Nicotine as a female reproductive toxicant-A review

The preceding decades have seen an extensive emergence of the harmful effects of tobacco smoke on systemic health. Among the various compounds of tobacco, nicotine is one of the principal, potentially hazardous, and toxic components which is an oxidant agent that can affect both men's and women's fertility. Nicotine exerts its effect by modulating the expression of transmembrane ligand-gated ion channels called nicotinic acetylcholine receptors. The activities of female reproduction might be disrupted by exposure to nicotine at various sites, such as the ovary or reproductive tract. It's been demonstrated that nicotine might cause oxidative stress, apoptosis, hormonal imbalance, abnormalities in chromosomal segregation, impact oocyte development, and disruption in ovarian morphology and functions. This review paper summarizes the findings and provides an updated overview of the evidence on the harmful effects of nicotine use on women's reproductive health and the resulting detrimental impacts on the body. Additionally, it provides the detailed possible mechanisms involved in impairing reproductive processes like folliculogenesis, oocyte maturation, steroidogenesis, and pregnancy in different animal species.

Maternal use of snus as smokeless tobacco in pregnancy and infant lung function

Background

Smoking in pregnancy has detrimental effects on infant respiratory health, while the effects of other nicotine-containing products on infant lung function are unclear. We aimed to explore if smokeless tobacco such as snus used in pregnancy increased the risk of lower lung function in infancy and if the associations differed by sex.

Methods

From the Scandinavian population-based Preventing Atopic Dermatitis and ALLergies in Children birth cohort, we included 1163 infants with available tidal flow-volume measurements at 3 months of age and maternal self-reported use of nicotine-containing products in pregnancy. The risk of a ratio of time to peak tidal expiratory flow to total expiratory time <25th percentile by any nicotine exposure, snus exclusively and cigarette smoking with or without other nicotine-containing products was explored by regression analyses adjusting for maternal age, education and asthma.

Results

Overall 120 out of 1163 (10.3%) infants were exposed to any nicotine in utero, 71 out of 120 by snus exclusively and 49 out of 120 by smoking, with six also exposed to snus. By pregnancy week 6, 85.8% of mothers reported stopping nicotine use. The risk of lower lung function was higher in children exposed in utero to nicotine-containing products with an odds ratio (OR) of 1.63 (95% confidence interval (CI) 1.02-2.59) with a similar tendency for snus exclusively (OR 1.55, 95% CI 0.88-2.71) and smoking (OR 1.79, 0.84-3.84). Effect estimates were similar after adjusting for covariates. No differences of the effect by sex were observed.

Conclusion

Our study suggests that in utero exposure to not only cigarettes, but also snus, may negatively affect infant lung function.

Determinants of tobacco use among pregnant women in sub-Saharan Africa. A multilevel mixed-effect logistic regression model

INTRODUCTION

Although it is known that maternal tobacco use during pregnancy substantially declined in higher-income countries, information on the magnitude and determinants of tobacco use among pregnant women in sub-Saharan Africa (SSA) remains limited. Establishing evidence on maternal tobacco during pregnancy is crucial for guiding targeted interventions in SSA. This study aimed to determine the overall prevalence of tobacco use and its determinants among pregnant women in SSA countries.

METHODS

The study used data from Demographic and Health Surveys conducted in 33 countries across SSA from 2010 and 2021. Our analysis included a total weighted sample of 40,291 pregnant women. A multilevel logistic regression model was used to identify factors associated with maternal tobacco use during pregnancy. The measure of association between explanatory variables and the outcome was reported using adjusted odds ratios (AORs) with 95% confidence intervals (CIs).

RESULTS

The pooled prevalence of tobacco use among pregnant women in SSA was 1.76% (95% CI: 1.41, 2.12). Our findings showed that pregnant women in the age groups of 25-34 years (AOR 1.44; 95% CI: 1.14, 1.82) and 35+ years (AOR 2.18; 95% CI: 1.68, 2.83) had higher odds of tobacco use during pregnancy. Pregnant women who attained primary education (AOR 0.57; 95% CI: 0.46, 0.70) and secondary or higher education (AOR 0.39; 95% CI: 0.30, 0.53) were associated with lower odds of tobacco use. Similarly, pregnant women who resided in households with a high wealth index (AOR 0.36; 95% CI: 0.55 0.90) and those with media exposure (AOR 0.81; 95% CI: 0.67, 0.99) were less likely to use tobacco during pregnancy.

CONCLUSION

This study revealed that the overall prevalence of maternal tobacco use during pregnancy was relatively low in SSA, but some countries exhibited higher estimates. To address this, it is crucial to implement targeted smoking prevention and cessation strategies, particularly for young pregnant women, those facing socioeconomic disadvantages, and those with lower educational status.

Low levels of nicotine and cotinine but not benzo[a]pyrene induce human trophoblast cell proliferation

E-cigarettes use constitutes a source of thirdhand nicotine exposure. The increasing use of electronic cigarettes in homes and public places increases the risk of exposure of pregnant women to thirdhand nicotine. The effects of exposure of pregnant women to very low levels of nicotine have not been studied in humans but detrimental in experimental animals. The objective of this study is to investigate the effect of nanomolar concentrations of nicotine and its metabolite cotinine on the proliferation of JEG-3, a human trophoblast cell line. We also studied the proliferative effect of nanomolar concentrations of benzo[a]pyrene (B[a]P), a polycyclic hydrocarbon in tobacco smoke, for comparison. We treated JEG-3 cells in culture with nanomolar concentrations of nicotine, cotinine, and B[a]P. Their effect on cell proliferation was determined, relative to untreated cells, by MTT assay. Western blotting was used to assess the mitogenic signaling pathways affected by nicotine and cotinine. In contrast to the inhibitory effects reported with higher concentrations, we showed that nanomolar concentrations of nicotine and cotinine resulted in significant JEG-3 cell proliferation and a rapid but transient increase in levels of phosphorylated ERK and AKT, but not STAT3. Biphasic, non-monotonic effect on cell growth is characteristic of endocrine disruptive chemicals like nicotine. The mitogenic effects of nicotine and cotinine potentially contribute to increased villous epithelial thickness, seen in placentas of some smoking mothers. This increases the diffusion distance for oxygen and nutrients between mother and fetus, contributing to intrauterine growth restriction in infants of smoking mothers.

Prevalence of preterm birth in Scandinavian countries: a systematic review and meta-analysis

OBJECTIVES

As welfare societies, Scandinavian countries share characteristics of equality related to healthcare access, gender, and social services. However, cultural and lifestyle variations create country-specific health differences. This meta-analysis assessed the prevalence of preterm birth (PTB) and its categories in Scandinavian countries.

METHODS

A systematic search in key databases of literature published between 1990 and 2021 identified studies of the prevalence of PTB and its categories. Following the use of the Freeman-Tukey double arcsine transformation, a meta-analysis of weighted data was performed using the random-effects model and meta-prop method.

