Active Maternal Smoking Research Articles

The importance of smoking cessation during pregnancy and its association with perinatal outcomes

Abstract In utero exposure to tobacco smoke is associated with an increased risk of multiple adverse perinatal outcomes. Smoking cessation during pregnancy has been related to the improvement of these outcomes, but often relies on self-reporting, impairing an accurate assessment of smoking cessation impact on newborńs health. Building on data obtained in the frame of the NEOGENE project, this work aimed to estimate the association between smoking cessation among pregnant women, confirmed by maternal urinary cotinine concentrations, and perinatal outcomes. The study population included 595 pregnant women who sought prenatal care in a public hospital in Porto (Portugal), from April 2017 to July 2018. Data on tobacco consumption and cessation was obtained in a face-to-face interview, during the hospital stay. Perinatal outcomes, namely birth weight (BW), length (BL) and head circumference (HC) were retrieved from the hospital medical records. Maternal self-reported tobacco use was validated by urinary cotinine concentrations, using the solid-phase competitive ELISA technique. Maternal active smoking was associated with a significant decrease in BW, BL and HC of 157.66 g (p < 0.001), 0.78 cm (p = 0.001) and 0.39 cm (p = 0.016). Notably, maternal smoking cessation led to a significant increase in BW of approximately 172 g (p = 0.006), when compared to mothers who have not ceased. Increases in BL and HC did not reach significance. This study upholds that tobacco consumption is still an important public health threat in Portugal and that smoking cessation during pregnancy reverses smoking-associated deficits in perinatal outcomes, emphasizing the crucial need for awareness campaigns to promote smoking cessation during pregnancy. Acknowledgments: This work was supported by FCT and FAPESP (FAPESP/19914/2014). AIS, JM and CC also acknowledge FCT for individual funding (SFRH/BD/145101/2019, SFRH/BPD/115112/2016 and SFRH/BPD/96196/2013 grants, respectively). Key messages Maternal active smoking was significantly associated with lower birth weight, length and head circumference. Maternal smoking cessation reverses the smoking-associated deficits in birth weight.

Maternal Cigarette Smoking and Cleft Lip and Palate: A Systematic Review and Meta-Analysis.

Objectives A systematic review and meta-analysis to determine the association between active maternal smoking and cleft lip and palate etiology. Data sources Medline, Embase, Web of Science and the Cochrane Library from inception to November, 2020. Study selection Observational studies of cigarette smoking habits in pregnant women. Outcomes included cleft lip and/or palate, cleft lip ± palate and cleft palate only. Data analysis Publication bias analyses were performed and the Newcastle Ottawa scales were used to assess study quality. Fixed or random effect models were used in the meta-analysis, dependent on risk of statistical heterogeneity. Results Forty-five studies were eligible for inclusion of which 11 were cohort and 34 were case–control studies. Sixteen studies were of sufficient standard for inclusion in the meta-analysis. The summary odds ratio for the association between smoking and cleft lip and/or palate was 1.42 (95%CI 1.27-1.59) with a population attributable fraction of 4% (95%CI 3%-5%). There was limited evidence to show a dose–response effect of smoking. Conclusions This review reports a moderate association between maternal smoking and orofacial cleft but the overall quality of the conventional observational studies included was poor. There is a need for high quality and novel research strategies to further define the role of smoking in the etiology of cleft lip and palate.

Maternal tobacco exposure during pregnancy and allergic rhinitis in offspring: A systematic review and meta-analysis.

