcohol-treated group and with high specificity but low sensitivity. Mean body weight of the pups was lower in the treatment groups compared to the control groups. Ethyl palmitate concentration correlated negatively to the pups' mean body and brain weights. Therefore, ethyl palmitate, stearate, and linolenate, in meconium of rat pups prenatally exposed to alcohol, are useful biomarkers of prenatal alcohol exposure, with ethyl palmitate a good biomarker of adverse effect on the pups' body and brain weight.

The causal web of foetal alcohol spectrum disorders: a review and causal diagram

Foetal alcohol spectrum disorders (FASDs) are a leading cause of developmental disability. Prenatal alcohol use is the sole necessary cause of FASD, but it is not always sufficient. Multiple factors influence a child's susceptibility to FASD following prenatal alcohol exposure. Much of the FASD risk factor literature has been limited to discussions of association, rather than causation. While knowledge of predictor variables is important for identifying who is most at risk of FASD and for targeting interventions, causal knowledge is important for identifying effective mechanisms for prevention and intervention programmes. We conducted a systematic search and narrative synthesis of the evidence and used this to create a causal diagram (directed acyclic graph; DAG) to describe the causal pathways to FASD. Our results show that the aetiology of FASD is multifaceted and complex. FASD risk is determined by a range of lifestyle, sociodemographic, maternal, social, gestational, and genetic factors. The causal diagram that we present in this review provides a comprehensive summary of causal risk factors for FASD and can be used as a tool to inform data collection and statistical modelling strategies to minimise bias in future studies of FASD.

Using Macaques to Address Critical Questions in Zika Virus Research

Zika virus (ZIKV) and nonhuman primates have been inextricably linked since the virus was first discovered in a sentinel rhesus macaque in Uganda in 1947. Soon after ZIKV was epidemiologically associated with birth defects in Brazil late in 2015, researchers capitalized on the fact that rhesus macaques are commonly used to model viral immunity and pathogenesis, quickly establishing macaque models for ZIKV infection. Within months, the susceptibility of pregnant macaques to experimental ZIKV challenge and ZIKV-associated abnormalities in fetuses was confirmed. This review discusses key unanswered questions in ZIKV immunity and in the pathogenesis of thecongenital Zika virus syndrome. We focus on those questions that can be best addressed in pregnant nonhuman primates and lessons learned from developing macaque models for ZIKV amid an active epidemic.

Epigenetic mechanisms in alcohol- and adversity-induced developmental origins of neurobehavioral functioning

The long-term effects of developmental alcohol and stress exposure are well documented in both humans and non-human animal models. Damage to the brain and attendant life-long impairments in cognition and increased risk for psychiatric disorders are debilitating consequences of developmental exposure to alcohol and/or psychological stress. Here we discuss evidence for a role of epigenetic mechanisms in mediating these consequences. While we highlight some of the common ways in which stress or alcohol impact the epigenome, we point out that little is understood of the epigenome's response to experiencing both stress and alcohol exposure, though stress is a contributing factor as to why women drink during pregnancy. Advancing our understanding of this relationship is of critical concern not just for the health and well-being of individuals directly exposed to these teratogens, but for generations to come.

Sensory Processing in Rhesus Monkeys: Developmental Continuity, Prenatal Treatment, and Genetic Influences

Neonatal sensory processing (tactile and vestibular function) was tested in 78 rhesus macaques from two experiments. At ages 4-5 years, striatal dopamine D2 receptor binding was examined using positron emission tomography. At ages 5-7 years, adult sensory processing was assessed. Findings were: (a) prenatal stress exposure yielded less optimal neonatal sensory processing; (b) animals carrying the short rh5-HTTLPR allele had less optimal neonatal sensory scores than monkeys homozygous for the long allele; (c) neonatal sensory processing was significantly related to striatal D2 receptor binding for carriers of the short allele, but not for animals homozygous for the long allele; and (d) there was moderate developmental continuity in sensory processing from the neonatal period to adulthood.

Neurobehavioral Disorder Associated with Prenatal Alcohol Exposure (ND-PAE): Proposed DSM-5 Diagnosis

Over the past 40 years, a significant body of animal and human research has documented the teratogenic effects of prenatal alcohol exposure (PAE). Neurobehavioral Disorder associated with PAE is proposed as a new clarifying term, intended to encompass the neurodevelopmental and mental health symptoms associated with PAE. Defining this disorder is a necessary step to adequately characterize these symptoms and allow clinical assessment not possible using existing physically-based diagnostic schemes. Without appropriate diagnostic guidelines, affected individuals are frequently misdiagnosed and treated inappropriately (often to their considerable detriment) by mental health, educational, and criminal justice systems. Three core areas of deficits identified from the available research, including neurocognitive, self-regulation, and adaptive functioning impairments, are discussed and information regarding associated features and disorders, prevalence, course, familial patterns, differential diagnosis, and treatment of the proposed disorder are also provided.