RESULTS

We identified 109 observational studies that involved 86,420,188 live births. The overall pooled prevalence (PP) of PTB was 5.3% (PP = 5.3%, 95% confidence interval [CI] 5.1%, 5.5%). The highest prevalence was in Norway (PP = 6.2%, 95% CI 5.3%, 7.0%), followed by Sweden (PP = 5.3%, 95% CI 5.1%, 5.4%), Denmark (PP = 5.2%, 95% CI 4.9%, 5.3%), and Iceland (PP = 5.0%, 95% CI 4.4%, 5.7%). Finland had the lowest PTB rate (PP = 4.9%, 95% CI 4.7%, 5.1%).

CONCLUSIONS

The overall PP of PTB was 5.3%, with small variations among countries (4.9%-6.2%). The highest and lowest PPs of PTB were in Norway and Finland, respectively.

Health and economic outcomes of a universal early intervention for parents and children from birth to age five: evaluation of the Salut Programme using a natural experiment

BACKGROUND

The aim of this study was to investigate the health and economic outcomes of a universal early intervention for parents and children, the Salut Programme, from birth to when the child completed five years of age.

METHODS

This study adopted a retrospective observational design using routinely collected linked register data with respect to both exposures and outcomes from Västerbotten county, in northern Sweden. Making use of a natural experiment, areas that received care-as-usual (non-Salut area) were compared to areas where the Programme was implemented after 2006 (Salut area) in terms of: (i) health outcomes, healthcare resource use and costs around pregnancy, delivery and birth, and (ii) healthcare resource use and related costs, as well as costs of care of sick child. We estimated total cumulative costs related to inpatient and specialised outpatient care for mothers and children, and financial benefits paid to mothers to stay home from work to care for a sick child. Two analyses were conducted: a matched difference-in difference analysis using the total sample and an analysis including a longitudinal subsample.

RESULTS

The longitudinal analysis on mothers who gave birth in both pre- and post-measure periods showed that mothers exposed to the Programme had on average 6% (95% CI 3-9%) more full-term pregnancies and 2% (95% CI 0.03-3%) more babies with a birth weight ≥ 2500 g, compared to mothers who had care-as-usual. Savings were incurred in terms of outpatient care costs for children of mothers in the Salut area ($826). The difference-in-difference analysis using the total sample did not result in any significant differences in health outcomes or cumulative resource use over time.

CONCLUSIONS

The Salut Programme achieved health gains, as a health promotion early intervention for children and parents, in terms of more full-term pregnancies and more babies with a birth weight ≥ 2500 g, at reasonable cost, and may lead to lower usage of outpatient care. Other indicators point towards positive effects, but the small sample size may have led to underestimation of true differences.

Use of Swedish smokeless tobacco during pregnancy: A systematic review of pregnancy and early life health risk

BACKGROUND AND AIMS

Smokeless tobacco is a heterogeneous product group with diverse composition and prevalence globally. Tobacco use during pregnancy is concerning due to the risk of adverse pregnancy outcomes and effects on child health. Nicotine may mediate several of these effects. This systematic review measured health outcomes from Swedish smokeless tobacco (snus) use during pregnancy.

METHOD

Literature search was conducted by an information specialist in May 2022. We included human studies of snus use during pregnancy compared with no tobacco use, assessed risk of bias, conducted a meta-analysis and assessed confidence in effect-estimates using Grading of Recommendations, Assessment, Development and Evaluations (GRADE).

RESULTS

We included 18 cohort studies (42 to 1 006 398 participants). Snus use during pregnancy probably (moderate confidence in risk estimates) increase the risk of neonatal apnea, adjusted odds ratio 95% confidence interval [aOR (95% CI)] 1.96 (1.30 to 2.96). Snus use during pregnancy possibly (low confidence in risk estimates) increase the risk of stillbirths aOR 1.43 (1.02 to 1.99), extremely premature births aOR 1.69 (1.17 to 2.45), moderately premature birth aOR 1.26 (1.15 to 1.38), SGA aOR 1.26 (1.09 to 1.46), reduced birth weight mean difference of 72.47 g (110.58 g to 34.35 g reduction) and oral cleft malformations aOR 1.48 (1.00 to 2.21). It is uncertain (low confidence in risk estimates, CI crossing 1) whether snus use during pregnancy affects risk of preeclampsia aOR 1.11 (0.97 to 1.28), antenatal bleeding aOR 1.15 (0.92 to 1.44) and very premature birth aOR 1.26 (0.95 to 1.66). Risk of early neonatal mortality and altered heart rate variability is uncertain, very low confidence. Snus using mothers had increased prevalence of caesarean sections, low confidence.

CONCLUSIONS

This systematic review reveals that use of smokeless tobacco (snus) during pregnancy may adversely impact the developing child.

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSIONS

This research is the first to demonstrate that the maternal use of Australian Nicotiana spp. (pituri) as smokeless tobacco may negatively impact placental and neonatal outcomes.

IMPLICATIONS FOR PUBLIC HEALTH

Maternal smokeless tobacco use is a potential source of placental and foetal nicotine exposure. Maternal antenatal screening should be expanded to capture a broader range of tobacco and nicotine products, and appropriate cessation support is required.

Toxic effects of smokeless tobacco on female reproductive health: A review

•

Smokeless tobacco use can lead to impairments of ovarian function, morphology, oocyte quality and hormonal regulation.

•

Use of smokeless tobacco during pregnancy has adverse health effects on both the mother and fetus.

•

Exposure to smokeless tobacco in utero has long term health consequences on offspring.

The habitual consumption of tobacco in its various form is widespread and a serious public health issue globally. In particular, the use of smokeless tobacco has increased substantially due to its easy availability and misconception that it is relatively harmless compared to smoking. Tobacco use has been well established from numerous studies as a causative agent of devastating illnesses such as cancer, insulin resistance, hypertension, acute respiratory disease, osteoporosis, etc. Limited but growing evidence have also suggested its role in adversely affecting reproductive capabilities and outcomes in women of reproductive age and during pregnancy. This paper provides an updated review on available literature regarding the negative effects of smokeless tobacco use on female reproductive health, during pregnancy and its adverse consequences on the offspring. Existing data suggests the association between chronic smokeless tobacco use and impairment of ovarian morphology and function, oocyte quality, hormonal perturbations, fetal development and long-term health effects on the fetus. Improved understanding of these issues can contribute to better awareness of the dangers of smokeless tobacco products.

An Evaluation of Human Induced Pluripotent Stem Cells to Test for Cardiac Developmental Toxicity

To prevent congenital defects arising from maternal exposure, safety regulations require pre-market developmental toxicity screens for industrial chemicals and pharmaceuticals. Traditional embryotoxicity approaches depend heavily on the use of low-throughput animal models which may not adequately predict human risk. The validated embryonic stem cell test (EST) developed in murine embryonic stem cells addressed the former problem over 15 years ago. Here, we present a proof-of-concept study to address the latter challenge by updating all three endpoints of the classic mouse EST with endpoints derived from human induced pluripotent stem cells (hiPSCs) and human fibroblasts. Exposure of hiPSCs to selected test chemicals inhibited differentiation at lower concentrations than observed in the mouse EST. The hiPSC-EST also discerned adverse developmental outcomes driven by novel environmental toxicants. Evaluation of the early cardiac gene TBX5 yielded similar toxicity patterns as the full-length hiPSC-EST. Together, these findings support the further development of hiPSCs and early molecular endpoints as a biologically relevant embryotoxicity screening approach for individual chemicals and mixtures.

