Maternal Smoking and Attention-Deficit/Hyperactivity Disorder in Offspring: A Meta-analysis

In utero aspirin exposure and child neurocognitive development: A propensity score-matched analysis

OBJECTIVE

To evaluate the association between a short-period, high-dose in utero aspirin exposure and child neurocognitive development.

DESIGN

A propensity score-matched analysis of a multicentre prospective cohort study.

SETTING

The US Collaborative Perinatal Project (1959-1976).

POPULATION

A total of 50 565 singleton live births with maternal information.

METHODS

We performed a propensity score matching to balance maternal characteristics between women with and without aspirin exposure. Inverse probability-weighted marginal structural models were used to estimate associations between aspirin exposure and child neurocognitive assessments.

MAIN OUTCOME MEASURES

Child neurocognitive development was assessed using the Bayley Scales at 8 months, the Stanford Binet Intelligence Scale at 4 years, and the Wechsler Intelligence Scale and Wide-Range Achievement Test (WRAT) at 7 years.

RESULTS

Children exposed to aspirin in utero were associated with an 8%-16% reduced risk of having suspect/abnormal or below-average scores in most neurocognitive assessments. A trend of lower risks of having suspect/abnormal or below-average scores was further observed in children with in utero aspirin exposure for more than 7 days, particularly on Bayley Mental (relative risk [RR] 0.82, 95% CI 0.74-0.92), WRAT Reading (RR 0.88, 95% CI 0.78-0.98) and WRAT Arithmetic tests (RR 0.76, 95% CI 0.66-0.86). This association was mainly observed in the second trimester of pregnancy.

CONCLUSIONS

In utero aspirin exposure was associated with improved child neurocognitive development in a prospective cohort study. Further studies are warranted to evaluate the impact of long-period and low-dose in utero aspirin exposure on child short- and long-term neurodevelopment.

Vaporized nicotine in utero results in reduced birthweight, increased locomotion, and decreased voluntary exercise, dependent on sex and diet in offspring

Rationale Clinical research has shown that prenatal exposure to nicotine may result in increased obesity risk later in life. Preclinical research has corroborated this finding, but few studies have investigated inhaled nicotine or the interaction with diet on obesity risk. Objective The aim of this study was to investigate the effects of prenatal nicotine exposure on both direct and indirect obesity measures, with both sex and diet as factors. Methods Pregnant rats were exposed to either vehicle or nicotine vapor (24 mg/mL or 59 mg/mL) throughout the entire gestational period. Offspring from each treatment group were given either a normal diet or a high fat diet starting at postnatal day 22. Caloric intake, body weight, spontaneous locomotion, sleep/wake activity, and voluntary exercise were measured throughout adolescence. Pregnancy weight gain and pup birthweights were collected to further measure developmental effects of prenatal nicotine exposure. Results Both maternal weight gain during pregnancy and pup weight at birth were decreased with prenatal nicotine exposure. Early adolescent males showed increased spontaneous activity in the open field following prenatal nicotine exposure compared to vehicle counterparts, particularly those given high-fat diet. Additionally, high dose nicotine prenatal treated males ran significantly less distance on the running wheel in late adolescence compared to vehicle counterparts, in the normal diet group only. Conclusion The results presented here show decreased birthweight, hyperactivity, and decreased voluntary exercise in adolescence following prenatal nicotine exposure in dose, sex, and diet dependent manners, which could lead to increased obesity risk in adulthood.

Maternal diabetes and risk of attention-deficit/hyperactivity disorder in offspring in a multinational cohort of 3.6 million mother-child pairs

Previous studies report an association between maternal diabetes mellitus (MDM) and attention-deficit/hyperactivity disorder (ADHD), often overlooking unmeasured confounders such as shared genetics and environmental factors. We therefore conducted a multinational cohort study with linked mother-child pairs data in Hong Kong, New Zealand, Taiwan, Finland, Iceland, Norway and Sweden to evaluate associations between different MDM (any MDM, gestational diabetes mellitus (GDM) and pregestational diabetes mellitus (PGDM)) and ADHD using Cox proportional hazards regression. We included over 3.6 million mother-child pairs between 2001 and 2014 with follow-up until 2020. Children who were born to mothers with any type of diabetes during pregnancy had a higher risk of ADHD than unexposed children (pooled hazard ratio (HR) = 1.16, 95% confidence interval (CI) = 1.08-1.24). Higher risks of ADHD were also observed for both GDM (pooled HR = 1.10, 95% CI = 1.04-1.17) and PGDM (pooled HR = 1.39, 95% CI = 1.25-1.55). However, siblings with discordant exposure to GDM in pregnancy had similar risks of ADHD (pooled HR = 1.05, 95% CI = 0.94-1.17), suggesting potential confounding by unmeasured, shared familial factors. Our findings indicate that there is a small-to-moderate association between MDM and ADHD, whereas the association between GDM and ADHD is unlikely to be causal. This finding contrast with previous studies, which reported substantially higher risk estimates, and underscores the need to reevaluate the precise roles of hyperglycemia and genetic factors in the relationship between MDM and ADHD.

The causal impact of maternal smoking around birth on offspring ADHD: A two-sample Mendelian randomization study

BACKGROUND

The previous literature highlights a relationship between maternal smoking around birth (MSAB) and offspring attention-deficit/hyperactivity disorder (ADHD). These studies have focused on the causal effects of MSAB on offspring ADHD.

METHOD

A Mendelian randomization analysis was conducted using summary statistics. Data on MSAB were obtained from a recent study including 391,992 participants. ADHD data were obtained from six sources for 246,888 participants. The present study used five methods to examine the causal impact from outcomes on exposures. The inverse variance weighted (IVW) was the main method of analysis, while the other four methods were supplementary methods.

RESULT

The IVW revealed that MSAB was a risk factor for offspring ADHD (OR: 2.54; 95 % confidence interval [CI]: 1.61-4.00, p = 6.04 × 10-5). Concerning ADHD in both sexes, MSAB was associated with females (OR = 3.96, 95 % CI: 1.99-7.90, p = 8.98 × 10-5) and males (OR = 3.74, 95 % CI: 1.74-5.72, p = 1.48 × 10-4). In different diagnosis periods for ADHD, MSAB increased the risk of childhood (OR = 3.63, 95 % CI: 2.25-5.87, p = 1.31 × 10-7), late-diagnosed (OR = 2.99, 95 % CI: 1.74-5.14, p = 7.33 × 10-5), and persistent (OR = 4.77, 95 % CI: 1.88-12.14, p = 1.03 × 10-3) ADHD. The final analysis did not reveal heterogeneity.

CONCLUSIONS

A causal impact of MSAB on offspring ADHD was observed. These findings highlight the need for careful consideration of prenatal exposure (MSAB) during the assessment of offspring ADHD. Additionally, it can provide targeted guidance for prenatal interventions. Future studies should analyze the effects of different doses of maternal smoking on ADHD.

Associations of maternal and personal smoking with all-cause and cause-specific mortality risk and life expectancy: a prospective cohort study

OBJECTIVES

The aim of this study was to evaluate the individual and combined effects of maternal smoking during pregnancy (MSDP) and personal smoking on mortality and life expectancy.

STUDY DESIGN

A prospective cohort study based on the UK Biobank, with a median follow-up of 12.47 years.

METHODS

This study employed multivariate Cox regression to determine the relative risks of mortality from all causes and specific diseases according to maternal and/or personal smoking status and pack-years of smoking (0, 1-20, 21-30, >30). Additionally, this study estimated the additive interaction between the two exposures. Life table analyses were performed using the estimated age-specific mortality rates to forecast life expectancy.

RESULTS

Results indicated that MSDP elevated the risk of all-cause mortality (HR = 1.12, 95% CI: 1.09-1.15) and mortality due to neoplasms (HR = 1.10, 95% CI: 1.06-1.12), circulatory (HR = 1.13, 95% CI: 1.06-1.19), respiratory (HR = 1.27, 95% CI: 1.16-1.40) and digestive system diseases (HR = 1.22, 95% CI: 1.08-1.38). Notably, both multiplicative and additive interactions were observed between maternal and personal smoking, with Relative Excess Risk due to Interaction (RERI) values for mortality from all causes, neoplasms, circulatory, and respiratory diseases being 0.21, 0.22, 0.16, and 0.76, respectively. This study also found a trend towards shorter gained life expectancy when maternal smoking and increasing pack-years of personal smoking were combined.

CONCLUSIONS

In this cohort study of UK Biobank, MSDP was associated with an increased risk of all-cause mortality and reduced life expectancy, suggesting that quitting smoking during pregnancy might have health and longevity benefits for both generations.

Maternal smoking during pregnancy and cortical structure in children with attention-deficit/hyperactivity disorder

Maternal smoking during pregnancy (MSDP) is considered a risk factor for ADHD. While the mechanisms underlying this association are not well understood, MSDP may impact the developing brain in ways that lead to ADHD. Here, we investigated the effect of prenatal smoking exposure on cortical brain structures in children with ADHD using two methods of assessing prenatal exposure: maternal recall and epigenetic typing. Exposure groups were defined according to: (1) maternal recall (+MSDP: n = 24; -MSDP: n = 85) and (2) epigenetic markers (EM) (+EM: n = 14 -EM: n = 21). CIVET-1.1.12 and RMINC were used to acquire cortical brain measurements and perform statistical analyses, respectively. The vertex with highest significance was tested for association with Continuous Performance Test (CPT) dimensions. While no differences of brain structures were identified between +MSDP and -MSDP, +EM children (n = 10) had significantly smaller surface area in the right orbitofrontal cortex (ROFc), middle temporal cortex (RTc) and parahippocampal gyrus (RPHg) (15% FDR) compared to -EM children (n = 20). Cortical surface area in the RPHg significantly correlated with CPT commission errors T-scores. This study suggests that molecular markers may better define exposure to environmental risks, as compared to human recall.

