Epigenetic Alterations of Maternal Tobacco Smoking during Pregnancy: A Narrative Review

Maternal e-cigarette exposure alters DNA methylome, site-specific CpG and CH methylation, and transcriptomic signatures in the neonatal brain

Maternal use of e-cigarette (e-cig) aerosols poses significant risks to fetal brain development, potentially increasing susceptibility to neurodevelopmental disorders in later life. However, the underlying mechanisms remain incompletely understood. This study aimed to understand the effects of fetal e-cig exposure on DNA methylome and transcriptomic changes in the neonatal brain. Pregnant rats were exposed to e-cig aerosols, and neonatal brains (5 males and 5 females/group) from both control and e-cig-exposed groups were used for experimental analysis. Results indicated that prenatal e-cig exposure altered site-specific DNA methylation patterns at both CpG and CH (non-CpG) sites, predominantly in intergenic and intronic regions, with sex dimorphism in methylation and gene expression changes. Gene ontology analysis revealed that e-cig exposure not only affected neuron projection development and axonogenesis but also altered pathways related to neurodegeneration and long-term depression. These findings provide novel insights into the dynamic changes of CpG and CH methylation induced by e-cig exposure, underscoring the susceptibility of the developing brain to maternal e-cig exposure and its potential implications for developmental disorders and neurodegenerative diseases later in life.

Nutrition, Other Environmental Influences, and Genetics in the Determination of Human Stature

Linear growth during three distinct stages of life determines attained stature in adulthood: namely, in utero, early postnatal life, and puberty and the adolescent period. Individual host factors, genetics, and the environment, including nutrition, influence attained human stature. Each period of physical growth has its specific biological and environmental considerations. Recent epidemiologic investigations reveal a strong influence of prenatal factors on linear size at birth that in turn influence the postnatal growth trajectory. Although average population height changes have been documented in high-income regions, stature as a complex human trait is not well understood or easily modified. This review summarizes the biology of linear growth and its major drivers, including nutrition from a life-course perspective, the genetics of programmed growth patterns or height, and gene-environment interactions that determine human stature in toto over the life span. Implications for public health interventions and knowledge gaps are discussed.

Maternal smoking cessation in the first trimester still poses an increased risk of attention-deficit/hyperactivity disorder and learning disability in offspring

Background

Studies have found maternal smoking during pregnancy was linked to attention-deficit/hyperactivity disorder (ADHD) risk. It is unclear if maternal smoking cessation during pregnancy lowers ADHD and learning disability (LD) risk in offspring. This study aimed to explore the associations between maternal smoking cessation during pregnancy and ADHD and LD risk in offspring.

Methods

Data from the National Health and Nutrition Examination Survey 1999-2004 (8,068 participants) were used. Logistic regression was used to analyze the associations between maternal smoking and smoking cessation during pregnancy and ADHD and LD risk in offspring.

Results

Compared to non-smokers' offspring, maternal smoking during pregnancy increased the risk of ADHD (odds ratios [OR] = 2.07, 95% confidence interval [CI]: 1.67-2.56) and LD (OR = 1.93, 95% CI: 1.61-2.31) in offspring, even if mothers quit smoking later (ORADHD = 1.91, 95%CIADHD: 1.38-2.65, ORLD = 1.65, 95%CILD: 1.24-2.19). Further analysis of the timing of initiation of smoking cessation during pregnancy revealed that, compared to non-smokers' offspring, maternal quitting smoking in the first trimester still posed an increased risk of ADHD (OR = 1.72, 95% CI: 1.41-2.61) and LD (OR = 1.52, 95% CI: 1.06-2.17) in offspring. Maternal quitting smoking in the second or third trimester also had a significantly increased risk of ADHD (OR = 2.13, 95% CI: 1.26-3.61) and LD (OR = 1.82, 95% CI: 1.16-2.87) in offspring. Furthermore, maternal smoking but never quitting during pregnancy had the highest risk of ADHD (OR = 2.17, 95% CI: 1.69-2.79) and LD (OR = 2.10, 95% CI: 1.70-2.58) in offspring. Interestingly, a trend toward a gradual increase in the risk-adjusted OR for ADHD and LD risk was observed among the three groups: maternal quitting smoking in the first trimester, maternal quitting smoking in the second or third trimester, and maternal smoking but never quitting.

Conclusion

Maternal smoking cessation in the first trimester still poses an increased risk of ADHD and LD in offspring. Furthermore, it seems that the later the mothers quit smoking during pregnancy, the higher the risk of ADHD and LD in their offspring. Therefore, early intervention of maternal smoking in preconception and prenatal care is vital for offspring neurodevelopment.

Early environmental predictors for attention-deficit hyperactivity disorder (ADHD), autism spectrum disorder (ASD) and their co-occurrence: The prospective ABIS-Study

ADHD and ASD are highly heritable and show a high co-occurrence and persistence into adulthood. This study aimed to identify pre and perinatal risk factors, and early psychosocial exposures related to later diagnosis of ADHD, ASD, and their co-occurrence. 16,365 children born 1997-1999 and their families, involved in the prospective population-based ABIS study (All Babies in Southeast Sweden), were included in this sub-study. Pre and perinatal factors and early environmental psychosocial exposures were collected from parental-questionnaires at birth and 1-year follow-up. Diagnoses from birth up to 23 years of age were obtained from the Swedish National Diagnosis Register in 2020. The cumulative incidence of ADHD, ASD, and their co-occurrence in the ABIS-cohort Study were 4.6%, 1.7%, and 1.1%, respectively. Being male was associated with an increased risk for ADHD, ASD, and their co-occurrence (aOR 1.30, 1.56, and 1.91, respectively), while higher household income reduced it (aOR 0.82, 0.73, and 0.64). Serious life events during pregnancy (aOR 1.40) and maternal smoking (aOR 1.51) increased the risk of ADHD, while older maternal age (aOR 0.96), higher parental education (aOR 0.72 maternal and aOR 0.74 paternal) and longer exclusive breastfeeding (aOR 0.72) reduced it. Non-Swedish paternal nationality (aOR 0.40) and higher maternal education (aOR 0.74) were associated with a lower risk of ASD, while a family history of autoimmune diseases increased the risk of the co-occurrence of both disorders (aOR 1.62). Obtained results suggest that the etiology of ADHD, ASD, and their co-occurrence is independently associated with environmental psychosocial predictors. The co-occurrence seems to overlap the etiology of ADHD, in which psychosocial determinants have a larger role, however, it is also independently influenced by a family history of autoimmune diseases.

