Effect of nicotine patches in pregnancy on infant and maternal outcomes at 2 years: follow-up from the randomised, double-blind, placebo-controlled SNAP trial

[Smoking cessation during pregnancy]

Smoking during pregnancy is associated with negative pregnancy and perinatal health outcomes. Physiological and societal particularities can modify the smoking behavior of pregnant women. Pregnancy is a teachable moment for smoking cessation. Increased nicotine clearance may lead to exacerbated tobacco withdrawal symptoms and desire to smoke, which need to be taken into account when helping pregnant smokers to quit. Although most pregnant smokers try to quit on their own, 12% of pregnant women in France reported smoking in 2021 during the 3rd trimester of pregnancy. Health care professionals should screen for tobacco consumption and assess the level of addiction. Management of smoking cessation can be multidisciplinary, including non-pharmacological support such as counselling, behavioral support, financial reward contingent on abstinence, and medication (nicotine replacement therapies). Assessment and limitation of secondhand smoke exposure (SHS) is needed because SHS can also have negative maternal and fetal consequences. Management of relapse during the postpartum period is also to be anticipated; in 2021, it concerned 22.4% of women who had stopped smoking during pregnancy. While electronic cigarette use is increasing overall and among pregnant women who smoke (5.4 before pregnancy, 1.3% during the 3rd trimester in 2021), well-conducted smoking cessation studies are necessary to assess its benefits and potential risks in this specific group of smokers.

The Effect of E-Cigarette Indoor Vaping Restrictions on Infant Mortality

We estimate the effect of county-level e-cigarette indoor vaping restrictions (IVRs) on infant mortality using United States birth certificates from 2010 to 2015. We estimate difference-in-differences models and find that e-cigarette indoor vaping restrictions increased infant mortality by 0.39 infants per 1,000 live births (12.9%). These effects were disproportionately higher for infants born to younger mothers and in locations with higher baseline levels of prenatal smoking. Infant mortality increased by 34.1% between 100 days to 1 year after IVRs. Infant mortality due to infections and neoplasms were particularly elevated.

Smoking, nicotine and pregnancy 2 (SNAP2) trial: protocol for a randomised controlled trial of an intervention to improve adherence to nicotine replacement therapy during pregnancy

INTRODUCTION

Smoking during pregnancy is harmful to unborn babies, infants and women. Nicotine replacement therapy (NRT) is offered as the usual stop-smoking support in the UK. However, this is often used in insufficient doses, intermittently or for too short a time to be effective. This randomised controlled trial (RCT) explores whether a bespoke intervention, delivered in pregnancy, improves adherence to NRT and is effective and cost-effective for promoting smoking cessation.

METHODS AND ANALYSIS

A two-arm parallel-group RCT was conducted for pregnant women aged ≥16 years and who smoke ≥1 daily cigarette (pre-pregnancy smoked ≥5) and who agree to use NRT in an attempt to quit. Recruitment is from antenatal care settings and via social media adverts. Participants are randomised using blocked randomisation with varying block sizes, stratified by gestational age (<14 or ≥14 weeks) to receive: (1) usual care (UC) for stop smoking support or (2) UC plus an intervention to increase adherence to NRT, called 'Baby, Me and NRT' (BMN), comprising adherence counselling, automated tailored text messages, a leaflet and website. The primary outcome is biochemically validated smoking abstinence at or around childbirth, measured from 36 weeks gestation. Secondary outcomes include NRT adherence, other smoking measures and birth outcomes. Questionnaires collect follow-up data augmented by medical record information. We anticipate quit rates of 10% and 16% in the control and intervention groups, respectively (risk ratio=1.6). By recruiting 1320 participants, the trial should have 90% power (alpha=5%) to detect this intervention effect. An economic analysis will use the Economics of Smoking in Pregnancy model to determine cost-effectiveness.

ETHICS AND DISSEMINATION

Ethics approval was granted by Bloomsbury National Health Service's Research Ethics Committee (21/LO/0123). Written informed consent will be obtained from all participants. Findings will be disseminated to the public, funders, relevant practice/policy representatives, researchers and participants.

TRIAL REGISTRATION NUMBER

ISRCTN16830506.

PROTOCOL VERSION

5.0, 10 Oct 2023.

