Neuropsychological characteristics of Italian children with fetal alcohol spectrum disorders

Background: Children with fetal alcohol spectrum disorders (FASD) display many problems ranging from deficits in intelligence to behavioral difficulties. Thus, many studies have aimed at defining the neuropsychological characteristics of children with FASD. The current article describes the neuropsychological characteristics of Italian children with severe diagnosis within FASD and compares them with controls. It was expected that intellectual functioning, language comprehension, academic skills, and inattention/hyperactivity would discriminate children with FASD from randomly selected peers without FASD. Methods: This article presents data from a second cohort of children examined in 2005 as part of an in‐school epidemiological study of FASD in Italy. Of 80 children, 23 diagnosed with a FASD, and 57 randomly selected control children from the same first‐grade classes, participated. After screening for FASD via growth and dysmorphology, the children were administered a test of general intelligence (WISC‐R) as well as tests of nonverbal reasoning (Raven Colored Progressive Matrices), language comprehension (Rustioni), academic achievement (IPDA), and problem behavior (Disruptive Behavior Disorder Rating Scale). Results: Children diagnosed with a FASD achieved lower scores than control children on Verbal, Performance, and Full Scale IQ. Profile analysis of the WISC‐R indicates overall differences between the groups. However, some intact functioning within the FASD group was found, as the Similarities and Vocabulary subtests were similar to the controls. After an alpha adjustment to 0.004, the Block Design, Object Assembly, and Mazes subtests were significantly different from controls. On tests of nonverbal reasoning, language comprehension, and academic achievement, the children with a FASD scored significantly lower. Moreover, teachers rated children with a severe diagnosis within FASD as showing more inattentive symptoms than controls, while hyperactive/impulsive characteristics among children with a FASD were comparable with the control children. Significant correlations between head circumference, child dysmorphology, WISC‐R, and Raven CPM scores are also reported. Conclusions: This study indicates that a sample of Italian children with a FASD, when compared with control children, display poorer functioning on measures of general intelligence, nonverbal reasoning, academic achievement, and teacher‐rated problem behaviors. The findings also contribute to the formulation of a neuropsychological profile of children diagnosed with a FASD.     

Neurobehavioral characteristics of children with fetal alcohol spectrum disorders in communities from Italy: Preliminary results

BACKGROUND: There has been considerable effort expended on defining neurobehavioral characteristics of children with fetal alcohol spectrum disorders (FASD). Children with FASD display a range of cognitive deficits and behavioral problems. In this article, we report on the neurobehavioral characteristics of children with FASD in selected communities in Italy. It was expected that both inattentive and hyperactive/impulsive characteristics would discriminate children with FASD from controls and that the groups would also differ on intellectual functioning, language comprehension, and academic skills. METHODS: Eighty-two children, 22 diagnosed with FASD and 60 control children, participated in this study. The children were administered tests of nonverbal reasoning, language comprehension, academic achievement, and behavior. RESULTS: On tests of nonverbal reasoning and language comprehension, the FASD group earned lower scores than did controls. Moreover, on a test of academic achievement the FASD group scored lower. When comparing these 2 groups on disruptive behavioral symptomatology, similar results were obtained, the FASD group showing greater attentional difficulties and hyperactivity/impulsivity behaviors and more overall behavioral problems. Stepwise logistic regression analysis showed that a model containing inattention and error scores on the language comprehension task correctly classified 85% of the participants. Compared with the control group, a significantly greater proportion of children with FASD met the Diagnostic and Statistical Manual of Mental Disorders-fourth edition (DSM-IV) criteria of ADD, inattentive type, as reported by teachers. In contrast, hyperactive symptoms among children with FASD were comparable with the control group. Teachers rated children with FASD as having more inattentive behaviors and as performing lower in academic skills than controls. The association between reported hyperactivity symptoms and achievement scores was nonsignificant for both language and math scores, suggesting that it is not the hyperactivity causing problems, but the child's inattention. CONCLUSIONS: This research indicates that a nonclinic-referred sample of Italian children with FASD display a profile of neurobehavioral functioning consistent with that reported by other researchers. Furthermore, the neurobehavioral characteristic most identified with children diagnosed with FASD was inattention followed by hyperactivity.     

