Prenatal Maternal Smoking Research Articles

Maternal smoking and low family income during pregnancy as predictors of the relationship between depression and adiposity in young adults

There is an increasing incidence of overweight/obesity and mental health disorders in young adults and the two conditions often coexist. We aimed to investigate the influence of antenatal and postnatal factors that may underlie this association with a focus on maternal prenatal smoking, socio-economic status and gender. Data from the Western Australian Pregnancy Cohort (Raine) Study (women enrolled 1989-1991) including 1056 offspring aged 20 years (cohort recalled 2010-2012) were analyzed (2015-2016) using multivariable models for associations between offspring depression scores (DASS-21 Depression-scale) and body mass index (BMI), adjusting for pregnancy and early life factors and offspring behaviours. There was a significant positive relationship between offspring depression-score and BMI independent of gender and other psychosocial covariates. There was a significant interaction between maternal prenatal smoking and depression-score (interaction coefficient=0.096; 95% CI: 0.006, 0.19, P=0.037), indicating the relationship between depression-score and BMI differed according to maternal prenatal smoking status. In offspring of maternal prenatal smokers, a positive association between BMI and depression-score (coefficient=0.133; 95% CI: 0.05, 0.21, P=0.001) equated to 1.1 kg/m2 increase in BMI for every 1standard deviation (8 units) increase in depression-score. Substituting low family income during pregnancy for maternal prenatal smoking in the interaction (interaction coefficient=0.091; 95% CI: 0.01, 0.17, P=0.027) showed a positive association between BMI and depression score only among offspring of mothers with a low family income during pregnancy (coefficient=0.118; 95% CI: 0.06, 0.18, P<0.001). There were no significant effects of gender on these associations. Whilst further studies are needed to determine whether these associations are supported in other populations, they suggest potentially important maternal behavioural and socio-economic factors that identify individuals vulnerable to the coexistence of obesity and depression in early adulthood.

Impact of maternal prenatal smoking on fetal to infant neurobehavioral development.

Despite recent emphasis on the profound importance of the fetal environment in "programming" postnatal development, measurement of offspring development typically begins after birth. Using a novel coding strategy combining direct fetal observation via ultrasound and actocardiography, we investigated the impact of maternal smoking during pregnancy (MSDP) on fetal neurobehavior; we also investigated links between fetal and infant neurobehavior. Participants were 90 pregnant mothers and their infants (52 MSDP-exposed; 51% minorities; ages 18-40). Fetal neurobehavior at baseline and in response to vibro-acoustic stimulus was assessed via ultrasound and actocardiography at M = 35 weeks gestation and coded via the Fetal Neurobehavioral Assessment System (FENS). After delivery, the NICU Network Neurobehavioral Scale was administered up to seven times over the first postnatal month. MSDP was associated with increased fetal activity and fetal limb movements. Fetal activity, complex body movements, and cardiac-somatic coupling were associated with infants' ability to attend to stimuli and to self-regulate over the first postnatal month. Furthermore, differential associations emerged by MSDP group between fetal activity, complex body movements, quality of movement, and coupling, and infant attention and self-regulation. The present study adds to a growing literature establishing the validity of fetal neurobehavioral measures in elucidating fetal programming pathways.

DNA methylation of imprinted genes at birth is associated with child weight status at birth, 1\xa0year, and 3\xa0years

BackgroundThis study assessed the associations between nine differentially methylated regions (DMRs) of imprinted genes in DNA derived from umbilical cord blood leukocytes in males and females and (1) birth weight for gestational age z score, (2) weight-for-length (WFL) z score at 1 year, and (3) body mass index (BMI) z score at 3 years.MethodsWe conducted multiple linear regression in n = 567 infants at birth, n = 288 children at 1 year, and n = 294 children at 3 years from the Newborn Epigenetics Study (NEST). We stratified by sex and adjusted for race/ethnicity, maternal education, maternal pre-pregnancy BMI, prenatal smoking, maternal age, gestational age, and paternal race. We also conducted analysis restricting to infants not born small for gestational age.ResultsWe found an association between higher methylation of the sequences regulating paternally expressed gene 10 (PEG10) and anthropometric z scores at 1 year (β = 0.84; 95% CI = 0.34, 1.33; p = 0.001) and 3 years (β = 1.03; 95% CI = 0.37, 1.69; p value = 0.003) in males only. Higher methylation of the DMR regulating mesoderm-specific transcript (MEST) was associated with lower anthropometric z scores in females at 1 year (β = − 1.03; 95% CI − 1.60, − 0.45; p value = 0.001) and 3 years (β = − 1.11; 95% CI − 1.98, − 0.24; p value = 0.01). These associations persisted when we restricted to infants not born small for gestational age.ConclusionOur data support a sex-specific association between altered methylation and weight status in early life. These methylation marks can contribute to the compendium of epigenetically regulated regions detectable at birth, influencing obesity in childhood. Larger studies are required to confirm these findings.