Neurobehavioral development of common marmoset monkeys

Common marmoset (Callithrix jacchus) monkeys are a resource for biomedical research and their use is predicted to increase due to the suitability of this species for transgenic approaches. Identification of abnormal neurodevelopment due to genetic modification relies upon the comparison with validated patterns of normal behavior defined by unbiased methods. As scientists unfamiliar with nonhuman primate development are interested to apply genomic editing techniques in marmosets, it would be beneficial to the field that the investigators use validated methods of postnatal evaluation that are age and species appropriate. This review aims to analyze current available data on marmoset physical and behavioral postnatal development, describe the methods used and discuss next steps to better understand and evaluate marmoset normal and abnormal postnatal neurodevelopment.

Moderate-level prenatal alcohol exposure induces sex differences in dopamine d1 receptor binding in adult rhesus monkeys

BACKGROUND

We examined the effects of moderate prenatal alcohol exposure and/or prenatal stress exposure on (D1 R) binding in a non human primate model. The dopamine D1 R is involved in executive function, and it may play a role in cognitive behavioral deficits associated with prenatal alcohol and/or stress exposure. Little is known, however, about the effects of prenatal alcohol and/or stress exposure on the D1 R. We expected that prenatal insults would lead to alterations in D1 R binding in prefrontal cortex (PFC) and striatum in adulthood.

METHODS

Rhesus macaque females were randomly assigned to moderate alcohol exposure and/or mild prenatal stress as well as a control condition during pregnancy. Thirty-eight offspring were raised identically and studied as adults by noninvasive in vivo neuroimaging using positron emission tomography with the D1 antagonist radiotracer [(11) C]SCH 23390. Radiotracer binding in PFC and striatum was evaluated by 2 (alcohol) × 2 (stress) × 2 (sex) analysis of variance.

RESULTS

In PFC, a significant alcohol × sex interaction was observed with prenatal alcohol exposure leading to increased [(11) C]SCH 23390 binding in male monkeys. No main effect of prenatal alcohol or prenatal stress exposure was observed.

CONCLUSIONS

These results suggest that prenatal alcohol exposure results in long-term increases in prefrontal dopamine D1 R binding in males. This may help explain gender differences in the prevalence of neurodevelopmental disorders consequent to prenatal alcohol exposure.

Development of a novel postnatal neurobehavioral scale for evaluation of common marmoset monkeys

Common marmoset (Callithrix jacchus) monkeys when compared to rhesus macaques (Macaca mullatta) present several advantages for disease modeling, especially transgenic initiatives, as they commonly give birth to twins, which increases sample size, have accelerated development and a shorter life span that facilitates the analysis of the onset of age-related diseases. Yet, no tools are currently available to assess marmoset neurodevelopment during the initial first month of life. Here we report the creation of a novel Primate Postnatal Neurobehavioral Assessment Scale for marmoset monkeys (PPNAS-M) that was based on currently available scales for human and rhesus monkeys. Twenty-four healthy marmoset infants (12 females, 12 males) from 12 families were evaluated. The infant assessments involved 10-minute testing administered at 15 and 30 days after birth. The PPNAS-M consists of 41 noninvasive tests grouped into 5 testing categories: visual orienting, auditory and spatial orienting, motor responses, righting and body strength, and temperament tests. Testing at these two ages did not affect the overall health of the infants, suggesting that the PPNAS-M is a non-invasive testing tool. Significant maturation was demonstrated by increased scores in each of the five testing categories from postnatal day 15 to 30, with developmental patterns unique to marmosets. Principal component analysis defined 4 item groups (Orientation, State Control, Motor Maturity and Sensory Sensitivity) with 5 variables each. Orientation and State Control factors were highly similar to each other at both ages and correlated highly with previous item groupings used with rhesus macaques. Our results indicate that the PPNAS-M is a useful assessment tool for detecting neuromotor, attention, and temperament status of infant marmosets and that it is sensitive to developmental effects. Further studies to validate the PPNAS-M for the assessment of normal development versus early effects of developmental perturbations associated to prenatal exposures and transgenesis are warranted.