Brain metabolic alterations in adolescents and young adults with fetal alcohol spectrum disorders

BACKGROUND: Prenatal alcohol exposure affects brain structure and function. This study examined brain metabolism using magnetic resonance spectroscopy (MRS) and searched for regions of specific vulnerability in adolescents and young adults prenatally exposed to alcohol. METHODS: Ten adolescents and young adults with confirmed heavy prenatal alcohol exposure and a diagnosis within the fetal alcohol spectrum disorders (FASD) were included. Three of them had fetal alcohol syndrome (FAS), 3 had partial FAS (PFAS), and 4 had alcohol-related neurobehavioral disorder (ARND). The control group consisted of 10 adolescents matched for age, sex, head circumference, handedness, and body mass. Exclusionary criteria were learning disorders and prenatal alcohol exposure. Three-dimensional (1)H magnetic resonance spectroscopic imaging ((1)H MRSI) was performed in the cerebrum and cerebellum. Metabolite ratios N-acetylaspartate/choline (NAA/Cho), NAA/creatine (Cr) and Cho/Cr, and absolute metabolite intensities were calculated for several anatomic regions. RESULTS: In patients with FASD, lower NAA/Cho and/or NAA/Cr compared with controls were found in parietal and frontal cortices, frontal white matter, corpus callosum, thalamus, and cerebellar dentate nucleus. There was an increase in the absolute intensity of the glial markers Cho and Cr but no change in the neuronal marker NAA. CONCLUSIONS: Our results suggest that prenatal alcohol exposure alters brain metabolism in a long-standing or permanent manner in multiple brain areas. These changes are in accordance with previous findings from structural and functional studies. Metabolic alterations represent changes in the glial cell pool rather than in the neurons.     

A review of social skills deficits in individuals with fetal alcohol spectrum disorders and prenatal alcohol exposure: profiles, mechanisms, and interventions

Background: Individuals gestationally exposed to alcohol experience a multitude of sociobehavioral impairments, including deficits in adaptive behaviors such as social skills. Methods: The goal of this report is to critically review research on social skills deficits in individuals with prenatal alcohol exposure, including individuals with and without fetal alcohol spectrum disorders (FASD). Results: Social deficits are found in alcohol‐exposed children, adults, and adolescents with and without a clinical presentation. These deficits tend to persist across the lifespan and may even worsen with age. Social deficits in this population appear to be independent of facial dysmorphology and IQ and are worse than can be predicted based on atypical behaviors alone. Abnormalities in neurobiology, executive function, sensory processing, and communication likely interact with contextual influences to produce the range of social deficits observed in FASD. Conclusions: Future investigations should strive to reconcile the relationship between social skills deficits in FASD and variables such as gender, age, cognitive profile, and structural and functional brain impairments to enable better characterization of the deficits observed in this population, which will enhance diagnosis and improve remediation.     

Maternal risk factors for fetal alcohol syndrome and partial fetal alcohol syndrome in South Africa: a third study