Consistent cord blood DNA methylation signatures of gestational age between South Asian and white European cohorts

BACKGROUND

Epigenetic modifications, particularly DNA methylation (DNAm) in cord blood, are an important biological marker of how external exposures during gestation can influence the in-utero environment and subsequent offspring development. Despite the recognized importance of DNAm during gestation, comparative studies to determine the consistency of these epigenetic signals across different ethnic groups are largely absent. To address this gap, we first performed epigenome-wide association studies (EWAS) of gestational age (GA) using newborn cord blood DNAm comparatively in a white European (n = 342) and a South Asian (n = 490) birth cohort living in Canada. Then, we capitalized on established cord blood epigenetic GA clocks to examine the associations between maternal exposures, offspring characteristics and epigenetic GA, as well as GA acceleration, defined as the residual difference between epigenetic and chronological GA at birth.

RESULTS

Individual EWASs confirmed 1,211 and 1,543 differentially methylated CpGs previously reported to be associated with GA, in white European and South Asian cohorts, respectively, with a similar distribution of effects. We confirmed that Bohlin's cord blood GA clock was robustly correlated with GA in white Europeans (r = 0.71; p = 6.0 × 10-54) and South Asians (r = 0.66; p = 6.9 × 10-64). In both cohorts, Bohlin's clock was positively associated with newborn weight and length and negatively associated with parity, newborn female sex, and gestational diabetes. Exclusive to South Asians, the GA clock was positively associated with the newborn ponderal index, while pre-pregnancy weight and gestational weight gain were strongly predictive of increased epigenetic GA in white Europeans. Important predictors of GA acceleration included gestational diabetes mellitus, newborn sex, and parity in both cohorts.

CONCLUSIONS

These results demonstrate the consistent DNAm signatures of GA and the utility of Bohlin's GA clock across the two populations. Although the overall pattern of DNAm is similar, its connections with the mother's environment and the baby's anthropometrics can differ between the two groups. Further research is needed to understand these unique relationships.

The effect of maternal prenatal tobacco smoking on offspring academic achievement: A systematic review and meta-analysis

BACKGROUND

Previous epidemiological studies examining the prospective association between maternal prenatal tobacco smoking and offspring academic achievement have reported conflicting results. Therefore, this systematic review and meta-analysis was conducted to examine the magnitude and consistency of association reported by those studies.

METHODS

This systematic review and meta-analysis was guided by the PRISMA protocol. Relevant epidemiological studies on the topic were extracted from four main databases (PubMed/Medline, Embase, PsycINFO, and Scopus). The Newcastle-Ottawa Scale (NOS) was used to appraise the methodological quality of the included studies. We conducted a narrative assessment of the studies that did not report effect estimates. Inverse variance-weighted random effect meta-analysis was used to combine studies reporting effect sizes to estimate pooled adjusted odds ratio with 95% confidence intervals (95% CI). The review was prospectively registered in PROSPERO (CRD42022350901).

RESULTS

Nineteen observational studies, published between 1973 and 2021 with a total of 1.25 million study participants were included in the final review. Of these, fifteen studies (79 %) reported reduced academic achievement in offspring exposed to maternal prenatal tobacco smoking. The eight primary studies (sample size = 723,877) included in the meta-analysis together suggested a 49 % higher risk of reduced academic achievement in offspring exposed to maternal prenatal tobacco smoking when compared to non-exposed offspring (Pooled odds ratio = 1.49, 95 % CI:1.17-1.91).

CONCLUSION

Our review found a positive association between maternal prenatal tobacco smoking and offspring reduced academic achievement. However, variation in the adjustment of potential confounders and significant heterogeneity across included studies limited more conclusive inference. Mechanistic studies to identify causal pathways and specific academic impacts are needed to inform targeted developmental programs to assist child learning and academic performance.

Ambient air pollution and adverse birth outcomes: A review of underlying mechanisms

Epidemiological data provide varying degrees of evidence for associations between prenatal exposure to ambient air pollutants and adverse birth outcomes (suboptimal measures of fetal growth, preterm birth and stillbirth). To assess further certainty of effects, this review examines the experimental literature base to identify mechanisms by which air pollution (particulate matter, nitrogen dioxide and ozone) could cause adverse effects on the developing fetus. It likely that this environmental insult impacts multiple biological pathways important for sustaining a healthy pregnancy, depending upon the composition of the pollutant mixture and the exposure window owing to changes in physiologic maturity of the placenta, its circulations and the fetus as pregnancy ensues. The current body of evidence indicates that the placenta is a target tissue, impacted by a variety of critical processes including nitrosative/oxidative stress, inflammation, endocrine disruption, epigenetic changes, as well as vascular dysregulation of the maternal-fetal unit. All of the above can disturb placental function and, as a consequence, could contribute to compromised fetal growth as well increasing the risk of stillbirth. Furthermore, given that there is often an increased inflammatory response associated with preterm labour, inflammation is a plausible mechanism mediating the effects of air pollution on premature delivery. In the light of increased urbanisation and an ever-changing climate, both of which increase ambient air pollution and negatively affect vulnerable populations such as pregnant individuals, it is hoped that the collective evidence may contribute to decisions taken to strengthen air quality policies, reductions in exposure to air pollution and subsequent improvements in the health of those not yet born.

Understanding risk and causal mechanisms for developing obesity in infants and young children: A National Institutes of Health workshop

Obesity in children remains a major public health problem, with the current prevalence in youth ages 2-19 years estimated to be 19.7%. Despite progress in identifying risk factors, current models do not accurately predict development of obesity in early childhood. There is also substantial individual variability in response to a given intervention that is not well understood. On April 29-30, 2021, the National Institutes of Health convened a virtual workshop on "Understanding Risk and Causal Mechanisms for Developing Obesity in Infants and Young Children." The workshop brought together scientists from diverse disciplines to discuss (1) what is known regarding epidemiology and underlying biological and behavioral mechanisms for rapid weight gain and development of obesity and (2) what new approaches can improve risk prediction and gain novel insights into causes of obesity in early life. Participants identified gaps and opportunities for future research to advance understanding of risk and underlying mechanisms for development of obesity in early life. It was emphasized that future studies will require multi-disciplinary efforts across basic, behavioral, and clinical sciences. An exposome framework is needed to elucidate how behavioral, biological, and environmental risk factors interact. Use of novel statistical methods may provide greater insights into causal mechanisms.