Tobacco or marijuana use and infertility: a committee opinion

In the United States, approximately 21% of adults report some form of tobacco use, although 18% report marijuana use. Although the negative impact of tobacco use in pregnancy is well documented, the impact of tobacco and marijuana on fertility and reproduction is less clear. This committee opinion reviews the potential deleterious effects of tobacco, nicotine, and marijuana use on conception, ovarian follicular dynamics, sperm parameters, gamete mutations, early pregnancy, and assisted reproductive technology outcomes. It also reviews the current status of tobacco smoking cessation strategies. This document replaces the 2018 American Society for Reproductive Medicine Practice Committee document entitled Smoking and Infertility: a committee opinion (Fertil Steril 2018).

Helping pregnant smokers quit: a multi-centre randomised controlled trial of electronic cigarettes versus nicotine replacement therapy

Background

Some pregnant smokers try e-cigarettes, but effectiveness and safety of such use are unknown.

Objectives

To compare effectiveness and safety of nicotine patches and e-cigarettes in pregnancy.

Design

A pragmatic multi-centre randomised controlled trial.

Setting

Twenty-three hospitals across England, and a Stop Smoking Service in Scotland.

Participants

One thousand one hundred and forty pregnant daily smokers (12-24 weeks' gestation) motivated to stop smoking, with no strong preference for using nicotine patches or e-cigarettes.

Interventions

Participants in the e-cigarette arm were posted a refillable e-cigarette device with two 10 ml bottles of tobacco-flavoured e-liquid (18 mg nicotine). Participants in the nicotine patches arm were posted a 2-week supply of 15 mg/16-hour nicotine patches. Supplies were provided for up to 8 weeks. Participants sourced further supplies themselves as needed. Participants in both arms received support calls prior to their target quit date, on the quit date, and weekly for the next 4 weeks.

Outcome measures

The primary outcome was validated prolonged abstinence at the end of pregnancy. Participants lost to follow-up or not providing biochemical validation were included as non-abstainers. Secondary outcomes included self-reported abstinence at different time points, treatment adherence and safety outcomes.

Results

Only 55% of self-reported abstainers mailed back useable saliva samples. Due to this, validated sustained abstinence rates were low (6.8% vs. 4.4% in the e-cigarettes and nicotine patches arms, respectively, risk ratio = 1.55, 95% confidence interval 0.95 to 2.53; Bayes factor = 2.7). In a pre-specified sensitivity analysis that excluded abstainers using non-allocated products, the difference became significant (6.8% vs. 3.6%, risk ratio = 1.93, 95% confidence interval 1.14 to 3.26; Bayes factor = 10). Almost a third of the sample did not set a target quit date and the uptake of support calls was low, as was the initial product use. At end of pregnancy, 33.8% versus 5.6% of participants were using their allocated product in the e-cigarettes versus nicotine patches arm (risk ratio = 6.01, 95% confidence interval 4.21 to 8.58). Regular use of e-cigarettes in the nicotine patches arm was more common than use of nicotine replacement products in the e-cigarette arm (17.8% vs. 2.8%). Rates of adverse events and adverse birth outcomes were similar in the two study arms, apart from participants in the e-cigarette arm having fewer infants with low birthweight (<2500 g) (9.6% vs. 14.8%, risk ratio = 0.65, 95% confidence interval 0.47 to 0.90; Bayes factor = 10.3).

Limitations

Low rates of validation reduced the study power. A substantial proportion of participants did not use the support on offer sufficiently to test its benefits. Sample size may have been too small to detect differences in less frequent adverse effects.

Conclusions

E-cigarettes were not significantly more effective than nicotine patches in the primary analysis, but when e-cigarettes use in the nicotine patches arm was accounted for, e-cigarettes were almost twice as effective as patches in all abstinence outcomes. In pregnant smokers seeking help, compared to nicotine patches, e-cigarettes are probably more effective, do not pose more risks to birth outcomes assessed in this study and may reduce the incidence of low birthweight.

Future work

Routine monitoring of smoking cessation and birth outcomes in pregnant women using nicotine patches and e-cigarettes and further studies are needed to confirm these results.

Trial registration

This trial is registered as ISRCTN62025374 and Eudract 2017-001237-65.

Funding

This project was funded by the National Institute for Health and Care Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 27, No. 13. See the NIHR Journals Library website for further project information.

Safety of Nicotine Replacement Therapy during Pregnancy: A Narrative Review

BACKGROUND

Smoking during pregnancy is a public health problem worldwide and the leading preventable cause of fetal morbidity and mortality and obstetric disease. Although the risk of tobacco-related harm can be substantially reduced if mothers stop smoking in the first trimester, the proportion of women who do so remains modest; therefore, the treatment of smoking in pregnant women will be the first therapeutic measure that health professionals should adopt when providing care to pregnant women. The recommendation of nicotine replacement therapy during pregnancy remains controversial due to the potential effects on the health of the fetus.