Background:Maternal tobacco exposure during pregnancy is known to cause a potential hazard to the offspring's health. So far, published studies have shown no consistent results with whether tobacco exposure in utero is causally linked to the development of allergic rhinitis in offspring. The aim of this study was to comprehensively evaluate the association between maternal tobacco exposure during pregnancy and allergic rhinitis in offspring by meta-analysis and to provide reference for clinical work.Methods:Literatures were searched in CNKI, Wanfang Data, VIP, SinoMed, PubMed, Web of science and Embase up to September 30,2020. Screening, inclusion, quality assessment, data extraction and data analysis of the literatures were conducted. Meta-analysis was performed with Revman 5.3 and State15.1 software. Odds ratio (OR) and 95%CI were used as observation indicators.Results:We had retrieved 16 articles with 22 independent datasets and 11,49,879 sample size. When all the studies were analyzed together, the results showed that maternal smoking exposure during pregnancy would increase the risk of allergic rhinitis in offspring (OR = 1.13, 95%CI:1.02–1.26), especially maternal passive smoking during pregnancy (OR = 1.39, 95%CI:1.05–1.84). But subgroup analysis showed that maternal active smoking during pregnancy was only significantly associated with offspring allergic rhinitis in cross-sectional studies (OR = 1.24, 95%CI:1.07–1.45) and study done in America study (OR = 1.22, 95%CI:1.05–1.42).Conclusions:Tobacco exposure during pregnancy could increase the risk of allergic rhinitis in offspring. The importance of avoiding prenatal tobacco exposure should be emphasized more for the health of next generation in the public.

Urinary cotinine assessment of maternal smoking and environmental tobacco smoke exposure status and its associations with perinatal outcomes: a cross-sectional birth study

Tobacco consumption and environmental tobacco smoke (ETS) exposure remains an important public health concern. Pregnant women require particular attention as active and passive smoking during pregnancy are associated with multiple adverse perinatal outcomes. This study aimed to biochemically validate self-reported smoking and ETS exposure status among pregnant women, to more precisely ascertain its association with adverse perinatal outcomes. Data refers to 595 pregnant women who sought prenatal care in a public hospital in Porto, Portugal. A standard questionnaire on smoking and ETS-related variables was completed. Urinary cotinine (UC) concentrations were assessed by solid-phase competitive ELISA, in maternal urine samples collected on the day of delivery. The results showed that the optimal UC cut-off value to distinguish smokers from non-smokers and within non-smokers those who were exposed to ETS from those non-exposed in the third trimester of pregnancy was 74.1 ng/mL (sensitivity and specificity of 96.7% and 98.0%, respectively) and 1.6 ng/mL (sensitivity of 66.2% and specificity of 75.7%, respectively). The agreement between maternal self-reported and UC-based smoking status was very good (κ=0.919, p<0.001), but much lower for ETS exposure (κ=0.386, p<0.001). Maternal active smoking in the third trimester of pregnancy was associated with a significant decrease in birth weight, length and head circumference of 157.66 g (95% CI: −245.81, −69.52; p<0.001), 0.78 cm (95% CI: −1.22, −0.34; p=0.001) and 0.39 cm (95% CI: −0.70, −0.07; p=0.016), respectively. Maternal ETS exposure in the third trimester of pregnancy was associated with a non-significant increase in birth weight of 38.37 g (95% CI: −28.91, 105.64; p=0.263). Furthermore, maternal smoking cessation was associated with the increase of approximately 172 g in birth weight (95% CI: 50.00, 293.19). As such, there is an urgent need for increased public health awareness campaigns to encourage smoking cessation during pregnancy, in order to improve perinatal outcomes.

Passive Smoking and Congenital Heart Defects in Offspring among Bangladesh

Objective: Maternal active smoking is significantly associated with an increased risk of congenital heart defects (CHDs), but the association between maternal passive smoking and risk of CHDs is inconclusive. This study was conducted to evaluate the effect of passive smoking and the risk of development of CHD among Bangladeshi population. Methodology: It was a case control study, conducted from July 2018 to July 2019 in Paediatric Cardiology department of Dhaka Shishu (Children) Hospital. Parents of the children with CHD visiting the out-patient department of Dhaka Shishu Hospital was considered as cases. Controls were taken from parents of the children who don’t have congenital heart disease. Face-to-face interviews were conducted to collect information on maternal active and passive smoking. Data was collected by using a structured questionnaire containing all the variables of interest and analyzed by using SPSS version 21. Chi square test (ꭓ2), Odds ratio (OR) and 95% confidence intervals (CIs) were calculated to estimate the associations between maternal passive smoking and all CHDs. Risk factors on bivariate analysis were introduced into a logistic regression model as independent factors and dependent variable was CHDs to find out the association between CHDs and maternal passive smoking. Results: Among case group no mother was active smoker, 51.9% were passive smoker and most of the cases source was husband, 19.6% took smokeless tobacco or green tobacco, 55.8% took tea and 5.8% took coffee during pregnancy period. On logistic regression analysis passive smoking (p=0.019) was independently associated with CHDs. Mother with passive smoking exposure had 1.5 times risk of developing CHDs compared to those who were not exposed. Conclusions: Passive smoking is significantly associated with CHDs.

