Use of electronic nicotine delivery systems by pregnant women II: Hair biomarkers for exposures to nicotine and tobacco-specific nitrosamines

Vaping during pregnancy: a systematic review of health outcomes

INTRODUCTION

Smoking during pregnancy is harmful to maternal and child health. Vaping is used for smoking cessation but evidence on health effects during pregnancy is scarce. We conducted a systematic review of health outcomes of vaping during pregnancy.

METHODS

We searched six databases for maternal/fetal/infant outcomes and vaping, including quantitative, English language, human studies of vaping during pregnancy, to November 10th, 2023. We assessed study quality with the Mixed-Methods Appraisal Tool. We focused on comparisons of exclusive-vaping with non-use of nicotine and tobacco products and with smoking. Presentation is narrative as the studies were of insufficient quality to conduct meta-analysis.

RESULTS

We included 26 studies, with 765,527 women, with one randomised controlled trial (RCT) comparing vaping and nicotine replacement therapy for smoking cessation, 23 cohort studies and two case-control studies. While the RCT met 4/5 quality criteria, the quality of the cohort studies and case-control studies was poor; none adequately assessed exposure to smoking and vaping. For studies comparing exclusive-vaping with 'non-use', more reported no increased risk for vaping (three studies) than reported increased risk for maternal pregnancy/postpartum outcomes (one study) and for fetal and infant outcomes (20 studies no increased risk, four increased risk), except for birth-weight and neurological outcomes where two studies each observed increased and no increased risk. When the RCT compared non-users with those not smoking but vaping or using NRT, irrespective of randomisation, they reported no evidence of risk for vaping/NRT. For studies comparing exclusive-vaping and exclusive-smoking, most studies provided evidence for a comparable risk for different outcomes. One maternal biomarker study revealed a lower risk for vaping. For small-for-gestational-age/mean-birth-centile equal numbers of studies found lower risk for vaping than for smoking as found similar risk for the two groups (two each).

CONCLUSIONS

While more studies found no evidence of increased risk of exclusive-vaping compared with non-use and evidence of comparable risk for exclusive-vaping and exclusive-smoking, the quality of the evidence limits conclusions. Without adequate assessment of exposure to vaping and smoking, findings cannot be attributed to behaviour as many who vape will have smoked and many who vape may do so at low levels.

STUDY REGISTRATION

https://osf.io/rfx4q/ .

E-cigarette effects on vascular function in animals and humans

Smoking tobacco cigarettes is a significant (cardiovascular) health risk factor. Although the number of tobacco cigarette users declined over the last decades, shisha smoking and e-cigarette vaping partially compensated for this health benefit. E-cigarettes may create highly addicted dual users (vaping and smoking). E-cigarettes seem not to represent a healthier alternative to tobacco smoking, although they may be less harmful. E-cigarette vaping causes oxidative stress, inflammation, endothelial dysfunction, and associated cardiovascular sequelae. This is primarily due to a significant overlap of toxic compounds in the vapor compared to tobacco smoke and, accordingly, a substantial overlap of pathomechanistic features between vaping and smoking. Whereas the main toxins in vapor are reactive aldehydes such as formaldehyde and acrolein, the toxic mixture in smoke is more complex, comprising particulate matter, reactive gases, transition metals, volatile organic compounds, and N-nitrosamines. However, it seems that both lifestyle drugs impair endothelial function to a quite similar extent, which may be due to the role of oxidative stress as the central pathomechanism to mediate endothelial dysfunction and vascular damage. Finally, the main selling argument for e-cigarette use that they help to quit smoking and get rid of nicotine addiction may be false because it seems that e-cigarettes instead trigger the opposite-younger entrance age and more frequent use. With our review, we summarize the adverse health impact of tobacco cigarettes and e-cigarettes, emphasizing the detrimental effects on endothelial function and cardiovascular health.