Effects of prenatal exposure to cigarettes on anthropometrics, energy intake, energy expenditure, and screen time in children.

Maternal prenatal smoking is associated with downstream childhood obesity. Although animal research suggests reduced resting energy expenditure (REE), decreased physical activity (PA), and increased energy intake as mechanisms, these relationships are unclear in humans. The objectives were to examine the association of prenatal maternal smoking with non-volitional energy expenditure (REE and the thermic effect of feeding [TEF]), child adiposity, energy intake, free-living PA (daily light PA (LPA), daily moderate-to-vigorous PA (MVPA), daily sedentary behavior (SB)), and screen time (television and computer/video game) in children. As part of a longitudinal study, 46 children (n = 27 controls and n = 19 smoking exposed) with mean age 7.6 ± 2 years were recruited. Body weight and composition (Bioelectrical Impedance), height (Stadiometer), waist circumference (cm; tape), BMI (kg/m2), REE (kcal/day; indirect calorimetry), PA (minutes; Accelerometry), screen time (hours; self-report) and ad libitum energy intake (lunch buffet; 7-day food log) were measured. Effects sizes were evaluated using Cohen's d. Relative to controls, after controlling for age and family income, children who were exposed to cigarette smoke in utero exhibited greater waist circumference (p = 0.04, Cohen's d = 1.03), percent body fat (%BF; p = 0.02, Cohen's d = 0.97), and a trend for BMI (p = 0.05, Cohen's d = 0.86). Exposed children did not differ in REE (trend for lower: p = 0.1, Cohen's d = 0.42) or TEF but were shown to have significantly higher ad libitum energy intake (p = 0.02, Cohen's D = 0.70) from the palatable lunch buffet, but not from the out of laboratory 7-day energy intake (p = 0.8). Examining screen time behaviors, exposed children spent more time watching television during the week (p = 0.03, Cohen's D = 0.82), and overall television watching (p = 0.02, Cohen's D = 0.80); there were no group differences in any other screen time behaviors. Children exposed to cigarette smoke in utero exhibit greater adiposity, and this exposure may have as contributing factors higher screen time, ad libitum energy intake, and a trend for reduced REE. The data suggest that lifestyle factors such as diet and screen time represent targets for obesity prevention in a high-risk population of young children exposed to prenatal cigarette smoke. Findings also highlight the need for smoking cessation programs to reduce downstream obesity in offspring.

Contrasting associations of maternal smoking and pre-pregnancy BMI with wheeze and eczema in children

BackgroundChildhood allergies are dynamic and associated with environmental factors. The influence of prenatal maternal smoking and obesity on childhood allergies and their comorbidities remains unclear, especially in prospective cohorts with serial longitudinal observations. ObjectiveWe examined time trends in the prevalence and comorbidity of childhood allergies, including wheeze, eczema, and rhinoconjunctivitis, using a large-scale, population-based birth cohort in Japan, and assessed the effects of prenatal maternal smoking and BMI on the risk of childhood allergies. MethodsParents completed the International Study of Asthma and Allergies in Childhood (ISAAC) questionnaires about symptoms of allergies and their risk factors at age 1, 2, 4, and 7 years. Complete data from all pre- and postnatal questionnaires at age 1, 2, 4, and 7 were available for 3296 mother–child pairs. ResultsWe observed significant overlap of childhood allergies at 1, 2, 4, and 7 years. Maternal serum cotinine during pregnancy was associated with increased risk of wheezing in the children at age 1, 2, and 4 but disappeared at age 7. In contrast, maternal cotinine levels were inversely associated with the prevalence of eczema in children at age 7. We additionally observed that maternal pre-pregnancy BMI, not children's BMI, had a positive association with wheeze and an inverse association with eczema in 7-year-old children, respectively. We did not find any association of examined maternal factors and rhinoconjunctivitis. ConclusionsWe demonstrated contrasting association of prenatal maternal smoking and high BMI with postnatal wheeze and eczema. For precise assessment of allergy-associated risk factors, we need to contrast risk factors for different allergic diseases since focusing solely on one allergic disease may result in misleading information on the role of different risk factors.