Intergenerational transmission of tobacco smoking: The role of the child's behavioral difficulties. Data from the Danish National Birth cohort (DNBC)

AIMS

This study explores the role of offspring behavioral difficulties in the intergeneration transmission of tobacco smoking.

METHODS

This longitudinal cohort study is based on children born in Denmark in 1996-2003 participating in the Danish National Birth Cohort (DNBC), followed-up until 18years of age. We included mother-child pairs with complete data regarding the exposure (4 trajectories of maternal daily smoking quantity during pregnancy: low, intermediate/stable, intermediate/decreasing and high), outcome (offspring daily smoking status at 18 years) and mediator (offspring symptoms of hyperactivity-inattention at 11 years), that is 24,588 mother-child pairs.

RESULTS

In our study population, during pregnancy respectively 86.2%, 6.80%, 4.08% and 2.97% mothers belonged to the low, intermediate/stable, intermediate/decreasing and high smoking trajectory groups. After controlling for covariates using propensity scores, the direct effect of maternal smoking in pregnancy on offspring smoking in adolescence was statistically significant, especially when the mother belonged to the intermediate/stable smoking trajectory group (ORIPW = 2.09, 95% CI: 1.70 - 2.61) or to the high smoking trajectory group (ORIPW = 2.08, 95% CI: 1.52 - 3.11) compared to the low smoking trajectory group. None of the indirect effects of maternal smoking in pregnancy were statistically significant, and neither were the proportions mediated.

CONCLUSION

Maternal pregnancy smoking seems to have an influence on offspring smoking in early adulthood, which does not appear to be mediated by offspring behavioral difficulties. Women should be strongly encouraged to quit smoking in pregnancy to reduce both short and long-term health risks among their offspring.

Maternal smoking during pregnancy increases the risk of gut microbiome-associated childhood overweight and obesity

Childhood obesity is linked to maternal smoking during pregnancy. Gut microbiota may partially mediate this association and could be potential targets for intervention; however, its role is understudied. We included 1,592 infants from the Canadian Healthy Infants Longitudinal Development Cohort. Data on environmental exposure and lifestyle factors were collected prenatally and throughout the first three years. Weight outcomes were measured at one and three years of age. Stool samples collected at 3 and 12 months were analyzed by sequencing the V4 region of 16S rRNA to profile microbial compositions and magnetic resonance spectroscopy to quantify the metabolites. We showed that quitting smoking during pregnancy did not lower the risk of offspring being overweight. However, exclusive breastfeeding until the third month of age may alleviate these risks. We also reported that maternal smoking during pregnancy significantly increased Firmicutes abundance and diversity. We further revealed that Firmicutes diversity mediates the elevated risk of childhood overweight and obesity linked to maternal prenatal smoking. This effect possibly occurs through excessive microbial butyrate production. These findings add to the evidence that women should quit smoking before their pregnancies to prevent microbiome-mediated childhood overweight and obesity risk, and indicate the potential obesogenic role of excessive butyrate production in early life.

Epigenetic mechanisms of nicotine dependence

Smoking continues to be a leading cause of preventable disease and death worldwide. Nicotine dependence generates a lifelong propensity towards cravings and relapse, presenting an ongoing challenge for the development of treatments. Accumulating evidence supports a role for epigenetics in the development and maintenance of addiction to many drugs of abuse, however, the involvement of epigenetics in nicotine dependence is less clear. Here we review evidence that nicotine interacts with epigenetic mechanisms to enable the maintenance of nicotine-seeking across time. Research across species suggests that nicotine increases permissive histone acetylation, decreases repressive histone methylation, and modulates levels of DNA methylation and noncoding RNA expression throughout the brain. These changes are linked to the promoter regions of genes critical for learning and memory, reward processing and addiction. Pharmacological manipulation of enzymes that catalyze core epigenetic modifications regulate nicotine reward and associative learning, demonstrating a functional role of epigenetic modifications in nicotine dependence. These findings are consistent with nicotine promoting an overall permissive chromatin state at genes important for learning, memory and reward. By exploring these links through next-generation sequencing technologies, epigenetics provides a promising avenue for future interventions to treat nicotine dependence.

Effectiveness of smoking cessation interventions among pregnant women: An updated systematic review and meta-analysis

OBJECTIVE

To carry out a systematic review of systematic reviews with an update of the existing evidence relating to a broad range of smoking cessation interventions, including psycho-social, digital and pharmacologic interventions, for pregnant women.

DATA-SOURCES

Search was conducted in March 2022 in PubMed, EMBASE, and Cochrane in two stages: 1) a search of systematic reviews and meta-analyses, published from January 2012 through January 2022; 2) an update of those that fulfilled eligibility criteria reproducing the primary search strategy.

STUDY ELIGIBILITY CRITERIA

We selected randomized clinical trials (RCTs) that evaluated the effectiveness of pharmacological, digital, and psychosocial interventions in aged 18 years and over who were daily smokers, and compared these with routine care, less intense interventions or placebo.

STUDY APPRAISAL AND SYNTHESIS METHODS

Data from eligible studies were manually extracted by two authors and reviewed by a third. The quality of the reviews was evaluated using the AMSTAR scale, and risk of bias was measured with the Rob-2 tool and GRADE level of evidence.

RESULTS

The meta-analysis included 63 RCTs (n = 19849 women). The interventions found to be effective were: financial incentives (RR:1.77; 95%CI:1.21-2.58), counseling (RR:1.27; 95%CI:1.13-1.43) and long-term nicotine replacement therapy (NRT) (RR:1.53; 95%CI:1.16-2.01). Short-term NRT, bupropion, digital interventions, feedback, social support, and exercise showed no effectiveness. The GRADE level of evidence was moderate-to-high for all interventions, with the exception of long-term NRT.

CONCLUSIONS

Non-pharmacological interventions for smoking cessation are the most effective for pregnant women. The moderator analysis suggests that pregnant women of low socioeconomic status might benefit less from smoking cessation interventions than women of a high socioeconomic status. These women are usually heavier smokers that live in pro-smoking environments and could require more intensive and targeted interventions.

Nicotine-induced Genetic and Epigenetic Modifications in Primary Human Amniotic Fluid Stem Cells

BACKGROUND

Smoking during pregnancy has been linked to adverse health outcomes in offspring, but the underlying mechanisms are not fully understood. To date, the effect of maternal smoking has been tested in primary tissues and animal models, but the scarcity of human tissues limits experimental studies. Evidence regarding smoking-related molecular alteration and gene expression profiles in stem cells is still lacking.