Adverse Maternal and Infant Outcomes of Women Who Differ in Smoking Status: E-Cigarette and Tobacco Cigarette Users

The electronic cigarette (e-cigarette) became commercially available around 2004, yet the characteristics of pregnant women who use these devices and their effects on maternal and infant health remain largely unknown. This study aimed to investigate maternal characteristics and pregnancy outcomes according to maternal smoking status. We conducted a cross-sectional study of Dutch women with reported pregnancies between February 2019 and May 2022, using an online questionnaire to collect data on smoking status and demographic, lifestyle, pregnancy, and infant characteristics. Smoking status is compared among non-smokers, tobacco cigarette users, e-cigarette users, and dual users (tobacco and e-cigarette). We report descriptive statistics and calculate differences in smoking status between women with the chi-square or Fisher (Freeman-Halton) test. Of the 1937 included women, 88.1% were non-smokers, 10.8% were tobacco cigarette users, 0.5% were e-cigarette users, and 0.6% were dual users. Compared with tobacco users, e-cigarette users more often reported higher education, having a partner, primiparity, and miscarriages. Notably, women who used e-cigarettes more often had small infants for gestational age. Despite including few women in the e-cigarette subgroup, these exploratory results indicate the need for more research to examine the impact of e-cigarettes on pregnancy outcomes.

Exposure-response analysis of the association of maternal smoking and use of electronic cigarettes (vaping) in relation to preterm birth and small-for-gestational-age in a national US sample, 2016-2018

Introduction

The US experienced a surge in use of e-cigarettes. Smoking women may consider e-cigarettes during pregnancy as an alternative to smoking. E-cigarettes typically contain nicotine, an established cause of reduction in fetal growth in animal studies.

Methods

This cohort study included 99,201 mothers who delivered live singletons in 2016-2018 from the Pregnancy Risk Assessment Monitoring System. We created exposure categories based on self-reported number of cigarettes smoked per day and vaping frequency and evaluated their associations with preterm birth and small-for-gestational-age (SGA) birth (two established cigarette smoking-related risks).

Results

Dual users in late pregnancy were a heterogeneous group: 29% lightly smoked and occasionally vaped; 19% lightly smoked and frequently vaped; 36% heavily smoked and occasionally vaped; and 15% heavily smoked and frequently vaped. While dual users who heavily smoked and occasionally vaped had the highest adjusted OR for SGA (3.4, 95% CI 2.0, 5.7), all the dual users had, on average, about twice the odds of having SGA than non-users. While the risks of preterm birth were higher among sole light smokers (adjusted OR 1.3, 95% CI 1.1, 1.5) and sole heavy smokers (adjusted OR 1.5. 95% CI 1.2, 1.8) than non-users, the adjusted odds of preterm birth for dual users were not noticeably higher than those of non-users.

Conclusion

Relative to non-users, both smoking and vaping during pregnancy appear to increase risk of SGA, but excess risk of preterm birth appears to be primarily attributable to smoking alone. Higher levels of exposure tended to confer more risk.

The Health Effects of Real-World Dual Use of Electronic and Conventional Cigarettes versus the Health Effects of Exclusive Smoking of Conventional Cigarettes: A Systematic Review

BACKGROUND

A high prevalence of dual use of e-cigarettes and conventional cigarettes has been reported across the world.

METHODS

A systematic search was carried out. We included original articles on any topic relevant to health, excluding mental health, in all languages. The PRISMA guidelines were followed. Both reviewers independently screened and read all publications. We compared dual use with exclusive smoking of conventional cigarettes (ESCC).

RESULTS

Fifty-two publications (49 studies) were included. Thirteen papers/10 studies were prospective. There was great heterogeneity across studies. Many methodological weaknesses, such as inaccurate exposure measurement, lack of adjustment for former tobacco consumption, and lack of significance testing were identified. Most prospective studies found dual use to be at least as harmful as ESCC. The longest follow-up was six years. Most of the best available cross-sectional studies found dual use associated with the same and, in several studies, significantly higher risk of self-reported symptoms/disease than in ESCC. The intensity of cigarette smoking seems associated with worse health.

CONCLUSION

Existing studies indicate that dual use is at least as, or probably even more, harmful than ESCC. Due to the predominance of cross-sectional studies and the methodological weaknesses we judged the overall certainty of the evidence as "low certainty".

Changes in e-cigarette and cigarette use during pregnancy and their association with small-for-gestational-age birth

BACKGROUND

Despite increased e-cigarette use, limited research has focused on changes in e-cigarette and combustible cigarette use around pregnancy and the subsequent effects on infant health.

OBJECTIVE

This study aimed to characterize changes in e-cigarette and cigarette use from before to during pregnancy and examine their associations with small-for-gestational-age birth.