Smoking cessation in pregnancy: a continuing challenge in the United States.

Despite significant population level declines, smoking during pregnancy remains a major public health issue in the United States (US). Approximately 360,000-500,000 smoke-exposed infants are born yearly, and prenatal smoking remains a leading modifiable cause of poor birth outcomes (e.g. birth < 37 gestational weeks, low birth weight, perinatal mortality). Women who smoke during pregnancy are more likely to be younger and from disadvantaged socioeconomic and racial and ethnic groups, with some US geographic regions reporting increased prenatal smoking rates since 2000. Such disparities in maternal prenatal smoking suggests some pregnant women face unique barriers to cessation. This paper reviews the current state and future direction of smoking cessation in pregnancy in the US. We briefly discuss the etiology of smoking addiction among women, the pathophysiology and effects of tobacco smoke exposure on pregnant women and their offspring, and the emerging issue of electronic nicotine delivery systems. Current population-based and individual smoking cessation interventions are reviewed in the context of pregnancy and barriers to cessation among US women. Finally, we consider interventions that are on the horizon and areas in need of further investigation.

Prenatal and postnatal tobacco smoke exposure and risk of severe bronchiolitis during infancy.

Maternal prenatal smoking has adverse effects on the growing fetus including those of respiratory nature. Although postnatal smoke exposure is a risk factor for respiratory infections, the effects of prenatal smoking independent of postnatal smoke exposure are less established. We hypothesized that both maternal prenatal smoking, and postnatal smoke exposure are risk factors for severe bronchiolitis during infancy. We performed a case-control study of 1353 children born between 1996 and 2011 at a single teaching hospital. Cases were admitted to the same hospital for bronchiolitis during infancy. Maternal prenatal smoking was collected from birth records. Postnatal smoke exposure was collected from review of electronic health records. Multivariable logistic regression was used to evaluate the independent associations of the two smoking variables with severe bronchiolitis. 6% of cases were exposed to maternal prenatal smoking, compared with 4% of controls (P = 0.10). Postnatal smoke exposure was present in the households of 17% of cases compared with 3% of controls (P < 0.001). In a multivariable model with both smoking variables and adjustment for 10 covariates, maternal prenatal smoking was not a significant risk factor for severe bronchiolitis (adjusted OR = 1.02, 95%CI 0.56-1.84). By contrast, postnatal smoke exposure was associated with >300% increased odds (adjusted OR 4.19, 95%CI 2.51-6.98). Although maternal prenatal smoking has many known adverse effects, it was not associated with increased odds of severe bronchiolitis in either unadjusted or multivariable analyses. Postnatal smoke exposure was a consistently strong risk factor. Our findings support ongoing efforts to decrease infant exposure to ambient smoke.

DNA methylation signatures of educational attainment

Educational attainment is a key behavioural measure in studies of cognitive and physical health, and socioeconomic status. We measured DNA methylation at 410,746 CpGs (N = 4152) and identified 58 CpGs associated with educational attainment at loci characterized by pleiotropic functions shared with neuronal, immune and developmental processes. Associations overlapped with those for smoking behaviour, but remained after accounting for smoking at many CpGs: Effect sizes were on average 28% smaller and genome-wide significant at 11 CpGs after adjusting for smoking and were 62% smaller in never smokers. We examined sources and biological implications of education-related methylation differences, demonstrating correlations with maternal prenatal folate, smoking and air pollution signatures, and associations with gene expression in cis, dynamic methylation in foetal brain, and correlations between blood and brain. Our findings show that the methylome of lower-educated people resembles that of smokers beyond effects of their own smoking behaviour and shows traces of various other exposures.