Alcohol odor elicits appetitive facial expressions in human neonates prenatally exposed to the drug

Specific memories arise during prenatal life as a function of fetal processing of chemosensory stimuli present in the amniotic fluid. Preclinical studies indicate that fetal exposure to alcohol modifies subsequent neonatal and infantile responsiveness towards the sensory attributes of the drug. It has been previously demonstrated that 1-2day-old human neonates recognize ethanol odor as a function of moderate maternal alcohol consumption during gestation. In the present study 7-14day-old newborns were assessed in terms of behavioral responsiveness to alcohol's chemosensory attributes or to a novel odor (lemon). These newborns were representative of mothers that exhibited infrequent or frequent alcohol drinking patterns during pregnancy. Different clinical assessments indicated that all newborns did not suffer congenital or genetic diseases and that they were completely healthy when behaviorally evaluated. Testing was defined by brief presentations of ethanol or lemon odorants. Two sequences of olfactory stimulation were employed. One sequence included five initial trials defined by ethanol odor stimulation followed by one trial with lemon and five additional trials with the scent of the drug (EtOH-Lem-EtOH). The alternative sequence (Lem-EtOH-Lem) was primarily defined by lemon olfactory exposure. The dependent variables under analysis were duration and frequency of overall body movements and of facial expressions categorized as aversive or appetitive. The main results of this study were as follows: a) at the end of the testing procedure and independent of the sequence of olfactory stimulation, babies born to frequent drinkers exhibited signs of distress as operationalized through higher durations of aversive facial expressions, b) despite this effect, babies born to frequent drinkers relative to newborns delivered by infrequent drinkers exhibited significantly higher frequencies of appetitive facial responses when primarily stimulated with ethanol odor (EtOH-Lem-EtOH sequence) and c) when merging both samples of babies, a positive and significant correlation was found between overall maternal absolute alcohol consumption per month and frequency of appetitive facial expressions elicited by alcohol odor. In conjunction with previous preclinical research, the present results indicate that human prenatal exposure to the drug that yields no evident teratological effects is sufficient to modify the hedonic value of alcohol's chemosensory attributes.

Impact of Moderate Prenatal Alcohol Exposure on Problem Behaviors in Preschool and School Children

Data on the relation between moderate prenatal alcohol exposure (PAE) and behavioral disorders are inconsistent, and this raises new questions. We examined (1) the association between moderate PAE and problem behaviors and (2) whether these associations differed by levels of socioeconomic status (SES), fetal smoke exposure, or exposure to environmental tobacco smoke (ETS). Data were taken from the German Health Interview and Examination Survey for Children and Adolescents (KiGGS) study. Parents evaluated children’s behaviors using the Strengths and Difficulties Questionnaire (SDQ). Results showed a slight, but insignificant, increase of problem behaviors in children with moderate PAE. In 3- to 6-year-olds, PAE had a stronger effect on hyperactivity/inattention in combination with fetal smoke exposure (odds ratio = 2.82), than did PAE alone. Effects were not stronger in low-SES children, but they were stronger in children with ETS. We conclude that moderate PAE might have adverse effects on neurodevelopment, with stronger effects in disadvantaged populations. To confirm our preliminary findings, further research should be conducted.

Binge drinking prior to pregnancy detection in a nonhuman primate: behavioral evaluation of offspring

BACKGROUND

Minimal scientific information is available to inform public health policy on binge drinking prior to pregnancy detection. The nonhuman primate provides a valuable animal model for examining consequences to reproduction and offspring function that may result from this common pattern of alcohol abuse.

METHODS

Adult female rhesus monkeys were dosed with 1.5 g/kg per day ethanol (EtOH) by gavage 2 d/wk beginning 7 months prior to mating and continuing to pregnancy detection at 19 to 20 days gestation. Postnatal evaluation of control (n = 6) and EtOH-treated (n = 4) infants included a neonatal neurobehavioral assessment, a visual paired comparison (cognitive) test at 35 days of age, and mother-infant interaction at 100 to 112 days of age.

RESULTS

Alcohol-exposed neonates did not differ from controls in posture and reflex measures. Longer durations of visual fixation, suggesting slower visual processing, and greater novelty preference were seen in the alcohol group. At early weaning age, as infants spent more time away from their dams, more of the reunions between mother and infant were initiated by the mothers in the alcohol-exposed group, suggesting a more immature mother-infant interaction.

CONCLUSIONS

Intermittent high-dose alcohol exposure (binge drinking) discontinued at early pregnancy detection in rhesus monkey can result in altered behavioral function in the infant. Mediating effects on ovum, reproductive tract, and early embryo can be explored in this model. Studies of longer-term consequences in human populations and animal models are needed.