STUDY DESIGN

This was a secondary data analysis of 2016-2018 data of the US Pregnancy Risk Assessment Monitoring System. We analyzed women aged ≥18 years who had a recent live birth (unweighted: n=105,438; weighted: n=5,446,900). Women were grouped on the basis of their self-reported e-cigarette and/or cigarette use 3 months before pregnancy (exclusive e-cigarette users, exclusive cigarette smokers, dual users, and nonusers) and change in e-cigarette and cigarette use during pregnancy (continuing use, quitting, switching, and initiating use). Small-for-gestational-age was defined as a birthweight below the 10th percentile for infants of the same sex and gestational age. We described the distributions of women's sociodemographic and pregnancy characteristics in both weighted and unweighted samples. We used multivariable log-binomial regression models to estimate the relative risks for the associations between changes in e-cigarette and cigarette use during pregnancy and risk of small-for-gestational-age, adjusting for significant covariates.

RESULTS

The rates of cessation during pregnancy were the highest among exclusive e-cigarette users (weighted percentage, 80.7% [49,378/61,173]), followed by exclusive cigarette users (54.4% [421,094/773,586]) and dual users (46.4% [69,136/149,152]). Among exclusive e-cigarette users, continued users of e-cigarettes during pregnancy had a higher risk of small-for-gestational-age than nonusers (16.5% [1849/11,206]) vs 8.8% [384,338/4,371,664]; confounder-adjusted relative risk, 1.52 [95% confidence interval, 1.45-1.60]), whereas quitters of e-cigarettes had a similar risk of small-for-gestational-age with nonusers (7.7% [3730/48,587] vs 8.8% [384,338/4,371,664]; relative risk, 0.84 [95% confidence interval, 0.82-0.87]). Among exclusive cigarette users, those who completely switched to e-cigarettes during pregnancy also had a similar risk of small-for-gestational-age with nonusers (7.6% [259/3412] vs 8.8% [384,338/4,371,664]; relative risk, 0.83 [95% confidence interval, 0.73-0.93]). Among dual users before pregnancy, the risk of small-for-gestational-age decreased from 23.2% (7240/31,208) (relative risk, 2.53 [95% confidence interval, 2.47-2.58]) if continuing use to 16.9% (6617/39,142) (relative risk, 1.88 [95% confidence interval, 1.83-1.92]) if only quitting e-cigarettes or 15.1% (1254/8289) (relative risk, 1.61 [95% confidence interval, 1.52-1.70]) if only quitting cigarettes and further to 11.2% (7589/67,880) (relative risk, 1.23 [95% confidence interval, 1.20-1.25]) if both quitting e-cigarettes and cigarettes during pregnancy, compared with nonusers.

CONCLUSION

Among exclusive e-cigarette users, quitting e-cigarettes during pregnancy normalized the risk of small-for-gestational-age. Among exclusive cigarette users, quitting smoking or completely switching to e-cigarettes normalized small for gestational age risk. Among dual users, smoking cessation has a greater effect than quitting e-cigarettes only, although discontinuing the use of both may lead to the greatest reduction in the risk of small-for-gestational-age.

Use of electronic nicotine delivery systems (ENDS) among U.S. women of reproductive age: Prevalence, reported reasons for use, and toxin exposure

Given the rapidly expanding marketplace for Electronic Nicotine Delivery Systems (ENDS), it is important to monitor patterns of use, particularly among vulnerable populations. This study examined ENDS prevalence, reasons for use (i.e., to help quit smoking and for appealing flavors), and toxin exposure among U.S. women of reproductive age using data from the Population Assessment of Tobacco and Health (PATH) Study (2013-17). Exclusive ENDS users, dual users of ENDS and cigarettes, and exclusive cigarette smokers were compared within and between pregnant and not-pregnant women. Among pregnant women, prevalence of exclusive ENDS and dual use was similar (0.8%; 95%CI = 0.4-1.2% vs. 1.4%; 95%CI = 0.9-2.0%, respectively), but exclusive ENDS use was less prevalent than dual use among not-pregnant women (1.1%; 95%CI = 0.9-1.4% vs. 3.7%; 95%CI = 3.3-4.0%, respectively). Most women reported ENDs were used to help quit smoking (66.5-90.0%) and for appealing flavors (57.6-87.4%), and endorsement rates did not differ by use pattern or pregnancy status. Except for metals, toxin exposure was substantially lower for exclusive ENDS users relative to dual users and exclusive cigarette smokers regardless of pregnancy status. Pregnant and not-pregnant U.S. women regularly report using ENDS for help with quitting smoking and for appealing flavors. Although no type or pattern of tobacco/nicotine use is safe, especially during pregnancy, using ENDS exclusively is consistent with lower overall toxin exposure for pregnant and not-pregnant women. This study advances understanding of ENDS use and toxin exposure in women of reproductive age, a population highly vulnerable to the effects of nicotine/tobacco consumption.