Objectives: This is a third exploration of risk factors for the two most severe forms of fetal alcohol spectrum disorders (FASD), fetal alcohol syndrome (FAS) and Partial FAS (PFAS), in a South African community with the highest reported prevalence of FAS in the world. Methods: In a case control design, interview and collateral data concerning mothers of 72 first grade children with FAS or PFAS are compared with 134 randomly selected maternal controls of children from the same schools. Results: Significant differences were found between the mothers of FASD children and controls in socio‐economic status, educational attainment, and a higher prevalence of FASD among rural residents. The birth order of the index children, gravidity, and still birth were significantly higher among mothers of FASD children. Mothers of children with a FASD are less likely to be married and more likely to have a male partner who drank during the index pregnancy. Current and gestational alcohol use by mothers of FASD children is bingeing on weekends, with no reduction in drinking reported in any trimester in 75 to 90% of the pregnancies that resulted in an FAS child or during 50 to 87% of PFAS‐producing pregnancies. There was significantly less drinking among the controls in the second and third trimesters (11 to 14%). Estimated peak blood alcohol concentrations (BAC)s of the mothers of PFAS children range from 0.155 in the first trimester to 0.102 in the third, and for mothers of FAS children the range is from 0.197 to 0.200 to 0.191 in the first, second, and third. Smoking percentage during pregnancy was significantly higher for mothers of FASD children (82 to 84%) than controls (35%); but average quantity smoked is low in the 3 groups at 30 to 41 cigarettes per week. A relatively young average age of the mother at the time of FAS and PFAS births (28.8 and 24.8 years respectively) is not explained by early onset of regular drinking (mean = 20.3 to 20.5 years of age). But the mean years of alcohol consumption is different between groups, 16.3, 10.7, and 12.1 years respectively for mothers of FAS, FASD, and drinking controls. Mothers of FAS and PFAS children were significantly smaller in height and weight than controls at time of interview. The child’s total dysmorphology score correlates significantly with mother’s weight (?0.46) and BMI (?0.39). Bivariate correlations are significant between the child’s dysmorphology and known independent demographic and behavioral maternal risk factors for FASD: higher gravidity and parity; lower education and income; rural residence; drinks consumed daily, weekly, and bingeing during pregnancy; drinking in all trimesters; partner's alcohol consumption during pregnancy; and use of tobacco during pregnancy. Similar significant correlations were also found for most of the above independent maternal risk variables and the child’s verbal IQ, non‐verbal IQ and behavioral problems. Conclusions: Maternal data in this population are generally consistent with a spectrum of effects exhibited in the children. Variation within the spectrum links greater alcohol doses with a greater severity of effects among children of older and smaller mothers of lower socio economic status in their later pregnancies. Prevention is needed to address known maternal risk factors for FASD in this population.     

Maternal oral intake mouse model for fetal alcohol spectrum disorders: ocular defects as a measure of effect

BACKGROUND: This work was conducted in an effort to establish an oral intake model system in which the effects of ethanol insult that occur during early stages of embryogenesis can be easily examined and in which agents that may modulate ethanol's teratogenicity can be readily tested in vivo. The model system described utilizes the alcohol deprivation effect to obtain teratogenic levels of maternal ethanol intake on days 7 and 8 of pregnancy in C57Bl/6J mice. Ocular defects including microphthalmia and uveal coloboma, which have previously been shown to result from ethanol administered by gavage or via intraperitoneal injection on these days, served as the developmental end point for this study. The ocular defects are readily identifiable and their degree of severity is expected to correlate with concurrently developing defects of the central nervous system (CNS). METHODS: Female C57Bl/6J mice were maintained on an ethanol-containing (4.8% v/v) liquid diet for 14 days and then mated during a subsequent abstinence period. Mice were then reexposed to ethanol on days 7 and 8 of pregnancy only. Control as well as ethanol-exposed dams were killed on their 14th day of pregnancy. Fetuses were then weighed, measured for crown rump length, photographed, and analyzed for ocular abnormalities. Globe size, palpebral fissure length, and pupil size and shape were noted for both the right and left eyes of all fetuses and informative comparisons were made. RESULTS: This exposure paradigm resulted in peak maternal blood alcohol concentrations that ranged from 170 to 220 mg/dL on gestational day (GD) 8. Compared with the GD 14 fetuses from the normal control group, the pair-fed, acquisition controls, as well as the ethanol-exposed fetuses, were developmentally delayed and had reduced weights. Confirming previous studies, comparison of similarly staged control and treated GD 8 embryos illustrated reductions in the size of the forebrain in the latter. Subsequent ocular malformations were noted in 33% of the right eyes and 25% of the left eyes of the 103 GD 14 ethanol-exposed fetuses examined. This incidence of defects is twice that observed in the control groups. Additionally, it was found that the palpebral fissure length is directly correlated with globe size. CONCLUSIONS: The high incidence of readily identifiable ocular malformations produced by oral ethanol intake in this model and their relevance to human fetal alcohol spectrum disorders (FASD) makes this an excellent system for utilization in experiments involving factors administered to the embryo that might alter ethanol's teratogenic effects. Additionally, the fact that early ethanol insult yields ocular and forebrain abnormalities that are developmentally associated allows efficient specimen selection for subsequent detailed analyses of CNS effects in this in vivo mammalian FASD model.     