Maternal smoking and smokeless tobacco use during pregnancy and offspring development: sibling analysis in an intergenerational Swedish cohort

Background

The association between maternal smoking in pregnancy and offspring intellectual disability (ID) is less well understood than that of smoking and fetal growth restriction. As fetal growth and cognitive development may share similar confounding structures, comparison of the two associations may improve understanding of the causal nature of the association with ID. Furthermore, comparisons of smoking with smokeless tobacco use may aid identification of mechanisms of action.

Methods

This was a cohort study of all Swedish births between 1999 and 2012 (n = 1 070 013), with prospectively recorded data. We assessed the association between maternal smoking during pregnancy and offspring outcomes ID and born small for gestational age (SGA). Analyses were repeated for snus use in pregnancy. Using a sibling design, we estimated within-family effects that control for shared sibling characteristics.

Results

Those exposed to maternal smoking in pregnancy had increased odds of ID [odds ratio (OR) = 1.24, 95% confidence interval (CI): 1.16-1.33] and SGA (OR = 2.19, 95% CI: 2.11-2.27) after confounder adjustment. Within-family effects were found for SGA (OR = 1.44, 95% CI: 1.27-1.63) but not ID (OR = 0.92, 95% CI: 0.74-1.14). For snus use, the results for ID were similar to smoking. We found increased odds of offspring SGA among mothers who used snus in pregnancy in sensitivity analyses but not in primary analyses.

Conclusions

Our findings are consistent with a causal effect of maternal smoking in pregnancy on risk of offspring born SGA but not on risk of ID. We found no evidence for a causal effect of snus use in pregnancy on ID and inconclusive evidence for SGA.

Trends in maternal use of snus and smoking tobacco in pregnancy. A register study in southern Norway

BACKGROUND

The use of tobacco products including Swedish snus (moist snuff) in pregnancy may cause adverse health outcomes. While smoking prevalence has decreased among fertile women in Norway, snus use has increased during the last years. We investigated whether these trends were reflected also during pregnancy in a population of women in Southern Norway.

METHODS

Data on smoking tobacco and snus use at three time points before and during pregnancy for 20,844 women were retrieved from the electronic birth record for the years 2012-2017. The results for the three-year period 2015-2017 were compared with a previously studied period 2012-2014. Prevalence and quit rates of tobacco use within groups of age, parity and education were reported. Within the same groups adjusted quit rates were analyzed using logistic regression. Mean birthweight and Apgar score of offspring were calculated for tobacco-users and non-users.

RESULTS

There was an increase of snus use before pregnancy from the period 2012-2014 to the period 2015-2017 from 5.1% (CI; 4.6 to 5.5) to 8.4% (CI; 7.8 to 8.9). Despite this, the use of snus during pregnancy did not increase from the first to the second period, but stabilized at 2.8% (CI; 2.5 to 3.2) in first trimester and 2.0% (CI; 1.7 to 2.2) in third trimester. Cigarette smoking decreased significantly both before and during pregnancy. Snus use and smoking during pregnancy were associated with a reduction in average birthweight, but no significant effects on Apgar scores. Odds ratios for quitting both snus and smoking tobacco during pregnancy were higher for women aged 25-34 years, for the primiparas and for those with a high level of education. Pregnant women were more likely to have quit tobacco use in the last time period compared to the first.

CONCLUSIONS

While smoking during pregnancy was decreasing, the use of snus remained constant, levelling off to around 3% in first trimester and 2% in third trimester. Approximately 25% of those that used snus, and 40% that smoked before pregnancy, continued use to the third trimester. This calls for a continuous watch on the use of snus and other nicotine products during pregnancy.

An update on prevalence and risk of snus and nicotine replacement therapy during pregnancy and breastfeeding

AIM

In parallel with falling smoking rates, use of the oral moist tobacco product snus increases among women in reproductive age. We report an update on prevalence and effects of maternal use of snus and nicotine replacement therapy (NRT) during pregnancy and breastfeeding.

METHODS

A literature search of human studies in Medline, PubMed and EMBASE was conducted from September 2016 to May 2018, with stepwise screening of abstracts and subsequent relevant full-text papers for inclusion in Scandinavian and English languages.

RESULTS

Based on three studies, the prevalence of snus use in pregnancy was up to 3.4% in the first trimester and 2.1% in the third trimester. In 12 studies, we found increased risk of several adverse effects, especially preterm delivery, stillbirth and small for gestational age associated with maternal snus use during pregnancy. Knowledge on effects of NRT during pregnancy was conflicting and inconclusive in 10 studies. We did not identify any studies on prevalence or potential health effects of snus or NRT during breastfeeding.

CONCLUSION

Few studies with updated data on the prevalence and adverse health effects of maternal use of snus and NRT during pregnancy were found. No studies during breastfeeding were identified.

Prevention of snus use: Attitudes and activities in the Public Dental Service in the south-eastern part of Norway

Dental health care professionals have the opportunity to play a key role in tobacco prevention and cessation among adolescents. Snus use has increased in Norway, especially in the age group 16-24, whereas there has been a decline in smoking. This study investigated attitudes and activities related to snus prevention among dental health care professionals working in the Public Dental Service (PDS) in south-eastern Norway. A web-based survey with a total of 557 dentists and dental hygienists in seven counties in Norway, with a response rate of 53.5%, was carried out in 2017. Dentists' and dental hygienists' activities regarding preventive snus use intervention were analysed using the chi-square test. Intervention was measured with a score (1-5) based on four questions. Bivariate and multivariate linear regression analyses were used to investigate the associations between the explanatory variables of attitudes/activities and the outcome intervention variable. Approximately 87% of the dentists and 58% of the dental hygienists were not familiar with the "minimum intervention method" for tobacco prevention and cessation. Dental hygienists were most active in informing and supporting their patients in prevention and cessation of snus use. The PDS is an underutilized arena for tobacco prevention and cessation among adolescents, and the intervention potential is particularly high among the dentists.