PURPOSE

The aim of this review was to provide an overview of human studies about the use of nicotine replacement therapy during pregnancy, evaluating the efficacy and safety of the different formulations.

METHODS

The electronic databases PubMed and EMBASE were searched from May 2012 to May 2022. A total of 95 articles were identified through database searching using a combination of keywords. Out of 79 screened articles and after the removal of duplicates, 28 full-text articles were assessed for eligibility and 12 articles were finally included for review.

RESULTS

Although demonstrated to be effective in adult smokers, evidence in support of NRT in pregnant women is limited. The results of the apparent safety of the use of NRT during pregnancy contradict the FDA classification of the different NRT formulations. Faster-acting formulations seem to be the safest and even most beneficial forms for the offspring.

CONCLUSIONS

NRT is not completely harmless for the fetus or for the mother; however, if an adequate assessment of the risk-benefit binomial is made, its use during pregnancy to aid in quitting smoking does seem appropriate. It is necessary to establish individual recommendations on the formulation and dose to be used during pregnancy based on individual nicotinic needs.

Investigating the cost-effectiveness of three cessation interventions on a national scale using the Economics of Smoking in Pregnancy (ESIP) decision analytical model

AIM

To measure the cost-effectiveness of adding text message (TMB), exercise (EB) and abstinent-contingent financial incentive-based (CFIB) stop smoking interventions to standard smoking cessation support for pregnant women in England.

DESIGN

Modelling cost-effectiveness outcomes by separately adding three cessation interventions to standard cessation care offered to pregnant women in England. English National Health Service Stop Smoking Services (NHS SSS) statistics from 2019 to 2020 were used for estimating the base quit rate. Intervention effectiveness and cost data for interventions were taken from trial reports. Cost-effectiveness was derived using the economics of smoking in pregnancy (ESIP) model from a health service and personal social services perspective. Interventions were compared with each other as well as against standard cessation care.

SETTING

English NHS SSS.

PARTICIPANTS/CASES

A total of 13 799 pregnant women who accessed NHS SSS. Interventions and comparator; comparator: standard stop smoking support comprising behavioural intervention and an offer of nicotine replacement therapy (NRT). Three additive interventions were TMB, EB and CFIB.

MEASUREMENTS

Incremental cost-effectiveness ratios per quality-adjusted life-years gained for both mothers and offspring over their life-times; return on investment (ROI); and cost-effectiveness acceptability curves (CEACs).

FINDINGS

The addition of any of the interventions compared with standard care alone was preferred, but only significant for the addition of CFIB, with the CEAC suggesting an at least 90% chance of being favoured to standard care alone. When compared against each other CFIB appeared to yield the largest returns, but this was not significant. The estimated ROI for CFIB was £2 [95% confidence interval (CI) = £1-3] in health-care savings for every £1 spent by the NHS on the cessation intervention.

CONCLUSIONS

For a health system which currently provides behavioural support and an offer of nicotine replacement therapy as standard stop smoking support for pregnant women, the greatest economic gains would be provided by operating an abstinent-contingent financial incentives scheme alongside this.

Strategies for Prevention or Treatment of Tobacco and Cannabis Use Disorder

Tobacco and cannabis use in pregnancy are associated with increased adverse perinatal and long-term offspring outcomes. Products for both have evolved with various forms available on the market, challenging accurate counseling of risks and quantification of tobacco and cannabis usage during the perinatal period. Health care providers are recommended to screen for any type of use, provide consistent messaging of harms of tobacco and cannabis use in pregnancy, and offer individualized interventions. The journey to cessation can be complicated by barriers and triggers, lack of social supports, and mental health challenges that should be addressed to prevent relapse and withdrawals.