Vaping in Pregnancy: A Systematic Review

INTRODUCTION

Smoking in pregnancy increases the risk of negative health outcomes. Vaping can be effective for smoking cessation in nonpregnant populations. We conducted a systematic review of vaping in pregnancy, covering prevalence, patterns of use, reasons for use, smoking cessation, and health effects.

METHODS

Five academic databases were searched on 17 February 2020. Studies reporting prevalence, patterns, reasons, cessation, or health effects of vaping in pregnancy were included; animal and in vitro studies were excluded. A narrative review was used, with risk of bias assessed using Hoy and colleague's tool, the Newcastle-Ottawa scale, and the Consolidated Criteria for reporting Qualitative Research.

RESULTS

Twenty-three studies were identified: 11 survey, 7 qualitative, 3 cohort, and 2 secondary analyses of randomized clinical trials. Prevalence of vaping in pregnancy (four studies) was between 1.2% and 7.0% overall, and <1% among nonsmokers. Twelve studies reported patterns of use, but findings were inconsistent. Twelve of 14 studies asking why pregnant women vaped reported that most vaped to reduce or quit smoking. Mixed findings were reported from six studies on smoking cessation. Of three studies with health-related outcomes, two were underpowered and one reported similar birthweights for babies born to nonsmokers and women who vaped, with both higher (p < .0001) than the birthweight of babies born to smokers.

CONCLUSIONS

There were insufficient data to draw conclusions about prevalence, patterns, and effects of vaping in pregnancy on smoking cessation. The limited literature suggests that vaping in pregnancy has little or no effect on birthweight.

IMPLICATIONS

Smoking causes many negative health outcomes for pregnant women and to babies born to people who smoke. There remains a paucity of research on the effects of vaping in pregnancy. There is, however, the potential for vaping products to reduce the negative health outcomes associated with smoking. More research is needed to develop an evidence base in this area.

Electronic cigarette use (vaping) and patterns of tobacco cigarette smoking in pregnancy-evidence from a population-based maternity survey in England

OBJECTIVES

Exposure to tobacco products during pregnancy presents a potential harm to both mother and baby. This study sought to estimate the prevalence of vaping during pregnancy and to explore the factors and outcomes associated with vaping in pregnancy.

SETTING

England.

PARTICIPANTS

Women who gave birth between 15th and 28th October 2017.

METHODS

A cross-sectional population-based postal survey of maternal and infant health, the National Maternity Survey (NMS) 2018. The prevalence of vaping and patterns of cigarette smoking were estimated, and regression analysis was used to explore associations between maternal characteristics and vaping, and between vaping and birth outcomes.

OUTCOME MEASURES

Unweighted and weighted prevalence of vaping with 95% confidence intervals, and unadjusted and adjusted relative risks or difference in means for the association of participant characteristics and secondary outcomes with vaping. Secondary outcome measures were: preterm birth, gestational age at birth, birthweight, and initiation and duration of breastfeeding.

RESULTS

A total of 4,509 women responded to the survey. The prevalence of vaping in pregnancy was 2.8% (95%CI 2.4% to 3.4%). This varied according to the pattern of cigarette smoking in pregnancy: 0.3% in never-smokers; 3.3% in ex-smokers; 7.7% in pregnancy-inspired quitters; 9.5% in temporary quitters; and 17.7% in persistent smokers. Younger women, unmarried women, women with fewer years of formal education, women living with a smoker, and persistent smokers were more likely to vape, although after adjusting for pattern of cigarette smoking and maternal characteristics, persistent smoking was the only risk factor. We did not find any association between vaping and preterm birth, birthweight, or breastfeeding.

