Binge drinking during pregnancy and risk of seizures in childhood: a study based on the Danish National Birth Cohort

Alcohol use in pregnancy and its impact on the mother and child

AIMS

To review the impact of prenatal alcohol exposure on the outcomes of the mother and child.

DESIGN

Narrative review.

SETTING

Review of literature.

PARTICIPANTS

Mothers and infants affected by prenatal alcohol use.

MEASUREMENTS

Outcomes of mothers and children.

FINDINGS

Prenatal alcohol exposure is one of the most important causes of preventable cognitive impairment in the world. The developing neurological system is exquisitely sensitive to harm from alcohol and there is now also substantial evidence that alcohol-related harm can extend beyond the individual person, leading to epigenetic changes and intergenerational vulnerability and disadvantage. There is no known safe level or timing of drinking for pregnant or lactating women and binge drinking (> four drinks within 2 hours for women) is the most harmful. Alcohol-exposure increases the risk of congenital problems, including Fetal Alcohol Spectrum Disorder (FASD) and its most severe form, Fetal Alcohol Syndrome (FAS).

CONCLUSION

The impact of FASD and FAS is enduring and life-long with no current treatment or cure. Emerging therapeutic options may mitigate the worst impact of alcohol exposure but significant knowledge gaps remain. This review discusses the history, epidemiology and clinical presentations of prenatal alcohol exposure, focusing on FASD and FAS, and the impact of evidence on future research, practice and policy directions.

Understanding pathways to inequalities in child mental health: a counterfactual mediation analysis in two national birth cohorts in the UK and Denmark

OBJECTIVES

We assessed social inequalities in child mental health problems (MHPs) and how they are mediated by perinatal factors, childhood illness and maternal mental health in two national birth cohorts.

DESIGN

Longitudinal cohort study SETTING: We used data from the UK Millennium Cohort Study and the Danish National Birth Cohort.

PRIMARY AND SECONDARY OUTCOME MEASURES

We applied causal mediation analysis to longitudinal cohort data. Socioeconomic conditions (SECs) at birth were measured by maternal education. Our outcome was child MHPs measured by the Strength and Difficulty Questionnaire at age 11. We estimated natural direct, indirect and total effects (TEs) of SECs on MHPs. We calculated the proportion mediated (PM) via three blocks of mediators-perinatal factors (smoking/alcohol use during pregnancy, birth weight and gestational age), childhood illness and maternal mental health.

RESULTS

At age 11 years, 9% of children in the UK and 3.8% in Denmark had MHPs. Compared with high SECs, children in low SECs had a higher risk of MHPs (relative risk (RR)=4.3, 95% CI 3.3 to 5.5 in the UK, n=13 112; and RR=6.2, 95% CI 4.9 to 7.8 in Denmark, n=35 764). In the UK, perinatal factors mediated 10.2% (95% CI 4.5 to 15.9) of the TE, and adding maternal mental health tripled the PM to 32.2% (95% CI 25.4 to 39.1). In Denmark, perinatal factors mediated 16.5% (95% CI 11.9 to 21.1) of the TE, and including maternal mental health increased the PM to 16.9% (95% CI 11.2 to 22.6). Adding childhood illness made little difference in either country.

CONCLUSION

Social inequalities in child mental health are partially explained by perinatal factors in the UK and Denmark. Maternal mental health partially explained inequalities in the UK but not in Denmark.

Seizure prevalence in children aged up to 3 years: a longitudinal population-based cohort study in Japan

OBJECTIVE

To investigate the prevalence of seizures/febrile seizures in children up to 3 years of age and examine the effects of gestational age at birth on the risk for febrile seizures.

DESIGN

Retrospective longitudinal population-based cohort study.

SETTING

Kobe City public health center, Kobe, Japan, from 2010 to 2018.

PARTICIPANTS

Children who underwent a medical check-up at 3 years of age.