Comparison of motor delays in young children with fetal alcohol syndrome to those with prenatal alcohol exposure and with no prenatal alcohol exposure

BACKGROUND: Researchers are increasingly considering the importance of motor functioning of children with fetal alcohol spectrum disorder (FASD). The purpose of this study was to assess the motor development of young children with fetal alcohol syndrome (FAS) to determine the presence and degree of delay in their motor skills and to compare their motor development with that of matched children without FAS. METHODS: The motor development of 14 children ages 20 to 68 months identified with FAS was assessed using the Vineland Adaptive Behavior Scales (VABS). In addition, 2 comparison groups were utilized. Eleven of the children with FAS were matched for chronological age, gender, ethnicity, and communication age to: (1) 11 children with prenatal alcohol exposure who did not have FAS and (2) 11 matched children without any reported prenatal alcohol exposure. The motor scores on the VABS were compared among the 3 groups. RESULTS: Most of the young children with FAS in this study showed clinically important delays in their motor development as measured on the VABS Motor Domain, and their fine motor skills were significantly more delayed than their gross motor skills. In the group comparisons, the young children with FAS had significantly lower Motor Domain standard (MotorSS) scores than the children not exposed to alcohol prenatally. They also had significantly lower Fine Motor Developmental Quotients than the children in both the other groups. No significant group differences were found in gross motor scores. For MotorSS scores and Fine Motor Developmental Quotients, the means and standard errors indicated a continuum in the scores from FAS to prenatal alcohol exposure to nonexposure. CONCLUSIONS: These findings strongly suggest that all young children with FAS should receive complete developmental evaluations that include assessment of their motor functioning, to identify problem areas and provide access to developmental intervention programs that target deficit areas such as fine motor skills. Fine motor delays in children with FAS may be related to specific neurobehavioral deficits that affect fine motor skills. The findings support the concept of an FASD continuum in some areas of motor development.     

Callosal thickness reductions relate to facial dysmorphology in fetal alcohol spectrum disorders

Background: Structural abnormalities of the corpus callosum (CC), such as reduced size and increased shape variability, have been documented in individuals with fetal alcohol spectrum disorders (FASD). However, the regional specificity of altered CC structure, which may point to the timing of neurodevelopmental disturbances and/or relate to specific functional impairments, remains unclear. Furthermore, associations between facial dysmorphology and callosal structure remain undetermined. Methods: One hundred and fifty‐three participants (age range 8 to 16) including 82 subjects with FASD and 71 nonexposed controls were included in this study. The structural magnetic resonance imaging data of these subjects was collected at 3 sites (Los Angeles and San Diego, California, and Cape Town, South Africa) and analyzed using classical parcellation schemes, as well as more refined surface‐based geometrical modeling methods, to identify callosal morphological alterations in FASD at high spatial resolution. Results: Reductions in callosal thickness and area, specifically in the anterior third and the splenium, were observed in FASD compared with nonexposed controls. In addition, reduced CC thickness and area significantly correlated with reduced palpebral fissure length. Conclusions: Consistent with previous reports, findings suggest an adverse effect of prenatal alcohol exposure on callosal growth and further indicate that fiber pathways connecting frontal and parieto‐occipital regions in each hemisphere may be particularly affected. Significant associations between callosal and facial dysmorphology provide evidence for a concurrent insult to midline facial and brain structural development in FASD.     