CONCLUSIONS

The prevalence of vaping during pregnancy in the NMS 2018 was low overall but much higher in smokers. Smoking was the factor most strongly associated with vaping. Co-occurrence of vaping with persistent smoking has the potential to increase the harms of tobacco exposure in pregnant women and their infants.

Pregnant women's use of e-cigarettes in the UK: a cross-sectional survey

OBJECTIVE

To estimate prevalence of vaping in pregnancy. Compare characteristics and attitudes between exclusive smokers and vapers, and between exclusive vapers and dual users (smoke and vape).

DESIGN

Cross-sectional survey.

SETTING

Hospitals across England and Scotland.

POPULATION

Pregnant women attending antenatal clinics in 2017.

METHODS

Women at 8-24 weeks' gestation completed screening questions about their smoking and vaping. Current or recent ex-smokers and/or vapers completed a full detailed survey about vaping and smoking.

MAIN OUTCOME MEASURES

The prevalence of vaping, characteristics and attitudes of women who vape and/or smoke.

RESULTS

Of 3360 pregnant women who completed screening questions, 515 (15.3%, 95% CI 14.1-16.6) were exclusive smokers, 44 (1.3%, 95% CI 1.0-1.8) exclusive vapers and 118 (3.5%, 95% CI 2.9-4.2) dual users. In total, 867 (25.8%) women completed the full survey; compared with smokers (n = 434), vapers (n = 140) were more likely to hold higher educational qualifications (odds ratio [OR) 1.51, 95% CI 1.01-2.25). Compared with exclusive vapers (n = 33), dual users (n = 107) were younger (OR 0.91 95% CI 0.85-0.98) and less likely to hold high qualifications (OR 0.43, 95% CI 0.20-0.96). Compared with smokers, dual users were more likely to be planning to quit smoking (OR 2.27, 95% CI 1.24-4.18). Compared with smokers, vapers were more likely to think vaping was safer than smoking (78.6% versus 36.4%).

CONCLUSIONS

One in 20 pregnant women report vaping, and most also smoke. Dual users are more motivated towards stopping smoking than smokers. Where women have tried but cannot stop smoking, clinicians could encourage them to consider vaping for smoking cessation.

TWEETABLE EXTRACT

One in 20 women report vaping during pregnancy but of those that do vape, most also smoke, despite having intentions to quit.

Online In-Tube Solid-Phase Microextraction Coupled to Liquid Chromatography-Tandem Mass Spectrometry for the Determination of Tobacco-Specific Nitrosamines in Hair Samples

Active and passive smoking are serious public health concerns Assessment of tobacco smoke exposure using effective biomarkers is needed. In this study, we developed a simultaneous determination method of five tobacco-specific nitrosamines (TSNAs) in hair by online in-tube solid-phase microextraction (SPME) coupled to liquid chromatography-tandem mass spectrometry (LC-MS/MS). TSNAs were extracted and concentrated on Supel-Q PLOT capillary by in-tube SPME and separated and detected within 5 min by LC-MS/MS using Capcell Pak C18 MGIII column and positive ion mode multiple reaction monitoring systems. These operations were fully automated by an online program. The calibration curves of TSNAs showed good linearity in the range of 0.5-1000 pg mL-1 using their stable isotope-labeled internal standards. Moreover, the limits of detection (S/N = 3) of TSNAs were in the range of 0.02-1.14 pg mL-1, and intra-day and inter-day precisions were below 7.3% and 9.2% (n = 5), respectively. The developed method is highly sensitive and specific and can easily measure TSNA levels using 5 mg hair samples. This method was used to assess long-term exposure levels to tobacco smoke in smokers and non-smokers.

Healthcare Professionals' Beliefs, Attitudes, Knowledge, and Behavior Around Vaping in Pregnancy and Postpartum: A Qualitative Study

INTRODUCTION

Finding effective ways to help pregnant women quit smoking and maintain long-term abstinence is a public health priority. Electronic cigarettes (ie, vaping) could be a suitable cessation tool in pregnancy for those who struggle to quit; however, healthcare professionals (HCP) must be informed about these devices to offer appropriate advice. This study used the Capability, Opportunity, Motivation, and Behavior (COM-B) model and Theoretical Domains Framework (TDF) to explore HCP attitudes towards vaping in pregnancy and postpartum; beliefs about the health risks of vaping; perceived barriers and facilitators of vaping in pregnancy; knowledge of current guidelines and policies; and training needs.