The associations of secondhand smoke exposure with neurodevelopmental disorders and critical time window identification: A systematic review and meta-analysis

BACKGROUND

Secondhand smoke (SHS) exposure was harmful for brain development. However, the association between SHS exposure and NDDs diagnosis were unclear.

OBJECTIVES

To evaluate associations between SHS exposure and NDDs diagnosis, identify critical time windows, and summarize the strength of evidence.

METHODS

To investigate the associations of SHS exposure and the development of NDDs, we searched Ovid, EMBASE, Web of Science, Cochrane Library, and PubMed for all the relevant studies up to 31 March 2023. The risk estimates and standardized mean differences (SMD) for the individuals with any NDDs who were exposed to SHS exposure compared with those unexposed or low-exposed.

RESULTS

The results showed that a total of 31,098 citations were identified, of which 54 studies were included. We identified significant associations between SHS exposure and the risks of NDDs including specific types of NDDs like attention deficit hyperactivity disorder (ADHD) and learning disabilities (LD) despite the observed heterogeneity for NDDs and ADHD. We also observed a significant association between cotinine exposure and ADHD. However, inconsistent ratings between the two quality-of-evidence methods for all the meta-analyses indicated the current evidence of the associations and the potential exposure window remained inconclusive.

DISCUSSION

Our findings suggested that SHS exposure was associated with a higher risk of developing ADHD and LD, with inconclusive quality-of-evidence. In addition, period-specific associations remained unclear based on current evidence.

Attention-deficit/hyperactivity disorder

Attention-deficit/hyperactivity disorder (ADHD; also known as hyperkinetic disorder) is a common neurodevelopmental condition that affects children and adults worldwide. ADHD has a predominantly genetic aetiology that involves common and rare genetic variants. Some environmental correlates of the disorder have been discovered but causation has been difficult to establish. The heterogeneity of the condition is evident in the diverse presentation of symptoms and levels of impairment, the numerous co-occurring mental and physical conditions, the various domains of neurocognitive impairment, and extensive minor structural and functional brain differences. The diagnosis of ADHD is reliable and valid when evaluated with standard diagnostic criteria. Curative treatments for ADHD do not exist but evidence-based treatments substantially reduce symptoms and/or functional impairment. Medications are effective for core symptoms and are usually well tolerated. Some non-pharmacological treatments are valuable, especially for improving adaptive functioning. Clinical and neurobiological research is ongoing and could lead to the creation of personalized diagnostic and therapeutic approaches for this disorder.

Prevalence, comorbidities, and profiles of neurodevelopmental disorders according to the DSM-5-TR in children aged 6 years old in a European region

Background

There are no studies that measure the prevalence and real comorbidities of neurodevelopmental disorders (NDDs) according to the DSM-5-TR in 6-year-old children in population and clinical samples or studies that measure them as a whole. The data on the prevalence of these disorders are usually disparate because of the estimation methods (direct/indirect), the type of sample (population/clinical/school), and the ages studied.

Methods

The initial sample (289 subjects) was representative of 6-year-old children in the entire population of Menorca, obtained from pediatric primary care services (100% of the sample). The patients were divided into two groups based on the criterion of verification of clinical warning signs. One of the groups represented the clinical or experimental sample (EG) (81 subjects) at risk of NDDs; the other group was considered the control sample (CG) (210 subjects), and they were subjects without risk of suffering NDDs. A direct clinical assessment of the clinical sample was carried out, and they were administered the Wechsler Intelligence Scale for Children (WISC-V), the Clinical Evaluation of Language Fundamentals (CELF-5), the Battery for the evaluation of the processes of revised reading (Batería para la evaluación de los procesos de lectura revisada - PROLEC-R), the Test for the Diagnosis of Basic Mathematical Competences, (TEDI-MATH), and the Developmental Coordination Disorder Questionnaire (DCDQ).

Results

A total of 21.5% of the initial sample suffered from an NDD. A total of 2.4% presented autism spectrum disorder (ASD); 14% presented attention-deficit hyperactivity disorder (ADHD); 0.34% presented mild intellectual disability; 9.54% presented communication disorder (CD) (5.8% language disorder, 3.4% phonological disorder, and 0.34% stuttering); 10% presented learning disorder with reading difficulties; 5.8% presented learning disorder with difficulties in writing; 3.11% presented learning disorder with difficulties in mathematics; 1% presented transitory tic disorder; 0.34% presented chronic tic disorder; 1% presented Tourette syndrome; 2% presented motor coordination disorder (MCD); and 0.34% presented stereotypic movement disorders. Male children were more affected than female children in general, with male/female ORs of 0.14/0.92 for the presence of comorbidities, 0.11/0.88 for combined ADHD, 0.06/0.87 for language disorder, 1.02/1.27 for MCD, and 1.39/1.02 for inattentive ADHD.

Conclusion

In disadvantaged contexts, there was a higher prevalence of NDDs and comorbidities, unless the disorder was extreme, in which case only the NDD manifestations were presented. A significant proportion of the sample had not been previously diagnosed (88.6%); therefore, early detection programs are recommended to identify warning signs and develop policies that help and support the most disadvantaged sectors of the population.

The Prevalence of Risk Factors Among Children Diagnosed With Attention-Deficit/Hyperactivity Disorder, Aged 4-17 Years: A Cross-Sectional Study

INTRODUCTION

Attention-deficit/hyperactivity disorder (ADHD) is a neurodevelopmental disorder commonly observed in children. Although the etiology of ADHD is still unclear, many risk factors have been shown to increase the prevalence of ADHD, such as genetics, environmental factors, socioeconomic status, maternal smoking, and low birth weight.

AIM

The current cross-sectional study aimed to assess the prevalence of several risk factors associated with ADHD-diagnosed children aged 4-17 years using parent-reported data.

METHODS

An observational cross-section study was conducted between December 2022 and February 2023 using a self-constructed questionnaire that we sent to parents whose children were diagnosed with ADHD. The questionnaire included socioeconomic information (income, gender, parent education, number of children), child information (age, ADHD type, academic achievement), pregnancy and neonatal period (smoking status, gestation age, mode of delivery, child weight), and if there is a history of ADHD in the family.

RESULTS

A total of 306 parents responded to the questionnaire. The majority of our study population was males (77.8%). The combined type, which includes symptoms of both hyperactivity and inattention, represented 70% of the population in our study, which is higher than the inattention type (23%) and the hyperactivity type (6%). The prevalence of several risk factors known to be associated with ADHD, such as family income, parental education, complications during pregnancy, and the low birth weight of the child, were also reported.

CONCLUSION

To the best of our knowledge, this is the first study that examines the frequency of risk factors among children diagnosed with ADHD in Saudi Arabia. The study revealed that males are more likely to be diagnosed with ADHD than females. We also found that the combined type is the most diagnosed ADHD among children. Furthermore, there are no significant differences in the prevalence of the risk factors during the gestational or neonatal period among ADHD-diagnosed children. Therefore, a large-scale prospective study is needed to aid in evaluating the frequency and significance of various risk factors among diagnosed children.

Neonatal AVPR1a Methylation and In-Utero Exposure to Maternal Smoking

(1) Introduction: Epigenetic changes have been proposed as a biologic link between in-utero exposure to maternal smoking and health outcomes. Therefore, we examined if in-utero exposure to maternal smoking was associated with infant DNA methylation (DNAm) of cytosine-phosphate-guanine dinucleotides (CpG sites) in the arginine vasopressin receptor 1A AVPR1a gene. The AVPR1a gene encodes a receptor that interacts with the arginine vasopressin hormone and may influence physiological stress regulation, blood pressure, and child development. (2) Methods: Fifty-two infants were included in this cohort study. Multivariable linear models were used to examine the effect of in-utero exposure to maternal smoking on the mean DNAm of CpG sites located at AVPR1a. (3) Results: After adjusting the model for substance use, infants with in-utero exposure to maternal smoking had a reduction in DNAm at AVPR1a CpG sites by -0.02 (95% CI -0.03, -0.01) at one month of age. In conclusion, in-utero exposure to tobacco smoke can lead to differential patterns of DNAm of AVPR1a among infants. Conclusions: Future studies are needed to identify how gene expression in response to early environmental exposures contributes to health outcomes.

Prenatal nicotine exposure during pregnancy results in adverse neurodevelopmental alterations and neurobehavioral deficits

Maternal tobacco use and nicotine exposure during pregnancy have been associated with adverse birth outcomes in infants and can lead to preventable pregnancy complications. Exposure to nicotine and other compounds in tobacco and electronic cigarettes (e-cigarettes) has been shown to increases the risk of miscarriage, prematurity, stillbirth, low birth weight, perinatal morbidity, and sudden infant death syndrome (SIDS). Additionally, recent data provided by clinical and pre-clinical research demonstrates that nicotine exposure during pregnancy may heighten the risk for adverse neurodevelopmental disorders such as Attention-Deficit Hyperactivity (ADHD), anxiety, and depression along with altering the infants underlying brain circuitry, response to neurotransmitters, and brain volume. In the United States, one in 14 women (7.2%) reported to have smoked cigarettes during their pregnancy with the global prevalence of smoking during pregnancy estimated to be 1.7%. Approximately 1.1% of women in the United States also reported to have used e-cigarettes during the last 3 months of pregnancy. Due to the large percentage of women utilizing nicotine products during pregnancy in the United States and globally, this review seeks to centralize pre-clinical and clinical studies focused on the neurobehavioral and neurodevelopmental complications associated with prenatal nicotine exposure (PNE) such as alterations to the hypothalamic-pituitary-adrenal (HPA) axis and brain regions such as the prefrontal cortex (PFC), ventral tegmental area (VTA), nucleus accumbens (NA), hippocampus, and caudate as well as changes to nAChR and cholinergic receptor signaling, long-term drug seeking behavior following PNE, and other related developmental disorders. Current literature analyzing the association between PNE and the risk for offspring developing schizophrenia, attention-deficit hyperactivity disorder (ADHD), autism spectrum disorder (ASD), anxiety, and obesity will also be discussed.