The association of in utero tobacco smoke exposure, quantified by serum cotinine, and Autism Spectrum Disorder.

Previous studies on in utero exposure to maternal environmental tobacco smoke (ETS) or maternal active smoking and Autism Spectrum Disorder (ASD) have not been entirely consistent, and no studies have examined in utero cotinine concentrations as an exposure classification method. We measured cotinine in stored second trimester maternal serum for 498 ASD cases and 499 controls born in California in 2011-2012. We also obtained self-reported maternal cigarette smoking during and immediately prior to pregnancy, as well as covariate data, from birth records. Using unconditional logistic regression, we found no association between log10 cotinine concentrations and odds for developing ASD among children of non-smokers (aOR: 0.93 [95% CI: 0.69, 1.25] per ng/ml), which represents exposure to ETS, though there may be a possible interaction with race. We found no association between cotinine-defined smoking (≥3.08 ng/ml vs. <3.08 ng/ml) (adjusted odds ratio [aOR]: 0.73 (95% confidence interval [95% CI]: 0.35, 1.54)) or self-reported smoking (aOR: 1.64 [95% CI: 0.65, 4.16]) and ASD. In one of the few studies of ETS and the first with measured cotinine, our results indicate no overall relationship between in utero exposure to tobacco smoke from maternal ETS exposure or active smoking, and development of ASD. LAY SUMMARY: This study found that women who smoke or are exposed to tobacco smoke during pregnancy are not more likely to have children with Autism Spectrum Disorder (ASD). This is the first ASD study to measure a chemical in the mother's blood during pregnancy to identify exposure to tobacco smoke.

Associations and interaction effects of maternal smoking and genetic polymorphisms of cytochrome P450 genes with risk of congenital heart disease in offspring: A case-control study.

To assess associations and interactions of maternal smoking and cytochrome P450 (CYP450) genetic variants with the developments of congenital heart disease (CHD) and specific subtypes.A case–control study of 654 cases and 666 controls was conducted from November 2017 to March 2020. The exposures of interest were maternal active and passive smoking before/in the early pregnancy and CYP450 genetic polymorphisms. Data were analyzed using the Chi-square test and logistic regression analysis.After adjusting for the potential confounding factors, our study showed maternal active (ORadj = 2.34, 95%CI: 1.19–4.60) or passive (ORadj = 1.76, 95%CI: 1.34–2.31) smoking before pregnancy, passive smoking in the early pregnancy (ORadj = 3.05, 95%CI: 2.26–4.12), as well as polymorphisms of CYP450 at rs1065852 (G/A vs G/G: ORadj = 1.46, 95%CI: 1.07–1.99; A/A vs G/G: ORadj = 1.63, 95%CI: 1.15–2.33) and rs16947 (A/A vs G/G: ORadj = 3.61, 95%CI: 2.09–6.23), were significantly associated with risk of total CHD in offspring. Similar results were also found for some subtypes of CHD. Additionally, significant interactions between maternal smoking and CYP450 genes on the risk of CHD were observed.Maternal smoking and CYP450 genetic variants were associated with increased risk of CHD and specific subtypes in offspring. And the effects of CYP450 genes on CHD may be modified by maternal smoking.