From mother to child: the effects of prenatal maternal passive smoking on academic outcomes in the United States

This is the first study in the United States to examine the effect of prenatal maternal passive smoking on student learning outcomes. We use a national sample of children in combination with ordinary least squares regression and matching methods to examine this effect. We find evidence that prenatal maternal exposure to secondhand smoke leads to lower academic performance in language/literacy and mathematics in the later years of elementary school, particularly for mothers who did not actively smoke while pregnant. Our results provide persuasive empirical evidence in support of public policies that address prenatal maternal exposure to secondhand smoking.

The effect of prenatal maternal cigarette smoking on children's BMI z-score with SGA as a mediator.

The goal of this study was to assess the effect of prenatal maternal cigarette smoking on children's BMI z-score trajectories, and to evaluate whether small-for-gestational-age (SGA) acts as a potential mediator between prenatal maternal cigarette smoking and child's BMI z-score at 4 years of age. Group-based trajectory modeling (GBTM) methods were employed to describe and classify developmental BMI z-score trajectories (the outcome of interest) in children from 9 months to 4 years of age (n = 5221) in the Early Childhood Longitudinal Study, Birth Cohort (ECLS-B) study (2001-2005). Further analysis examined whether the identified BMI z-score trajectories varied with the exposure, prenatal maternal cigarette smoking. Mediation analyses were utilized to examine whether being SGA (binary measure) acted as a potential mediator in the relationship between prenatal maternal cigarette smoking and BMI z-score among 4-year-old children. Using GBTM, two BMI z-score trajectory groups were identified: normal BMI z-score (57.8%); and high BMI z-score (42.2%). Children of mothers who smoked cigarettes during pregnancy were 2.1 times (RR 95% CI: 1.1-4.0, P value = 0.023) more at risk of being in the high BMI z-score trajectory group. Prenatal cigarette smoking was positively related to SGA at birth, but SGA was inversely related to BMI z-score at 4 years. The direct effect (0.19, 95% CI: 0.18, 0.19; P value < 0.001) of maternal cigarette smoking status during pregnancy on BMI z-score among 4-year-old children was stronger and in the opposite direction of the indirect effect (-0.04, 95% CI: -0.04, -0.04; P value < 0.001) mediated through SGA. In this study, prenatal maternal cigarette smoking was positively associated with the high BMI z-score group, as well with SGA. The effects of prenatal smoking on BMI z-score at 4 years appears to act through pathways other than SGA.

730: Prenatal maternal smoking and offspring respiratory morbidity: Results of a population based cohort study

730: Prenatal maternal smoking and offspring respiratory morbidity: Results of a population based cohort study

Age at Pubertal Onset in Girls and Tobacco Smoke Exposure During Pre- and Postnatal Susceptibility Windows.

Tobacco smoke contains known hormonally active chemicals and reproductive toxicants. Several studies have examined prenatal maternal smoking and offspring age at menarche, but few examined earlier pubertal markers, nor accounted for exposure during childhood. Our objective was to examine pre- and postnatal smoke exposure in relation to timing of early pubertal events. An ethnically diverse cohort of 1239 girls was enrolled at age 6-8 years old for a longitudinal study of puberty at three US sites. Girls participated in annual or semi-annual exams to measure anthropometry and Tanner breast and pubic hair stages. Prenatal and current tobacco smoke exposures, as well as covariates, were obtained from parent questionnaire. Cotinine was measured in urine collected at enrollment. Using accelerated failure time models, we calculated adjusted time ratios for age at pubertal onset (maturation stages 2 or higher) and smoke exposure. Girls with higher prenatal (≥5 cigarettes per day) or secondhand smoke exposure had earlier pubic hair development than unexposed (adjusted time ratio: 0.92 [95% CI = 0.87, 0.97] and 0.94 [95% CI = 0.90, 0.97], respectively). Including both exposures in the same model yielded similar associations. Higher urinary cotinine quartiles were associated with younger age at breast and pubic hair onset in unadjusted models, but not after adjustment. Greater prenatal and childhood secondhand smoke exposure were associated with earlier onset of pubic hair, but not breast, development. These exposures represent modifiable risk factors for early pubertal development that should be considered for addition to the extensive list of adverse effects from tobacco smoke.

Effect of Prenatal Exposure to Waterpipe Tobacco Smoke on Learning and Memory of Adult Offspring Rats.