METHODS

Information regarding seizures was collected from the parents of 96 014 children. We identified the occurrence of seizure/febrile seizure in 74 017 children, whose gestational ages at birth were noted. We conducted a multivariate analysis with the parameter, gestational age at birth, to analyse the risk of seizure. We also stratified the samples by sex and birth weight (<2500 g or not) and compared the prevalence of seizure between those with the term and late preterm births.

RESULTS

The prevalence of seizure was 12.1% (11.8%-12.3%), 13.2% (12.2%-14.4%), 14.6% (12.4%-17.7%) and 15.7% (10.5%-22.8%) in children born at 37-41, 34-36, 28-33 and 22-27 gestational weeks, respectively. The prevalence of febrile seizures was 9.0% (8.8%-9.2%), 10.5% (9.5%-11.5%), 11.8% (9.7%-14.5%) and 11.2% (6.9%-17.7%) in children born at 37-41, 34-36, 28-33 and 22-27 gestational weeks, respectively. Male was an independent risk factor for seizures (OR: 1.15, 95% CI 1.09 to 1.20; absolute risk increase 0.014, 95% CI 0.010 to 0.019) and febrile seizures (OR: 1.21, 95% CI 1.15 to 1.28; absolute risk increase 0.016, 95% CI 0.012 to 0.020), respectively. Late preterm birth was not associated with an increased risk of seizure/febrile seizure.

CONCLUSIONS

Although very preterm birth may increase the risk of seizure/febrile seizure, the risk associated with late preterm birth is considerably small and less than that associated with male.

Prenatal alcohol exposure in the second trimester-equivalent increases the seizure susceptibility in developing rats

We have previously reported that prenatal alcohol exposure (PAE) in the 2nd trimester-equivalent of gestation is associated with increased N-methyl-d-aspartate (NMDA)-induced generalized tonic-clonic seizures (GTCSs) prevalence in postpartum developing rats. Whether the 1st trimester-equivalent of gestation is also a vulnerable period for developing GTCSs following PAE is unknown. Here, we investigated the effects of a single episode of PAE at embryonic day 8 (E8, in the 1st trimester-equivalent) or E18 (in the 2nd trimester-equivalent) on NMDA-induced seizures in developing rats at postnatal day 7 (P7, the equivalent of preterm newborns) and P15 (the equivalent of term infants). Pregnant Sprague-Dawley rats were given a single oral dose of ethanol (5 g/kg body weight) at E8 or E18 and the postpartum rats were tested for the susceptibility to NMDA-induced seizures at either P7 or P15. NMDA-induced seizures consisted of wild running-like behavior (WRLB), flexion seizures (FSs), clonic seizures (CSs), GTCSs, and tonic seizures (TSs); these seizures were observed in both control-treated and PAE-treated, male and female, P7 and P15 rats. Quantification reveals that the overall prevalence of CSs, GTCSs and TSs occurrence were significantly increased in the E18-PAE group compared to E8-PAE group, adjusting for sex and postnatal day. Furthermore, the overall prevalence of FSs and TSs occurrence was significantly increased in PAE-treated males compared to females, adjusting for embryonic stage and postnatal day. The overall prevalence of WRLB and FSs occurrence was also increased in PAE-P7 rats compared to PAE-P15 rats, adjusting for sex and embryonic stage. We conclude that the susceptibility to develop GTCSs was higher when PAE occurred in the 2nd rather than in the 1st trimester-equivalent of gestation.

Breastfeeding and risk of febrile seizures in infants: The Japan Environment and Children's Study

OBJECTIVE

Our study was conducted to examine the association between breastfeeding and febrile seizures (FS) in the first year of life.

METHODS

We used data from a birth cohort study, the Japan Environment and Children's Study (JECS). In a self-administered questionnaire, we asked participants the duration of breastfeeding and whether their children were diagnosed as having FS during their first 12 months. We estimated the association of duration and exclusiveness of breastfeeding with the FS by using multiple logistic regression analysis.