Implicit strategy affects learning in children with heavy prenatal alcohol exposure

BACKGROUND: Learning and memory deficits are commonly reported in children with heavy prenatal alcohol exposure. Our recent work suggested that children with heavy prenatal alcohol exposure retained information as well as controls on a verbal learning test but not on a test of nonverbal learning and memory. To better understand the cause of this differential pattern of performance, the current study re-analyzed data from our previous study to determine if the presence of an implicit learning strategy may account, at least in part, for the finding of spared retention. METHODS: The current study examined verbal learning and memory abilities in 35 children with Fetal Alcohol Spectrum Disorders (FASD) and 34 nonexposed controls (CON) matched for age (9-16 years), sex, ethnicity, handedness, and socioeconomic status. Groups were compared on two measures of verbal learning, one with an implicit strategy (California Verbal Learning Test-Children's Version; CVLT-C) and one without (Verbal Learning subtest of the Wide Range Assessment of Memory and Learning; VL-WRAML). RESULTS: Children with FASD learned less information overall than children in the CON group. Both groups learned a greater percentage of information and reached a learning plateau earlier on the CVLT-C compared with the VL-WRAML. Groups also showed comparable rates of retention after a delay on the CVLT-C. In contrast, on the VL-WRAML, children with FASD showed poorer retention rates than children in the CON group. Interestingly, children with FASD did not differ from children in the CON group on CVLT-C semantic clustering scores for learning trials 1 through 3, and greater utilization of semantic clustering was correlated with better learning and memory performance in both groups. This overall pattern of results was not related to overall intellectual level. CONCLUSIONS: The finding of spared retention of verbal information on the CVLT-C in our earlier studies may be related to test characteristics of the CVLT-C rather than a finding of spared verbal retention per se, given that spared retention was not found on a separate test of verbal learning and memory without an implicit learning strategy. These results suggest that the use of an implicit strategy positively affected the ability of alcohol-exposed children to learn and retain new verbal information.     

Prenatal alcohol exposure affects frontal-striatal BOLD response during inhibitory control

BACKGROUND: Prenatal alcohol exposure can lead to widespread cognitive impairment and behavioral dysregulation, including deficits in attention and response inhibition. This study characterized the neural substrates underlying the disinhibited behavioral profile of individuals with fetal alcohol spectrum disorders (FASD). METHODS: Children and adolescents (ages 8-18) with (n=13) and without (n=9) histories of heavy prenatal alcohol exposure underwent functional magnetic resonance imaging while performing a response inhibition (go/no-go) task. RESULTS: Despite similar task performance (mean response latency, performance accuracy, and signal detection), blood oxygen level-dependent (BOLD) response patterns differed by group. Region-of-interest analyses revealed that during portions of the behavioral task that required response inhibition, alcohol-exposed participants showed greater BOLD response across prefrontal cortical regions (including the left medial and right middle frontal gyri), while they showed less right caudate nucleus activation, compared with control participants. CONCLUSIONS: These data provide an account of response inhibition-related brain functioning in youth with FASD. Furthermore, results suggest that the frontal-striatal circuitry thought to mediate inhibitory control is sensitive to alcohol teratogenesis.     

Reducing adverse outcomes from prenatal alcohol exposure: a clinical plan of action

Fetal alcohol spectrum disorders (FASDs) are among the leading preventable causes of developmental disorders in the United States; however, recognition and prevention of these conditions cannot be achieved without informed and educated health providers. This commentary addresses the importance of recognition and prevention of FASDs through the use of well-established standardized practices of diagnosis, screening, and brief alcohol reduction counseling. It is hoped that more knowledge on currently available procedures will encourage their use in the provision of routine health care to all women of childbearing age.     