Waterpipe tobacco smoking has increased in prevalence worldwide, including among pregnant women. In this study, we investigated the effect of prenatal maternal waterpipe tobacco smoke (WTS) exposure during different stages of pregnancy on learning and memory of adult offspring rats. Pregnant rats received either fresh air or mainstream WTS (2 hours daily) during early, mid, late, or whole gestational period. Male offspring rats were followed through 20 weeks. Outcomes included (1) spatial learning and memory using the radial arm water maze (RAWM), (2) levels of brain derived neurotrophic factor (BDNF) in the hippocampus, and (3) oxidative stress biomarkers (superoxide dismutase, catalase, glutathione peroxidase and thiobarbituric acid reactive substances). Relative to offspring whose mothers were exposed to fresh air, prenatal exposure to WTS at any stage of pregnancy resulted in short- and long-term memory impairment in adult offspring rats (p < .05). This impairment was associated with reduced levels of BDNF in hippocampus (p < .05). However, prenatal WTS did not affect the level of oxidative stress biomarkers in hippocampus. Prenatal WTS during late gestation increased the activity of catalase as compared to control. Prenatal maternal WTS exposure can impair the memory of adult male offspring. These results support development of interventions that target pregnant women who smoke waterpipe during pregnancy. We examined for the first time the effect of prenatal waterpipe tobacco smoke exposure on learning and memory of offspring. The results showed that in utero exposure to waterpipe tobacco smoke was associated with impaired memory and decreased brain derived neurotrophic factor in hippocampus of adult male offspring rats.

Using Linked Administrative Data to Examine the Educational Outcomes of Children in Care in Manitoba

ABSTRACT&#x0D; ObjectivesManitoba has one of the highest rates of children in out-of-home care in the world. Our aims were to: 1) describe characteristics of children in care; 2) determine differences in educational outcomes for children in care, children receiving in-home protection services and children not involved with child welfare; and, 3) identify factors contributing to educational success for children in care.&#x0D; ApproachPopulation-level administrative data from the Population Health Research Data Repository at the Manitoba Centre for Health Policy, were used. Several data sources were linked together at an individual level: child welfare services (e.g., in care, in-home services; hospital birth records (e.g., birth weight, gestational age); health status (e.g., from hospitalizations, physician visits); family risk factors (e.g., maternal prenatal smoking and/or drinking, maternal education); family characteristics (e.g., number of children in family, receipt of income assistance); education assessments at kindergarten, grades 3, 7, 8, 9 and 12. Children in care from 1998 onward were included. Number of children analyzed differed depending on the educational outcome examined: e.g., analyses at kindergarten include 1,893 children in care, 4,229 children receiving in-home services, and 32,280 children not involved with child welfare services; for high school completion these numbers were 11,234, 40,671, and 162,265 respectively. Multivariate regressions identified characteristics associated with educational outcomes for children in care.&#x0D; ResultsOver one-third of children in care first entered care as infants, and of those, close to half were apprehended at birth. 5.5% of children in Manitoba spent some time in care before their 15th birthday, with an almost tenfold difference for Indigenous (16.6%) and non-Indigenous (1.7%) children. Across the range of educational outcomes, children in care did more poorly than children receiving in-home services, who in turn did more poorly than children with no child welfare involvement. For example, only 33.4% of children in care completed high school compared to 66.8% of children receiving in-home services and 89.3% of children with no child welfare involvement. Adjusting covariates reduced differences but all remained statistically significant. Factors associated with positive outcomes for children in care differed depending on the outcome and included measures like poverty (at Kindergarten, p&lt;0.05; at high school, p&lt;0.0001) and total number of care placements (at Kindergarten, p&lt;0.05; at grade 9, p&lt;0.01).&#x0D; ConclusionsChildren in care are at risk of experiencing poor educational outcomes, from school entry onwards. Identifying factors associated with educational success for children in care can inform policy and program development.