METHODS

We developed a cell culture model of human amniotic fluid stem cells (hAFSCs) of nicotine (NIC) exposure to examine the impact of maternal smoking on epigenetic alterations of the fetus.

RESULTS

NIC 0.1 μM (equivalent to "light" smoking, i.e., 5 cigarettes/day) did not significantly affect cell viability; however, significant alterations in DNA methylation and N6-methyladenosine (m6A) RNA methylation in hAFSCs occurred. These epigenetic changes may influence the gene expression and function of hAFSCs. Furthermore, NIC exposure caused time-dependent alterations of the expression of pluripotency genes and cell surface markers, suggesting enhanced cell stemness and impaired differentiation potential. Furthermore, NICtreated cells showed reduced mRNA levels of key adipogenic markers and hypomethylation of the promoter region of the imprinted gene H19 during adipogenic differentiation, potentially suppressing adipo/lipogenesis. Differential expression of 16 miRNAs, with predicted target genes involved in various metabolic pathways and linked to pathological conditions, including cognitive delay and fetal growth retardation, has been detected.

CONCLUSION

Our findings highlight multi-level effects of NIC on hAFSCs, including epigenetic modifications, altered gene expression, and impaired cellular differentiation, which may contribute to long-term consequences of smoking in pregnancy and its potential impact on offspring health and development.

Early developmental risks for tobacco addiction: A probabilistic epigenesis framework

Considerable progress has been made in elucidating the relationships between early life psychobiological and environmental risk factors and the development of tobacco addiction. However, a comprehensive understanding of the heterogeneity in tobacco addiction phenotypes requires integrating research findings. The probabilistic epigenesis meta-theory offers a valuable framework for this integration, considering systemic, multilevel, developmental, and evolutionary perspectives. In this paper, we critically review relevant research on early developmental risks associated with tobacco addiction and highlight the integrative heuristic value of the probabilistic epigenesis framework for this research. For this, we propose a four-level systems approach as an initial step towards integration, analyzing complex interactions among different levels of influence. Additionally, we explore a coaction approach to examine key interactions between early risk factors. Moreover, we introduce developmental pathways to understand interindividual differences in tobacco addiction risk during development. This integrative approach holds promise for advancing our understanding of tobacco addiction etiology and informing potentially effective intervention strategies.

Epigenome-wide association studies of prenatal maternal mental health and infant epigenetic profiles: a systematic review

Prenatal stress and poor maternal mental health are associated with adverse offspring outcomes; however, the biological mechanisms are unknown. Epigenetic modification has linked maternal health with offspring development. Epigenome-wide association studies (EWAS) have examined offspring DNA methylation profiles for association with prenatal maternal mental health to elucidate mechanisms of these complex relationships. The objective of this study is to provide a comprehensive, systematic review of EWASs of infant epigenetic profiles and prenatal maternal anxiety, depression, or depression treatment. We conducted a systematic literature search following PRISMA guidelines for EWAS studies between prenatal maternal mental health and infant epigenetics through May 22, 2023. Of 645 identified articles, 20 fulfilled inclusion criteria. We assessed replication of CpG sites among studies, conducted gene enrichment analysis, and evaluated the articles for quality and risk of bias. We found one repeated CpG site among the maternal depression studies; however, nine pairs of overlapping differentially methylatd regions were reported in at least two maternal depression studies. Gene enrichment analysis found significant pathways for maternal depression but not for any other maternal mental health category. We found evidence that these EWAS present a medium to high risk of bias. Exposure to prenatal maternal depression and anxiety or treatment for such was not consistently associated with epigenetic changes in infants in this systematic review and meta-analysis. Small sample size, potential bias due to exposure misclassification and statistical challenges are critical to address in future efforts to explore epigenetic modification as a potential mechanism by which prenatal exposure to maternal mental health disorders leads to adverse infant outcomes.

Demystifying the impact of prenatal tobacco exposure on the placental immune microenvironment: Avoiding the tragedy of mending the fold after death

Prenatal tobacco exposure (PTE) correlates significantly with a surge in adverse pregnancy outcomes, yet its pathological mechanisms remain partially unexplored. This study aims to meticulously examine the repercussions of PTE on placental immune landscapes, employing a coordinated research methodology encompassing bioinformatics, machine learning and animal studies. Concurrently, it aims to screen biomarkers and potential compounds that could sensitively indicate and mitigate placental immune disorders. In the course of this research, two gene expression omnibus (GEO) microarrays, namely GSE27272 and GSE7434, were included. Gene set enrichment analysis (GSEA) and immune enrichment investigations on differentially expressed genes (DEGs) indicated that PTE might perturb numerous innate or adaptive immune-related biological processes. A cohort of 52 immune-associated DEGs was acquired by cross-referencing the DEGs with gene sets derived from the ImmPort database. A protein-protein interaction (PPI) network was subsequently established, from which 10 hub genes were extracted using the maximal clique centrality (MCC) algorithm (JUN, NPY, SST, FLT4, FGF13, HBEGF, NR0B2, AREG, NR1I2, SEMA5B). Moreover, we substantiated the elevated affinity of tobacco reproductive toxicants, specifically nicotine and nitrosamine, with hub genes through molecular docking (JUN, FGF13 and NR1I2). This suggested that these genes could potentially serve as crucial loci for tobacco's influence on the placental immune microenvironment. To further elucidate the immune microenvironment landscape, consistent clustering analysis was conducted, yielding three subtypes, where the abundance of follicular helper T cells (p < 0.05) in subtype A, M2 macrophages (p < 0.01), neutrophils (p < 0.05) in subtype B and CD8+ T cells (p < 0.05), resting NK cells (p < 0.05), M2 macrophages (p < 0.05) in subtype C were significantly different from the control group. Additionally, three pivotal modules, designated as red, blue and green, were identified, each bearing a close association with differentially infiltrated immunocytes, as discerned by the weighted gene co-expression network analysis (WGCNA). Functional enrichment analysis was subsequently conducted on these modules. To further probe into the mechanisms by which immune-associated DEGs are implicated in intercellular communication, 20 genes serving as ligands or receptors and connected to differentially infiltrating immunocytes were isolated. Employing a variety of machine learning techniques, including one-way logistic regression, LASSO regression, random forest and artificial neural networks, we screened 11 signature genes from the intersection of immune-associated DEGs and secretory protein-encoding genes derived from the Human Protein Atlas. Notably, CCL18 and IFNA4 emerged as prospective peripheral blood markers capable of identifying PTE-induced immune disorders. These markers demonstrated impressive predictive power, as indicated by the area under the curve (AUC) of 0.713 (0.548-0.857) and 0.780 (0.618-0.914), respectively. Furthermore, we predicted 34 potential compounds, including cyclosporine, oestrogen and so on, which may engage with hub genes and attenuate immune disorders instigated by PTE. The diagnostic performance of these biomarkers, alongside the interventional effect of cyclosporine, was further corroborated in animal studies via ELISA, Western blot and immunofluorescence assays. In summary, this study identifies a disturbance in the placental immune landscape, a secondary effect of PTE, which may underlie multiple pregnancy complications. Importantly, our research contributes to the noninvasive and timely detection of PTE-induced placental immune disorders, while also offering innovative therapeutic strategies for their treatment.