RESULTS

Of 84,082 children, 995 (1.2%) were diagnosed as having FS by the age of 12 months. The prevalence of FS was higher in children who were breastfed for shorter duration. Multiple logistic regression analysis showed that, compared with children breastfed for less than 1 month, those breastfed for 4-6 months and 7-12 months had lower risks of FS (adjusted odds ratio [aOR], 0.65 [95% confidence interval {CI}, 0.42-0.99]; aOR, 0.66 [95% CI: 0.45-0.96], respectively). Moreover, compared with infants who received both breast milk and formula milk for 6 months, infants who were breastfed exclusively for 6 months had lower risk of FS (aOR: 0.78 [95% CI: 0.64-0.95]).

CONCLUSIONS

Our results suggest that breastfeeding has a protective effect against FS in the first year of life.

Prenatal alcohol exposure enhances the susceptibility to NMDA-induced generalized tonic-clonic seizures in developing rats

AIMS

Prenatal alcohol exposure (PAE) is associated with a higher likelihood of developing generalized tonic-clonic seizures (GTCS) in infants and children. However, experimental studies of PAE-related seizures have yielded conflicting results. Here, we investigated the effect of acute PAE on N-methyl-D-aspartate (NMDA)-induced seizures in developing rats.

METHODS

Pregnant Sprague Dawley rats were given an oral dose of either ethanol (5 g/kg body weight) or vehicle on embryonic day 18. The offspring were tested for susceptibility to NMDA-induced seizures on postnatal day 7 (P7), 21 (P21), 35 (P35), and 42 (P42). Specifically, the prevalence and latency of NMDA-induced continuous wild running-like behaviors (CWR), flexion seizures (FS), wild running seizures (WRS), GTCS, and tonic seizures (TS) were recorded and analyzed.

RESULTS

N-methyl-D-aspartate-induced seizures consisted of CWR, FS, GTCS, and TS in <P21 rats, while WRS, GTCS, and TS were observed in >P21 rats. Thus, GTCS were consistently observed during development. PAE significantly increases the prevalence of GTCS in female and male P7-P21 rats and P7-P35 rats, respectively, but not in older rats. PAE also increases the prevalence of TS in male, but not female P21-P35 rats.

CONCLUSIONS

The PAE animal model of GTCS may provide a new opportunity to investigate the mechanisms that underlie neuronal hyperexcitability in developing animals prenatally-exposed to alcohol.

Embryonic exposure to ethanol increases the susceptibility of larval zebrafish to chemically induced seizures

Prenatal ethanol exposure is known to cause neurodevelopmental disorders. While high prevalence of epilepsy is observed among the children whose mothers abused alcohol during pregnancy, the results from animal studies are conflicting. Here, we investigated whether embryonic exposure to ethanol can increase the susceptibility to pentylenetetrazole (PTZ)-induced seizures in larval zebrafish. Embryos at 3 hours post-fertilization (hpf) were exposed to ethanol at the concentrations ranging from 0.25% to 1% for 21 hours. Control and ethanol-exposed larvae were challenged with PTZ at 7 days post-fertilization (dpf) at the concentrations of 2.5, 5 or 15 mM. The seizure behavior of larvae was recorded and analyzed using EthoVision XT 11. We found that embryonic ethanol exposure increased the percentage of larvae exhibiting typical stage II and III seizure and resulted in a significant reduction in stage I, II and III seizure latency in an ethanol concentration-dependent manner. Embryonic exposure to ethanol also significantly increased the severity of PTZ-induced seizures in larvae, as demonstrated by increased total distance traveled and the duration of mobility. This is the first demonstration that ethanol exposure during early embryonic stage can reduce the threshold for chemically induced seizures and increase the severity of seizure behavior in larval fish.