METHODS

Interviews (n = 60) were conducted with midwives (n = 17), health visitors (n = 10), general practitioners (n = 15) and stop smoking specialists (n = 18) across the United Kingdom. Interview transcriptions were analyzed thematically using the framework approach and the COM-B.

RESULTS

Discussing vaping as a tool for quitting smoking in pregnancy was prevented by a lack of capability (limited knowledge of vaping, lack of training in smoking cessation); lack of opportunity (restricted by organizational policies and guidelines, lack of time and financial issues impacting on training), and negative social influences (sensationalist media and stigma associated with vaping in pregnancy); and lack of motivation (fear of future litigation and comebacks should adverse effects from vaping arise).

CONCLUSIONS

Factors related to capability, opportunity, and motivation were identified that influence HCPs attitudes and behaviors towards vaping in pregnancy. Gaps in knowledge and training needs were identified, which could inform the development of targeted vaping training.

IMPLICATIONS

Vaping could be suitable in pregnancy for those struggling to quit smoking. However, HCPs must be informed about these devices to offer appropriate advice. These data extend our knowledge of factors influencing HCP attitudes and behaviors towards vaping in pregnancy. Generally, vaping was perceived as safer than cigarettes, but a perceived lack of evidence, health and safety risks, dependency, and regulation issues were concerning. Considering our findings, greater efforts are needed to ensure HCPs are sufficiently informed about vaping and guidelines available. More importance should be placed on training for all HCPs who have contact with pregnant women.

A Qualitative Study of Factors Influencing Adherence among Pregnant Women Taking Part in a Trial of E-Cigarettes for Smoking Cessation

Use of e-cigarettes (vaping) has potential to help pregnant women stop smoking. This study explored factors influencing adherence among participants in the vaping arm of the first trial of vaping for smoking cessation in pregnancy. We conducted semi-structured telephone interviews (n = 28) with women at three-months postpartum. Interviews were analysed using thematic analysis, informed by the Theoretical-Domains Framework, Necessity-Concerns Framework and Perceptions and Practicalities Approach. Interviewees generally reported high levels of vaping. We found that: (1) intervention adherence was driven by four necessity beliefs-stopping smoking for the baby, and vaping for harm reduction, smoking cessation or as a last resort; (2) necessity beliefs outweighed vaping concerns, such as dependence and safety; (3) adherence was linked to four practicalities themes, acting as barriers and facilitators to vaping-device and e-liquid perceptions, resources and support, whether vaping became habitual, and social and environmental factors; and (4) intentional non-adherence was rare; unintentional non-adherence was due to device failures, forgetting to vape, and personal circumstances and stress. Pregnant smokers provided with e-cigarettes, and with generally high levels of vaping, had positive beliefs about the necessity of vaping for smoking cessation which outweighed concerns about vaping. Non-adherence was mainly due to unintentional factors.

Effects of E-Cigarette Exposure on Prenatal Life and Childhood Respiratory Health: A Review of Current Evidence

In the last decade, widespread use of E-cigarettes (EC) has occurred all over the world. Whereas, a large amount of evidence on harm to children from conventional cigarette exposure is available, data on health effects in this population throughout different vulnerability windows are still a matter of concern. Exposure to EC during pregnancy may compromise placental function, resulting in fetal structural abnormalities. Specifically, this may cause physio-pathologic changes in the developing lung, which in turn may impair respiratory health later in life. Furthermore, there is evidence that using EC can cause both short- and long-term respiratory problems in the pediatric population and there is great concern for future young people with nicotine addiction. The low parental perception of the risks connected to EC exposure for children increases their susceptibility to harmful effects from passive vaping. This minireview aims to summarize the current evidence focusing on: (i) prenatal effects of EC passive exposure; (ii) post-natal respiratory effects of EC exposure in youth; (iii) parental attitudes toward EC use and perception of children's health risks connected to EC exposure; and (iv) addressing gaps in our current evidence.

Vaping During Pregnancy: What Are the Potential Health Outcomes and Perceptions Pregnant Women Have?