Prenatal stress induces increased striatal dopamine transporter binding in adult nonhuman primates

BACKGROUND

To determine the effects in adult offspring of maternal exposure to stress and alcohol during pregnancy, we imaged striatal and midbrain dopamine transporter (DAT) binding by positron emission tomography in rhesus monkeys (Macaca mulatta). We also evaluated the relationship between DAT binding and behavioral responses previously found to relate to dopamine D2 receptor density (responsivity to tactile stimuli, performance on a learning task, and behavior during a learning task).

METHODS

Subjects were adult offspring derived from a 2 × 2 experiment in which pregnant monkeys were randomly assigned to control, daily mild stress exposure (acoustic startle), voluntary consumption of moderate-level alcohol, or both daily stress and alcohol. Adult offspring (n = 38) were imaged by positron emission tomography with the DAT ligand [(18)F]2β-carbomethoxy-3β-(4-chlorophenyl)-8-(2-fluoroethyl)-nortropane ([(18)F]FECNT).

RESULTS

Results showed that prenatal stress yielded an overall increase of 15% in [(18)F]FECNT binding in the striatum (p = .016), 17% greater binding in the putamen (p = .012), and 13% greater binding in the head of the caudate (p = .028) relative to animals not exposed to prenatal stress. Striatal [(18)F]FECNT binding correlated negatively with habituation to repeated tactile stimulation and positively with tactile responsivity. There were no significant effects of prenatal alcohol exposure on [(18)F]FECNT binding.

CONCLUSIONS

Maternal exposure to mild daily stress during pregnancy yielded increases in striatal DAT availability that were apparent in adult offspring and were associated with behavioral characteristics reflecting tactile hyperresponsivity, a condition associated with problem behaviors in children.

Moderate-level prenatal alcohol exposure enhances acoustic startle magnitude and disrupts prepulse inhibition in adult rhesus monkeys

BACKGROUND

Prenatal alcohol exposure can contribute to a wide range of neurodevelopmental impairments in children and adults including behavioral and neuropsychiatric disorders. In rhesus monkeys, we examined whether moderate-level prenatal alcohol exposure would alter acoustic startle responses and prepulse inhibition (PPI) of the acoustic startle. PPI is a highly quantifiable measure of inhibitory neural processes or sensorimotor gating associated with neuropsychiatric disorders.

METHODS

Acoustic startle and PPI of the acoustic startle were tested in 37 adult rhesus monkeys (Macaca mulatta) from 4 experimental conditions: (i) moderate-level prenatal alcohol-exposed, (ii) prenatally stressed, (iii) moderate-level prenatal alcohol-exposed + prenatally stressed, and (iv) sucrose controls.

RESULTS

Prenatal alcohol-exposed monkeys showed a higher magnitude of acoustic startle response and disrupted PPI compared with monkeys not exposed to alcohol prenatally. Monkeys in all conditions showed higher hypothalamic-pituitary-adrenocortical (HPA) axis responses after undergoing the startle procedure, but HPA responses were unrelated to startle response magnitude, latency, or PPI.

CONCLUSIONS

Finding altered PPI in monkeys prenatally exposed to a moderate dose of alcohol suggests that reduced sensorimotor gating is 1 effect of prenatal alcohol exposure. Because reduced sensorimotor gating is observed in many neuropsychiatric disorders, sensorimotor gating deficits could be an aspect of the comorbidity between fetal alcohol spectrum disorder and mental health conditions.

Preterm birth and small for gestational age in relation to alcohol consumption during pregnancy: stronger associations among vulnerable women? Results from two large Western-European studies

BACKGROUND

Inconsistent data on the association between prenatal alcohol exposure and a range of pregnancy outcomes, such as preterm birth (PTB) and small for gestational age (SGA) raise new questions. This study aimed to assess whether the association between low-moderate prenatal alcohol exposure and PTB and SGA differs according to maternal education, maternal mental distress or maternal smoking.

METHODS

The Amsterdam Born Children and their Development (ABCD) Study (N = 5,238) and the German Health Interview and Examination Survey for Children and Adolescents (KiGGS) (N = 16,301) are both large studies. Women provide information on alcohol intake in early pregnancy, 3 months postpartum and up to 17 years retrospectively. Multivariate logistic regression analyses and stratified regression analyses were performed to examine the association between prenatal alcohol exposure and PTB and SGA, respectively.

RESULTS

No association was found between any level of prenatal alcohol exposure (non-daily, daily, non-abstaining) and SGA. The offspring of daily drinkers and non-abstainers had a lower risk of PTB [ABCD: odds ratio (OR) 0.31, 95% confidence interval (CI) 0.13, 0.77; KiGGS: OR 0.75, 95% CI 0.57, 0.99]. Interactions with maternal education, maternal distress or maternal smoking were not significant.