Radiological studies of fetal alcohol spectrum disorders in humans and animal models: An updated comprehensive review

Fetal Alcohol Spectrum Disorders encompass a wide range of birth defects in children born to mothers who consumed alcohol during pregnancy. Typical mental impairments in FASD include difficulties in life adaptation and learning and memory, deficits in attention, visuospatial skills, language and speech disabilities, mood disorders and motor disabilities. Multimodal imaging methods have enabled in vivo studies of the teratogenic effects of alcohol on the central nervous system, giving more insight into the FASD phenotype. This paper offers an up-to-date comprehensive review of radiological findings in the central nervous system in studies of prenatal alcohol exposure in both humans and translational animal models, including Magnetic Resonance Imaging, Computed Tomography, Positron Emission Tomography, Single Photon Emission Tomography and Ultrasonography.

Age at Menarche and Risk of Multiple Sclerosis: A Prospective Cohort Study Based on the Danish National Birth Cohort

Few studies have addressed the possible association between age at menarche and multiple sclerosis (MS), and results are conflicting. We studied this issue in a large prospective cohort study. The study cohort comprised 77,330 women included in the Danish National Birth Cohort (1996-2002). Information on menarcheal age was ascertained at the first interview, which took place in the 16th week of pregnancy. Women were followed for MS from the first interview to December 31, 2011. Associations between age at menarche and risk of MS were evaluated with hazard ratios and 95% confidence intervals using Cox proportional hazards regression models. Overall, 226 women developed MS during an average follow-up period of 11.7 years. Age at menarche among women with MS was generally lower than that among women without MS (Wilcoxon rank-sum test; P = 0.002). We observed an inverse association between age at menarche and MS risk. For each 1-year increase in age at menarche, risk of MS was reduced by 13% (hazard ratio = 0.87, 95% confidence interval: 0.79, 0.96). Early age at menarche appears to be associated with an increased risk of MS. The mechanisms behind this association remain to be established.

Interactive effects of prenatal exposure to restraint stress and alcohol on pentylenetetrazol-induced seizure behaviors in rat offspring

Prenatal exposure to stress or alcohol increases vulnerability of brain regions involved in neurobehavioral development and programs susceptibility to seizure. To examine how prenatal alcohol interferes with stress-sensitive seizures, corticosterone (COS) blood levels and pentylenetetrazol (PTZ)-induced seizure behaviors were investigated in rat pups, prenatally exposed to stress, alcohol, or both. Pregnant rats were exposed to stress and saline/alcohol on 17, 18, and 19 days of pregnancy and divided into four groups of control-saline (CS), control-alcohol (CA), restraint stress-saline (RS), and restraint stress-alcohol (RA). In CS/CA groups, rats received saline/alcohol (20%, 2 g/kg, intraperitoneally [i.p.]). In RS/RA groups, rats were exposed to restraint stress by being held immobile in a Plexiglas^® tube (twice/day, 1 h/session), and received saline/alcohol, simultaneously. After parturition, on postnatal days 6 and 15 (P6 & P15), blood samples were collected from the pups to determine COS level. On P15 and P25, PTZ (45 mg/kg) was injected into the rest of the pups and seizure behaviors were then recorded. COS levels increased in pups of the RS group but not in pups of the RA group. Both focal and tonic-clonic seizures were prevalent and severe in pups of the RS group, whereas only focal seizures were prominent in pups of the CA group. However, pups prenatally exposed to co-administration of alcohol and stress, unexpectedly, did not show additive epileptic effects. The failure of pups prenatally exposed to alcohol to show progressive or facilitatory epileptic responses to stressors, indicates decreased plasticity and adaptability, which may negatively affect HPA-axis performance or hippocampal structure/function.