Exposure to tobacco use in pregnancy and its determinants among sub-Saharan Africa women: analysis of pooled cross-sectional surveys

Background: Tobacco use in any form and exposure to second-hand smoking are major threat to human health globally. Worse still, it is an important threat to the health of pregnant women and their children. However, the prevalence of tobacco use among pregnant women in sub-Saharan Africa countries remains uncertain. This study assessed the prevalence and factors of tobacco use among pregnant women in sub-Saharan Africa countries.Methods: This study utilized data from Demographic and Health Surveys (DHS) conducted in 31 sub-Saharan Africa countries between 2008 and 2017, comprising 44,715 pregnant women (aged 15-49 years). We calculated sampling weights to account for differentials in probabilities of selection and estimated proportions and 95% CIs for tobacco use in pregnant women across various countries. The factors associated with tobacco use were examined using multivariable binary logistic regression models at a significant level of 5%.Results: Prevalence of tobacco use among pregnant women was ∼2%. In Madagascar, the prevalence of tobacco use was 11.0%, while Lesotho (5.4%), Sierra Leone (4.8%), Namibia (4.4%) and Burundi (4.2%) were among the leading countries with high tobacco use pregnancy. The results of multivariable binary logistic regression model showed that pregnant women aged 25-34 years and ≥35 years were 2.26 times (OR = 2.26; 95%CI: 1.23, 4.15) and 2.45 times (OR = 2.45; 95%CI: 1.10, 5.45) as likely to use tobacco products, compared to women aged ≤24 years. The religious beliefs of pregnant women, who belong to other religion besides Islam, were 2.26 times as likely to use tobacco products compared to Christian women (OR = 2.26; 95%CI: 1.19, 4.31). In addition, pregnant women from households with middle-class wealth index had 64% reduction in tobacco products use among pregnant women, compared to those from poor households (OR = 0.36; 95%CI: 0.15-0.87).Conclusion: Overall, tobacco use in pregnant women in sub-Saharan Africa was low; however high prevalence estimates were noted in some countries. Prevention and management of tobacco use and exposure to second-hand smoke during pregnancy is crucial to protect maternal and child health in Africa continent. Pregnant women should be examined about their tobacco use preferably with a biochemical test and those who use tobacco products be encouraged to use cessation supports such as nicotine replacement therapy (NRT) where available. Health professionals should identify tobacco products users and advise to quit, most importantly by offer cessation support. When tobacco products users become pregnant, the health benefits of cessation of tobacco use should be well discussed with them especially during antenatal care. The tobacco use of other members of the household is also crucial, as having a user partner could widely predict the exposure of a pregnant woman.

Implementation of Article 20 of the World Health Organization Framework Convention on Tobacco Control

BACKGROUND & OBJECTIVES

Article 20 of the World Health Organization (WHO) Framework Convention on Tobacco Control (FCTC) deals with surveillance and research on all tobacco products including smokeless tobacco (SLT). Here we describe the availability of indicators related to SLT among 180 Parties to the convention (countries ratifying the WHO FCTC are referred as Parties to the Convention).

METHODS

Data on SLT use among adults and adolescents and SLT-related economic and health indicators among Parties were obtained through rigorous literature search. Data analysis for high-burden parties was done using SPSS.

RESULTS

Nearly 92 per cent (166) of the Parties reported SLT use prevalence among adults or adolescents at national or subnational level, of these nearly one-fifth of the Parties (20.5%) were high-burden Parties. Comparable SLT tax incidence rate was available for 19.4 per cent (n=35) Parties, and SLT attributable morbidity and mortality risks of major diseases were available for only five per cent (n=10) of Parties.

INTERPRETATION & CONCLUSIONS

SLT use is a global epidemic widespread among Parties to the Convention. There are a data gap and dearth of research on SLT-related issues. Parties need to monitor SLT use and related health and economic indicators regularly at periodic intervals.

Tobacco use, exposure to second-hand smoke among pregnant women and their association with birth weight: A retrospective cohort study

Background:

There is paucity of studies on prevalence of SHS among pregnant women and its association with low birth weight (LBW).

Objectives:

The study was designed to determine the proportion of tobacco use, exposure to second hand smoke among pregnant women and their association with LBW.

Materials and Methods:

A Retrospective cohort study was conducted from March–June 2017 among 1043 pregnant women admitted for delivery in the Department of Obstetrics and Gynecology, JIPMER. Socio-demographic and obstetric characteristics, tobacco use and exposure to SHS during pregnancy were assessed by interviews. Birth weight of the baby was also extracted. Data was analysed using STATA v12. Univariate analysis was used to assess the association of socio-demographic, obstetric characteristics and exposure to SHS with LBW.

Results:

Out of 1043 pregnant women, the mean age was 25 (±3.9) years. More than half (57.4%) of women were primigravida. The proportion of women exposed to SHS during pregnancy was 69.9% (95% CI: 67.0-72.6) among which 24% of the women belonged to family, where family members were smokers. Only four had ever used tobacco in the past. However, none used any form of tobacco during pregnancy. LBW was present in 21.4% of the babies. There was no association between exposure to SHS and LBW [PR:0.98 (95% CI:0.71-1.35)].

Conclusion:

The study shows that there was no significant association between the SHS exposure of pregnant women and low birth weight.

Non-Smoking Tobacco Affects Endothelial Function in Healthy Men in One of the Largest Health Studies Ever Performed; The Nord-Trøndelag Health Study in Norway; HUNT3

BACKGROUND

Oral tobacco (snuff) is taking a large market share in Scandinavia, especially with young users. However, long-term health effects are unknown. Small studies show association between snuff and reduced endothelial function, representing an early stage of vascular injury that often precedes manifest cardiovascular disease by several years. We therefore determined the associations between snuff and endothelial function in a large sample of healthy Norwegian men.

METHODS AND DESIGN

In the Fitness substudy of the Nord-Trøndelag Health Study (HUNT3), endothelial function was measured by flow-mediated dilation (FMD). Aerobic fitness was measured by peak oxygen uptake (VO2peak). A cross-sectional design including 1 592 self-reported healthy men compared these observations with records of present tobacco use, standard cardiovascular risk factors, and socioeconomic status, using general linear models.

RESULTS

FMD was lower in snuff users (FMD: 4.12%, 3.63, 4.61) compared to non-users (FMD: 4.52%, 4.27, 4.78) after adjustment for age (difference: -0.57%, -1.12, -0.01). After further adjustment for potential confounders, FMD still tended to be lower in snuff users than in non-users (difference: -0.53%, -1.09, 0.02). This difference was even more pronounced in the inactive snuff users (-0.83%, -1.59, -0.06) and in the low fit snuff users (-0.74%, CI -0.55, 0.079).

CONCLUSIONS

Oral tobacco is associated with a tendency towards reduced endothelial function, indicating vascular changes that precede cardiovascular disease. The strongest associations were found in men with low physical activity or reduced aerobic fitness.