Maternal adverse childhood experiences and behavioral problems in preschool offspring: the mediation role of parenting styles

BACKGROUND

Maternal history of adverse childhood experiences (ACEs) has been found to be associated with children's health outcomes. However, the underlying mechanisms were unclear. This study aimed to examine the association between maternal ACEs and behavioral problems in their preschool offspring and to explore the potential mediating role of maternal parenting styles in the association.

METHODS

A cross-sectional study was conducted involving 4243 mother-child dyads in Chengdu, China. Mothers completed the Adverse Childhood Experiences-International Questionnaire (ACE-IQ) to assess their history of ACEs (i.e., physical abuse, emotional abuse, physical neglect, emotional neglect, witnessing domestic violence, household substance abuse, household mental illness, incarcerated household member, parental separation or divorce, parental death, bullying, and community violence), the short Egna Minnen Beträffande Uppfostran Parent Form (S-EMBU-P) to evaluate their parenting styles (i.e., emotional warmth, rejection, and overprotection), and the 48-item Conners' Parent Rating Scale (CPRS-48) to measure behavioral problems in their children. Logistic regression models were established to examine the association between cumulative number of maternal ACEs and children's behavioral problems. The mediating role of parenting styles in this association was explored by generalized structural equation models (GSEM).

RESULTS

Of the participating mothers, 85.8% (n = 3641) reported having experienced at least one type of ACE. Children of mothers with ≥2 ACEs showed a significantly increased risk of behavioral problems across all dimensions, including conduct problems, learning problems, psychosomatic problems, impulsive-hyperactive, anxiety, and hyperactivity index, in both crude and adjusted models (all p-values < 0.05). Dose-response patterns were also observed between the cumulative number of maternal ACEs and children's behavioral problems. In addition, maternal parenting styles of rejection emerged as a significant mediator, accounting for approximately 8.4-15.0% of the associations.

CONCLUSIONS

Our findings indicated an intergenerational association of maternal ACEs with behavioral problems in preschool offspring, which was mediated by maternal parenting styles of rejection. Early screening and targeted intervention strategies are critical to mitigate the downstream consequences of maternal ACEs on young children's outcomes. Providing support and resources to improve parenting skills may prove beneficial.

Maternal cortisol in 3rd trimester is associated with traits of neurodevelopmental disorder in offspring. Odense Child Cohort

BACKGROUND

Prenatal cortisol exposure is essential for neurodevelopment. Maternal cortisol levels could be associated with offspring autism spectrum disorder (ASD) and attention deficit hyperactivity disorder (ADHD).

AIM

To investigate associations between maternal 3rd trimester cortisol and offspring traits of ASD and ADHD.

MATERIAL AND METHODS

Mother-child pairs were included from the prospective study Odense Child Cohort. Morning serum cortisol and 24-hour urine cortisol/cortisone were collected at gestational week 27-30. Offspring ASD and ADHD traits were assessed at age three and five years using the Child Behavior Checklist. Maternal cortisol measurements and offspring ASD and ADHD traits assessment were available in (n = 1131; 52% boys) mother-child pairs at age three and (n = 717; 54% boys) at five years of age. Maternal 24-hour urine measurement was available in a subset, at offspring three years of age (n = 300) and at five years of age (n = 217). Associations between maternal cortisol (continuous and tertiles) and offspring ASD or ADHD traits were examined in regression models adjusted for offspring sex, maternal age, pre-pregnancy BMI, parity, maternal education level, parental psychiatric disorders, and maternal smoking and stratified for offspring sex.

RESULTS

Maternal mean age ( ± SD) was 30 years ( ± 4.4) and median BMI (25%; 75% percentiles) 23.5 kg/m² (21.3; 26.6). Higher maternal serum cortisol levels were associated with higher prevalence of offspring ASD traits at three years of age in the total study cohort and in boys after stratifying for offspring sex. In the total population, tertiles of serum cortisol showed a significant dose-response relationship to ASD traits in unadjusted and adjusted models (p-values for linear trend, p < 0.01 and p = 0.02, respectively). In offspring at five years, associations between maternal cortisol and offspring ASD traits were non-significant (all p-values > 0.2). Maternal cortisol was not associated with offspring ADHD traits (all p-values > 0.07) in offspring at three and five years. Maternal 24-hour urine cortisol, cortisone, or cortisol/cortisone ratio were not associated with offspring ASD or ADHD traits.

CONCLUSION

Higher maternal serum cortisol in 3rd trimester was associated with offspring ASD traits at three years of age in the whole study cohort and in boys, but not in girls. This association was non-significant at five years of age.

Maternal e-cigarette use can disrupt postnatal blood-brain barrier (BBB) integrity and deteriorates motor, learning and memory function: influence of sex and age

Electronic nicotine delivery systems (ENDS), also commonly known as electronic cigarettes (e-cigs) are considered in most cases as a safer alternative to tobacco smoking and therefore have become extremely popular among all age groups and sex. It is estimated that up to 15% of pregnant women are now using e-cigs in the US which keeps increasing at an alarming rate. Harmful effects of tobacco smoking during pregnancy are well documented for both pregnancy and postnatal health, however limited preclinical and clinical studies exist to evaluate the long-term effects of prenatal e-cig exposure on postnatal health. Therefore, the aim of our study is to evaluate the effect of maternal e-cig use on postnatal blood-brain barrier (BBB) integrity and behavioral outcomes of mice of varying age and sex. In this study, pregnant CD1 mice (E5) were exposed to e-Cig vapor (2.4% nicotine) until postnatal day (PD) 7. Weight of the offspring was measured at PD0, PD7, PD15, PD30, PD45, PD60 and PD90. The expression of structural elements of the BBB, tight junction proteins (ZO-1, claudin-5, occludin), astrocytes (GFAP), pericytes (PDGFRβ) and the basement membrane (laminin α1, laminin α4), neuron specific marker (NeuN), water channel protein (AQP4) and glucose transporter (GLUT1) were analyzed in both male and female offspring using western blot and immunofluorescence. Estrous cycle was recorded by vaginal cytology method. Long-term motor and cognitive functions were evaluated using open field test (OFT), novel object recognition test (NORT) and morris water maze test (MWMT) at adolescence (PD 40-45) and adult (PD 90-95) age. In our study, significantly reduced expression of tight junction proteins and astrocyte marker were observed in male and female offspring until PD 90 (P < 0.05). Additionally, prenatally e-cig exposed adolescent and adult offspring showed impaired locomotor, learning, and memory function compared to control offspring (P < 0.05). Our findings suggest that prenatal e-cig exposure induces long-term neurovascular changes of neonates by disrupting postnatal BBB integrity and worsening behavioral outcomes.

Maternal age at childbirth and the risk of attention-deficit/hyperactivity disorder and learning disability in offspring

Background

Studies have shown that young maternal age at childbirth can increase the risk of attention-deficit/hyperactivity disorder (ADHD) in offspring, but a study of the U.S. population has not been reported. Moreover, there is no reported research on young and advanced maternal age at childbirth and whether it can contribute to the risk of learning disability (LD) in offspring.

Methods

This study evaluated the association between young and advanced maternal age at childbirth and offspring risk of ADHD and LD in the U.S. population. Using data from 8,098 participants included in the National Health and Nutrition Examination Survey (NHANES) conducted in 1999-2004, we analyzed the association between maternal age at childbirth and ADHD and LD risk in offspring. Odds ratios (ORs) and 95% confidence intervals (CIs) for maternal age at childbirth in association with ADHD and LD risk in offspring were estimated using multivariate logistic regression models after adjustment for age, sex, race, body mass index (BMI), poverty income ratio, smoking status during pregnancy, and NHANES cycle. Restricted cubic spline (RCS) models were used to evaluate potential non-linear relationships. Sensitivity analyses were performed to ensure the reliability of the results.

Results

Among all participants, the offspring of subjects with a maternal age at childbirth of 18-24 years had an increased risk of ADHD (OR = 1.34, 95% CI: 1.01, 1.79) and LD (OR = 1.36, 95% CI: 1.06, 1.79) or either ADHD or LD (OR = 1.48, 95% CI: 1.20, 1.81). Additionally, compared with subjects with a maternal age at childbirth of 25-29 years, subjects with a maternal age at childbirth of 35-39 years had lower odds of having offspring with ADHD (OR = 0.60, 95% CI: 0.36, 1.00) and higher odds of having offspring with LD (OR = 1.34, 95% CI: 1.01, 1.78). The relationship between maternal age at childbirth and LD risk presented a U-shaped curve.

Conclusions

These results provide epidemiological evidence showing that young and advanced maternal age at childbirth are associated with ADHD and LD risk.

Maternal age at birth and child attention-deficit hyperactivity disorder: causal association or familial confounding?

BACKGROUND

Causal explanations for the association of young motherhood with increased risk for child attention-deficit hyperactivity disorder (ADHD) remain unclear.

METHODS

The ABCD Study recruited 11,878 youth from 22 sites across the United States between June 1, 2016 and October 15, 2018. This cross-sectional analysis of 8,514 children aged 8-11 years excluded 2,260 twins/triplets, 265 adopted children, and 839 younger siblings. We examined associations of maternal age with ADHD clinical range diagnoses based on the Child Behavior Checklist and NIH Toolbox Flanker Attention Scores using mixed logistic and linear regression models, respectively. We conducted confounding and causal mediation analyses using genotype array, demographic, socioeconomic, and prenatal environment data to investigate which genetic and environmental variables may explain the association between young maternal age and child ADHD.