CONCLUSIONS

Although these results should be interpreted with caution, both studies showed no adverse effects of low-moderate prenatal alcohol exposure on PTB and SGA, not even in the offspring of women who were disadvantaged in terms of low education, high levels of distress, or smoking during pregnancy.

Pregnancy-related maternal risk factors of attention-deficit hyperactivity disorder: a case-control study

Background. The etiology of attention-deficit hyperactivity disorder (ADHD) is complex.This study was conducted to evaluate the pregnancy-related maternal risk factors of ADHD. Methods. 164 ADHD children attending to Child and Adolescent Psychiatric Clinics compared with 166 normal children selected in a random-cluster method from primary schools. ADHD rating scale and clinical interview based on Schedule for Affective disorders and Schizophrenia for School-Aged Children (K-SADS) were used to diagnose ADHD cases and to select the control group. Results. The mean maternal age at pregnancy, duration of pregnancy, and the mean paternal age were alike in two groups. The ADHD children's mothers compared with those of control group had higher frequencies of somatic diseases, psychiatric disorders, and alcohol and cigarette exposure during the pregnancies (P < 0.01). Also birth by cesarean section was more common among mothers of ADHD children (P < 0.001). These factors plus trauma to the abdomen during pregnancy were significantly predictors of ADHD in children. Conclusions. Some pregnancy-related maternal factors may be considered as environmental risk factors for ADHD. Each of these factors considered in our study as a risk factor needs to be tested and confirmed through next methodologically appropriate researches in this field.

The effects of prenatal alcohol exposure on behavior: rodent and primate studies

The use of alcohol by women during pregnancy is a continuing problem. In this review the behavioral effects of prenatal alcohol from animal models are described and related to studies of children and adults with FASD. Studies with monkeys and rodents show that prenatal alcohol exposure adversely affects neonatal orienting, attention and motor maturity, as well as activity level, executive function, response inhibition, and sensory processing later in life. The primate moderate dose behavioral findings fill an important gap between human correlational data and rodent mechanistic research. These animal findings are directly translatable to human findings. Moreover, primate studies that manipulated prenatal alcohol exposure and prenatal stress independently show that prenatal stress exacerbates prenatal alcohol-induced behavioral impairments, underscoring the need to consider stress-induced effects in fetal alcohol research. Studies in rodents and primates show long-term effects of prenatal and developmental alcohol exposure on dopamine system functioning, which could underpin the behavioral effects.

Challenges to maternal wellbeing during pregnancy impact temperament, attention, and neuromotor responses in the infant rhesus monkey

The relative maturity, alertness, and reactivity of an infant at birth are sensitive indices of the neonate's health, the quality of the pregnancy, and the mother's wellbeing. Even when fetal growth and gestation length have been normal, the maturing fetus can still be adversely impacted by both physical events and psychological challenges to the mother during the prenatal period. The following research evaluated 413 rhesus monkeys from 7 different types of pregnancies to determine which conditions significantly influenced the behavioral responsiveness and state of the young infant. A standardized test battery modeled after the Neonatal Behavioral Assessment Scale for human newborns was employed. The largest impairments in orientation and increases in infant emotional reactivity were seen when female monkeys drank alcohol, even though consumed at only moderate levels during part of the pregnancy. The infants' ability to focus and attend to visual and auditory cues was also affected when the gravid female's adrenal hormones were transiently elevated for 2 weeks by ACTH administration. In addition, responses to tactile and vestibular stimulation were altered by both this ACTH treatment and psychological disturbance during gestation. Conversely, a 2-day course of antenatal corticosteroids 1 month before term resulted in infants with lower motor activity and reactivity. These findings highlight several pregnancy conditions that can affect a young infant's neurobehavioral status, even when otherwise healthy, and demonstrate that alterations or deficits are specific to the type of insult experienced by the mother and fetus.

Maternal influenza infection during pregnancy impacts postnatal brain development in the rhesus monkey

BACKGROUND

Maternal infection with influenza and other pathogens during pregnancy has been associated with increased risk for schizophrenia and neurodevelopmental disorders. In rodent studies, maternal inflammatory responses to influenza affect fetal brain development. However, to verify the relevance of these findings to humans, research is needed in a primate species with more advanced prenatal corticogenesis.