The Effects of Chewing Betel Nut with Tobacco and Pre-pregnancy Obesity on Adverse Birth Outcomes Among Palauan Women

The small Pacific Island nation of Palau has alarmingly high rates of betel nut with tobacco use and obesity among the entire population including pregnant women. This study aimed to determine the effects of betel nut with tobacco use and pre-pregnancy obesity on adverse birth outcomes. This study used retrospective cohort data on 1171 Palauan women who gave birth in Belau National Hospital in Meyuns, Republic of Palau between 2007 and 2013. The exposures of interest were pre-pregnancy obesity and reported betel nut with tobacco use during pregnancy. The primary outcomes measured were preterm birth and low birth weight among full-term infants. A significantly increased risk for low birth weight among full-term infants was demonstrated among those women who chewed betel nut with tobacco during pregnancy when other known risk factors were controlled for. Additionally, pre-pregnancy obesity was associated with a significantly increased risk for preterm birth when other known risk factors were controlled for. Both betel nut with tobacco use and pre-pregnancy obesity were associated with higher risks for adverse birth outcomes. These findings should be used to drive public health efforts in Palau, as well as in other Pacific Island nations where these studies are currently lacking.

Risk Factors for premature birth in a hospital

Objective:

to determine the risk factors for premature birth.

Methods:

retrospective case-control study of 600 pregnant women assisted in a hospital, with 298 pregnant women in the case group (who gave birth prematurely <37 weeks) and 302 pregnant women who gave birth to a full-term newborn in the control group. Stata software version 12.2 was used. The Chi-square test was used in bivariate analysis and logistic regression was used in multivariate analysis, from which Odds Ratios (OR) and Confidence Intervals (CI) of 95% were derived.

Results:

risk factors associated with premature birth were current twin pregnancy (adjusted OR= 2.4; p= 0.02), inadequate prenatal care (< 6 controls) (adjusted OR= 3.2; p <0.001), absent prenatal care (adjusted OR= 3.0; p <0.001), history of premature birth (adjusted OR= 3.7; p <0.001) and preeclampsia (adjusted OR= 1.9; p= 0.005).

Conclusion:

history of premature birth, preeclampsia, not receiving prenatal care and receiving inadequate prenatal care were risk factors for premature birth.

The Role of Nicotine in the Effects of Maternal Smoking during Pregnancy on Lung Development and Childhood Respiratory Disease. Implications for Dangers of E-Cigarettes

Use of e-cigarettes, especially among the young, is increasing at near-exponential rates. This is coupled with a perception that e-cigarettes are safe and with unlimited advertising geared toward vulnerable populations, the groups most likely to smoke or vape during pregnancy. There is now wide appreciation of the dangers of maternal smoking during pregnancy and the lifelong consequences this has on offspring lung function, including the increased risk of childhood wheezing and subsequent asthma. Recent evidence strongly supports that much of the effect of smoking during pregnancy on offspring lung function is mediated by nicotine, making it highly likely that e-cigarette use during pregnancy will have the same harmful effects on offspring lung function and health as do conventional cigarettes. In fact, the evidence for nicotine being the mediator of harm of conventional cigarettes may be most compelling for its effects on lung development. This raises concerns about both the combined use of e-cigarettes plus conventional cigarettes by smokers during pregnancy as well as the use of e-cigarettes by e-cigarette-only users who think them safe or by those sufficiently addicted to nicotine to not be able to quit e-cigarette usage during pregnancy. Thus, it is important for health professionals to be aware of the risks of e-cigarette usage during pregnancy, particularly as it pertains to offspring respiratory health.

Maternal tobacco use and extremely premature birth - a population-based cohort study

OBJECTIVE

To study the associations of maternal tobacco use (smoking or use of snuff) and risk of extremely preterm birth, and if tobacco cessation before antenatal booking influences this risk. To study the association between tobacco use and spontaneous or medically indicated onset of delivery.

DESIGN

Population-based cohort study.

SETTING

Sweden.

POPULATION

All live singleton births, registered in the Swedish Medical Birth Register, 1999-2012.

METHODS

Odds ratios (OR) with 95% confidence intervals (CI) were calculated using multiple logistic regression analysis.

MAIN OUTCOME MEASURES

Extremely preterm birth (<28 weeks of gestation), very preterm birth (28-31 weeks), moderately preterm birth (32-36 weeks).

RESULTS

Maternal snuff use (OR 1.58; 95% CI: 1.14-2.21) and smoking (OR 1.61; 95% CI: 1.39-1.87 and OR 1.91; 95% CI: 1.53-2.39 for moderate and heavy smoking, respectively) were associated with an increased risk of extremely preterm birth. When cessation of tobacco use was obtained there was no increased risk of preterm birth. Snuff use was associated with a twofold risk increase of medically indicated extremely preterm birth, whereas smoking was associated with increased risks of both medically indicated and spontaneous extremely preterm birth.

CONCLUSIONS

Snuff use and smoking in pregnancy were associated with increased risks of extremely preterm birth. Women who stopped using tobacco before the antenatal booking had no increased risk. These findings indicate that nicotine, the common substance in cigarettes and snuff, is involved in the mechanisms behind preterm birth. The use of nicotine should be minimized in pregnancy.

TWEETABLE ABSTRACT

Tobacco use increases risk of extremely preterm birth. Cessation is preventive. Avoid nicotine in pregnancy.

Protecting Children From Tobacco, Nicotine, and Tobacco Smoke

This technical report serves to provide the evidence base for the American Academy of Pediatrics' policy statements "Clinical Practice Policy to Protect Children From Tobacco, Nicotine, and Tobacco Smoke" and "Public Policy to Protect Children From Tobacco, Nicotine, and Tobacco Smoke." Tobacco use and involuntary exposure are major preventable causes of morbidity and premature mortality in adults and children. Tobacco dependence almost always starts in childhood or adolescence. Electronic nicotine delivery systems are rapidly gaining popularity among youth, and their significant harms are being documented. In utero tobacco smoke exposure, in addition to increasing the risk of preterm birth, low birth weight, stillbirth, placental abruption, and sudden infant death, has been found to increase the risk of obesity and neurodevelopmental disorders. Actions by pediatricians can help to reduce children's risk of developing tobacco dependence and reduce children's involuntary tobacco smoke exposure. Public policy actions to protect children from tobacco are essential to reduce the toll that the tobacco epidemic takes on our children.

Is there evidence for potential harm of electronic cigarette use in pregnancy?

BACKGROUND

Use of electronic cigarettes (e-cigarettes) and other nicotine containing products is increasing among women of reproductive age. The short- and long-term effects of these products on both mother and fetus are unknown.

METHODS

Because e-cigarettes are nicotine delivery systems, we sought to conduct a comprehensive review of the effects of nicotine on the fetus.

RESULTS

In utero nicotine exposure in animal models is associated with adverse effects for the offspring lung, cardiovascular system and brain. In the lung, this included reduced surface area, weight, and volume, as well as emphysema-like lesions. In adulthood, exposed offspring demonstrate elevated blood pressure and increased perivascular adipose tissue. In the brain, exposure alters offspring serotonergic, dopaminergic, and norepinephrine networks, which in turn are associated with behavioral and cognitive impairments. We also review current data on the lack of efficacy of nicotine replacement therapy in pregnant women, and highlight different nicotine containing products such as snuff, snus, and hookah.

CONCLUSION

We conclude that no amount of nicotine is known to be safe during pregnancy, and studies specifically addressing this risk are crucial and an imminent public health issue.