Prenatal environmental tobacco smoke exposure alters children’s cognitive control circuitry: A preliminary study

Background and ObjectivesPrenatal exposure to environmental tobacco smoke (ETS) is associated with increased attention problems in children, however, the effects of such exposure on children’s brain structure and function have not been studied. Herein, we probed effects of prenatal ETS on children’s cognitive control circuitry and behavior. MethodsForty-one children (7–9 years) recruited from a prospective longitudinal birth cohort of non-smoking mothers completed structural and task-functional magnetic resonance imaging to evaluate effects of maternal ETS exposure, measured by maternal prenatal urinary cotinine. Attention problems and externalizing behaviors were measured by parent report on the Child Behavior Checklist. ResultsCompared to non-exposed children, exposed children had smaller left and right thalamic and inferior frontal gyrus (IFG) volumes, with large effect sizes (p-FDR < .05, Cohen’s D range from 0.79 to 1.07), and increased activation in IFG during the resolution of cognitive conflict measured with the Simon Spatial Incompatibility Task (38 voxels; peak t(25) = 5.25, p-FWE = .005). Reduced thalamic volume was associated with increased IFG activation and attention problems, reflecting poor cognitive control. Mediation analyses showed a trend toward left thalamic volume mediating the association between exposure and attention problems (p = .05). ConclusionsOur findings suggest that maternal ETS exposure during pregnancy has deleterious effects on the structure and function of cognitive control circuitry which in turn affects attentional capacity in school-age children. These findings are consistent with prior findings documenting the effects of active maternal smoking on chidlren’s neurodevleoment, pointing to the neurotixicity of nicotine regardless of exposure pathway.

DNA methylation of GFI1 as a mediator of the association between prenatal smoking exposure and ADHD symptoms at 6\xa0years: the Hokkaido Study on Environment and Children\u2019s Health

BackgroundPrenatal smoking exposure has been associated with childhood attention-deficit/hyperactivity disorder (ADHD). However, the mechanism underlying this relationship remains unclear. We assessed whether DNA methylation differences may mediate the association between prenatal smoking exposure and ADHD symptoms at the age of 6 years.ResultsWe selected 1150 mother–infant pairs from the Hokkaido Study on the Environment and Children’s Health. Mothers were categorized into three groups according to plasma cotinine levels at the third trimester: non-smokers (≤ 0.21 ng/mL), passive smokers (0.21–11.48 ng/mL), and active smokers (≥ 11.49 ng/mL). The children’s ADHD symptoms were determined by the ADHD-Rating Scale at the age of 6 years. Maternal active smoking during pregnancy was significantly associated with an increased risk of ADHD symptoms (odds ratio, 1.89; 95% confidence interval, 1.14–3.15) compared to non-smoking after adjusting for covariates. DNA methylation of the growth factor-independent 1 transcriptional repressor (GFI1) region, as determined by bisulfite next-generation sequencing of cord blood samples, mediated 48.4% of the total effect of the association between maternal active smoking during pregnancy and ADHD symptoms. DNA methylation patterns of other genes (aryl-hydrocarbon receptor repressor [AHRR], cytochrome P450 family 1 subfamily A member 1 [CYP1A1], estrogen receptor 1 [ESR1], and myosin IG [MYO1G]) regions did not exert a statistically significant mediation effect.ConclusionsOur findings demonstrated that DNA methylation of GFI1 mediated the association between maternal active smoking during pregnancy and ADHD symptoms at the age of 6 years.

Population Attributable Fractions of Modifiable Risk Factors for Nonsyndromic Orofacial Clefts: A Prospective Cohort Study From the Japan Environment and Children's Study.