AHRR Hypomethylation mediates the association between maternal smoking and metabolic profiles in children

BACKGROUND

Tobacco smoking during pregnancy is associated with metabolic dysfunction in children, but mechanistic insights remain limited. Hypomethylation of cg05575921 in the aryl hydrocarbon receptor repressor (AHRR) gene is associated with in utero tobacco smoke exposure. In this study, we evaluated whether AHRR hypomethylation mediates the association between maternal smoking and metabolic dysfunction in children.

METHODS

We assessed metabolic dysfunction using liver fat content (LFC), serum, and clinical data in children aged 7-12 years (n=78) followed since birth. Maternal smoking was self-reported at 12 weeks gestation. Methylation was measured by means of pyrosequencing at 3 sequential CpG sites, including cg05575921, at birth and at ages 7-12. Regression models were used to evaluate whether AHRR methylation mediated the association between maternal smoking and child metabolic dysfunction.

RESULTS

Average AHRR methylation at birth was significantly higher among children of nonsmoking mothers compared with children of mothers who smoked (69.8% ± 4.4% vs. 63.5% ± 5.5, p=0.0006). AHRR hypomethylation at birth was associated with higher liver fat content (p=0.01), triglycerides (p=0.01), and alanine aminotransferase levels (p=0.03), and lower HDL cholesterol (p=0.01) in childhood. AHRR hypomethylation significantly mediated associations between maternal smoking and liver fat content (indirect effect=0.213, p=0.018), triglycerides (indirect effect=0.297, p=0.044), and HDL cholesterol (indirect effect = -0.413, p=0.007). AHRR methylation in childhood (n=78) was no longer significantly associated with prenatal smoke exposure or child metabolic parameters (p>0.05).

CONCLUSIONS

AHRR hypomethylation significantly mediates the association between prenatal tobacco smoke exposure and features of childhood metabolic dysfunction, despite the lack of persistent hypomethylation of AHRR into childhood. Further studies are needed to replicate these findings and to explore their causal and long-term significance.

Associations between nutrients in one-carbon metabolism and fetal DNA methylation in pregnancies with or without gestational diabetes mellitus

BACKGROUND

Gestational diabetes mellitus (GDM), characterized by hyperglycemia that develops during pregnancy, increases the risk of fetal macrosomia, childhood obesity and cardiometabolic disorders later in life. This process has been attributed partly to DNA methylation modifications in growth and stress-related pathways. Nutrients involved with one-carbon metabolism (OCM), such as folate, choline, betaine, and vitamin B12, provide methyl groups for DNA methylation of these pathways. Therefore, this study aimed to determine whether maternal OCM nutrient intakes and levels modified fetal DNA methylation and in turn altered fetal growth patterns in pregnancies with and without GDM.

RESULTS

In this prospective study at a single academic institution from September 2016 to June 2019, we recruited 76 pregnant women with and without GDM at 25-33 weeks gestational age and assessed their OCM nutrient intake by diet recalls and measured maternal blood OCM nutrient levels. We also collected placenta and cord blood samples at delivery to examine fetal tissue DNA methylation of the genes that modify fetal growth and stress response such as insulin-like growth factor 2 (IGF2) and corticotropin-releasing hormone (CRH). We analyzed the association between maternal OCM nutrients and fetal DNA methylation using a generalized linear mixed model. Our results demonstrated that maternal choline intake was positively correlated with cord blood CRH methylation levels in both GDM and non-GDM pregnancies (r = 0.13, p = 0.007). Further, the downstream stress hormone cortisol regulated by CRH was inversely associated with maternal choline intake (r = - 0.36, p = 0.021). Higher maternal betaine intake and serum folate levels were associated with lower cord blood and placental IGF2 DNA methylation (r = - 0.13, p = 0.049 and r = - 0.065, p = 0.034, respectively) in both GDM and non-GDM pregnancies. Further, there was an inverse association between maternal betaine intake and birthweight of infants (r = - 0.28, p = 0.015).

CONCLUSIONS

In conclusion, we observed a complex interrelationship between maternal OCM nutrients and fetal DNA methylation levels regardless of GDM status, which may, epigenetically, program molecular pathways related to fetal growth and stress response.

Polymorphisms in Glutathione S-Transferase (GST) Genes Modify the Effect of Exposure to Maternal Smoking Metabolites in Pregnancy and Offspring DNA Methylation

Maternal smoking in pregnancy (MSP) affects the offspring's DNA methylation (DNAm). There is a lack of knowledge regarding individual differences in susceptibility to exposure to MSP. Glutathione S-transferase (GST) genes are involved in protection against harmful oxidants such as those found in cigarette smoke. This study aimed to test whether polymorphisms in GST genes influence the effect of MSP on offspring DNAm. Using data from the Isle of Wight birth cohort, we assessed the association of MSP and offspring DNAm in 493 mother-child dyads (251 male, 242 female) with the effect-modifying role of GST gene polymorphism (at rs506008, rs574344, rs12736389, rs3768490, rs1537234, and rs1695). MSP was assessed by levels of nicotine and its downstream metabolites (cotinine, norcotinine, and hydroxycotinine) in maternal sera. In males, associations of hydroxycotinine with DNAm at cg18473733, cg25949550, cg11647108, and cg01952185 and norcotinine with DNAm at cg09935388 were modified by GST gene polymorphisms (p-values < 0.05). In females, associations of hydroxycotinine with DNAm at cg12160087 and norcotinine with DNAm at cg18473733 were modified by GST gene polymorphisms (p-values < 0.05). Our study emphasizes the role of genetic polymorphism in GST genes in DNAm's susceptibility to MSP.