Health risks related to dual use of cigarettes and snus - a systematic review

Reviews show that using snus (Swedish-type moist snuff) is much safer than smoking, with no increased risk from snus of cancer or circulatory disease yet demonstrated, but have not investigated possible health effects from dual use of cigarettes and snus. This review considers studies where health risks can be compared in dual users, those who only use snus or only smoke, and those who use neither product. The interaction RR, the ratio of RRs associated with snus use in smokers and in non-smokers, was used to test for special effects of dual use. Of 51 interaction RRs presented, only one (for gestational hypertension in a study based on the Swedish Medical Register) was significantly (p<0.05) above 1.0, and RRs below 1.0 were commoner, perhaps as cigarette consumption is lower in dual users than those who only smoke. Dual users more often initiate tobacco use with cigarettes than snus. Dual use is much commoner in adolescents than adults, possibly because many tobacco users try both products, eventually settling on one. Epidemiological evidence from various sources, though suffering from weaknesses, consistently suggests concomitant snus use increases smoking quit rates, and aligns with evidence from RCTs using snus to aid smoking cessation.

Smokeless tobacco use in pregnancy: an integrative review of the literature

OBJECTIVES

To systematically critique and summarise the available evidence on the outcomes of smokeless tobacco use in pregnancy to inform the public health response.

METHODS

In March 2013, a search was conducted of observational studies where the exposure to smokeless tobacco during pregnancy and maternal, placental and/or neonatal outcomes was assessed. Two reviewers extracted data and completed quality assessment of the literature utilizing the Agency for Healthcare Research and Quality criteria (West et al. 2002).

RESULTS

The search resulted in 211 articles, 21 (10%) of which met the final criteria for integrative review. Ten (10) of the studies are from India, seven (7) from Sweden, two (2) from Alaska and one (1) each from South Africa and Pakistan.

CONCLUSIONS

Many studies lacked sufficient power to estimate precise risks. Most reports were hindered by imprecise measures of exposure and lack of confounding variable control. However, there were indications that maternal smokeless tobacco use increases rates of stillbirth, low birth weight and alters the male:female live birth ratio. Maternal smokeless tobacco use may not be safe for mother or foetus.

Maternal snuff use and smoking and the risk of oral cleft malformations--a population-based cohort study

Objective

To determine if maternal use of snuff (containing high levels of nicotine, low levels of nitrosamines and no combustion products) is associated with an increased risk of oral cleft malformations in the infant and whether cessation of snuff use or smoking before the antenatal booking influences the risk.

Method

A population-based cohort study was conducted on all live born infants, recorded in the Swedish Medical Birth Register from 1999 through 2009 (n = 1 086 213). Risks of oral clefts were evaluated by multivariate logistic regression analyses (using adjusted odds ratios, with 95% confidence intervals [CI]).

Results

Among 975 866 infants that had information on maternal tobacco use, 1761 cases of oral clefts were diagnosed. More than 50% of the mothers who used snuff or smoked three months prior pregnancy stopped using before the antenatal booking. Almost 8% of the mothers were smoking at the antenatal booking and 1,1% of the mothers used snuff. Compared with infants of non-tobacco users, the adjusted odds ratios (95% CI) of any oral cleft for infants of mothers who continued to use snuff or to smoke were 1.48 [1.00–2.21] and 1.19 [1.01–1.41], respectively. In contrast, in infants of mothers who stopped using snuff or stopped smoking before the antenatal booking, the corresponding risks were not increased (adjusted odds ratios [95% CI] were 0.71 [0.44–1.14] and 0.88 [0.73–1.05], respectively).

Conclusion

Maternal snuff use or smoking in early pregnancy is associated with an increased risk of oral clefts. Infants of mothers who stopped using snuff or stopped smoking before the antenatal booking had no increased risk of oral cleft malformations. Oral snuff or other sources of nicotine should not be recommended as an alternative for smoke-cessation during pregnancy.

The effect of Swedish snuff (snus) on offspring birthweight: a sibling analysis

Current observational evidence indicates that maternal smoking during pregnancy is associated with reduced birthweight in offspring. However, less is known about the effect of smokeless tobacco on birthweight and about the possible mechanisms involved in this relationship. This paper studies the effect of Swedish smokeless tobacco (snus) on offspring birthweight comparing the results obtained from a conventional linear regression analysis and from a quasi-experimental sibling design using a multilevel linear regression analysis. From the Swedish Medical Birth Register, we investigated 604,804 singletons born between 2002 and 2010. From them, we isolated 8,861 siblings from 4,104 mothers with discrepant snus-use habits (i.e., women who had at least one pregnancy during which they used snus and at least one other pregnancy in which they did not). The conventional analysis shows that continuous snus use throughout the pregnancy reduces birthweight in 47 g while quitting or relapsing snus has a minor and statistically non-significant effect (−6 g and −4 g, respectively). However, using a sibling analysis the effect observed for mothers who continue to use snus during pregnancy is less intense than that observed with previous conventional analyses (−20 g), and this effect is not statistically significant. Sibling analysis shows that quitting or relapsing snus use after the first trimester slightly reduces birthweight (14 g).However, this small change is not statistically significant. The sibling analysis provides strong causal evidence indicating that exposure to snus during pregnancy has a minor effect on birthweight reduction. Our findings provide a new piece of causal evidence concerning the effect of tobacco on birthweight and support the hypothesis that the harmful effect of smoking on birthweight is not mainly due to nicotine.

Systematic review of Swedish snus for smoking cessation based on primary subject data from randomised clinical trials

Introduction: The ability of Swedish snus to serve as a smoking cessation aid has been documented in several observational, population surveys from Scandinavia, but randomised clinical trials provide more reliable information on efficacy. Aims: To perform a systematic review and meta-analysis of randomised clinical trials of Swedish snus as an aid to smoking cessation. Methods: Literature searches were conducted in MedLine, Cochrane Library, and Embase to identify relevant clinical trials. The primary outcome was defined as biologically confirmed smoking cessation during around six months. Meta-analyses based on primary subject data tested for effect of allocated treatment as well as selected baseline characteristics. Results: There were two relevant clinical trials, one conducted at five sites in the US (n = 250), the other at two sites in Serbia (n = 319). Based on the primary outcome, success was higher in the treated group in both Serbia (5.7% vs 1.9%) and the US (4.0% vs 1.6%). Meta-analysis estimated the relative success rate at 2.83 (95% CI 1.03–7.75), which was of borderline significance (exact p = 0.06, chi-squared p = 0.03). For smoking cessation in the last 4 weeks of each study, rates were 12.4% for snus and 6.6% for placebo (RR 1.86, 95% CI 1.09-3.18). Efficacy of snus was not clearly related to any baseline characteristic. Conclusions: Swedish snus increased quit rates similarly in US and Serbia. These results confirm and extend previous information based on observational population surveys.

Effects of maternal smokeless tobacco use on selected pregnancy outcomes in Alaska Native women: a case-control study

OBJECTIVE

To examine the potential effects of prenatal smokeless tobacco use on selected birth outcomes.