RESULTS

In crude models, each 10-year increase in maternal age was associated with 32% decreased odds of ADHD clinical range diagnosis (OR = 0.68; 95% CI [0.59, 0.78]) and 1.09-points increased NIH Flanker Attention Scores (β = 1.09; 95% CI [0.76, 1.41]), indicating better child visual selective attention. However, adjustment for confounders weakened these associations. The strongest confounders were family income, caregiver education, and ADHD polygenic risk score for ADHD clinical range diagnoses, and family income, caregiver education, and race/ethnicity for NIH Flanker Attention Scores. Breastfeeding duration, prenatal alcohol exposure, and prenatal tobacco exposure were responsible for up to 18%, 6%, and 4% mediation, respectively.

CONCLUSIONS

Socioeconomic disadvantages were likely the primary explanation for the association of young maternal age with child ADHD, although genetics and modifiable environmental factors also played a role. Public policies aimed at reducing the burden of ADHD associated with young motherhood should target socioeconomic inequalities and support young pregnant women by advocating for reduced prenatal tobacco exposure and healthy breastfeeding practices after childbirth.

An approach for prevention planning based on the prevalence and comorbidity of neurodevelopmental disorders in 6-year-old children receiving primary care consultations on the island of Menorca

BACKGROUND

Few studies have estimated the real prevalence of neurodevelopmental disorders according to the Diagnostic and Statistical Manual of Mental Disorders, 5th Edition (DSM-5) in Spain and worldwide. However, there are disparate prevalence figures. We consider research in this field essential to improve early detection, secondary prevention, and health planning.

METHODS

The Minikid ADHD and TICS-Mini International Neuropsychiatric Interview for Children and Adolescents, the Autism Spectrum Quotient (Children's version, AQ- Child) and a protocol of general medical questions were administered for screening purposes. The PROLEXIA battery for children aged from 4 to 6 years was used for direct assessments. Parents provided information on emotional, medical, and school aspects. The final population evaluated using these tools consisted of 291 6-year-old subjects.

RESULTS

The overall risk of presenting with a neurodevelopmental disorder was 55.4%. A 23.4% risk of presenting with attention-deficit/hyperactivity disorder (ADHD) in any modality (inattentive, hyperactive-impulsive and combined), a 2.8% risk of developing autism spectrum disorder (ASD), a 30.6% risk of presenting with a learning disorder with reading difficulties, a 5.5% risk of tics and a 22.5% risk of language problems (incomprehensible language or minor language problems) were detected in the sample. The most common combination of disorders was learning and language difficulties, accounting for 6.9% of the sample. The second most frequent combination was the presence of learning and language difficulties and ADHD, accounting for 4.5% of the sample.

CONCLUSIONS

The prevalence of risks detected in our sample seems to be consistent with national and international studies. A significant proportion of our sample had never been previously diagnosed (85%), so early detection programs are recommended.

An overview on neurobiology and therapeutics of attention-deficit/hyperactivity disorder

Attention-Deficit/Hyperactivity Disorder (ADHD) is a prevalent psychiatric condition characterized by developmentally inappropriate symptoms of inattention and/or hyperactivity/impulsivity, which leads to impairments in the social, academic, and professional contexts. ADHD diagnosis relies solely on clinical assessment based on symptom evaluation and is sometimes challenging due to the substantial heterogeneity of the disorder in terms of clinical and pathophysiological aspects. Despite the difficulties imposed by the high complexity of ADHD etiology, the growing body of research and technological advances provide good perspectives for understanding the neurobiology of the disorder. Such knowledge is essential to refining diagnosis and identifying new therapeutic options to optimize treatment outcomes and associated impairments, leading to improvements in all domains of patient care. This review is intended to be an updated outline that addresses the etiological and neurobiological aspects of ADHD and its treatment, considering the impact of the "omics" era on disentangling the multifactorial architecture of ADHD.

The role of psychosocial adversity in the aetiology and course of attention deficit hyperactivity disorder

INTRODUCTION

Attention deficit/hyperactivity disorder (ADHD) has genetic and environmental aetiological factors. There are few publications on the environmental factors. The objective of this review is to present the role of psychosocial adversity in the aetiology and course of ADHD.

METHODS

A search was carried out in the following databases: PubMed, ScienceDirect, SciELO, ClinicalKey, EMBASE, Lilacs, OVID, APA and PsycNET. English and Spanish were selected without being limited by type of study or year of publication. Finally, a qualitative synthesis was conducted.

RESULTS

ADHD development could be related to exposure to adverse factors in the family, school or social environment. It has been proposed as an explanatory mechanism that adversity interacts with genetic variants and leads to neurobiological changes. There may also be a gene-environment correlation whereby individual hereditary characteristics increase the risk of exposure to adversity, and indirectly increase the probability of developing ADHD. Research on psychosocial adversity represents a big challenge, not only due to the complexity of its construct, but also to the effect of subjective perception of a given event.

CONCLUSIONS

ADHD aetiology is complex and involves the interaction of both genetic and environmental factors, in which these factors correlate and cause the disorder. The study of the role of psychosocial adversity in ADHD is fundamental, but it remains a task that entails great difficulties.

Familial Factors Associated With Symptom Severity in Children and Adolescents With ADHD: A Meta-Analysis and Supplemental Review

OBJECTIVE

Both genetic and environmental factors contribute to the development of ADHD, but associations between risk factors and ADHD symptom severity in affected children remain unclear. This systematic review and meta-analysis synthesizes evidence on the association between familial factors and symptom severity in children with ADHD (PROSPERO CRD42020076440).

METHOD

PubMed and PsycINFO were searched for eligible studies.

RESULTS

Forty-three studies (N = 11,123 participants) were meta-analyzed. Five additional studies (N = 2,643 participants) were considered in the supplemental review. Parenting stress (r = .25), negative parenting practices (r = .19), broken parental partnership (r = .19), critical life events (r = .17), parental psychopathologies (r = .14-.16), socioeconomic status (r = -.10), and single-parent family (r = .10) were significantly associated with ADHD symptom severity.

CONCLUSION

These results suggest that psychosocial familial factors show small but significant associations with symptom severity in children with ADHD. Implications are discussed.

Identification of the Obstetric Factors Increasing Tendency to Smoking Cessation During Pregnancy

INTRODUCTION

Cigarette, one of the various forms of tobacco, is the most commonly used tobacco product in Turkey and in the world. Cigarette has several negative effects on general health and is a major problem in the pregnancy period. This study aims to identify pregnancy-related factors that affect the tendency to smoking cessation and their effect levels in pregnant women who continue to smoke during pregnancy.

METHOD

The sample of this descriptive and cross-sectional study was 430 pregnant women who smoked. Data were collected through an original interview form and face-to-face interviews. Data analysis was performed using chi-square, independent t test, and multiple logistic regression model in terms of demographic, obstetric, maternal, and fetal features.

RESULTS

The average number of cigarettes smoked before pregnancy was 13.28 ± 8.62, whereas the average number of cigarettes smoked during pregnancy was 6.60 ± 7.64. The tendency to decrease smoking increases 2.8 times ( OR = 2.825, 95% CI [1.631, 4.895]) with the number of pregnancies and approximately 2 times in case of a planned pregnancy ( OR = 1.946, 95% CI [1.076, 3.520]). The frequency of having prenatal visits showed a weak but significant relationship with the number of abortuses and the number of living children.

CONCLUSIONS

Developing a risk map in line with the findings of the study and considering the obstetric features of smoking women could enable to hypothesize about the types of behaviors in smoking in the following processes of pregnancy. With the precautions to be taken, the negative effects of smoking on maternal and fetal health could be prevented or minimized.

Impact of Prenatal Nicotine Exposure on Placental Function and Respiratory Neural Network Development

Smoking during pregnancy is associated with multiple undesirable outcomes in infants, such as low birth weight, increased neonatal morbidity and mortality, and catastrophic conditions like sudden infant death syndrome (SIDS). Nicotine, the most addictive and teratogenic substance in tobacco smoke, reaches and crosses the placenta and can be accumulated in the amniotic fluid and distributed by fetal circulation, altering the cholinergic transmission by acting on the nicotinic acetylcholine receptors (nAChRs) expressed from very early gestational stages in the placenta and fetal tissue. Because nAChRs influence the establishment of feto-maternal circulation and the emergence of neuronal networks, prenatal nicotine exposure can lead to multiple alterations in newborns. In this mini-review, we discuss the undeniable effects of nicotine in the placenta and the respiratory neural network as examples of how prenatal nicotine and smoking exposition can affect brain development because dysfunction in this network is involved in SIDS etiology.

A Potential Role for Neuroinflammation in ADHD

Attention deficit hyperactivity disorder (ADHD) is a neurobehavioural disorder in children and adolescents. Although increases in oxidative stress and disturbances of neurotransmitter system such as the dopaminergic and abnormalities in several brain regions have been demonstrated, the pathophysiology of ADHD is not fully understood. Nevertheless, ADHD involves several factors that have been associated with an increase in neuroinflammation. This chapter presents an overview of factors that may increase neuroinflammation and play a potential role in the development and pathophysiology of ADHD. The altered immune response, polymorphisms in inflammatory-related genes, ADHD comorbidity with autoimmune and inflammatory disorders and prenatal exposure to inflammation are associated with alterations in offspring brain development and are a risk factor; genetic and environmental risk factors that may increase the risk for ADHD and medications can increase neuroinflammation. Evidence of an association between these factors has been an invaluable tool for research on inflammation in ADHD. Therefore, evidence studies have made it possible to generate alternative therapeutic interventions using natural products as anti-inflammatories that could have great potential against neuroinflammation in ADHD.