Epigenome-Wide Associations of Placental DNA Methylation and Behavioral and Emotional Difficulties in Children at 3 Years of Age

The placenta is a key organ for fetal and brain development. Its epigenome can be regarded as a biochemical record of the prenatal environment and a potential mechanism of its association with the future health of the fetus. We investigated associations between placental DNA methylation levels and child behavioral and emotional difficulties, assessed at 3 years of age using the Strengths and Difficulties Questionnaire (SDQ) in 441 mother-child dyads from the EDEN cohort. Hypothesis-driven and exploratory analyses (on differentially methylated probes (EWAS) and regions (DMR)) were adjusted for confounders, technical factors, and cell composition estimates, corrected for multiple comparisons, and stratified by child sex. Hypothesis-driven analyses showed an association of cg26703534 (AHRR) with emotional symptoms, and exploratory analyses identified two probes, cg09126090 (intergenic region) and cg10305789 (PPP1R16B), as negatively associated with peer relationship problems, as well as 33 DMRs, mostly positively associated with at least one of the SDQ subscales. Among girls, most associations were seen with emotional difficulties, whereas in boys, DMRs were as much associated with emotional than behavioral difficulties. This study provides the first evidence of associations between placental DNA methylation and child behavioral and emotional difficulties. Our results suggest sex-specific associations and might provide new insights into the mechanisms of neurodevelopment.

Maternal Cigarette Smoking and Congenital Upper and Lower Limb Differences: A Systematic Review and Meta-Analysis

Maternal smoking during pregnancy has been associated with adverse effects on foetal development, including congenital limb anomalies. This systematic review aimed to provide an updated assessment of the association between maternal smoking during pregnancy and the risk of congenital limb anomalies. A systematic search was conducted to identify relevant studies published up to February 2023. Studies reporting on the relationship between maternal smoking during pregnancy and congenital digital anomalies or congenital limb reduction defects were included. Two independent reviewers screened the studies, extracted data, and assessed the quality of the included studies. Meta-analyses were performed to estimate the pooled odds ratios with 95% confidence intervals using fixed and random-effects models. In total, 37 publications comprising 11 cohort and 26 case-control studies were included in the systematic review. The meta-analysis demonstrated a significant increased risk of congenital limb reduction defects (pooled OR: 1.27, 95% CI: 1.18-1.38) in infants born to mothers who smoked during pregnancy. Similarly, a significant relationship was observed for the development of polydactyly/syndactyly/adactyly when considered as a single group (pooled OR: 1.32, 95% CI: 1.25-1.40). Yet, in contrast, no significant association was observed when polydactyly (pooled OR: 1.06, 95% CI: 0.88-1.27) or syndactyly (pooled OR: 0.91, 95% CI: 0.77-1.08) were considered individually. This systematic review provides updated evidence of a significant relationship between maternal smoking during pregnancy and increased risk of congenital limb anomalies. These findings highlight the potential detrimental effects of smoking on foetal limb development and underscore the importance of smoking cessation interventions for pregnant women to mitigate these risks.

Advances in Genetics and Epigenetics of Developmental Coordination Disorder in Children

Developmental coordination disorder (DCD) is a developmental disorder characterized by impaired motor coordination, often co-occurring with attention deficit disorder, autism spectrum disorders, and other psychological and behavioural conditions. The aetiology of DCD is believed to involve brain changes and environmental factors, with genetics also playing a role in its pathogenesis. Recent research has identified several candidate genes and genetic factors associated with motor impairment, including deletions, copy number variations, single nucleotide polymorphisms, and epigenetic modifications. This review provides an overview of the current knowledge in genetic research on DCD, highlighting the importance of continued research into the underlying genetic mechanisms. While evidence suggests a genetic contribution to DCD, the evidence is still in its early stages, and much of the current evidence is based on studies of co-occurring conditions. Further research to better understand the genetic basis of DCD could have important implications for diagnosis, treatment, and our understanding of the condition's aetiology.

High-Dimensional Mediation Analysis: A New Method Applied to Maternal Smoking, Placental DNA Methylation, and Birth Outcomes

BACKGROUND

High-dimensional mediation analysis is an extension of unidimensional mediation analysis that includes multiple mediators, and increasingly it is being used to evaluate the indirect omics-layer effects of environmental exposures on health outcomes. Analyses involving high-dimensional mediators raise several statistical issues. Although many methods have recently been developed, no consensus has been reached about the optimal combination of approaches to high-dimensional mediation analyses.

OBJECTIVES

We developed and validated a method for high-dimensional mediation analysis (HDMAX2) and applied it to evaluate the causal role of placental DNA methylation in the pathway between exposure to maternal smoking (MS) during pregnancy and gestational age (GA) and birth weight of the baby at birth.

METHODS

HDMAX2 combines latent factor regression models for epigenome-wide association studies with max2 tests for mediation and considers CpGs and aggregated mediator regions (AMRs). HDMAX2 was carefully evaluated using simulated data and compared to state-of-the-art multidimensional epigenetic mediation methods. Then, HDMAX2 was applied to data from 470 women of the Etude des Déterminants pré et postnatals du développement de la santé de l'Enfant (EDEN) cohort.

RESULTS

HDMAX2 demonstrated increased power in comparison with state-of-the-art multidimensional mediation methods and identified several AMRs not identified in previous mediation analyses of exposure to MS on birth weight and GA. The results provided evidence for a polygenic architecture of the mediation pathway with a posterior estimate of the overall indirect effect of CpGs and AMRs equal to 44.5g lower birth weight representing 32.1% of the total effect [standard deviation (SD)=60.7g]. HDMAX2 also identified AMRs having simultaneous effects both on GA and on birth weight. Among the top hits of both GA and birth weight analyses, regions located in COASY, BLCAP, and ESRP2 also mediated the relationship between GA and birth weight, suggesting reverse causality in the relationship between GA and the methylome.

DISCUSSION

HDMAX2 outperformed existing approaches and revealed an unsuspected complexity of the potential causal relationships between exposure to MS and birth weight at the epigenome-wide level. HDMAX2 is applicable to a wide range of tissues and omic layers. https://doi.org/10.1289/EHP11559.