The prevalence of electronic nicotine delivery systems, such as vaping, is a growing public health concern, and there is limited information on the use of these devices during pregnancy. The objective of this rapid review was to summarize the available literature on human studies of the potential maternal or fetal health effects of vaping or women's perceptions of vaping during pregnancy. A systematic search was completed in the following databases: Medline, EMBASE, Scopus, Web of Science, and CINAHL. A search strategy was developed combining the terms pregnancy and vaping. Findings were divided into two groups and summarized as: 1) Health outcomes following vaping during pregnancy; and 2) Perceptions pregnant women have related to vaping during pregnancy. A total of 760 articles were retrieved and, after applying the inclusion/exclusion criteria and screening, 19 studies were included. Five included studies provided evidence on potential health outcomes and 14 were focused on perceptions. There is emerging evidence that vaping during pregnancy may increase the risk of small for gestational age newborns. Pregnant women generally report that they used vaping products during pregnancy for smoking cessation and perceived that this was a healthier alternative to traditional cigarettes. Overall, there was consensus that there is a lack of information on maternal and fetal health outcomes following vaping during pregnancy. Based on the findings of this rapid review, there is an urgent need for high-quality studies in pregnant women to evaluate the potential in utero and long-term effects of exposure to prenatal vaping.

Dual use of cigarettes and electronic nicotine delivery systems during pregnancy and the risk of small for gestational age neonates

PURPOSE

The purpose of this study was to estimate the effect of cigarette smoking and electronic nicotine delivery systems (ENDS) use during pregnancy on small for gestational age (SGA).

METHODS

We used data from the 2016-2017 Arkansas Pregnancy Risk Assessment Monitoring System, estimated the risk ratio (RR) for SGA for maternal prenatal cigarette smoking-only use, cigarette smoking, and ENDS use (i.e., dual use), with no prenatal tobacco use as referent, accounting for the complex survey design. We also explored these effects for women who stopped smoking cigarettes during pregnancy among cigarette smokers and dual users.

RESULTS

Estimated adjusted RR for SGA for cigarette-only users was 1.7 (95% confidence interval [CI]: 1.1, 2.7), and 1.8 (95% CI: 1.0, 3.4) for dual users. These RR estimates increased after correcting for tobacco use misclassification. Women who were dual users (cigarette smokers and ENDS users) and continued using ENDS but stopped smoking cigarettes had an increased risk for SGA compared with nontobacco users, 3.2 (95% CI: 1.5, 6.6).

CONCLUSIONS

Our results in a population representative sample are consistent with the hypothesis that exposure to both maternal cigarette smoking and ENDS use increased the risk of SGA. Dual users still had an elevated risk of SGA after smoking cessation.

E-Cigarette Use Patterns and High-Risk Behaviors in Pregnancy: Behavioral Risk Factor Surveillance System, 2016-2018

INTRODUCTION

The prevalence of e-cigarette use has increased dramatically in the last decade in the U.S. Understanding the prevalence, patterns of use, and risk factor associations of e-cigarette use in pregnant women is particularly important, as this could have potential health implications for the mother and the developing child.

METHODS

Using Behavioral Risk Factor Surveillance System Survey data from 2016 to 2018, adult women of reproductive age (18-49 years) who reported being pregnant (n=7,434) were studied. Self-reported current e-cigarette use was the main exposure. Other measures included combustible cigarette smoking status and high-risk behaviors (including other tobacco, marijuana, or heavy alcohol use; binge drinking; and others). All analyses were done in 2019.

RESULTS

Approximately 2.2% of pregnant women reported current e-cigarette use, of whom 0.6% reported daily use. The highest prevalence of e-cigarette use was observed in the youngest age group of pregnant women (3.2%), with 41.7% of all pregnant current e-cigarette users being aged 18-24 years. There was a marked increase in the prevalence of current use of e-cigarettes among pregnant women from 1.9% in 2016 to 3.8% in 2018. Approximately 46% of pregnant current e-cigarette users reported concomitant cigarette smoking. Compared with pregnant never e-cigarette users, pregnant current e-cigarette users had a higher prevalence of other tobacco product use, marijuana use, heavy alcohol intake, binge drinking, and other high-risk behaviors.