Electronic cigarettes versus nicotine patches for smoking cessation in pregnancy: a randomized controlled trial

Nicotine replacement therapy, in the form of nicotine patches, is commonly offered to pregnant women who smoke to help them to stop smoking, but this approach has limited efficacy in this population. Electronic cigarettes (e-cigarettes) are also used by pregnant women who smoke but their safety and efficacy in pregnancy are unknown. Here, we report the results of a randomized controlled trial in 1,140 participants comparing refillable e-cigarettes with nicotine patches. Pregnant women who smoked were randomized to e-cigarettes (n = 569) or nicotine patches (n = 571). In the unadjusted analysis of the primary outcome, validated prolonged quit rates at the end of pregnancy in the two study arms were not significantly different (6.8% versus 4.4% in the e-cigarette and patch arms, respectively; relative risk (RR) = 1.55, 95%CI: 0.95-2.53, P = 0.08). However, some participants in the nicotine patch group also used e-cigarettes during the study. In a pre-specified sensitivity analysis excluding abstinent participants who used non-allocated products, e-cigarettes were more effective than patches (6.8% versus 3.6%; RR = 1.93, 95%CI: 1.14-3.26, P = 0.02). Safety outcomes included adverse events and maternal and birth outcomes. The safety profile was found to be similar for both study products, however, low birthweight (<2,500 g) was less frequent in the e-cigarette arm (14.8% versus 9.6%; RR = 0.65, 95%CI: 0.47-0.90, P = 0.01). Other adverse events and birth outcomes were similar in the two study arms. E-cigarettes might help women who are pregnant to stop smoking, and their safety for use in pregnancy is similar to that of nicotine patches. ISRCTN62025374.

Electronic Nicotine Delivery Systems (ENDS) Use and Pregnancy II: Perinatal Outcomes Following ENDS Use During Pregnancy

Purpose of Review

This review examines the risk of adverse perinatal outcomes following electronic nicotine delivery system (ENDS) use during pregnancy, and considers whether there are sufficient data to support ENDS as a harm reduction approach during pregnancy.

Recent Findings

Seven papers assessed perinatal outcomes following ENDS use during pregnancy. There was evidence that ENDS use was associated with increased risk for some adverse perinatal outcomes (e.g., small for gestational age). However, the repeated use of data sets, insufficient data (e.g., timing of ENDS use, type of ENDS products used), and limited samples size, contributed to mixed findings on the degree to which ENDS use (alone or in combination with combustible cigarettes (CC)) impacts the risk of adverse perinatal outcomes relative to CC smoking alone.

Summary

The current data are still insufficient to support ENDS as a harm reduction approach, though findings do warrant concern and more detailed investigation of ENDS use during pregnancy. Future research directions, as well as implications for clinical recommendations and tobacco regulatory science are discussed.

Electronic cigarettes, vaping-related lung injury and lung cancer: where do we stand?

Electronic cigarettes have been considered a promising alternative to nicotine replacement products to help heavy tobacco smokers quit smoking. They work thanks to a heating coil causing evaporation of the liquid rapidly followed by cooling, thus creating an aerosol, a completely different mechanism from the combustion of tobacco in traditional cigarettes. The term 'vaping' indicates the use of electronic cigarettes or other devices to inhale heated, aerosolized nicotine, or other substances like cannabidiol, tetrahydrocannabinol, or butane hash oils together with solvents, mainly propylene glycol and vegetable glycerine or their combination. A very fast increase of vaping among adolescents has been observed since electronic cigarettes and other vaping devices first appeared. Although electronic cigarettes have been advocated as a short-term cessation aid for tobacco smokers or as a long-term alternative, there is the concrete risk that they can be perceived by young nonsmokers as a less dangerous alternative to tobacco smoking, thus stimulating nonsmokers to start smoking rather than helping heavy tobacco smokers to quit smoking. Moreover, several cases of exogenous lipoid pneumonia and diffuse alveolar hemorrhage with proven alveolar injury, as well as vaping-associated bronchiolitis obliterans, have been recently reported among electronic cigarette smokers, with severe clinical impact, thus posing the risk of the life-threatening toxic potential of vaping. At the moment, no definitive assessment can be made about the efficacy of electronic cigarettes as a smoking cessation aid, and further studies are required about vaping-related life-threatening acute lung injury.

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.

Nicotine Replacement Therapy during Pregnancy and Child Health Outcomes: A Systematic Review

Tobacco smoking in pregnancy is a worldwide public health problem. A majority of pregnant smokers need assistance to stop smoking. Most scientific societies recommend nicotine replacement therapy (NRT) during pregnancy but this recommendation remains controversial because of the known fetal toxicity of nicotine. The objective of this systematic review was to provide an overview of human studies about child health outcomes associated with NRT use during pregnancy. The electronic databases MEDLINE, the Cochrane Database, Web of Science, and ClinicalTrials.gov were searched from the inception of each database until 26 December 2020. A total of 103 articles were identified through database searching using combination of keywords. Out of 75 screened articles and after removal of duplicates, ten full-text articles were assessed for eligibility and five were included in the qualitative synthesis. NRT prescription seems to be associated with higher risk of infantile colic at 6 months as in case of smoking during pregnancy, and with risk of attention-deficit/hyperactivity disorder. No association between NRT during pregnancy and other infant health disorders or major congenital anomalies has been reported. Well-designed controlled clinical trials with sufficient follows-up are needed to provide more information on the use of NRT or other pharmacotherapies for smoking cessation during pregnancy on post-natal child health outcomes.