Associations of maternal prenatal smoking with umbilical cord blood hormones: the Project Viva cohort

BackgroundMaternal smoking during pregnancy is associated with low fetal growth and adverse cardiometabolic health in offspring. However, hormonal pathways underlying these associations are unclear. Therefore, we examined maternal smoking habits and umbilical cord blood hormone profiles in a large, prospective cohort. MethodsWe studied 978 mother/infant pairs in Project Viva, a Boston-area cohort recruited 1999–2002. We categorized mothers as early pregnancy smokers, former smokers, or never smokers. Outcomes were cord blood concentrations of IGF-1, IGF-2, IGFBP-3, leptin, adiponectin, insulin, and C-peptide. We used linear regression models adjusted for maternal pre-pregnancy body mass index (BMI), race/ethnicity, parity, education, and infant sex. We conducted analyses in the full cohort and stratified by infant sex. ResultsThirteen percent of women were early pregnancy smokers, 20% former smokers, and 68% never smokers. Infants of early pregnancy smokers had lower IGF-1 adjusted for IGFBP-3 [−5.2ng/mL (95% CI: −8.6, −1.7)], with more pronounced associations in girls [−10.7ng/mL (95% CI: −18.5, −2.9) vs. −4.0ng/mL (95% CI: −8.4, 0.4) for boys]. Early pregnancy smoking was not associated with cord blood hormones other than IGF-1. Infants of former smokers had a cord blood hormone profile similar to infants of never smokers. ConclusionsAs compared to mothers who never smoked, early pregnancy smokers had infants with lower cord blood IGF-1 which could prime adverse metabolic outcomes. This provides further reason to support smoking cessation programs in women of reproductive age.

Paternal smoking during early developmental period and risk of offspring's attention deficit hyperactivity disorder

IntroductionAlthough prenatal maternal smoking is an established risk factor for offspring's attention deficit hyperactivity disorder (ADHD), the studies of association between paternal smoking and childhood ADHD have produced inconsistent results.ObjectiveThe objective of the present study was to determine whether paternal smoking during early developmental period is associated with an increased risk of offspring's ADHD.MethodsWe conducted hospital-based case-control study with 107 medically diagnosed ADHD cases and 205 controls (aged 6–12 years). The diagnoses of ADHD were assessed with DSM-IV based semi-structured diagnostic interviews. Paternal smoking behavior was assessed with spouse-report questionnaire. The association between exposure to paternal smoking and ADHD were analyzed using multivariate logistic regression analysis. The primary outcome of interest was an odds ratio (ORs) reflecting the risk of offspring's ADHD incidence associated with father's smoking during the index pregnancy, up to one year after birth, and current smoking status. Control variables in our regression model were age, sex, financial status, parents’ education levels, low birth weight, and premature birth.ResultsOur final regression model revealed that paternal smoking during pregnancy (OR = 1.68, 95% CI = 1.03–2.76) and up to one year after birth (OR = 1.69, 95% CI = 1.04–2.77) were significantly related to their offspring's ADHD.ConclusionsThe current results suggest that exposure to paternal smoking during the fetal and newborn period is associated with increased risk of ADHD. This study warrants public health policies to reduce children's exposure to secondhand smoke and their risk of ADHD.Disclosure of interestThe authors have not supplied their declaration of competing interest.

Lifetime secondhand smoke exposure and childhood and adolescent asthma: findings from the PIAMA cohort

BackgroundSecondhand smoke (SHS) exposure is a modifiable risk factor associated with childhood asthma. Associations with adolescent asthma and the relevance of the timing and patterns of exposure are unclear. Knowledge of critical windows of exposure is important for targeted interventions.MethodsWe used data until age 17 from 1454 children of the Dutch population-based PIAMA birth cohort. Residential SHS exposure was assessed through parental questionnaires completed at ages 3 months, 1–8 (yearly), 11, 14, and 17 years. Lifetime exposure was determined as; a) time window-specific exposure (prenatal, infancy, preschool, primary school, and secondary school); b) lifetime cumulative exposure; c) longitudinal exposure patterns using latent class growth modeling (LCGM). Generalized estimation equations and logistic regression were used to analyze associations between exposure and asthma at ages 4 to 17 years, adjusting for potential confounders.ResultsWith all three methods, we consistently found no association between SHS exposure and asthma at ages 4 to 17 years e.g. adjusted overall odds ratio (95% confidence interval) 0.67 (0.41–1.12), 1.00 (0.66–1.51) and 0.67 (0.41–1.11) for prenatal maternal active smoking, infancy, and preschool school time window exposures, respectively.ConclusionWe assessed lifetime SHS exposure using different methods. Different timing and patterns of SHS exposure were not associated with an increased risk of asthma in childhood and adolescence in our study. More longitudinal studies could investigate effects of lifetime SHS exposure on asthma in adolescence and later life.