The Effects of Fetal Alcohol Syndrome on Response Execution and Inhibition: An Event-Related Potential Study

Background: Both executive function deficits and slower processing speed are characteristic of children with fetal alcohol exposure, but the temporal dynamics of neural activity underlying cognitive processing deficits in fetal alcohol spectrum disorder have rarely been studied. To this end, event‐related potentials (ERPs) were used to examine the nature of alcohol‐related effects on response inhibition by identifying differences in neural activation during task performance. Methods: We recorded ERPs during a Go/No‐go response inhibition task in 2 groups of children in Cape Town, South Africa (M age = 11.7 years; range = 10 to 13)—one diagnosed with fetal alcohol syndrome (FAS) or partial FAS (FAS/PFAS; n = 7); the other, a control group whose mothers abstained or drank only minimally during pregnancy (n = 6). Children were instructed to press a “Go” response button to all letter stimuli presented except for the letter “X,” the “No‐go” stimulus, which occurred relatively infrequently. Results: Task performance accuracy and reaction time did not differ between groups, but differences emerged for 3 ERP components—P2, N2, and P3. The FAS/PFAS group showed a slower latency to peak P2, suggesting less efficient processing of visual information at a relatively early stage (～200 ms after stimulus onset). Moreover, controls showed a larger P2 amplitude to Go versus No‐go, indicating an early discrimination between conditions that was not seen in the FAS/PFAS group. Consistent with previous literature on tasks related to cognitive control, the control group showed a well‐defined, larger N2 to No‐go versus Go, which was not evident in the FAS/PFAS group. Both groups showed the expected larger P3 amplitude to No‐go versus Go, but this condition difference persisted in a late slow wave for the FAS/PFAS group, suggesting increased cognitive effort. Conclusions: The timing and amplitude differences in the ERP measures suggest that slower, less efficient processing characterizes the FAS/PFAS group during initial stimulus identification. Moreover, the exposed children showed less sharply defined components throughout the stimulus and response evaluation processes involved in successful response inhibition. Although both groups were able to inhibit their responses equally well, the level of neural activation in the children with FAS/PFAS was greater, suggesting more cognitive effort. The specific deficits in response inhibition processing at discrete stages of neural activation may have implications for understanding the nature of alcohol‐related deficits in other cognitive domains as well.     

Toward a Neurobehavioral Profile of Fetal Alcohol Spectrum Disorders

Background: A primary goal of recent research is the development of neurobehavioral profiles that specifically define fetal alcohol spectrum disorders (FASD), which may assist differential diagnosis or improve treatment. In the current study, we define a preliminary profile using neuropsychological data from a multisite study. Methods: Data were collected using a broad neurobehavioral protocol from 2 sites of a multisite study of FASD. Subjects were children with heavy prenatal alcohol exposure and unexposed controls. The alcohol‐exposed group included children with and without fetal alcohol syndrome (FAS). From 547 neuropsychological variables, 22 variables were selected for analysis based on their ability to distinguish children with heavy prenatal alcohol exposure from nonexposed controls. These data were analyzed using latent profile analysis (LPA). Results: The results indicated that a 2‐class model best fit the data. The resulting profile was successful at distinguishing subjects with FAS from nonexposed controls without FAS with 92% overall accuracy; 87.8% of FAS cases and 95.7% of controls were correctly classified. The same analysis was repeated with children with heavy prenatal alcohol exposure but without FAS and nonexposed controls with similar results. The overall accuracy was 84.7%; 68.4% of alcohol‐exposed cases and 95% of controls were correctly classified. In both analyses, the profile based on neuropsychological variables was more successful at distinguishing the groups than was IQ alone. Conclusions: We used data from 2 sites of a multisite study and a broad neuropsychological test battery to determine a profile that could be used to accurately identify children affected by prenatal alcohol exposure. Results indicated that measures of executive function and spatial processing are especially sensitive to prenatal alcohol exposure.     