CONCLUSIONS

These findings underscore the need to strengthen prevention and policy efforts, specifically in the vulnerable subgroup of pregnant women.

Reviewing the oral carcinogenic potential of E-cigarettes using the Bradford Hill criteria of causation

The past decade has seen a surge in the use of e-cigarettes, which has prompted the medical community to assess any associated potential health hazards. A major concern was the risk of cancer. Chemical analysis of e-cigarettes has shown the presence of volatile organic compounds with the potential for carcinogenicity. Comparative toxicology analysis has shown e-cigarette to have relatively lower dosages of toxins than conventional combustible cigarettes. Based on comparative analysis, e-cigarettes have been increasingly advocated as a safe alternative to conventional cigarettes. It is vital to recognize that presence of relatively lower toxin level does not preclude carcinogenic potential. The nicotine present in the e-cigarette was presumed to be the major cytotoxic agents, thus nicotine-free e-cigarette was considered as inert. On the contrary, experimental studies on oral cell lines have shown DNA strand breaks on exposure to e-cigarette vapors with or without nicotine. In addition, dysregulations of genes associated with carcinogenic pathways have also been demonstrated in oral tissues exposed to e-cigarette vapors. Despite alarming molecular data, the oral carcinogenic potential of e-cigarette remains unclear, which can be attributed to the lack of long-term prospective and large-scale case-control studies. As e-cigarette users often have other well-established risk factors (conventional cigarette smoking, alcohol, etc.) as associated habits, it is difficult to assess e-cigarette as an independent risk factor for oral cancer. Thus, the present manuscript aims to review the published literature using the Brad Ford Hill criteria of causation to determine the oral carcinogenic potential of e-cigarettes.

Smoking and pregnancy: The era of electronic nicotine delivery systems

Electronic nicotine delivery systems have been commercially available in the United States since 2007. Despite a decrease in combustible cigarette use, electronic nicotine delivery systems use has dramatically increased among both adults and adolescents. These devices have been marketed as smoking cessation aids, although data on their efficacy are scarce. Pregnant women are an especially vulnerable population susceptible to claims of safety and efficacy, and the medical community remains inadequately informed on how to counsel these women. The purpose of this article is to review known literature regarding the use of electronic nicotine delivery systems in pregnancy, to understand the differences between cigarettes and electronic nicotine delivery systems use in pregnancy, and to further guide clinicians on how to advise the pregnant woman on their use.

Use of Electronic Nicotine Delivery Systems (ENDS) by pregnant women I: Risk of small-for-gestational-age birth

INTRODUCTION

The 2016 US Surgeon General's Report suggests that the use of electronic nicotine delivery systems (ENDS) is a fetal risk factor. However, no previous study has estimated their effect on adverse pregnancy outcomes. We assessed the prevalence of current ENDS use in pregnant women and explored the effect on birth weight and smallness-for-gestational-age (SGA), correcting for misclassification from nondisclosure of smoking status.

METHODS

We conducted a cohort study with 248 pregnant women using questionnaire data and biomarkers (salivary cotinine, exhaled carbon monoxide, and hair nicotine). We evaluated the association between birth weight and the risk of SGA by applying multivariate linear and log-binomial regression to reproductive outcome data for 232 participants. Participants who did not disclose their smoking status were excluded from the referent group. Sensitivity analysis corrected for misclassification of smoking/ENDS use status.

RESULTS

The prevalence of current ENDS use among pregnant women was 6.8% (95% CI: 4.4-10.2%); most of these (75%) were concurrent smokers. Using self-reports, the estimated risk ratio of SGA for ENDS users was nearly two times the risk in the unexposed (RR=1.9, 95% CI: 0.6-5.5), and over three times that for ENDS-only users versus the unexposed (RR=3.1, 95% CI: 0.8-11.7). Excluding from the referent group smokers who did not disclose their smoking status, the risk of SGA for ENDS-only use was 5 times the risk in the unexposed (RR=5.1, 95% CI: 1.1- 22.2), and almost four times for all types of ENDS users (RR=3.8, 95% CI: 1.3-11.2). SGA risk ratios for ENDS users, corrected for misclassification due to self-report, were 6.5-8.5 times that of the unexposed.

CONCLUSIONS

Our data suggest that ENDS use is associated with an increased risk of SGA.