Association between prenatal maternal cigarette smoking and early childhood caries. A systematic review.

BackgroundThe aim of the present study was to assess the relationship between prenatal maternal cigarette smoking (PMCS) and early childhood caries (ECC) through a systematic review of currently available scientific evidence.Material and MethodsTo address the focused question: “Is there an association between PMCS and ECC?” an electronic literature search without time or language restrictions was conducted till May 2017 in indexed databases using various key words including dental caries, pregnancy, smoking, tobacco products and child. Letters to the editor, commentaries, reviews, case reports and case series and studies in which, ECC was investigated without clinical dental examination, were excluded.ResultsEight observational cross-sectional studies were included. The number of participants ranged between 1102 and 76920 children with age ranging between 24 months and 72 months. Seven studies reported a positive association between PMCS and ECC. One study reported that children whose mother smoked at least five cigarettes/day during pregnancy presented a higher caries severity level compared with to those whose mothers did not smoke. One study showed no association between ECC and PMCS.ConclusionsThe association between PMCS and ECC remains debatable. Further well-designed longitudinal studies are needed in this regard. Key words:Cigarette, early childhood caries, pregnancy, risk factors, smoking.

Daughters of Mothers Who Smoke: A Population-based Cohort Study of Maternal Prenatal Tobacco use and Subsequent Prenatal Smoking in Offspring.

Prenatal exposure to tobacco is associated with adverse health outcomes for the mother and child, and has been associated with an increased risk of tobacco smoking and nicotine dependence in offspring. The objective of this study was to examine the risk of prenatal smoking, among daughters, associated with maternal prenatal smoking. We used a population-based cohort study design, with linked vital records data of mothers and daughters delivering 1984-96 and 1996-2013, respectively, in Washington State. The exposure of interest was mothers' prenatal smoking (any vs. no smoking at any time during pregnancy), while the outcome was daughters' prenatal smoking (similarly assessed). We used multivariable log-binomial regression to obtain estimates of the relative risk (RR) and 95% confidence interval (CI). Daughters exposed to maternal prenatal smoking were more likely to smoke during their pregnancy, compared to unexposed daughters (RR 1.78, 95% CI 1.72, 1.84, adjusted for the year the daughter delivered, her marital status and educational attainment, and the mothers' race/ethnicity). In this relatively young population, we found that daughters exposed to maternal prenatal smoking have an increased risk of smoking later on during their own pregnancy, emphasizing the importance of exposures during the prenatal period. The mechanisms leading to prenatal smoking are multifactorial and likely include behavioural, genetic, epigenetic and environmental factors. An understanding of this risk factor for prenatal smoking may guide health care providers to better target smoking cessation interventions to at-risk populations.

DNA methylation and substance-use risk: a prospective, genome-wide study spanning gestation to adolescence.

Epigenetic processes have been implicated in addiction; yet, it remains unclear whether these represent a risk factor and/or a consequence of substance use. Here, we believe we conducted the first genome-wide, longitudinal study to investigate whether DNA methylation patterns in early life prospectively associate with substance use in adolescence. The sample comprised of 244 youth (51% female) from the Avon Longitudinal Study of Parents and Children (ALSPAC), with repeated assessments of DNA methylation (Illumina 450k array; cord blood at birth, whole blood at age 7) and substance use (tobacco, alcohol and cannabis use; age 14–18). We found that, at birth, epigenetic variation across a tightly interconnected genetic network (n=65 loci; q<0.05) associated with greater levels of substance use during adolescence, as well as an earlier age of onset amongst users. Associations were specific to the neonatal period and not observed at age 7. Key annotated genes included PACSIN1, NEUROD4 and NTRK2, implicated in neurodevelopmental processes. Several of the identified loci were associated with known methylation quantitative trait loci, and consequently likely to be under significant genetic control. Collectively, these 65 loci were also found to partially mediate the effect of prenatal maternal tobacco smoking on adolescent substance use. Together, findings lend novel insights into epigenetic correlates of substance use, highlight birth as a potentially sensitive window of biological vulnerability and provide preliminary evidence of an indirect epigenetic pathway linking prenatal tobacco exposure and adolescent substance use.