DESIGN

A population-based, case-control study using a retrospective medical record review.

POPULATION

Singleton deliveries 1997-2005 to Alaska Native women residing in western Alaska.

METHODS

Hospital discharge codes were used to identify potential case deliveries and a random control sample. Data on tobacco use and confirmation of pregnancy outcomes were abstracted from medical records for 1123 deliveries. Logistic regression was used to examine associations between tobacco use and pregnancy outcomes. Adjusted odds ratios (OR), 95% confidence intervals (95% CI), and p-values were calculated.

MAIN OUTCOMES MEASURES

Preterm delivery, pregnancy-associated hypertension, and placental abruption.

RESULTS

In unadjusted analysis, smokeless tobacco use was not significantly associated with preterm delivery (OR 1.44, 95% CI 0.97-2.15). After adjustment for parity, pre-pregnancy body mass index, and maternal age, the point estimate was attenuated and remained non-significant. No significant associations were observed between smokeless tobacco use and pregnancy-associated hypertension (adjusted OR 0.92, 95% CI 0.56-1.51) or placental abruption (adjusted OR 1.11, 95% CI 0.53-2.33).

CONCLUSIONS

Prenatal smokeless tobacco use does not appear to reduce risk of pregnancy-associated hypertension or to substantially increase risk of abruption. An association between smokeless tobacco and preterm delivery could not be ruled out. Components in tobacco other than nicotine likely play a major role in decreased pre-eclampsia risk in smokers. Nicotine adversely affects fetal neurodevelopment and our results should not be construed to mean that smokeless tobacco use is safe during pregnancy.

Changes in snuff and smoking habits in Swedish pregnant women and risk for small for gestational age births

OBJECTIVE

To examine associations between antenatal exposure to Swedish oral moist snuff (which includes essentially only nicotine) and to smoking and risks of small-for-gestational-age (SGA) births and to compare risks among women who stopped or continued using snuff or smoking during pregnancy.

DESIGN

Population-based cohort study.

SETTING

Sweden.

POPULATION

All live singleton births in Sweden 1999-2010.

METHODS

Odds ratios (OR) with 95% confidence intervals (CI) were calculated using multiple logistic regression analysis.

MAIN OUTCOME MEASURES

SGA birth, also stratified into preterm (≤36 weeks of gestation) and term (≥37 weeks of gestation) SGA births.

RESULTS

Compared with non-tobacco users in early pregnancy, snuff users and above all smokers in early pregnancy had increased risks of SGA births: adjusted ORs (95% CI) were 1.26 (1.09-1.46) and 2.55 (2.43-2.67), respectively). Snuff use had, if anything, a stronger association with preterm SGA than term SGA, whereas the opposite was true for smoking. Compared with non-tobacco users, women who stopped using snuff before their first visit to antenatal care had no increased risks of preterm or term SGA, and women who stopped using snuff later during pregnancy had no increased risk of term SGA. Smoking cessation early in pregnancy was associated with a larger reduction in risk than smoking cessation later in pregnancy.

CONCLUSIONS

As both smoking and snuff use influence risk of SGA, both nicotine but above all tobacco combustion products are involved in the mechanisms by which maternal smoking increases the risk of SGA.

Use of snus and acute myocardial infarction: pooled analysis of eight prospective observational studies

The use of snus (also referred to as Scandinavian or Swedish moist smokeless tobacco), which is common in Sweden and increasing elsewhere, is receiving increasing attention since considered a tobacco smoke "potential reduction exposure product". Snus delivers a high dose of nicotine with possible hemodynamic effects, but its impact on cardiovascular morbidity and mortality is uncertain. The aim of this study was to investigate whether snus use is associated with risk of and survival after acute myocardial infarction (AMI). Data from eight prospective cohort studies set in Sweden was pooled and reanalysed. The relative risk of first time AMI and 28-day case-fatality was calculated for 130,361 men who never smoked. During 2,262,333 person-years of follow-up, 3,390 incident events of AMI were identified. Current snus use was not associated with risk of AMI (pooled multivariable hazard ratio 1.04, 95 % confidence interval 0.93 to 1.17). The short-term case fatality rate appeared increased in snus users (odds ratio 1.28, 95 % confidence interval 0.99 to 1.68). This study does not support any association between use of snus and development of AMI. Hence, toxic components other than nicotine appear implicated in the pathophysiology of smoking related ischemic heart disease. Case fatality after AMI is seemingly increased among snus users, but this relationship may be due to confounding by socioeconomic or life style factors.

Influence of smoking and snuff cessation on risk of preterm birth

The mechanisms by which antenatal smoking exposure increases the risk of preterm birth remain unknown. Swedish oral moist snuff contains quantities of nicotine comparable to those typically absorbed from cigarette smoking, but does not result in exposure to the products of combustion, for example carbon monoxide. In a nation-wide study of 776,836 live singleton births in Sweden from 1999 to 2009, the authors used multiple logistic regression models to examine associations between cessation of smoking and Swedish snuff use early in pregnancy and risk of preterm birth (before 37 weeks). Compared with non-tobacco users both before and in early pregnancy, the adjusted odds ratios (OR), 95% confidence interval (CI) were OR=0.92, 95% CI 0.84-1.01, for women who stopped using snuff, and OR=0.90, 95% CI 0.87-0.94, for women who stopped smoking. In contrast, continued snuff use and smoking were associated with increased risks of preterm birth (adjusted OR=1.29, 95% CI 1.17-1.43, adjusted OR=1.30, 95% CI 1.25-1.36, respectively). The snuff and smoking-related risks were, if anything, higher for very (before 32 weeks) than moderately (32-36 weeks) preterm birth, and also higher for spontaneous than induced preterm birth. These findings suggest that antenatal exposure to nicotine is involved in the mechanism by which tobacco use increase the risk of preterm birth.

Toxicology of smokeless tobacco: implications for immune, reproductive, and cardiovascular systems

The popularity of smokeless tobacco (ST), or noncombusted tobacco, usually placed within the mouth to be chewed, sucked, or swallowed, is growing rapidly and its prevalence of use is rising globally, due (in part) to greater convenience, as allowable cigarette smoking areas are rapidly decreasing, and increased social acceptability. Though data are limited, ST usage has been directly linked to a number of adverse health outcomes. The potential role that immune dysfunction, including dysregulation of immune cells and their components, may play in the progression of these adverse health outcomes is only just beginning to emerge. Evidence suggesting reproductive outcomes, such as perinatal mortality, preterm birth, and reduced sperm viability, also exists in conjunction with ST use. Cardiovascular health may also be impacted by ST use, resulting in increased blood pressure and endothelial dysfunction, both of which may potentially lead to cardiovascular diseases. This review describes the toxicological implications associated with ST use, with emphasis on immune, reproductive, and cardiovascular outcomes. Epidemiological studies are discussed with respect to experimental studies to help develop the relationship between ST and disease pathology. This review also summarizes the gaps in ST knowledge and potential future directions that are needed to more fully delineate the complex systems driving the adverse health outcomes associated with its use.