Seizures and electroencephalography findings in 61 patients with fetal alcohol spectrum disorders

Fetal alcohol spectrum disorders (FASD) cause neurodevelopmental abnormalities. However, publications about epilepsy and electroencephalographic features are scarce. In this study, we prospectively performed electroencephalography (EEG) and brain magnetic resonance (MR) imaging in 61 patients with diagnosis of FASD. One patient had multiple febrile seizures with normal EEGs. Fourteen children showed EEG anomalies, including slow background activity and interictal epileptiform discharges, focal and/or generalized, and 3 of them had epilepsy. In one patient, seizures were first detected during the EEG recording and one case had an encephalopathy with electrical status epilepticus during slow sleep (ESES). Focal interictal discharges in our patients did not imply the presence of underlying visible focal brain lesions in the neuroimaging studies, such as cortical dysplasia or polymicrogyria. However, they had nonspecific brain MR abnormalities, including corpus callosum hypoplasia, vermis hypoplasia or cavum septum pellucidum. The latter was significantly more frequent in the group with EEG abnormal findings (p < 0.01).

Prevalence and correlates of drinking in early pregnancy among women who stopped drinking on pregnancy recognition

Women of child bearing age that regularly drink alcohol are at risk for drinking in early pregnancy. Evidence indicates a majority of women stop alcohol consumption on pregnancy recognition. However, there is a dearth of studies reporting on patterns and correlates of drinking in early pregnancy prior to stopping on pregnancy recognition, which the current study aims to address. In 2005, a New Zealand nationwide cross-sectional survey was conducted on a random sample of 1,256 women aged 16-40 years. Data were collected via an interviewer-administered questionnaire using a web-assisted telephone interviewing system. Of the 1,256 women who participated, 127 (10 %) were currently pregnant and 425 women (34 %) were previously pregnant. Half of currently pregnant women and 37 % of previously pregnant women reported that they ceased drinking on recognising pregnancy. Women categorised as "risky drinkers" and those aged 16-24 years had higher odds to drink and binge drink in early pregnancy, compared with non-risky drinkers and women of other age categories respectively. A majority of women stop alcohol consumption on pregnancy recognition but prior to this, drink at levels posing a risk for the developing foetus. Women most at risk for drinking and binge drinking in early pregnancy were younger in age and exhibited risky drinking behaviour prior to pregnancy. A targeted intervention to reduce the risk for an alcohol exposed pregnancy is warranted for sexually active younger women in New Zealand and elsewhere.

Prevalence of fetal alcohol syndrome and maternal characteristics in a sample of schoolchildren from a rural province of Croatia

Fetal alcohol syndrome (FAS) is a congenital syndrome caused by maternal alcohol consumption during pregnancy and is entirely preventable by abstinence from alcohol drinking during this time. Little is known about the prevalence of FAS and maternal alcohol consumption during pregnancy in Western countries. We present the results of FAS/partial fetal alcohol syndrome (PFAS) prevalence study and maternal characteristics in a sample of schoolchildren from a rural province of Croatia. This study involved seven elementary schools with 1,110 enrolled children attending 1st to 4th grade and their mothers. We used an active case ascertainment method with passive parental consent and Clarified IOM criteria. The investigation protocol involved maternal data collection and clinical examination of children. Out of 1,110 mothers, 917 (82.6%) answered the questionnaire. Alcohol exposure during pregnancy was admitted by 11.5%, regular drinking by 4.0% and binge drinking by 1.4% of questioned mothers. Clinical examination involved 824 (74.2%) schoolchildren and disclosed 14 (1.7%) with clinical signs of FAS and 41 (5.0%) of PFAS. The observed FAS prevalence, based on 74.2% participation rate, was 16.9, PFAS 49.7 and combined prevalence was 66.7/1,000 examined schoolchildren. This is the first FAS prevalence study based on active ascertainment among schoolchildren and pregnancy alcohol drinking analysis performed in a rural community of Croatia and Europe. High prevalence of FAS/PFAS and pregnancy alcohol consumption observed in this study revealed that FAS is serious health problem in rural regions as well as a need to develop future studies and preventive measures for pregnancy alcohol drinking and FASD.

Increased risks of epilepsy and neuropsychiatric diseases in children of mothers with alcoholic liver disease

BACKGROUND

Pregnancy in women with liver disease may increase the risk of fetal complication. Data on disease frequencies in children born to mothers with alcoholic liver disease do not exist, although we do know that prenatal alcohol exposure may affect the fetus negatively.