The effects of maternal cigarette smoking on cadmium and lead levels, miRNA expression and biochemical parameters across the feto-placental unit

Several miRNAs have been previously identified to be associated with cigarette smoke and/or the toxic metals cadmium (Cd) and lead (Pb). The aim of this study was to investigate the associations of maternal cigarette smoking with cadmium (Cd) and lead (Pb) levels, candidate miRNA expression and biochemical parameters across the feto-placental unit. miRNAs were isolated according to protocols provided by manufacturer from 72 healthy postpartum women using Qiagens' kits based on phenol/guanidine samples lysis and silica-membrane purification of total RNA. Candidate miRNAs (miR-1537, miR-190b, miR-16, miR-21, and miR-146a) were quantified by real-time PCR. Biochemical parameters were analyzed in plasma samples by standardized and harmonized enzymatic methods using appropriate calibrators, while CRP was determined by immunoturbidimetric method. Concentration of Cd and Pb in whole blood and placenta samples were measured by inductively coupled plasma mass spectroscopy. Cd levels in smokers were higher in all of the analyzed compartments of the feto-placental unit, Pb in maternal blood and placenta than non-smokers. Smokers also had a higher expression of miR-16 in maternal and miR-146a in cord plasma, and lower expression of miR-21 in the placenta in comparison to non-smokers. Urate concentrations in the maternal plasma of smokers were lower than this value in non-smokers. The study has demonstrated that maternal smoking was associated with toxic metals (Cd and Pb) levels, urate concentration and alteration of miRNA expression. Given that the effects of maternal smoking on miRNA expression are inadequate, all compartments of the feto-placental unit should be analyzed to obtain a complete picture. This paper is the first to report on the results of expression of cellular and circulating miRNAs simultaneously in maternal and fetal compartments and in the placenta.

Higher blood nicotine concentrations following smokeless tobacco (pituri) and cigarette use linked to adverse pregnancy outcomes for Central Australian Aboriginal pregnancies

BACKGROUND

In central Australia, Aboriginal women use wild tobacco plants, Nicotiana spp. (locally known as pituri) as a chewed smokeless tobacco, with this use continuing throughout pregnancy and lactation. Our aim was to describe the biological concentrations of nicotine and metabolites in samples from mothers and neonates and examine the relationships between maternal self-reported tobacco use and maternal and neonatal outcomes.

METHODS

Central Australian Aboriginal mothers (and their neonates) who planned to birth at the Alice Springs Hospital (Northern Territory, Australia) provided biological samples: maternal blood, arterial and venous cord blood, amniotic fluid, maternal and neonatal urine, and breast milk. These were analysed for concentrations of nicotine and five metabolites.

RESULTS

A sample of 73 women were enrolled who self-reported: no-tobacco use (n = 31), tobacco chewing (n = 19), or smoking (n = 23). Not all biological samples were obtained from all mothers and neonates. In those where samples were available, higher total concentrations of nicotine and metabolites were found in the maternal plasma, urine, breast milk, cord bloods and Day 1 neonatal urine of chewers compared with smokers and no-tobacco users. Tobacco-exposed mothers (chewers and smokers) with elevated blood glucose had higher nicotine and metabolite concentrations than tobacco-exposed mothers without elevated glucose, and this was associated with increased neonatal birthweight. Neonates exposed to higher maternal nicotine levels were more likely to be admitted to Special Care Nursery. By Day 3, urinary concentrations in tobacco-exposed neonates had reduced from Day 1, although these remained higher than concentrations from neonates in the no-tobacco group.

CONCLUSIONS

This research provides the first evidence that maternal pituri chewing results in high nicotine concentrations in a wide range of maternal and neonatal biological samples and that exposure may be associated with adverse maternal and neonatal outcomes. Screening for the use of all tobacco and nicotine products during pregnancy rather than focusing solely on smoking would provide a more comprehensive assessment and contribute to a more accurate determination of tobacco and nicotine exposure. This knowledge will better inform maternal and foetal care, direct attention to targeted cessation strategies and ultimately improve long-term clinical outcomes, not only in this vulnerable population, but also for the wider population.

NOTE TO READERS

In this research, the central Australian Aboriginal women chose the term 'Aboriginal' to refer to themselves, and 'Indigenous' to refer to the broader group of Australian First Peoples. That choice has been maintained in the reporting of the research findings.

An Interplay between Epigenetics and Translation in Oocyte Maturation and Embryo Development: Assisted Reproduction Perspective

Germ cell quality is a key prerequisite for successful fertilization and early embryo development. The quality is determined by the fine regulation of transcriptomic and proteomic profiles, which are prone to alteration by assisted reproduction technology (ART)-introduced in vitro methods. Gaining evidence shows the ART can influence preset epigenetic modifications within cultured oocytes or early embryos and affect their developmental competency. The aim of this review is to describe ART-determined epigenetic changes related to the oogenesis, early embryogenesis, and further in utero development. We confront the latest epigenetic, related epitranscriptomic, and translational regulation findings with the processes of meiotic maturation, fertilization, and early embryogenesis that impact the developmental competency and embryo quality. Post-ART embryo transfer, in utero implantation, and development (placentation, fetal development) are influenced by environmental and lifestyle factors. The review is emphasizing their epigenetic and ART contribution to fetal development. An epigenetic parallel among mouse, porcine, and bovine animal models and human ART is drawn to illustrate possible future mechanisms of infertility management as well as increase the awareness of the underlying mechanisms governing oocyte and embryo developmental complexity under ART conditions.

Prenatal Maternal Smoke, DNA Methylation, and Multi-omics of Tissues and Child Health

PURPOSE OF REVIEW

Maternal tobacco smoking during pregnancy is of public health concern, and understanding the biological mechanisms can help to promote smoking cessation campaigns. This non-systematic review focuses on the effects of maternal smoking during pregnancy on offspring's epigenome, consistent in chemical modifications of the genome that regulate gene expression.

RECENT FINDINGS

Recent meta-analyses of epigenome-wide association studies have shown that maternal smoking during pregnancy is consistently associated with offspring's DNA methylation changes, both in the placenta and blood. These studies indicate that effects on blood DNA methylation can persist for years, and that the longer the duration of the exposure and the higher the dose, the larger the effects. Hence, DNA methylation scores have been developed to estimate past exposure to maternal smoking during pregnancy as biomarkers. There is robust evidence for DNA methylation alterations associated with maternal smoking during pregnancy; however, the role of sex, ethnicity, and genetic background needs further exploration. Moreover, there are no conclusive studies about exposure to low doses or during the preconception period. Similarly, studies on tissues other than the placenta and blood are scarce, and cell-type specificity within tissues needs further investigation. In addition, biological interpretation of DNA methylation findings requires multi-omics data, poorly available in epidemiological settings. Finally, although several mediation analyses link DNA methylation changes with health outcomes, they do not allow causal inference. For this, a combination of data from multiple study designs will be essential in the future to better address this topic.