BackgroundPopulation impact of modifiable risk factors on orofacial clefts is still unknown. This study aimed to estimate population attributable fractions (PAFs) of modifiable risk factors for nonsyndromic cleft lip with or without cleft palate (CL±P) and cleft palate only (CP) in Japan.MethodsWe conducted a prospective cohort study using data from the Japan Environment and Children’s Study, which recruited pregnant women from 2011 to 2014. We estimated the PAFs of maternal alcohol consumption, psychological distress, maternal active and passive smoking, abnormal body mass index (BMI) (<18.5 and ≥25 kg/m2), and non-use of a folic acid supplement during pregnancy for nonsyndromic CL±P and CP in babies.ResultsA total of 94,174 pairs of pregnant women and their single babies were included. Among them, there were 146 nonsyndromic CL±P cases and 41 nonsyndromic CP cases. The combined adjusted PAF for CL±P of the modifiable risk factors excluding maternal alcohol consumption was 34.3%. Only maternal alcohol consumption was not associated with CL±P risk. The adjusted PAFs for CL±P of psychological distress, maternal active and passive smoking, abnormal BMI, and non-use of a folic acid supplement were 1.4% (95% confidence interval [CI], −10.7 to 15.1%), 9.9% (95% CI, −7.0 to 26.9%), 10.8% (95% CI, −9.9 to 30.3%), 2.4% (95% CI, −7.5 to 14.0%), and 15.1% (95% CI, −17.8 to 41.0%), respectively. We could not obtain PAFs for CP due to the small sample size.ConclusionsWe reported the population impact of the modifiable risk factors on CL±P, but not CP. This study might be useful in planning the primary prevention of CL±P.

The Impact of Early Pregnancy and Exposure to Tobacco Smoke on Blood Antioxidant Status and Copper, Zinc, Cadmium Concentration-A Pilot Study.

The aim of the study was to evaluate the impact of early pregnancy and exposure to tobacco smoke on antioxidant status and copper, zinc, and cadmium concentrations in the blood of non-smoking and smoking, as well as non-pregnant or pregnant women. The study included 213 women. More specifically, 150 women in first trimester of pregnancy and 63 non-pregnant women. Women were divided into subgroups according to exposure to tobacco smoke. Pregnancy significant influences higher copper and lower zinc concentration in the serum, whereas exposure to tobacco smoke during pregnancy is mainly associated with an elevation in cadmium and zinc concentration. It seems that metallothionein, superoxide dismutase, and glutathione peroxidase are the important antioxidants during early pregnancy, when exposure to tobacco smoke occurs, whereas the pregnancy itself is associated with a higher concentration of metallothionein and activity of catalase. Both pregnancy in the first trimester and exposure to tobacco smoke decrease glutathione concentration. In addition, active and passive maternal smoking have a similarly negative effect on antioxidant status in the first trimester. Early pregnancy as well as exposure to tobacco smoke is associated with significant alteration in antioxidant status and copper, zinc, and cadmium concentration. Due to a small number of smoking subjects (11 cases of non-pregnant, active smokers and 14 pregnant active smokers), the obtained results should be treated as a pilot, and this should be considered for future studies.

The effect of active and passive maternal smoking before and during pregnancy on neonatal weight at birth.

IntroductionSmoking during pregnancy is a risk factor for adverse pregnancy outcomes. Data on the correlation between passive maternal smoking and pregnancy outcomes remain limited. We investigated the effect of active smoking and environmental tobacco smoke (ETS) during pregnancy on neonatal birthweight, including the risk for low birthweight (LBW).Material and methodsThe study was conducted between 2010 and 2012. A group of 8625 women were surveyed during postpartum hospitalization. Outcome measures included mean birthweight of newborns. Additionally, odds ratios with confidence intervals were calculated to investigate the risk for LBW in active and passive smoking groups of mothers.ResultsLower birthweight (46 g – 307 g; p < 0.05) and a higher risk for LBW (OR = 1.35, 95% CI: 1.05–1.75; p < 0.05) were observed in all infants born to smoking mothers. A negative effect of ETS in pregnancy on the reduction of mean birthweight was also found. Additionally, we analyzed the cumulative effect of active and passive smoking on neonatal birthweight. A statistically significant reduction in neonatal weight at birth was found in a group of women who smoked actively and passively during pregnancy (130 g; p < 0.05).ConclusionsSmoking is associated with decreased birthweight and in a group of active smoking mothers increased risk for LBW. This effect is dose-dependent and is also present in a group of women who smoked before pregnancy. There is also a cumulative effect of active smoking and ETS causing decreased neonatal birthweight and increased risk for low birthweight.