Association of maternal polygenic risk scores for mental illness with perinatal risk factors for offspring mental illness

We examined whether genetic risk for mental illness is associated with known perinatal risk factors for offspring mental illness to determine whether gene-environmental correlation might account for the associations of perinatal factors with mental illness. Among 8983 women with 19,733 pregnancies, we found that genetic risk for mental illness was associated with any smoking during pregnancy [attention-deficit hyperactivity disorder (ADHD) and overall genetic risk], breast-feeding for less than 1 month (ADHD, depression, and overall genetic risk), experience of intimate partner violence in the year before the birth (depression and overall genetic risk), and pregestational overweight or obesity (bipolar disorder). These results indicate that genetic risk may partly account for the association between perinatal conditions and mental illness in offspring.

Maternal iron status during pregnancy and attention deficit/hyperactivity disorder symptoms in 7-year-old children: a prospective cohort study

Evidence suggests that iron status may be linked to symptoms of childhood attention deficit/hyperactivity disorder (ADHD), but there is little data available on the relationship between iron status in pregnancy and the risk of developing ADHD. And the data that does exist is inconsistent. Our aim here is to assess the effect of maternal serum ferritin (SF) and haemoglobin (Hb) levels during pregnancy on manifestations of ADHD in children at 7 years of age. This prospective study analysed data from 1204 mother-child pairs from three Spanish cohorts participating in the INMA project. Maternal SF and Hb levels during pregnancy and other mother and child characteristics were collected. The children's ADHD behaviours were reported by their parents using Conners' Parent Rating Scale-Revised Short Form (CPRS-R:S). In the unadjusted regression analysis, maternal SF was positively associated with children's T-scores on the subscales Cognitive problems/Inattention (β: 0.63, 95%CI 0.06-1.19; p = 0.029) and ADHD index (β: 0.72, 95%CI 0.20-1.24; p = 0.007). These associations were not present after multivariate adjustment or stratification by first and second trimester of pregnancy. The Hb levels were not related to any of the CPRS-R:S subscales in unadjusted or multivariate-adjusted models. We observed no association between maternal SF or Hb levels and the risk of ADHD symptomatology (T-score ≥ 65 for CPRS-R:S subscales). Our results suggest that neither maternal SF nor Hb levels during pregnancy are related to ADHD symptoms in 7-year-old children.

PM2.5 exposure and incident attention-deficit/hyperactivity disorder during the prenatal and postnatal periods: A birth cohort study

Only a few studies have assessed the effects of fine particulate matter (PM_2.5) exposure during the prenatal and postnatal periods on the development of attention-deficit/hyperactivity disorder (ADHD). We investigated the association of exposure to PM_2.5 during pregnancy and early life with ADHD. This birth cohort consisted of 425,736 singleton live-term births between 2004 and 2015 in Taiwan. Daily PM_2.5 concentrations were derived from a 1-km satellite-based estimation model. A time-dependent Cox model was used to assess the effects of PM_2.5 on ADHD during the first, second, and third trimesters and from age 1-5 years after birth. The distributed lag nonlinear model was utilized to explore the dose-response relationship. Total 9,294 children were diagnosed with ADHD during the study period. The hazard ratio (HR) of ADHD was significantly associated with a 10 μg/m³ increase in PM_2.5 during the first trimester (HR = 1.26; 95% confidence interval [CI]: 1.13-1.40) and increased at PM_2.5 over 16 μg/m³. For postnatal periods, the HR of ADHD was significantly associated with increased PM_2.5 at the first to third year of life (HR ranged between 1.40 and 1.87). According to the dose-response relationship of exposure to PM_2.5 at the third year of life, the HR of ADHD was significantly associated with PM_2.5 above 16 μg/m³ and sharply increased as PM_2.5 >50 μg/m³. We did not observe a significant modification of sex on the relation between PM_2.5 and ADHD. Exposure of pregnant women to PM_2.5 above 16 μg/m³ from conception to the early life of their children may increase the risk of ADHD. The government should improve the criteria for air quality control and meet the WHO air quality guidelines to protect pregnant women and children from developing ADHD in the future.

Prenatal smoking, alcohol and caffeine exposure and offspring externalizing disorders: a systematic review and meta-analysis

BACKGROUND AND AIMS

Several studies have indicated an association between maternal prenatal substance use and offspring externalizing disorders; however, it is uncertain whether this relationship is causal. We conducted a systematic review to determine: (1) if the literature supports a causal role of maternal prenatal substance use on offspring externalizing disorders diagnosis and (2) whether these associations differ across externalizing disorders.

METHODS

We searched Web of Science, Embase, PsycINFO and Medline databases. Risk of bias assessment was conducted using the Newcastle-Ottawa Scale (NOS), and where possible meta-analysis was conducted for studies classed as low risk of bias. We included studies of any design that examined prenatal smoking, alcohol or caffeine use. Studies in non-English language, fetal alcohol syndrome and comorbid autism spectrum disorders were excluded. Participants in the included studies were mothers and their offspring. Measurements included prenatal smoking, alcohol or caffeine use as an exposure, and diagnosis of attention-deficit hyperactivity disorder (ADHD), conduct disorder (CD) and oppositional defiant disorder (ODD) in offspring as an outcome.

RESULTS

We included 63 studies, 46 of which investigated smoking and ADHD. All studies were narratively synthesized, and seven studies on smoking and ADHD were meta-analysed. The largest meta-analysis based on genetically sensitive design included 1 011 546 participants and did not find evidence for an association [odds ratio (OR)_{1-9 cigarettes}  = 0.90, 95% confidence interval (CI) = 0.83-1.11; OR _{> 10 cigarettes}  = 1.04, 95% CI = 0.79-1.36). Studies on alcohol exposure in all the outcomes reported inconsistent findings and no strong conclusions on causality can be made. Studies on caffeine exposure were mainly limited to ADHD and these studies do not support a causal effect.

CONCLUSIONS

There appears to be no clear evidence to support a causal relationship between maternal prenatal smoking and offspring attention-deficit hyperactivity disorder. Findings with alcohol and caffeine exposures and conduct disorder and oppositional-defiant disorder need more research, using more genetically sensitive designs.

DNA methylation as a potential mediator of the association between prenatal tobacco and alcohol exposure and child neurodevelopment in a South African birth cohort

Prenatal tobacco exposure (PTE) and prenatal alcohol exposure (PAE) have been associated with an increased risk of delayed neurodevelopment in children as well as differential newborn DNA methylation (DNAm). However, the biological mechanisms connecting PTE and PAE, DNAm, and neurodevelopment are largely unknown. Here we aim to determine whether differential DNAm mediates the association between PTE and PAE and neurodevelopment at 6 (N = 112) and 24 months (N = 184) in children from the South African Drakenstein Child Health Study. PTE and PAE were assessed antenatally using urine cotinine measurements and the ASSIST questionnaire, respectively. Cord blood DNAm was measured using the EPIC and 450 K BeadChips. Neurodevelopment (cognitive, language, motor, adaptive behavior, socioemotional) was measured using the Bayley Scales of Infant and Toddler Development, Third Edition. We constructed methylation risk scores (MRS) for PTE and PAE and conducted causal mediation analysis (CMA) with these MRS as mediators. Next, we conducted a high-dimensional mediation analysis to identify individual CpG sites as potential mediators, followed by a CMA to estimate the average causal mediation effects (ACME) and total effect (TE). PTE and PAE were associated with neurodevelopment at 6 but not at 24 months. PTE MRS reached a prediction accuracy (R2) of 0.23 but did not significantly mediate the association between PTE and neurodevelopment. PAE MRS was not predictive of PAE (R2 = 0.006). For PTE, 31 CpG sites and eight CpG sites were identified as significant mediators (ACME and TE P < 0.05) for the cognitive and motor domains at 6 months, respectively. For PAE, 16 CpG sites and 1 CpG site were significant mediators for the motor and adaptive behavior domains at 6 months, respectively. Several of the associated genes, including MAD1L1, CAMTA1, and ALDH1A2 have been implicated in neurodevelopmental delay, suggesting that differential DNAm may partly explain the biological mechanisms underlying the relationship between PTE and PAE and child neurodevelopment.

Embryonic exposure to benzo[a]pyrene causes age-dependent behavioral alterations and long-term metabolic dysfunction in zebrafish

Polycyclic aromatic hydrocarbons (PAH) are products of incomplete combustion which are ubiquitous pollutants and constituents of harmful mixtures such as tobacco smoke, petroleum and creosote. Animal studies have shown that these compounds exert developmental toxicity in multiple organ systems, including the nervous system. The relative persistence of or recovery from these effects across the lifespan remain poorly characterized. These studies tested for persistence of neurobehavioral effects in AB* zebrafish exposed 5-120 h post-fertilization to a typical PAH, benzo[a]pyrene (BAP). Study 1 evaluated the neurobehavioral effects of a wide concentration range of BAP (0.02-10 μM) exposures from 5 to 120 hpf during larval (6 days) and adult (6 months) stages of development, while study 2 evaluated neurobehavioral effects of BAP (0.3-3 μM) from 5 to 120 hpf across four stages of development: larval (6 days), adolescence (2.5 months), adulthood (8 months) and late adulthood (14 months). Embryonic BAP exposure caused minimal effects on larval motility, but did cause neurobehavioral changes at later points in life. Embryonic BAP exposure led to nonmonotonic effects on adolescent activity (0.3 μM hyperactive, Study 2), which attenuated with age, as well as startle responses (0.2 μM enhanced, Study 1) at 6 months of age. Similar startle changes were also detected in Study 2 (1.0 μM), though it was observed that the phenotype shifted from reduced pretap activity to enhanced posttap activity from 8 to 14 months of age. Changes in the avoidance (0.02-10 μM, Study 1) and approach (reduced, 0.3 μM, Study 2) of aversive/social cues were also detected, with the latter attenuating from 8 to 14 months of age. Fish from study 2 were maintained into aging (18 months) and evaluated for overall and tissue-specific oxygen consumption to determine whether metabolic processes in the brain and other target organs show altered function in late life based on embryonic PAH toxicity. BAP reduced whole animal oxygen consumption, and overall reductions in total basal, mitochondrial basal, and mitochondrial maximum respiration in target organs, including the brain, liver and heart. The present data show that embryonic BAP exposure can lead to neurobehavioral impairment across the life-span, but that these long-term risks differentially emerge or attenuate as development progresses.