Who is using snus? - Time trends, socioeconomic and geographic characteristics of snus users in the ageing Swedish population

BACKGROUND

The prevalence of smoking in Sweden has decreased in recent decades, and is now among the lowest in the world. During the same period, the use of Swedish moist oral snuff, a smokeless tobacco called snus, has increased. Few studies have evaluated time trends of the socioeconomic and geographic characteristics of snus users in Sweden. This paper contributes to filling that gap.

METHODS

This study utilized the Linnaeus Database, which links national registers with comprehensive individual data on socioeconomic status (SES) to health data from a large ongoing health survey, the Västerbotten Intervention Programme (VIP). The VIP targets the entire middle-aged population of Västerbotten county at ages 40, 50 and 60 years with yearly cross-sectional surveys including self-reported data on tobacco habits. Time trends of snus use among 92,563 VIP-participants across different areas of residence and smoking groups were investigated graphically. Logistic regression was performed to estimate the associations between SES and geographical variables and current use versus non-use of snus.

RESULTS

Overall, in parallel to decreasing smoking, the increasing trend of snus use in this middle-aged population continues, particularly in 40-year-olds. In both genders, the highest prevalence of snus use was observed among previous smokers. The prevalence of snus use also increased over time among smokers, and was consistently higher compared to those who had never smoked. Among males - both those who had never smoked and previous smokers - low education (OR 1.21, 95%CI 1.06-1.40 and OR 1.28, 95%CI 1.14-1.43), living alone (OR 1.16, 95%CI 1.07-1.27 and OR 1.13, 95%ci 1.04-1.23), low income and living in rural areas was associated with using snus, while this was not seen among male current smokers. Among women, living alone was associated with using snus irrespective of smoking habits. Among female smokers, the OR for snus use increased with higher education.

CONCLUSIONS

A disadvantaged social profile and also higher prevalence in rural areas is observed among male snus users who had never smoked or were previous smokers. Among male smokers there was no association between SES and use of snus. The prevalence of snus use among women is increasing, but is still considerably lower than that of men. The association between snus and SES characteristics is less pronounced among women, although snus is clearly linked to living alone. These patterns should be taken into consideration in tobacco control policies.

Relationship of maternal snuff use and cigarette smoking with neonatal apnea

BACKGROUND

Maternal smoking is associated with disturbed cardiorespiratory control in the infant. Despite lacking knowledge of whether the harmful effects of smoking are caused by combustion products in tobacco smoke or by nicotine, it has been argued that nicotine-replacement therapy during pregnancy is safer than smoking.

OBJECTIVE

The goal of this study was to investigate if the disturbances in cardiorespiratory control associated with maternal smoking are also seen in infants prenatally exposed to snuff. We hypothesized that prenatal nicotine exposure (via moist snuff) causes disturbances in autonomic control and thereby increases the risk of apnea in the newborn.

METHODS

In a nationwide Swedish cohort study, we studied associations between maternal tobacco use during pregnancy and neonatal apnea. Of 609 551 live-born singleton infants, 7599 were born to snuff-using mothers, 41 391 and 16 928 were born to light (1-9 cigarettes per day) and heavy (≥ 10 cigarettes per day) smokers, respectively. Logistic regression was used to calculate odds ratios, using 95% confidence intervals.

RESULTS

Compared with infants of nontobacco users, infants with prenatal exposure to snuff were at an increased risk of apnea even after adjustment for differences in gestational age (odds ratio: 1.96 [95% confidence interval: [1.30-2.96]) Smoking was associated with increased risk of apnea before, but not after, adjusting for gestational age.

CONCLUSIONS

Snuff use during pregnancy is associated with a higher risk of neonatal apnea than smoking. Maternal use of snuff or nicotine-replacement therapy cannot be regarded as an alternative to smoking during pregnancy.

The scientific foundation for tobacco harm reduction, 2006-2011

Over the past five years there has been exponential expansion of interest in tobacco harm reduction (THR), with a concomitant increase in the number of published studies. The purpose of this manuscript is to review and analyze influential contributions to the scientific and medical literature relating to THR, and to discuss issues that continue to stimulate debate. Numerous epidemiologic studies and subsequent meta-analyses confirm that smokeless tobacco (ST) use is associated with minimal risks for cancer and for myocardial infarction; a small increased risk for stroke cannot be excluded. Studies from Sweden document that ST use is not associated with benign gastrointestinal disorders and chronic inflammatory diseases. Although any form of nicotine should be avoided during pregnancy, the highest risks for the developing baby are associated with smoking. It is documented that ST use has been a key factor in the declining rates of smoking and of smoking-related diseases in Sweden and Norway. For other countries, the potential population health benefits of ST are far greater than the potential risks. In follow-up studies, dual users of cigarettes and ST are less likely than exclusive smokers to achieve complete tobacco abstinence, but they are also less likely to be smoking. The health risks from dual use are probably lower than those from exclusive smoking. E-cigarette users are not exposed to the many toxicants, carcinogens and abundant free radicals formed when tobacco is burned. Although laboratory studies have detected trace concentrations of some contaminants, it is a small problem amenable to improvements in quality control and manufacturing that are likely with FDA regulation as tobacco products. There is limited evidence from clinical trials that e-cigarettes deliver only small doses of nicotine compared with conventional cigarettes. However, e-cigarette use emulates successfully the cigarette handling rituals and cues of cigarette smoking, which produces suppression of craving and withdrawal that is not entirely attributable to nicotine delivery. THR has been described as having "the potential to lead to one of the greatest public health breakthroughs in human history by fundamentally changing the forecast of a billion cigarette-caused deaths this century."

Summary of the epidemiological evidence relating snus to health

Interest in snus (Swedish-type moist snuff) as a smoking alternative has increased. This wide-ranging review summarizes evidence relating snus to health and to initiation and cessation of smoking. Meta-analyses are included. After smoking adjustment, snus is unassociated with cancer of the oropharynx (meta-analysis RR 0.97, 95% CI 0.68-1.37), oesophagus (1.10, 0.92-1.33), stomach (0.98, 0.82-1.17), pancreas (1.20, 0.66-2.20), lung (0.71, 0.66-0.76) or other sites, or with heart disease (1.01, 0.91-1.12) or stroke (1.05, 0.95-1.15). No clear associations are evident in never smokers, any possible risk from snus being much less than from smoking. "Snuff-dipper's lesion" does not predict oral cancer. Snus users have increased weight, but diabetes and chronic hypertension seem unaffected. Notwithstanding unconfirmed reports of associations with reduced birthweight, and some other conditions, the evidence provides scant support for any major adverse health effect of snus. Although some claims that snus reduces initiation or encourages quitting are unsoundly based, snus seems not to increase initiation, as indicated by few smokers using snus before starting and current snus use being unassociated with smoking in adults (the association in children probably being due to uncontrolled confounding), and there are no reports that snus discourages quitting.