458 Maternal passive-smoking during pregnancy. the effect on pregnancy outcomes and placental-pathology. A prospective case-control study

The effect of maternal passive smoking (MPS) during pregnancy is difficult to investigate and was poorly studied before. This study was designed to investigate the effects of MPS during pregnancy- on placental pathology and pregnancy outcomes. We performed a prospective case-control study. We recruited low-risk laboring women at 37+0 to 41+0 weeks between 9/2019-7/2020. MPS was defined as exposure to a spouse that reported in-house tobacco smoking of > 20 cigarettes/day in the absence of maternal active smoking. In an attempt to "purify" the effect of MPS - we excluded cases with preeclampsia, diabetes, suspected fetal growth restriction (FGR), preterm labor, and illicit drug use. Maternal characteristics, pregnancy outcomes, and placental pathology were compared between the MPS group and a control group matched for gestational age, maternal age, and delivery date. Placental lesions were classified according to “Amsterdam” criteria. The study was powered to detect a 33% difference in placental malperfusion lesion and was calculated as 115 cases in each group. Multivariable regression analysis was performed to identify independent associations with placental malperfusion lesions. In labor, the MPS group (n=115) had higher rates of meconium-stained amniotic fluid (MSAF, p<0.001) and non-reassuring fetal heart rate (NRFHR) that necessitated immediate delivery (p=0.03), compared to controls (n=115). Neonates in the MPS group had higher rates of undiagnosed FGR (p=0.01) and NICU admissions (p=0.004). In placental pathology, the MPS group had higher rates of placental hypoplasia (p=0.02) and fetal vascular malperfusion (FVM) lesions (p=0.04). In regression analysis MPS was associated with FVM lesions independent of background confounders (aOR=2.3 95% CI 1.26-6.34). In otherwise low-risk pregnancies, MPS was associated with higher rates of MSAF, NRFHR, undiagnosed FGR, and NICU admissions, probably mediated via placental FVM. These worrisome findings mandate patient counseling and further investigation in larger population-based studies.View Large Image Figure ViewerDownload Hi-res image Download (PPT)

Risk Factors of Congenital Anomalies in South Sumatera Indonesia

Abstract&#x0D; &#x0D; Introduction. Congenital anomaly is one of the leading causes of neonatal death. It is the third leading cause of neonatal death in Indonesia. More than half of all congenital anomalies can’t be related to a specific cause, suggesting multiple risk factors. This study aims to identify patterns and risk factors of congenital anomalies in RSUP Dr. Mohammad Hoesin Palembang.&#x0D; Methods. This observational descriptive study with a cross-sectional design used 100 patients’ medical records, taken at RSUP Dr. Mohammad Hoesin Palembang, as samples. Missing data were complemented with a phone interview. Samples were picked using a proportional random sampling method. Collected data were counted within each category of congenital anomalies.&#x0D; Results. There were 366 neonatal patients diagnosed with congenital anomalies at RSUP Dr. Mohammad Hoesin Palembang in 2015. The most prevalent (44,8%) congenital anomalies belonged to congenital anomalies of the digestive system, followed by congenital anomalies of the circulatory system (18,6%), and cleft lip/palate (11,5%). Following risk factors were found: the history of maternal active or passive smoking (41%), maternal exposure to chemicals or solvents (31%), family member with congenital anomalies of the same category (27%), maternal drug consumption (26%), maternal infection (22%), maternal diabetes mellitus (4%), and maternal hypertension (4%).&#x0D; Conclusion. History of maternal active or passive smoking was the most frequently found risk factors among patients of congenital anomalies.

Perinatal smoking exposure and risk of asthma in the first three years of life: A prospective prebirth cohort study