Association of Maternal Tobacco Use During Pregnancy With Preadolescent Brain Morphology Among Offspring

IMPORTANCE

Maternal tobacco use during pregnancy has been associated with various health consequences, including suboptimal neurodevelopment in offspring. However, the effect of prenatal exposure to maternal smoking on child brain development has yet to be elucidated.

OBJECTIVE

To investigate the association between maternal smoking during pregnancy and offspring brain development in preadolescence as well as the mediating pathways.

DESIGN, SETTING, AND PARTICIPANTS

This prospective, population-based cohort study was embedded in the Generation R Study, Rotterdam, the Netherlands. The Generation R Study was launched in 2002, with follow-up ongoing. Child brain morphology was assessed at 9 to 11 years of age (ie, 10-12 years between exposure and outcome assessment). Data analysis was performed from March 1, 2021, to February 28, 2022, and at the time of manuscript revision. Participants included the singleton children of pregnant women residing in the study area with an expected date of delivery between April 1, 2002, and January 31, 2006; 2704 children with information on maternal smoking during pregnancy and structural neuroimaging at 9 to 11 years of age were included. A subsample of 784 children with data on DNA methylation at birth was examined in the mediation analysis.

EXPOSURES

Information on maternal smoking during pregnancy was collected via a questionnaire in each trimester. As a contrast, paternal smoking was assessed at recruitment.

MAIN OUTCOMES AND MEASURES

Brain morphology, including brain volumes and surface-based cortical measures (thickness, surface area, and gyrification), was assessed with magnetic resonance imaging. For mediation analysis, DNA methylation at birth was quantified by a weighted methylation risk score.

RESULTS

The 2704 participating children (1370 [50.7%] girls and 1334 [49.3%] boys) underwent brain imaging assessment at a mean (SD) age of 10.1 (0.6) years. Compared with nonexposed children (n = 2102), exposure to continued maternal smoking during pregnancy (n = 364) was associated with smaller total brain volume (volumetric difference [b] = -14.5 [95% CI, -25.1 to -4.0] cm3), cerebral gray matter volume (b = -7.8 [95% CI, -13.4 to -2.3] cm3), cerebral white matter volume (b = -5.9 [95% CI, -10.7 to -1.0] cm3), and surface area and less gyrification. These associations were not explained by paternal smoking nor mediated by smoking-associated DNA methylation patterns at birth. Children exposed to maternal smoking only in the first trimester (n = 238) showed no differences in brain morphology compared with nonexposed children.

CONCLUSIONS AND RELEVANCE

The findings of this cohort study suggest that continued maternal tobacco use during pregnancy was associated with lower brain volumes and suboptimal cortical traits of offspring in preadolescence, which seemed to be independent of shared family factors. Tobacco cessation before pregnancy, or as soon as pregnancy is known, should be recommended to women for optimal brain development of their offspring.

Maternal smoking during pregnancy and offspring intellectual disability: sibling analysis in an intergenerational Danish cohort

BACKGROUND

Maternal smoking has known adverse effects on fetal development. However, research on the association between maternal smoking during pregnancy and offspring intellectual disability (ID) is limited, and whether any associations are due to a causal effect or residual confounding is unknown.

METHOD

Cohort study of all Danish births between 1995 and 2012 (1 066 989 persons from 658 335 families after exclusions), with prospectively recorded data for cohort members, parents and siblings. We assessed the association between maternal smoking during pregnancy (18.6% exposed, collected during prenatal visits) and offspring ID (8051 cases, measured using ICD-10 diagnosis codes F70-F79) using logistic generalised estimating equation regression models. Models were adjusted for confounders including measures of socio-economic status and parental psychiatric diagnoses and were adjusted for family averaged exposure between full siblings. Adjustment for a family averaged exposure allows calculation of the within-family effect of smoking on child outcomes which is robust against confounders that are shared between siblings.

RESULTS

We found increased odds of ID among those exposed to maternal smoking in pregnancy after confounder adjustment (OR 1.35, 95% CI 1.28-1.42) which attenuated to a null effect following adjustment for family averaged exposure (OR 0.91, 95% CI 0.78-1.06).

CONCLUSIONS

Our findings are inconsistent with a causal effect of maternal smoking during pregnancy on offspring ID risk. By estimating a within-family effect, our results suggest that prior associations were the result of unmeasured genetic or environmental characteristics of families in which the mother smokes during pregnancy.

Tobacco use during pregnancy

The use of tobacco during pregnancy is the leading preventable cause of pregnancy complications and adverse birth outcomes. In high-income countries, around one in 10 pregnant women smokes tobacco, while smokeless tobacco is the primary form of tobacco used in many low- and middle-income countries. Although the risk of tobacco-related harms can be reduced substantially if mothers cease smoking in the first trimester of pregnancy, the proportion of women who successfully quit smoking during pregnancy remains modest. Psychosocial interventions are first-line treatment, with some high-quality evidence showing that counselling is effective in promoting smoking cessation among pregnant women. There is insufficient evidence regarding the efficacy and safety of smoking cessation pharmacotherapies when used during pregnancy, although in some countries nicotine replacement therapy is recommended for pregnant women who have been unable to quit without pharmacological assistance. E-cigarettes are increasingly being used as a smoking cessation aid in the general population of smokers, but more research is needed to determine if e-cigarettes are a safe and effective treatment option for pregnant women.

Prenatal risk factors and genetic causes of ADHD in children

BACKGROUND

Attention deficit/hyperactivity disorder (ADHD) is a common disease among children; it affected 5-7% of the population in 2015. ADHD is a multifactorial disease, and its etiology is still not clearly understood.

DATA SOURCES

This narrative review has been done by searching the PubMed and Embase databases using attention deficit/hyperactivity disorder, ADHD, risk factors; genetics; pediatrics; psychiatrics as keywords.

RESULTS

ADHD is considered to be a hereditary disorder in which genes play the fundamental role in the pathogenesis; however, findings from genetic-environmental studies support the hypothesis that genetic factors can exert effects on an individual's condition by determining his/her responses to environmental exposures, especially those during the prenatal stage.

CONCLUSION

ADHD is considered as a hereditary disorder in which genes and prenatal risk factors play fundamental roles in the pathogenesis.

Impact of prenatal tobacco smoking on infant telomere length trajectory and ADHD symptoms at 18 months: a longitudinal cohort study

BACKGROUND

Prenatal maternal tobacco smoking is a predictor of child attention-deficit/hyperactivity disorder (ADHD) and is associated with offspring telomere length (TL). In this study, we examine the relationship between maternal prenatal smoking, infant TL, and maternal report of early childhood symptoms of ADHD.

METHODS

One-hundred and eighty-one mother-infant dyads were followed prospectively for the infant's first 18 months of life. Prenatal smoking was assessed from maternal report and medical records. TL was measured from infant buccal swab DNA obtained across the first 18 months of life. ADHD symptoms were obtained from maternal report on the Child Behavior Check List. Multiple regression models tested the relation between prenatal smoking and both ADHD symptoms and infant TL. Additional analyses tested whether the change in infant TL influenced the relation between prenatal smoking and ADHD symptoms.

RESULTS

Sixteen percent of mothers reported prenatal smoking. Infant TL at 4, 12, and 18 months of age were correlated. Consistent with previous cross-sectional studies linking shorter offspring TL to maternal prenatal smoking, maternal prenatal smoking predicted greater telomere shortening from four to 18 months of infant age (β = - 5.797, 95% CI [-10.207, -1.386]; p = 0.010). Maternal depression was positively associated with both prenatal smoking (odds ratio (OR): 4.614, 95% CI [1.733, 12.282]; p = 0.002) and child ADHD symptoms (β = 4.713, 95% CI [2.073, 7.354]; p = 0.0006). To prevent confounding, analyses examined the relation between TL, ADHD symptoms, and prenatal smoking only in non-depressed mothers. In non-depressed mothers, infant TL attrition across the first 18 months moderated the relation between smoking and child ADHD.

CONCLUSIONS

The findings extend previous studies linking prenatal smoking to shorter infant TL by providing data demonstrating the effect on TL trajectory. The relation between prenatal smoking and early infant ADHD symptoms was moderated by the change in TL. The findings provide novel initial evidence suggesting that TL dynamics are one mechanistic pathway influencing the relation between maternal prenatal smoking and ADHD.

MEF2C gene variations are associated with ADHD in the Chinese Han population: a case-control study

Myocyte enhancer factor 2C (MEF2C) is associated with hyperactivity and might be a novel risk gene for susceptibility to attention deficit hyperactivity disorder (ADHD). Therefore, this study aimed to explore the association between MEF2C genetic variants and ADHD in the Chinese Han population. A total of 215 patients with ADHD and 233 controls were recruited for this study. The Swanson, Nolan, and Pelham version IV questionnaire was used to evaluate the clinical features of ADHD. In silico analysis was used to annotate the biological functions of the promising single nucleotide polymorphisms. Our findings indicated that MEF2C rs587490 was significantly associated with ADHD in the multiplicative model (OR = 0.640, p = 0.002). Participants with the rs587490 TT allele exhibited less hyperactivity/impulsivity than those with the rs587490 CC allele. Furthermore, the expression quantitative trait loci analysis suggested that rs587490 could regulate the gene expression of MEF2C in the hippocampus, putamen, thalamus, and frontal white matter. Our study concluded that the MEF2C rs587490 T allele is significantly associated with a reduced risk of ADHD in the Chinese Han population, which provides new insight into the genetic etiology of ADHD.