AIMS

The aim of this study was to assess the relative risk of neuropsychiatric diseases in children who were born to mothers with chronic liver diseases.

METHODS

We linked the Hospital Discharge Register, Medical Birth Register and Pharmaceutical Register in Sweden between 1969 and 2009 to identify women with liver disease. We identified their children, up to the age of 16 in the Medical Birth Register, born between 1973 and 2009. Between 2005 and 2009, we identified every prescription that was dispensed to these children.

RESULTS

We identified 5 124 children of mothers with alcoholic liver disease. There were 22,960 children of mothers with non-alcoholic liver disease. For controls, we used 10 sex-, age- and birthplace-matched children. There were more children born to mothers with alcoholic liver disease before the birth who had been dispensed antiepileptics (n = 11, RR = 3.2 (1.6-6.4)), neuroleptics (n = 7, RR = 5.0 (2.0-12.5)) and drugs to treat attention deficit hyperactivity disorders (n = 22, RR = 5.9 (3.7-9.4)) compared with sex-, age- and regionally adjusted controls. Children born to mothers with non-alcoholic liver disease had significantly increased risk of being dispensed drugs to treat attention deficit disorders (RR = 2.2 (1.8-2.6)).

CONCLUSIONS

Mothers with alcoholic liver disease have increased risks of having children with severe neurological and psychiatric disorders.

Alcohol and pregnancy: do abstinence policies have unintended consequences?

Most policies and guidelines recommend that women abstain from alcohol during pregnancy. This can be difficult to achieve in developed nations where the majority of women consume alcohol and almost half of pregnancies are unplanned, leading to many pregnancies being exposed to alcohol prior to pregnancy awareness. Concerns have been raised that abstinence policies may lead women in this situation to terminate their pregnancy out of fear that they have harmed their baby; however, the evidence is limited. A recent study found that while few women reported alcohol as the reason for seeking an abortion, in almost all cases where alcohol was the reason, the women were either binge drinking or reported alcohol-related problems and the pregnancy was unplanned.

Safety concerns regarding binge drinking in pregnancy: a review

BACKGROUND

There is ongoing debate about the risks to the fetus associated with maternal binge drinking. This makes it difficult to counsel patients about the potential risks associated with their use of alcohol during pregnancy.

METHODS

This article reviews the literature on animal and human studies regarding binge drinking (four to five drinks at one time in humans, or the equivalent in laboratory animals).

RESULTS

Animal studies provide evidence that high doses of alcohol over a short period of time can be more damaging than lower doses over a long period of time. Human data are more inconsistent, especially in terms of the association with malformations. Although neurobehavioral effects are the most commonly reported adverse outcome, some studies do not find such an association. Conclusions are confounded by the design of many studies, which fail to document pattern and total amount of alcohol consumption at one time. In addition, it has been suggested there is a bias against the null effect in publications.

CONCLUSION

Although the evidence in humans is not conclusive, the incidence of binge exposures in pregnancy is high, and it appears prudent to counsel patients to avoid this exposure whenever possible. Women inadvertently exposed to a single binge episode of alcohol early in the first trimester before pregnancy recognition can be reassured that the risks for adverse effects in their baby are likely low if they are able to discontinue use for the duration of the pregnancy. Unfortunately, there may be some residual fetal risk.

Magnetic resonance-based imaging in animal models of fetal alcohol spectrum disorder

Magnetic resonance imaging (MRI) techniques, such as magnetic resonance microscopy (MRM), diffusion tensor imaging (DTI), and magnetic resonance spectroscopy (MRS), have recently been applied to the study of both normal and abnormal structure and neurochemistry in small animals. Herein, findings from studies in which these methods have been used for the examination of animal models of Fetal Alcohol Spectrum Disorder (FASD) are discussed. Emphasis is placed on results of imaging studies in fetal and postnatal mice that have highlighted the developmental stage dependency of prenatal ethanol exposure-induced CNS defects. Consideration is also given to the promise of methodological advances to allow in vivo studies of aberrant brain and behavior relationships in model animals and to the translational nature of this work.