METHODS

Twelve pregnant rhesus monkeys were infected with influenza, A/Sydney/5/97 (H3N2), 1 month before term (early third trimester) and compared with 7 control pregnancies. Nasal swabs and blood samples confirmed viral shedding and immune activation. Structural magnetic resonance imaging was conducted at 1 year; behavioral development and cortisol reactivity were also assessed.

RESULTS

Maternal infections were mild and self-limiting. At birth, maternally derived influenza-specific immunoglobulin G was present in the neonate, but there was no evidence of direct viral exposure. Birth weight and gestation length were not affected, nor were infant neuromotor, behavioral, and endocrine responses. However, magnetic resonance imaging analyses revealed significant reductions in cortical gray matter in flu-exposed animals. Regional analyses indicated the largest gray matter reductions occurred bilaterally in cingulate and parietal areas; white matter was also reduced significantly in the parietal lobe.

CONCLUSIONS

Influenza infection during pregnancy affects neural development in the monkey, reducing gray matter throughout most of the cortex and decreasing white matter in parietal cortex. These brain alterations are likely to be permanent, given that they were still present at the monkey-equivalent of older childhood and thus might increase the likelihood of later behavioral pathology.

Alcohol taxes and birth outcomes

This study examines the relationships between alcohol taxation, drinking during pregnancy, and infant health. Merged data from the US Natality Detailed Files, as well as the Behavioral Risk Factor Surveillance System (1985-2002), data regarding state taxes on beer, wine, and liquor, a state- and year-fixed-effect reduced-form regression were used. Results indicate that a one-cent ($0.01) increase in beer taxes decreased the incidence of low-birth-weight by about 1-2 percentage points. The binge drinking participation tax elasticity is -2.5 for beer and wine taxes and -9 for liquor taxes. These results demonstrate the potential intergenerational impact of increasing alcohol taxes.

Alcohol consumption during pregnancy and its effects on neurodevelopment: what is known and what remains uncertain

It has been claimed that mothers' drinking during pregnancy may affect the neurodevelopment of around 1% of all children. If this is true, then prenatal alcohol exposure represents an important risk factor for neurodevelopmental problems, giving rise to a large burden of disability which could be potentially preventable. Evidence to support this idea has come from animal experiments and human observational studies. However, such findings need to be supported by more robust research designs. Because randomized controlled trials in this area are neither feasible nor ethical, suggestions are made for further research making more use of natural experiments.

Moderate level fetal alcohol exposure and serotonin transporter gene promoter polymorphism affect neonatal temperament and limbic-hypothalamic-pituitary-adrenal axis regulation in monkeys

BACKGROUND

A length polymorphism in the serotonin (5-HT) transporter gene promoter region in humans and rhesus monkeys affects functional characteristics of the brain 5-HT system. Prenatal alcohol exposure (FA-exposure) can have an impact on brain and psychosocial development that could interact with genetic endowment. This study determined whether moderate FA-exposure interacts with polymorphism in the 5-HT transporter gene to increase the incidence or severity of fetal alcohol effects in rhesus monkeys.

METHODS

The offspring of monkeys who did or did not consume moderate amounts of alcohol during pregnancy were assessed for temperament as neonates and adrenocorticotropic hormone (ACTH) and cortisol (CORT) in response to mother-infant separation at 6 months of age. Serotonin promoter region genotypes (homozygous s/s or heterozygous s/l versus homozygous l/l) were determined.

RESULTS

Prenatal alcohol exposed carriers of the s allele exhibited increased neonatal irritability and increased ACTH and CORT compared with FA-exposed monkeys homozygous for the l allele and monkeys that were not FA-exposed regardless of genotype.

CONCLUSIONS

The s allele of the 5-HT transporter increases the probability of neonatal irritability and increased stress responsiveness in FA-exposed monkeys, and this gene-environment interaction may affect psychosocial development. It is probable that FA-exposure contributes to 5-HT transporter gene-environment interactions in humans.

Enhancement of developmental toxicity effects of chemicals by gestational stress. A review