The Association between ADHD and Environmental Chemicals-A Scoping Review

The role of environmental chemicals in the etiology of attention deficit hyperactivity disorder (ADHD) has been of interest in recent research. This scoping review aims to summarize known or possible associations between ADHD and environmental exposures to substances selected as priority chemicals of the European Human Biomonitoring Initiative (HBM4EU). Literature searches were performed in PubMed to identify relevant publications. Only meta-analyses and review articles were included, as they provide more extensive evidence compared to individual studies. The collected evidence indicated that lead (Pb), phthalates and bisphenol A (BPA) are moderately to highly associated with ADHD. Limited evidence exists for an association between ADHD and polycyclic aromatic hydrocarbons (PAHs), flame retardants, mercury (Hg), and pesticides. The evidence of association between ADHD and cadmium (Cd) and per- and polyfluoroalkyl substances (PFASs) based on the identified reviews was low but justified further research. The methods of the individual studies included in the reviews and meta-analyses covered in the current paper varied considerably. Making precise conclusions in terms of the strength of evidence on association between certain chemicals and ADHD was not straightforward. More research is needed for stronger evidence of associations or the lack of an association between specific chemical exposures and ADHD.

Maternal tobacco smoking and offspring autism spectrum disorder or traits in ECHO cohorts

Given inconsistent evidence on preconception or prenatal tobacco use and offspring autism spectrum disorder (ASD), this study assessed associations of maternal smoking with ASD and ASD-related traits. Among 72 cohorts in the Environmental Influences on Child Health Outcomes consortium, 11 had ASD diagnosis and prenatal tobaccosmoking (n = 8648). and 7 had Social Responsiveness Scale (SRS) scores of ASD traits (n = 2399). Cohorts had diagnoses alone (6), traits alone (2), or both (5). Diagnoses drew from parent/caregiver report, review of records, or standardized instruments. Regression models estimated smoking-related odds ratios (ORs) for diagnoses and standardized mean differences for SRS scores. Cohort-specific ORs were meta-analyzed. Overall, maternal smoking was unassociated with child ASD (adjusted OR, 1.08; 95% confidence interval [CI], 0.72-1.61). However, heterogeneity across studies was strong: preterm cohorts showed reduced ASD risk for exposed children. After excluding preterm cohorts (biased by restrictions on causal intermediate and exposure opportunity) and small cohorts (very few ASD cases in either smoking category), the adjusted OR for ASD from maternal smoking was 1.44 (95% CI, 1.02-2.03). Children of smoking (versus non-smoking) mothers had more ASD traits (SRS T-score + 2.37 points, 95% CI, 0.73-4.01 points), with results homogeneous across cohorts. Maternal preconception/prenatal smoking was consistently associated with quantitative ASD traits and modestly associated with ASD diagnosis among sufficiently powered United States cohorts of non-preterm children. Limitations resulting from self-reported smoking and unmeasured confounders preclude definitive conclusions. Nevertheless, counseling on potential and known risks to the child from maternal smoking is warranted for pregnant women and pregnancy planners. LAY SUMMARY: Evidence on the association between maternal prenatal smoking and the child's risk for autism spectrum disorder has been conflicting, with some studies reporting harmful effects, and others finding reduced risks. Our analysis of children in the ECHO consortium found that maternal prenatal tobacco smoking is consistently associated with an increase in autism-related symptoms in the general population and modestly associated with elevated risk for a diagnosis of autism spectrum disorder when looking at a combined analysis from multiple studies that each included both pre- and full-term births. However, this study is not proof of a causal connection. Future studies to clarify the role of smoking in autism-like behaviors or autism diagnoses should collect more reliable data on smoking and measure other exposures or lifestyle factors that might have confounded our results.

Perinatal and birth correlates of childhood irritability in Taiwan's national epidemiological study

BACKGROUND

Childhood irritability, characterized by low frustration tolerance and developmentally-inappropriate temper outbursts, is a transdiagnostic symptom in child psychiatry. Little is known regarding the influences of early experience and environmental exposure on irritability from a perinatal perspective. This study examined the associations between irritability and multiple perinatal and birth factors.

METHODS

Drawn Taiwan's National Epidemiological Study of Child Mental Disorders, 5124 children (2591 females) aged 7.7 to 14.6 years (mean 11.2 years) and their parents completed the Affective Reactivity Index, a well-established irritability measure. Parents completed a survey on parental, perinatal, and birth characteristics. Multiple linear regression models were performed to examine the associations between perinatal and birth characteristics and child irritability reported across informants.

RESULTS

Maternal smoking, vaginal bleeding, and pre-eclampsia during pregnancy and phototherapy for jaundice >3 days were associated with high irritability after adjusting for child's age, sex, and parental characteristics. Findings were consistent across parent- and child-rated irritability.

LIMITATIONS

Retrospective assessment of early exposures may be subject to recall bias despite previously-established validity and reliability. Longitudinal research with prospective assessments of early life exposures is recommended to confirm our findings. This exploratory approach of multiple survey items also precludes more in-depth assessments of perinatal risks for developing irritability.

CONCLUSIONS

This study provides novel evidence suggesting a perinatal link with irritability in a national sample of youths. Given that irritability predicts adverse mental health and life outcomes, identifying its perinatal and birth predictors may inform early etiology, guiding timely assessment and intervention.

Epigenetic regulation of pediatric and neonatal immune responses

Epigenetic regulation of transcription is a collective term that refers to mechanisms known to regulate gene transcription without changing the underlying DNA sequence. These mechanisms include DNA methylation and histone tail modifications which influence chromatin accessibility, and microRNAs that act through post-transcriptional gene silencing. Epigenetics is known to regulate a variety of biological processes, and the role of epigtenetics in immunity and immune-mediated diseases is becoming increasingly recognized. While DNA methylation is the most widely studied, each of these systems play an important role in the development and maintenance of appropriate immune responses. There is clear evidence that epigenetic mechanisms contribute to developmental stage-specific immune responses in a cell-specific manner. There is also mounting evidence that prenatal exposures alter epigenetic profiles and subsequent immune function in exposed offspring. Early life exposures that are associated with poor long-term health outcomes also appear to impact immune specific epigenetic patterning. Finally, each of these epigenetic mechanisms contribute to the pathogenesis of a wide variety of diseases that manifest during childhood. This review will discuss each of these areas in detail. IMPACT: Epigenetics, including DNA methylation, histone tail modifications, and microRNA expression, dictate immune cell phenotypes. Epigenetics influence immune development and subsequent immune health. Prenatal, perinatal, and postnatal exposures alter immune cell epigenetic profiles and subsequent immune function. Numerous pediatric-onset diseases have an epigenetic component. Several successful strategies for childhood diseases target epigenetic mechanisms.

Developmental multi-trajectory of irritability, anxiety, and hyperactivity as psychological markers of heterogeneity in childhood aggression

BACKGROUND

A growing body of evidence suggests that child aggression is likely to be driven by multiple developmental pathways. However, little is known about the complex interactions between developmental trajectories of child psychological factors (such as anxiety, irritability, and hyperactivity/impulsivity dimensions) and their associations with aggression from childhood to adolescence. Therefore, the current study aimed to identify clusters of individuals with different developmental multi-trajectory, investigate their early risk factors, and describe their longitudinal associations with physical aggression.

METHOD

The sample comprised 4898 children derived from the Fragile Families and Child Wellbeing Study. A parallel process growth mixture model was used to identify developmental multi-trajectory groups at 5, 9 and 15 years old. Associations between multi-trajectory group membership and physical aggression were examined with Generalized Estimating Equations models. Finally, multinomial logistic regression was performed to assess perinatal and early risk factors for multi-trajectory groups.

RESULTS

Multi-trajectory groups differed in the magnitude of risk for exhibiting physical aggression, compared to typically developing children. The risk for physical aggression was the most prominent in children who were hyperactive/impulsive and irritable [odds ratio (OR) 6.47; 95% confidence interval (CI) 5.44-7.70] and hyperactive/impulsive, irritable, and anxious (OR 7.68; CI 6.62-8.91). Furthermore, maternal cigarette and alcohol use during pregnancy and maternal depression consistently predicted multi-trajectory groups characterized by problematic levels of at least two co-occurrent psychological symptoms.

CONCLUSIONS

Identified combinations of developmental trajectories of psychological characteristics were associated with different magnitude in risk for exhibiting physical aggression. These results may highlight the heterogeneity of developmental trajectories associated with childhood aggression.

Central Australian Aboriginal women's placental and neonatal outcomes following maternal smokeless tobacco, cigarette or no tobacco use

OBJECTIVE

To describe the placental characteristics and neonatal outcomes of Central Australian Aboriginal women based on maternal self-report of tobacco use.

METHODS

Placental and neonatal variables were collected from a prospective maternal cohort of 19 smokeless tobacco chewers, 23 smokers and 31 no-tobacco users.

RESULTS

Chewers had the lowest placental weight (460 g) while the no-tobacco group had the heaviest placental weight (565 g). Chewers and the no-tobacco group had placental areas of similar size (285 cm² and 288 cm² , respectively) while the placentas of smokers were at least 13 cm² smaller (272 cm² ). There were two stillbirths in the study and more than one-third (36%) of neonates (newborns) were admitted to the Special Care Nursery, with the chewers' neonates having a higher admission rate compared with smokers' neonates (44% vs. 23%). The cohort mean birthweight (3348 g) was not significantly different between the groups. When stratified for elevated maternal glucose, the chewers' neonates had the lowest mean birthweight (2906 g) compared to the neonates of the no-tobacco group (3242 g) and smokers (3398 g).

CONCLUSIONS

This research is the first to demonstrate that the maternal use of Australian Nicotiana spp. (pituri) as smokeless tobacco may negatively impact placental and neonatal outcomes. Implications for public health: Maternal smokeless tobacco use is a potential source of placental and foetal nicotine exposure. Maternal antenatal screening should be expanded to capture a broader range of tobacco and nicotine products, and appropriate cessation support is required.