BackgroundThere is limited evidence on the association between prenatal smoking exposure and the risk of asthma in children. The aim of this prebirth cohort study was to investigate the association between prenatal and postnatal tobacco smoke exposure and the risk of asthma in Japanese children. MethodsStudy subjects were 1304 mother–child pairs. Information on the variables under study was obtained using repeated questionnaires that were completed by mothers, first prior to delivery, then shortly after birth and subsequently around 4, 12, 24, and 36 months after delivery. Ever asthma was defined as a maternal report of physician-diagnosed asthma at any time since birth. Current asthma was defined as the use of asthma medication at the time of the sixth survey. ResultsLogistic regression models revealed that maternal active smoking, either before pregnancy or during pregnancy, was not associated with the risk of ever asthma or current asthma. Further, no association was observed between postnatally living with at least one household smoker and the risk of asthma. Among children whose mothers are never smokers, maternal second-hand smoke (SHS) exposure at work and/or at home during pregnancy increased the risk of ever asthma and current asthma in children; adjusted odds ratio (95% confidence intervals) for ever asthma and current asthma were 2.41 (1.13–5.05) and 4.82 (1.68–13.43), respectively. ConclusionsOur findings suggest that maternal SHS exposure during pregnancy might be associated with an increased risk of ever asthma and current asthma in young children whose mothers have never smoked.

Effect of maternal active smoking during pregnancy on the trajectory of childhood body mass index: A multilevel analysis using quartiles of birthweight.

INTRODUCTIONMaternal active smoking during pregnancy is associated with childhood obesity; however, whether maternal active smoking affects childhood body mass index (BMI) according to birthweight has not been examined.METHODSThe study participants were 1955 women and their single-born infants, born between 1 April 1991 and 31 March 2003, in Koshu City, Japan, for whom complete data for birthweight, pre-pregnancy maternal BMI and pregnancy smoking status were available. Maternal smoking status during pregnancy was recorded using a questionnaire at the time of pregnancy registration. Childhood BMI was estimated by the BMI z-score, established by the World Health Organisation. Birthweight quartiles were grouped by sex and parity (first vs second or higher). Multilevel analysis, including both the individual and time as different level variables by each birthweight quartile, was used to describe the trajectories of BMI z-scores for statistical analyses.RESULTSIn every quartile group, although children born to smoking mothers were leaner at birth, their BMI z-score increased around the age of 3 years. These children were larger than children born to non-smoking mothers. Significant interactions between maternal active smoking during pregnancy and child’s age were seen in those in the first and second quartiles of birthweight. Moreover, rapid growth in infancy was observed in the second quartile of birthweight.CONCLUSIONSThe effect of maternal active smoking during pregnancy on childhood growth was more apparent among children in the second quartile of birthweight.

Estimated Prevalence of Nonverbal Learning Disability Among North American Children and Adolescents

Nonverbal learning disability (NVLD) is a neurodevelopmental disorder characterized by deficits in visual-spatial processing but not in reading or verbal ability; in addition, problems in math calculation, visual executive functioning, fine-motor skills, and social skills are often present. To our knowledge, there are no population-based estimates of the prevalence of NVLD in community samples. To estimate the prevalence of the NVLD cognitive profile in 3 independent samples of children and adolescents from studies centered around brain imaging in the US and Canada. This cross-sectional study used data from 2 samples recruited from the community and overselected for children with psychiatric disorders (Healthy Brain Network [HBN], January 1, 2015, to December 31, 2019, and Nathan Kline Institute-Rockland Sample [NKI], January 1, 2011, to December 31, 2018) and 1 community-ascertained population sample (Saguenay Youth Study [SYS], January 1, 2003, to December 31, 2012) overselected for active maternal smoking during pregnancy. Prevalence of NVLD. Criteria for NVLD were based on clinical records of deficits in visual-spatial reasoning and impairment in 2 of 4 domains of function (fine-motor skills, math calculation, visual executive functioning, and social skills). Sample weighting procedures adjusted for demographic differences in sample frequencies compared with underlying target populations. Inflation factor weights accounted for overrepresentation of psychiatric disorders (HBN and NKI samples). Across 3 independent samples, the prevalence of NVLD was estimated among 2596 children and adolescents aged 6 to 19 years (mean [SD] age, 12.5 [3.4] years; 1449 male [55.8%]). After sample and inflation weights were applied, the prevalence of NVLD was 2.78% (95% CI, 2.03%-3.52%) in the HBN sample and 3.9% (95% CI, 1.96%-5.78%) in the NKI sample. In the SYS sample, the prevalence of NVLD was 3.10% (95% CI, 1.93%-4.27%) after applying the sample weight. Across samples and estimation strategies, the population prevalence of NVLD was estimated to range from 3% to 4%. When applied to the US population younger than 18 years, 2.2 million to 2.9 million children and adolescents were estimated to have NVLD. The findings suggest that the prevalence of NVLD in children and adolescents may be 3% to 4%. Given that few youths are diagnosed with NVLD and receive treatment, increased awareness, identification of the underlying neurobiological mechanisms, and development and testing interventions for the disorder are needed.