Risk assessment of developmental toxicants is almost exclusively based on single chemicals studied in animals under controlled experimental conditions, as to reduce stress. Although humans may be exposed simultaneously to numerous hazards, little is known about the interaction of prenatal chemical exposures with other factors, such as maternal stress, itself a modifier of fetal development. Gestational stress has been hypothesized to enhance the developmental toxicity of chemicals. This review identified 36 animal studies investigating if maternal stress may enhance the effects of prenatal chemical exposure, and evaluated the presented hypothesis. Studies of a broad range of chemicals and developmental endpoints support the notion, that maternal stress is able to enhance the effects of developmental toxicants, although stress mitigated chemically induced effects in a few cases. Maternal stress most often enhanced chemical developmental toxicity at dose levels associated with severe maternal toxicity or where test agents were already above threshold for effect. Thus, LOAEL(chemical) was generally similar to LOAEL(chemical+stress), although not necessarily for the same endpoint. It should be noted that the database contained a limited number of studies, and only a single high dose level was applied in most studies, rendering establishment of NOAELs for combined exposures impossible. Furthermore, for some compounds, the margin between human exposure levels and the LOAEL(chemical+stress) seems small. Future studies are recommended to investigate compounds, for which maternal stress was already proven as an enhancer, at lower dose levels. Interactive response seems to depend on stressor severity and timing of chemical exposure relative to maternal stress which should be further scrutinized.

Maternal smoking, drinking or cannabis use during pregnancy and neurobehavioral and cognitive functioning in human offspring

Teratological investigations have demonstrated that agents that are relatively harmless to the mother may have significant negative consequences to the fetus. Among these agents, prenatal alcohol, nicotine or cannabis exposure have been related to adverse offspring outcomes. Although there is a relatively extensive body of literature that has focused upon birth and behavioral outcomes in newborns and infants after prenatal exposure to maternal smoking, drinking and, to a lesser extent, cannabis use, information on neurobehavioral and cognitive teratogenic findings beyond these early ages is still quite limited. Furthermore, most studies have focused on prenatal exposure to heavy levels of smoking, drinking or cannabis use. Few recent studies have paid attention to low or moderate levels of exposure to these substances. This review endeavors to provide an overview of such studies, and includes animal findings and potential mechanisms that may explain the mostly subtle effects found on neurobehavioral and cognitive outcomes. It is concluded that prenatal exposure to either maternal smoking, alcohol or cannabis use is related to some common neurobehavioral and cognitive outcomes, including symptoms of ADHD (inattention, impulsivity), increased externalizing behavior, decreased general cognitive functioning, and deficits in learning and memory tasks.

Moderate level alcohol during pregnancy, prenatal stress, or both and limbic-hypothalamic-pituitary-adrenocortical axis response to stress in rhesus monkeys

This study examined the relationship between moderate-level prenatal alcohol exposure, prenatal stress, and postnatal response to a challenging event in 6-month-old rhesus monkeys. Forty-one rhesus monkey (Macaca mulatta) infants were exposed prenatally to moderate level alcohol, maternal stress, or both. Offspring plasma cortisol and adrenocorticotrophic hormone (ACTH) were determined from blood samples before maternal separation and after separation. Behavioral observations were made repeatedly across separation. Moderate-level prenatal alcohol exposure was associated with significantly higher plasma ACTH response to maternal separation. Offspring exposed to prenatal alcohol, prenatal stress, and prenatal alcohol and stress showed reduced behavioral adaptation to stress compared with controls. Baseline, 2-hr, and 26-hr plasma ACTH levels were intercorrelated and predicted behavior during separation.

Does prenatal stress affect the motoric development of rat pups?

Pregnant rats were exposed to an acute or a repeated stress (presence of a cat) either at the 10th or the 14th gestational day, and the development of their offspring was studied during the first 2 weeks of life. Motor development was measured by different tests: rooting reflex, vibrissae placing response, righting reflex, negative geotaxis. Other landmarks such as eye opening and spontaneous locomotor activity were also recorded. The results showed that, except for the rooting reflex which was most often enhanced (while not significantly) in prenatally stressed rats, the development of the vibrissae placing response, the righting reflex and the negative geotaxis behavior was delayed in the offspring of dams stressed at the 10th gestational day and not (or almost not) in the offspring of dams stressed at the 14th gestational day, the delay being more severe when the prenatal stress was repeated than when it was acutely administered. The spontaneous motor activity was also altered in repeatedly prenatally stressed rats, whatever the day of pregnancy when it was administered, while it was unaffected in acutely prenatally stressed animals. The delay in motor reflexes development was interpreted as alterations in maturation of nervous structures sustaining motor skills, while permanent decrease of spontaneous motor activity was explained by emotional and motivational alterations due to prenatal stress.