The Impact of the Main Negative Socio-Economic Factors on Female Fertility

The negative relationship between fertility and income is well known to economists and demographers. Developed countries have experienced a remarkable decline in their fertility rate as they have become richer. Lifestyle choices can affect a woman’s ability to conceive. Tobacco use and heavy drinking is associated with an increased risk of ovulation disorders, and being overweight or significantly underweight can inhibit normal ovulation. Our research is focused on evaluating the main risk factors that influence female fertility. We assembled a country-specific dataset on birth rate and socio-economic factors for 171 countries, using data integrated from publicly available data sources. The regression model shows that the negative factor with the greatest impact on female fertility is represented by the level of income per capita. The negative effects of smoking, alcohol consumption, and body weight on female fertility are also demonstrated, but with a lower impact compared to the average income per capita.

The impact of the environment on neurodevelopmental disorders in early childhood

OBJECTIVES

To review the literature about the environmental impact on children's mental, behavior, and neurodevelopmental disorders.

SOURCES OF DATA

A nonsystematic review of papers published on MEDLINE-PubMed was carried out using the terms environment and mental health or psychiatric disorders or neurodevelopmental disorders.

SUMMARY OF FINDINGS

Psychopathology emerges at different developmental times as the outcome of complex interactions between nature and nurture and may impact each person in different ways throughout childhood and determine adult outcomes. Mental health is intertwined with physical health and is strongly influenced by cultural, social and economic factors. The worldwide prevalence of psychiatric disorders in children and adolescents is 13.4%, and the most frequent are anxiety, disruptive behavior disorders, attention deficit hyperactivity disorder and depression. Neurodevelopment begins at the embryonic stage and continues through adulthood with genetic differences, environmental exposure, and developmental timing acting synergistically and contingently. Early life experiences have been linked to a dysregulation of the neuroendocrine-immune circuitry which results in alterations of the brain during sensitive periods. Also, the environment may trigger modifications on the epigenome of the differentiating cell, leading to changes in the structure and function of the organs. Over 200 million children under 5 years are not fulfilling their developmental potential due to the exposure to multiple risk factors, including poverty, malnutrition and unsafe home environments.

CONCLUSIONS

Continued support for the promotion of a protective environment that comprises effective parent-child interactions is key in minimizing the effects of neurodevelopmental disorders throughout the lifetime.

Epigenetic Biomarkers Screening of Non-Coding RNA and DNA Methylation Based on Peripheral Blood Monocytes in Smokers

This study aims to use bioinformatics methods to determine the epigenetic changes in microRNA expression and DNA methylation caused by cigarette smoking. The data of mRNA, miRNA expression, and methylation microarray were obtained from the GEO database to filter differentially expressed genes (DEGs), differentially expressed miRNAs (DEMs), and methylated CpG probes (DMPs) through the limma package. The R clusterProfile package was used for functional annotation and enrichment analysis. The protein-protein interaction (PPI) network was constructed by the String database and visualized in Cytoscape software. Starbase database was employed to predict lncRNA and CirRNA based on the sequence of miRNA, and to establish a regulatory network of ceRNA. By overlapping DEG and DEM, 107 down-miRNA-targeted up-regulated genes and 65 up-miRNA-target down-regulated genes were obtained, which were mainly enriched in autophagy signaling pathways and protein ubiquitination pathways, respectively. In addition, 324 genes with low methylation and high expression and 204 genes with high methylation and low expression were respectively related to the degeneration of the nervous system and the function of the cardiovascular system. Interestingly, 43 genes were up-regulated under the dual regulation of reduced miRNA and hypomethylation, while 14 genes were down-regulated under the dual regulation of increased miRNA and hypermethylation. Ten chemicals have been identified as putative therapeutic agents for pathological conditions caused by smoking. In addition, among these genes, HSPA4, GRB2, PRKCA, and BCL2L1 could play a fundamental role in related diseases caused by smoking and may be used as the biomarkers for precise diagnosis and targets for future therapies of smoking-related diseases.

Maternal smoking behaviour across the first two pregnancies and small for gestational age birth: Analysis of the SLOPE (Studying Lifecourse Obesity PrEdictors) population-based cohort in the South of England

Maternal smoking is established to cause adverse birth outcomes, but evidence considering maternal smoking change across successive pregnancies is sparse. We examined the association between self-reported maternal smoking during and between the first two pregnancies with the odds of small for gestational age (SGA) birth (<10th percentile) in the second infant. Records for the first two pregnancies for 16791 women within the SLOPE (Studying Lifecourse Obesity PrEdictors) study were analysed. This is a population-based cohort of prospectively collected anonymised antenatal and birth healthcare data (2003-2018) in Hampshire, UK. Logistic regression was used to relate maternal smoking change to the odds of SGA birth in the second infant. In the full sample, compared to never smokers, mothers smoking at the start of the first pregnancy had higher odds of SGA birth in the second pregnancy even where they stopped smoking before the first antenatal appointment for the second pregnancy (adjusted odds ratio (aOR) 1.50 [95% confidence interval 1.10, 2.03]). If a mother was not a smoker at the first antenatal appointment for either her first or her second pregnancy, but smoked later in her first pregnancy or between pregnancies, there was no evidence of increased risk of SGA birth in the second pregnancy compared to never smokers. A mother who smoked ten or more cigarettes a day at the start of both of her first two pregnancies had the highest odds of SGA birth (3.54 [2.55, 4.92]). Women who were not smoking at the start of the first pregnancy but who subsequently resumed/began smoking and smoked at the start of their second pregnancy, also had higher odds (2.11 [1.51, 2.95]) than never smokers. Smoking in the first pregnancy was associated with SGA birth in the second pregnancy, even if the mother quit by the confirmation of her second pregnancy.

Special Issue on the Effects of Prenatal Smoking/Nicotine Exposure on the Child's Health

Smoking increases the risk of negative pregnancy and perinatal outcomes and may have negative effects on a child's short and long-term health [...].