Association between maternal active smoking during pregnancy and placental weight: The Japan environment and Children's study

IntroductionMaternal smoking during pregnancy is a well-known risk factor for reduced birthweight. However, research investigating the association between maternal smoking and placental weight is scarce and inconsistent. Our study was conducted to evaluate the association between maternal smoking and placental weight and placental weight/birthweight ratio (PW/BW ratio). MethodsWe used data from a birth cohort study, the Japan Environment and Children's Study (JECS). Main outcome measures were placental weight, PW/BW ratio, and the risk of high PW/BW ratio. High PW/BW ratio was defined as PW/BW ratio above the 90th percentile for gestational age and sex of offspring. The association between maternal smoking and placental weight was estimated as crude and as adjusted beta coefficients by applying linear regression analyses. Logistic regression analyses were also performed to estimate the association between maternal smoking and the risk of high PW/BW ratio. ResultsOf the 91,951 pregnant women, the mean placental weight and the mean PW/BW ratio were lowest for the group of women who had never smoked. Smokers had higher odds ratio for high PW/BW ratio compared with non-smokers. Furthermore, among smokers, the mean placental weight and mean PW/BW ratio were lowest in women who smoked less than 5 daily cigarettes, and highest in women who smoked 20 or more daily cigarettes during pregnancy. DiscussionPlacental weight was greater and PW/BW ratio was higher among smokers compared with non-smokers. Moreover, the number of daily cigarettes was positively associated with heavy placental weight.

Exposure to tobacco smoke and stillbirth: a national prospective cohort study in rural China

IntroductionParental exposure to tobacco smoke has been associated with an increased risk of stillbirth, while only a few studies took the overall parental tobacco exposure status into consideration. We aim...

Prenatal tobacco exposure and ADHD symptoms at pre-school age: the Hokkaido Study on Environment and Children\u2019s Health

BackgroundThere have been inconsistent findings reported on maternal passive smoking during pregnancy and child risk of ADHD. In this study, ADHD symptoms at pre-school age children in association with prenatal passive and active tobacco smoke exposure determined by maternal plasma cotinine levels in the third trimester were investigated.MethodsThis was a follow-up study of the birth cohort: the Hokkaido Study on Environment and Children’s Health. Children whose parents answered Strengths and Difficulties Questionnaire (SDQ) to identify child ADHD symptoms (hyperactivity/inattention and conduct problems) and total difficulties at age 5 years with available maternal plasma cotinine level at the third trimester were included (n = 3216). Cotinine levels were categorized into 4 groups; ≦ 0.21 ng/ml (non-smoker), 0.22–0.51 ng/ml (low-passive smoker), 0.52–11.48 ng/ml (high-passive smoker), and ≧ 11.49 ng/ml (active smoker).ResultsMaternal cotinine levels of active smokers were significantly associated with an increased risk of total difficulties (OR = 1.67) and maternal low- and high-passive smoking also increased the risk (OR = 1.11, 1.25, respectively) without statistical significance. Similarly, maternal cotinine levels of active smokers were associated with an increased risk of hyperactivity/inattention (OR = 1.49). Maternal low- and high-passive smoking and active smoking increased the risk of hyperactivity/inattention (OR = 1.45, 1.43, and OR = 1.59, respectively) only in boys.ConclusionOur findings suggested that maternal active smoking during pregnancy may contribute to the increased risk of child total difficulties and hyperactivity/inattention at pre-school age. Pregnant women should be encouraged to quit smoking and avoid exposure to tobacco smoke.