Fetal Alcohol Spectrum Disorders: A Review of the Neurobehavioral Deficits Associated With Prenatal Alcohol Exposure

In utero alcohol exposure can disrupt the development of the fetal brain and result in a wide range of neurobehavioral outcomes collectively known as fetal alcohol spectrum disorders (FASD). This paper provides a comprehensive review of the cognitive and behavioral outcomes of prenatal alcohol exposure, including domains of general intelligence, executive functioning, language development, learning and memory, adaptive functioning, academic performance, and concurrent psychopathology. In addition, the current status of the neurobehavioral profile of FASD and its potential as a diagnostic tool will be discussed.     

Comparison of verbal learning and memory in children with heavy prenatal alcohol exposure or attention-deficit/hyperactivity disorder

Background: Children with fetal alcohol spectrum disorders (FASD) have deficits in verbal learning and recall. However, the specificity of these deficits has not been adequately tested. In the current study, verbal learning and memory performance of children with heavy prenatal alcohol exposure was compared to children with attention‐deficit/hyperactivity disorder (ADHD), a disorder commonly seen in alcohol‐exposed children. Methods: Performance on the California Verbal Learning Test—Children’s Version (CVLT‐C) was examined in 3 groups of children (N = 22/group): (i) heavy prenatal alcohol exposure and ADHD (ALC), (ii) nonexposed with ADHD (ADHD), and (iii) nonexposed typically developing (CON). Groups were matched on age, sex, race, ethnicity, handedness, and socioeconomic status (SES). Results: Group differences were noted on learning trials (CON > ADHD > ALC). On the delayed recall trial, CON children performed better than both clinical groups, who did not differ from each other. Children in the ALC group demonstrated poorer recognition than children in the CON and ADHD groups, who did not differ from each other. Marginally significant group differences were noted on retention of previously learned material. Post hoc analyses indicated that ADHD children showed worse retention relative to the CON group, whereas retention in the ALC children remained intact. Conclusions: These data suggest that children with heavy prenatal alcohol exposure and nonexposed children with ADHD show differential patterns of deficit on the CVLT‐C. Performance of alcohol‐exposed children reflects inefficient encoding of verbal material, whereas performance of the ADHD group may be better characterized by a deficit in retrieval of learned material. Differences noted between clinical groups add to a growing neurobehavioral profile of FASD that may aid in differential diagnosis.     

Prenatal alcohol exposure patterns and alcohol-related birth defects and growth deficiencies: a prospective study

Background: The physical features of fetal alcohol syndrome include smooth philtrum, thin vermillion border, short palpebral fissures, microcephaly, and growth deficiencies on weight and height. However, little is known about the specific quantities of alcohol exposure, pattern of drinking, timing of exposure, and magnitude of risk for each of these features. Methods: Using data on 992 subjects collected prospectively in California between 1978 and 2005, we examined the patterns and timing of alcohol exposure in relation to these features. Structural features were assessed by a dysmorphologist who performed a blinded physical examination of all infants. Patterns of drinking were evaluated by drinks per day, number of binge episodes, and maximum number of drinks. Timing of exposure was evaluated 0 to 6 weeks postconception, 6 to 12 weeks postconception, first trimester, second trimester, and third trimester. Results: Higher prenatal alcohol exposure in every pattern was significantly associated with the incidence of smooth philtrum but not with short palpebral fissures. The strongest associations were with timing of exposure in the second half of the first trimester (RR 1.25, 95% CI 1.14 to 1.36 for average number of drinks per day; RR 1.17, 95% CI 1.09 to 1.26 for maximum number of drinks in 1 episode). Similarly, thin vermillion border was most strongly associated with exposure in the second half of the first trimester. Findings with respect to timing of exposure were similar for microcephaly and reduced birth weight. However, reduced birth length was increased with exposure in any trimester. These associations were linear, and there was no evidence of a threshold. Conclusions: Reduced birth length and weight, microcephaly, smooth philtrum, and thin vermillion border are associated with specific gestational timing of prenatal alcohol exposure and are dose‐related without evidence of a threshold. Women should continue to be advised to abstain from alcohol consumption from conception throughout pregnancy.