Ventromedian forebrain dysgenesis follows early prenatal ethanol exposure in mice

Ethanol exposure on gestational day (GD) 7 in the mouse has previously been shown to result in ventromedian forebrain deficits along with facial anomalies characteristic of fetal alcohol syndrome (FAS). To further explore ethanol's teratogenic effect on the ventromedian forebrain in this mouse model, scanning electron microscopic and histological analyses were conducted. For this, time mated C57Bl/6J mice were injected with 2.9g/kg ethanol or saline twice, at a 4h interval, on their 7th day of pregnancy. On GD 12.5, 13 and 17, control and ethanol-exposed specimens were collected and processed for light and scanning electron microscopic analyses. Gross morphological changes present in the forebrains of ethanol-exposed embryos included cerebral hemispheres that were too close in proximity or rostrally united, enlarged foramina of Monro, enlarged or united lateral ventricles, and varying degrees of hippocampal and ventromedian forebrain deficiency. In GD 12.5 control and ethanol-exposed embryos, in situ hybridization employing probes for Nkx2.1 or Fzd8 to distinguish the preoptic area and medial ganglionic eminences (MGEs) from the lateral ganglionic eminences, respectively, confirmed the selective loss of ventromedian tissues. Immunohistochemical labeling of oligodendrocyte progenitors with Olig2, a transcription factor necessary for their specification, and of GABA, an inhibitory neurotransmitter, showed ethanol-induced reductions in both. To investigate later consequences of ventromedian forebrain loss, MGE-derived somatostatin-expressing interneurons in the subpallial region of GD 17 fetal mice were examined, with results showing that the somatostatin-expressing interneurons that were present were dysmorphic in the ethanol-exposed fetuses. The potential functional consequences of this insult are discussed.

Magnetic resonance microscopy-based analyses of the brains of normal and ethanol-exposed fetal mice

BACKGROUND

The application of magnetic resonance microscopy (MRM) to the study of normal and abnormal prenatal mouse development has facilitated discovery of dysmorphology following prenatal ethanol insult. The current analyses extend this work, providing a regional brain volume-based description of normal brain growth and illustrating the consequences of gestational day (GD) 10 ethanol exposure in the fetal mouse.

METHODS

To assess normal growth, control C57Bl/6J fetuses collected on GD 16, GD 16.5, and GD 17 were scanned using a 9.4-T magnet, resulting in 29-μm isotropic resolution images. For the ethanol teratogenicity studies, C57Bl/6J dams were administered intraperitoneal ethanol (2.9 g/kg) at 10 days, 0 hr, and 10 days, 4 hr, after fertilization, and fetuses were collected for analyses on GD 17. From individual MRM scans, linear measurements and regional brain volumes were determined and compared.

RESULTS

In control fetuses, each of the assessed brain regions increased in volume, whereas ventricular volumes decreased between GD 16 and GD 17. Illustrating a global developmental delay, prenatal ethanol exposure resulted in reduced body volumes, crown-rump lengths, and a generalized decrease in regional brain volumes compared with GD 17 controls. However, compared with GD 16.5, morphologically matched controls, ethanol exposure resulted in volume increases in the lateral and third ventricles as well as a disproportionate reduction in cortical volume.

CONCLUSIONS

The normative data collected in this study facilitate the distinction between GD 10 ethanol-induced developmental delay and frank dysmorphology. This work illustrates the utility of MRM-based analyses for developmental toxicology studies and extends our knowledge of the stage-dependency of ethanol teratogenesis.

The remarkably high prevalence of epilepsy and seizure history in fetal alcohol spectrum disorders

BACKGROUND

Fetal alcohol spectrum disorder (FASD) is the umbrella term that describes the range of adverse developmental outcomes that may occur in the offspring of mothers who drink alcohol during pregnancy. FASD is associated with several comorbidities including epilepsy. The objective of the study was to evaluate the prevalence of epilepsy or a history of seizures in subjects with FASD and the contribution of relevant risk factors.