Improving translational relevance: The need for combined exposure models for studying prenatal adversity

Prenatal environmental adversity is a risk factor for neurodevelopmental disorders (NDDs), with the neuroimmune environment proposed to play a role in this risk. Adverse maternal exposures are associated with cognitive consequences in the offspring that are characteristics of NDDs and simultaneous neuroimmune changes that may underlie NDD risk. In both animal models and human studies the association between prenatal environmental exposure and NDD risk has been shown to be complex. Maternal overnutrition/obesity and opioid use are two different examples of complex exposure epidemics, each with their own unique comorbidities. This review will examine maternal obesity and maternal opioid use separately, illustrating the pervasive comorbidities with each exposure to argue a need for animal models of compound prenatal exposures. Many of these comorbidities can impact neuroimmune function, warranting systematic investigation of combined exposures to begin to understand this complexity. While traditional approaches in animal models have focused on modeling a single prenatal exposure or second exposure later in life, a translational approach would begin to incorporate the most prevalent co-occurring prenatal exposures. Long term follow-up in humans is extremely challenging, so animal models can provide timely insight into neurodevelopmental consequences of complex prenatal exposures. Animal models that represent this translational context of comorbid exposures behind maternal obesity or comorbid exposures behind maternal opioid use may reveal potential synergistic neuroimmune interactions that contribute to cognitive consequences and NDD risk. Finally, translational co-exposure models can identify concerning exposure combinations to guide treatment in complex cases, and identify high risk children starting in the prenatal period where early interventions improve prognosis.

DNA methylome perturbations: an epigenetic basis for the emergingly heritable neurodevelopmental abnormalities associated with maternal smoking and maternal nicotine exposure†

Maternal smoking during pregnancy is associated with an ensemble of neurodevelopmental consequences in children and therefore constitutes a pressing public health concern. Adding to this burden, contemporary epidemiological and especially animal model research suggests that grandmaternal smoking is similarly associated with neurodevelopmental abnormalities in grandchildren, indicative of intergenerational transmission of the neurodevelopmental impacts of maternal smoking. Probing the mechanistic bases of neurodevelopmental anomalies in the children of maternal smokers and the intergenerational transmission thereof, emerging research intimates that epigenetic changes, namely DNA methylome perturbations, are key factors. Altogether, these findings warrant future research to fully elucidate the etiology of neurodevelopmental impairments in the children and grandchildren of maternal smokers and underscore the clear potential thereof to benefit public health by informing the development and implementation of preventative measures, prophylactics, and treatments. To this end, the present review aims to encapsulate the burgeoning evidence linking maternal smoking to intergenerational epigenetic inheritance of neurodevelopmental abnormalities, to identify the strengths and weaknesses thereof, and to highlight areas of emphasis for future human and animal model research therein.

Maternal Adverse Childhood Experiences and Child Behavior Problems: A Systematic Review

CONTEXT

A growing body of research has examined the role of maternal adverse childhood experiences (ACEs) on child behavior problems.

OBJECTIVE

To summarize the literature examining the association between maternal ACEs and child behavior problems via a systematic review.

DATA SOURCES

Electronic searches were conducted in Medline, PsycINFO, and Embase (1998-June 2020). Reference lists were reviewed. In total, 3048 records were screened.

STUDY SELECTION

Studies were included if an association between maternal ACEs and child externalizing (eg, aggression) and/or internalizing (eg, anxiety) problems was reported. In total, 139 full-text articles were reviewed for inclusion.

DATA EXTRACTION

Data from 16 studies met full inclusion criteria. Studies were synthesized by child externalizing and internalizing outcomes.

RESULTS

Maternal ACEs were significantly associated with child externalizing problems across all studies (number of studies synthesized per outcome [k] = 11). Significant associations were also found for inattention, hyperactivity, and impulsivity (k = 4), and aggression (k = 2). For internalizing problems (k = 11), significant associations were identified across 8 studies and nonsignificant associations were reported for 3 studies. Maternal ACEs were consistently associated with child anxiety and depression (k = 5). However, inconsistent findings were reported for somatization (k = 2).

LIMITATIONS

Results are limited to mother-child dyads and questionnaire measures of behavior problems in primarily North American countries.

CONCLUSIONS

Mothers' ACEs demonstrated largely consistent associations with children's behavior problems. Future research is needed to determine if specific types of maternal ACEs (eg, household dysfunction) are more strongly associated with child behavior problems.

The World Federation of ADHD International Consensus Statement: 208 Evidence-based conclusions about the disorder

BACKGROUND

Misconceptions about ADHD stigmatize affected people, reduce credibility of providers, and prevent/delay treatment. To challenge misconceptions, we curated findings with strong evidence base.

METHODS

We reviewed studies with more than 2000 participants or meta-analyses from five or more studies or 2000 or more participants. We excluded meta-analyses that did not assess publication bias, except for meta-analyses of prevalence. For network meta-analyses we required comparison adjusted funnel plots. We excluded treatment studies with waiting-list or treatment as usual controls. From this literature, we extracted evidence-based assertions about the disorder.

RESULTS

We generated 208 empirically supported statements about ADHD. The status of the included statements as empirically supported is approved by 80 authors from 27 countries and 6 continents. The contents of the manuscript are endorsed by 366 people who have read this document and agree with its contents.

CONCLUSIONS

Many findings in ADHD are supported by meta-analysis. These allow for firm statements about the nature, course, outcome causes, and treatments for disorders that are useful for reducing misconceptions and stigma.

Early childhood exposure to maternal smoking and behavioral development

We examined the association between early childhood exposure to maternal smoking and behavioral issues at 8 years old using a large nationwide population-based longitudinal survey in Japan that began in 2001. We included 46,737 children with information about maternal smoking taken from the 6-month survey. We used logistic regression analysis to examine the hypothesis. Early childhood exposure to maternal smoking increased the risk of behavioral problems related to attention and aggressive or disruptive behavior. The adjusted odds ratios (95% confidence intervals) were 1.37 (1.22-1.54) for inability to wait their turn during play and 1.40 (1.27-1.55) for destroying toys and, compared with children of nonsmoking mothers. Children of mothers who were heavy smokers were more likely to develop behavioral problems than others. Stopping early childhood exposure to maternal exposure can protect children's neurodevelopment.

Is Preterm Birth a Risk Factor for Subsequent Autism Spectrum Disorder and Attention Deficit Hyperactivity Disorder in Children with Febrile Seizure?-A Retrospective Study

Febrile seizure (FS) is the most prevalent childhood seizure; it is significantly related to subsequent epilepsy and has possible links to childhood neurodevelopmental disorders. Separately, premature births are believed to increase the risk of attention deficit hyperactivity disorder (ADHD) and autism spectrum disorder (ASD). Therefore, this study investigated whether preterm birth is a risk factor for subsequent epilepsy, ASD, and ADHD in children with FS. We retrospectively collected data for children aged < 5 years with FS from 1 January 2005, to 31 December 2013. We divided these children into two groups-the premature birth group and the full-term group-and compared their incidence rates of epilepsy, ASD and ADHD. The data of 426 patients with history of febrile convulsion were retrospectively collected. The premature birth group (FS+/preterm+) had 108 patients and the full-term group (FS+/preterm-) had 318 patients. The overall epilepsy risk in the FS+/preterm+ group was higher than in the FS+/preterm- group (odds ratio [OR], 2.52; 95% confidence interval [CI], 1.14-5.58; p = 0.02). The overall risk of ADHD in the FS+/preterm+ group was higher than that in the FS+/preterm- group (OR, 6.41; 95% CI, 3.39-12.09; p = 0.0001). In addition, children with FS+/preterm+ had 16.9 times (95% CI, 4.79-59.7; p = 0.0001) higher odds of having ASD compared with those with FS+/preterm-. Preterm birth may be a risk factor for subsequent epilepsy, ASD and ADHD in children with FS.

Effects of Prenatal Exposure to Alcohol and Smoking on Fetal Heart Rate and Movement Regulation

Negative associations of prenatal tobacco and alcohol exposure (PTE and PAE) on birth outcomes and childhood development have been well documented, but less is known about underlying mechanisms. A possible pathway for the adverse fetal outcomes associated with PTE and PAE is the alteration of fetal autonomic nervous system development. This study assessed PTE and PAE effects on measures of fetal autonomic regulation, as quantified by heart rate (HR), heart rate variability (SD-HR), movement, and HR-movement coupling in a population of fetuses at ≥ 34 weeks gestational age. Participants are a subset of the Safe Passage Study, a prospective cohort study that enrolled pregnant women from clinical sites in Cape Town, South Africa, and the Northern Plains region, United States. PAE was defined by six levels: no alcohol, low quit early, high quit early, low continuous, moderate continuous, and high continuous; while PTE by 4 levels: no smoking, quit early, low continuous, and moderate/high continuous. Linear regression analyses of autonomic measures were employed controlling for fetal sex, gestational age at assessment, site, maternal education, household crowding, and depression. Analyses were also stratified by sleep state (1F and 2F) and site (South Africa, N = 4025, Northern Plains, N = 2466). The final sample included 6491 maternal-fetal-dyad assessed in the third trimester [35.21 ± 1.26 (mean ± SD) weeks gestation]. PTE was associated with a decrease in mean HR in state 2F, in a dose dependent fashion, only for fetuses of mothers who continued smoking after the first trimester. In state 1F, there was a significant increase in mean HR in fetuses whose mother quit during the first trimester. This effect was driven by the Norther Plains cohort. PTE was also associated with a significant reduction in fetal movement in the most highly exposed group. In South Africa a significant increase in mean HR both for the high quit early and the high continuous group was observed. In conclusion, this investigation addresses a critical knowledge gap regarding the relationship between PTE and PAE and fetal autonomic regulation. We believe these results can contribute to elucidating mechanisms underlying risk for adverse outcomes.