Fetal safety of nicotine replacement therapy in pregnancy: systematic review and meta-analysis

BACKGROUND AND AIMS

Smoking in pregnancy causes substantial avoidable harm to mothers and offspring; nicotine replacement therapy (NRT) may prevent this, and is used to help women to quit. A recently updated Cochrane Review of randomized controlled trials (RCTs) investigating impacts of NRT in pregnancy focuses primarily on efficacy data, but also reports adverse impacts from NRT. Here we identify and summarize NRT impacts on adverse pregnancy outcomes reported in non-randomized controlled trials (non-RCTs).

METHODS

Systematic reviews and meta-analyses of RCTs and non-RCT studies of NRT in pregnancy, with design-specific risk of bias assessment and grading of recommendations, assessment, development and evaluations (GRADE) criteria applied to selected outcomes.

FINDINGS

Relevant Cochrane Review findings are reported alongside those from this new review. Seven RCTs were included; n = 2340. Nine meta-analyses were performed; non-statistically significant estimates indicated potentially reduced risk from NRT compared with smoking for mean birth weight, low birth weight, preterm birth, intensive care admissions, neonatal death, congenital anomalies and caesarean section and potentially increased risks for miscarriage and stillbirth. GRADE assessment for mean birth weight and miscarriage outcomes indicated 'low' confidence in findings. Twenty-three non-RCTs were included; n = 931 163. Eleven large studies from five routine health-care cohorts reported clinical outcomes; 12 small studies investigated mainly physiological outcomes within in-patient women given NRT. Findings from meta-analyses for congenital anomalies, stillbirth and preterm birth were underpowered and not in a consistent direction; GRADE assessment of confidence in findings was 'very low'. Routine health-care studies were of higher quality, but implications of reported findings were unclear as there was inadequate measurement and reporting of women's smoking.

CONCLUSIONS

Available evidence from randomized controlled trials and non-randomized comparative studies does not currently provide clear evidence as to whether maternal use of nicotine replacement therapy during pregnancy is harmful to the fetus.

Interventions for Tobacco Cessation in Adults, Including Pregnant Persons: Updated Evidence Report and Systematic Review for the US Preventive Services Task Force

IMPORTANCE

It has been estimated that in 2018 nearly 20% of adults in the US were currently using a tobacco product.

OBJECTIVE

To systematically review the effectiveness and safety of pharmacotherapy, behavioral interventions, and electronic cigarettes for tobacco cessation among adults, including pregnant persons, to inform the US Preventive Services Task Force.

DATA SOURCES

PubMed, PsycInfo, Database of Abstracts of Reviews of Effects, Cochrane Database of Systematic Reviews, Centre for Reviews and Dissemination of Health Technology Assessment; surveillance through September 25, 2020.

STUDY SELECTION

Systematic reviews of tobacco cessation interventions and randomized clinical trials that evaluated the effects of electronic cigarettes (e-cigarettes) or pharmacotherapy among pregnant persons.

DATA EXTRACTION AND SYNTHESIS

Independent critical appraisal and data abstraction; qualitative synthesis and random-effects meta-analyses.

MAIN OUTCOMES AND MEASURES

Health outcomes, tobacco cessation at 6 months or more, and adverse events.