Effects of cocaine/polydrug exposure and maternal psychological distress on infant birth outcomes

To assess teratogenic effects of cocaine exposure and maternal psychological distress on birth outcomes, we conducted a longitudinal prospective study of 415 infants (218 cocaine-exposed--CE, 197 nonexposed--NE). Drug exposure was determined through a combination of maternal self-report, urine, and meconium screens. Maternal psychological distress postpartum was evaluated through a standardized, normative, self-report assessment. An extensive set of confounding variables was controlled, including severity of exposure to alcohol, tobacco, marijuana and other drugs, maternal age, race, parity, number of prenatal care visits, educational, marital, and socioeconomic status, and verbal and nonverbal intelligence. CE infants were smaller on all birth parameters and more likely to be preterm, small for gestational age, and microcephalic than NE infants. Forty-one percent of cocaine users had clinically significant psychological symptoms, compared to 20% of a high-risk comparison group of noncocaine users. Consistent with a teratologic model, cocaine exposure independently predicted offspring birthweight, length, and head circumference. Maternal psychological distress self-reported postnatally also independently predicted head circumference. Tobacco, alcohol, and marijuana exposures were also significant independent predictors of some fetal growth parameters. In addition, maternal distress symptoms, which may be reflective of maternal mental health disorders or responses to stress, added significantly to the risk for poorer fetal growth.

The impact of prenatal stress, fetal alcohol exposure, or both on development: perspectives from a primate model

The question of whether psychosocial stress during pregnancy (alone or in combination with fetal alcohol exposure) has negative consequences for offspring has not been clearly established in human studies. In this article, we present an overview of three prospective longitudinal studies. Using rhesus monkeys as subjects, a noise or hormone stressor, alone or in combination with moderate level alcohol solution, was presented daily during different stages of pregnancy. Prenatal stress resulted in lighter birth weights in two of three studies, and males from the alcohol plus noise stress condition had reduced birth weights. There were no significant effects of any of the prenatal treatments on gestation duration. Both prenatal stress and moderate fetal alcohol exposure reduced attention span and neuromotor capabilities of offspring during the first month of life, while early gestation prenatal stress, during the period of neuronal migration, emerged as a period of enhanced vulnerability for these effects. Under conditions of challenge, prenatally stressed monkeys showed more disturbance behaviors and reduced locomotion and exploration as well as altered hypothalamic-pituitary-adrenal (HPA) axis reactivity to stress. Fetal alcohol exposed monkeys also showed increased HPA axis activity in response to stressful conditions. Finally, altered patterns of alcohol consumption during adolescence were associated with prenatal stress.

Prenatal stress alters early neurobehavior, stress reactivity and learning in non-human primates: a brief review

In this paper we review three prospective longitudinal studies from our laboratory examining the effects of prenatal stress on early neuro behavior, stress reactivity and learning performance in rhesus monkeys. Either a noise stressor or ACTH treatment was administered to pregnant monkeys during specific periods of pregnancy and offspring were examined repeatedly across development. In all three studies, the prenatally stressed monkeys showed reduced attention and impaired neuromotor functioning during the first month of life compared to controls from undisturbed pregnancies. When the monkeys were separated from their mothers or peers at 6-8 months of age, prenatally stressed monkeys exhibited more disturbance behavior and showed hypothalamic-pituitary-adrenal axis dysregulation. During adolescence, they exhibited impairments in learning, compared to controls.

Neurobehavioral outcomes of cocaine-exposed infants

The present study investigated the neurobehavioral outcomes of fetal cocaine exposure. Attempts were made to control, by design or statistical analysis, for significant confounders. Timing and amount of drug exposures were considered, and biologic measures of exposure were quantified to classify exposure severity. One hundred sixty-one non-cocaine and 158 cocaine-exposed (82 heavily and 76 lightly exposed) infants were seen at a mean-corrected age of 43 weeks post-conception and administered the Neurobehavioral Assessment (NB Assessment). Heavily cocaine-exposed infants had more jitteriness and attentional problems than lightly and non-exposed infants. They also had more movement and tone abnormalities, and sensory asymmetries than non-exposed infants. Heavily exposed infants were more likely to be identified with an abnormality than non-exposed infants and there was a trend toward heavily exposed infants being more likely to be identified with an abnormality than lightly exposed infants. Furthermore, there was a trend for heavily exposed infants to be less likely to be testable than non-exposed infants. After the confounding and mediating factors were considered, heavily cocaine-exposed infants were four times as likely to be jittery and nearly twice as likely to demonstrate any abnormality than lightly and non-exposed infants, but all other effects were no longer significant. Higher concentrations of the cocaine metabolites of cocaine, cocaethylene, and benzoylecgonine (BZE) were related to higher incidence of movement and tone abnormalities, jitteriness, and presence of any abnormality. Higher cocaethylene levels were related to attentional abnormalities and higher meta-hydroxybenzoylecgonine (m-OH-BZE) was related to jitteriness. Drug effects on attention were mediated by maternal psychological distress, suggesting that this factor should be considered in future studies of drug exposure effects.