METHODS

A retrospective chart review was conducted on all active charts (N = 1063) at two FASD clinics. After exclusion of subjects without a confirmed diagnosis, a total of 425 subjects between the ages of 2-49 were included in the analysis. The relationships between FASD diagnosis and other risk factors for co-occurrence of epilepsy or a seizure disorder (e.g., extent of exposure to alcohol and other drugs, type of birth, and trauma) were examined using chi-square and multivariate multinomial logistic regression.

RESULTS

Twenty-five (5.9%) individuals in the study population had a confirmed diagnosis of epilepsy, and 50 (11.8%) had at least one documented seizure episode, yielding an overall prevalence of 17.7% in this population. Importantly, a history of epilepsy or seizures was not different across the three diagnostic subgroups. In those subjects with available maternal drinking histories, first trimester exposure or drinking throughout all three trimesters were the predominant forms of fetal exposure. None of the other risk factors were associated with a greater prevalence of epilepsy or seizures.

CONCLUSIONS

There is a remarkably high prevalence of epilepsy/seizures in the FASD population.

A prospective study of smoking, caffeine, and alcohol as risk factors for seizures or epilepsy in young adult women: data from the Nurses' Health Study II

PURPOSE

Seizures and epilepsy are associated with significant disability and substantial treatment costs, yet little is known about primary prevention. We prospectively examined the association of cigarette smoking, caffeine use, and alcohol intake with risk of seizure or epilepsy among women, aged 25-42 years, in the Nurses' Health Study II.

METHODS

Participants provided dietary and cigarette smoking information on multiple questionnaires beginning in 1989. Among 116,363 women at-risk for incident seizure or epilepsy, we confirmed 95 cases of seizure and 151 cases of epilepsy occurring from 1989-2005 using information from a detailed supplementary questionnaire and medical records. Multivariable-adjusted relative risks (RRs) and 95% confidence intervals (CIs) were estimated using Cox proportional hazards regression.

RESULTS

Compared with never smoking, current cigarette smoking was associated with an increased risk of seizure (RR 2.60, 95% CI 1.53-4.42), after adjustment for stroke and other potential confounding factors. Past smoking was not associated with risk of seizure, but was associated with modestly increased risk of epilepsy (RR 1.46, 95% CI 1.01-2.12). Long-term caffeine and moderate alcohol intake were not associated with seizure or epilepsy.

DISCUSSION

Cigarette smoking may be associated with increased risk of seizure. More prospective studies are needed to investigate potential factors to ultimately prevent the development of seizures or epilepsy.

Register-based studies on febrile seizures in Denmark

During a short period of brain development, one out of 25 children experience seizures when exposed to fever. The risk and consequences of these febrile seizures remain incompletely understood. We have conducted a number of studies within a population-based cohort of 1.6 million children born in Denmark (1977-2004). We constructed the cohort by linking registers on civil service, health, and cause of death. We followed the cohort for up to 28 years with virtually no loss to follow-up. The aetiology of febrile seizures depends on a genetic susceptibility that can be transmitted through both parents. The risk of febrile seizures increases with decreasing birth weight and gestational age at birth indicating that pre- and perinatal risk factors play a causal role. Measles, mumps, and rubella vaccination increases the risk of febrile seizures for two weeks, but the absolute risk is small even in high-risk children. Febrile seizure is associated with an increased risk of epilepsy and the risk remained high well into adulthood. The risk of epilepsy is particular high for persons with cerebral palsy, low Apgar scores, or a family history of epilepsy. The risk of schizophrenia is slightly increased among persons with a history of febrile seizures even in persons without epilepsy, but the association need not be causal and more studies are needed. Febrile seizure is a common condition with a benign outcome for the vast majority of children. Genes and environmental factors operating in early life seem to play a causal role.