RESULTS

Sixty-seven reviews addressing pharmacotherapy and behavioral interventions were included as well as 9 trials (N = 3942) addressing e-cigarettes for smoking cessation and 7 trials (N = 2285) of nicotine replacement therapy (NRT) use in pregnancy. Combined pharmacotherapy and behavioral interventions (pooled risk ratio [RR], 1.83 [95% CI, 1.68-1.98]), NRT (RR, 1.55 [95% CI, 1.49-1.61]), bupropion (RR, 1.64 [95% CI, 1.52-1.77]), varenicline (RR, 2.24 [95% CI, 2.06-2.43]), and behavioral interventions such as advice from clinicians (RR, 1.76 [95% CI, 1.58-1.96]) were all associated with increased quit rates compared with minimal support or placebo at 6 months or longer. None of the drugs were associated with serious adverse events. Five trials (n = 3117) reported inconsistent findings on the effectiveness of electronic cigarettes on smoking cessation at 6 to 12 months among smokers when compared with placebo or NRT, and none suggested higher rates of serious adverse events. Among pregnant persons, behavioral interventions were associated with greater smoking cessation during late pregnancy (RR, 1.35 [95% CI, 1.23-1.48]), compared with no intervention. Rates of validated cessation among pregnant women allocated to NRT compared with placebo were not significantly different (pooled RR, 1.11 [95% CI, 0.79-1.56], n = 2033).

CONCLUSIONS AND RELEVANCE

There is strong evidence that a range of pharmacologic and behavioral interventions, both individually and in combination, are effective in increasing smoking cessation in nonpregnant adults. In pregnancy, behavioral interventions are effective for smoking cessation, but data are limited on the use of pharmacotherapy for smoking cessation. Data on the effectiveness and safety of electronic cigarettes for smoking cessation among adults are also limited and results are inconsistent.

Understanding pregnant women's adherence-related beliefs about Nicotine Replacement Therapy for smoking cessation: A qualitative study

INTRODUCTION

Reducing smoking during pregnancy is a public health priority. Nicotine replacement therapy (NRT) is offered routinely to pregnant women who smoke in the United Kingdom. However, evidence of treatment efficacy in this population is weak, most likely due to poor adherence. Guided by the Necessity-Concerns Framework, we conducted a qualitative study to better understand pregnant women's perceived needs and concerns regarding NRT use, with consideration of combination NRT.

METHODS

Semi-structured interviews were conducted by telephone with 18 pregnant or recently pregnant women in England and Wales, purposively sampled for different NRT-related experiences. Participants were recruited online via Facebook adverts and through a Stop Smoking Service. A hybrid approach of deductive and inductive thematic coding was used for analysis.

RESULTS

Findings were organized around three themes: 1) the role of motivation to stop smoking; 2) necessity beliefs about using NRT; and 3) concerns about NRT. Some women reported fluctuating motivation for stopping smoking which undermined their NRT use. Others used NRT to cut down the number of cigarettes they smoked. Reasons for low NRT necessity beliefs included a preference for quitting unassisted, low or unrealistic expectations of efficacy, and overconfidence in achieving cessation (necessity testing). Concerns included safety, particularly around increased nicotine exposure with combination NRT, addictiveness, side effects, and capability to use.

CONCLUSION

Pregnant women have multiple necessity beliefs and concerns that influence their use of NRT. Targeting these, alongside increasing and maintaining motivation to quit smoking, will likely help optimize NRT use in pregnancy and improve quit rates.

Factors influencing the uptake and use of nicotine replacement therapy and e-cigarettes in pregnant women who smoke: a qualitative evidence synthesis

BACKGROUND

Nicotine replacement therapy (NRT) delivers nicotine without the toxic chemicals present in tobacco smoke. It is an effective smoking cessation aid in non-pregnant smokers, but there is less evidence of effectiveness in pregnancy. Systematic review evidence suggests that pregnant women do not adhere to NRT as prescribed, which might undermine effectiveness. Electronic cigarettes (e-cigarettes) have grown in popularity, but effectiveness and safety in pregnancy are not yet established. The determinants of uptake and use of NRT and e-cigarettes in pregnancy are unknown.

OBJECTIVES

To explore factors affecting uptake and use of NRT and e-cigarettes in pregnancy.

SEARCH METHODS

We searched MEDLINE(R), CINAHL and PsycINFO on 1 February 2019. We manually searched OpenGrey database and screened references of included studies and relevant reviews. We also conducted forward citation searches of included studies.

SELECTION CRITERIA

We selected studies that used qualitative methods of data collection and analysis, included women who had smoked in pregnancy, and elicited participants' views about using NRT/e-cigarettes for smoking cessation or harm reduction (i.e. to smoke fewer cigarettes) during pregnancy.

DATA COLLECTION AND ANALYSIS

We identified determinants of uptake and use of NRT/e-cigarettes in pregnancy using a thematic synthesis approach. Two review authors assessed the quality of included studies with the Wallace tool. Two review authors used the CERQual approach to assess confidence in review findings. The contexts of studies from this review and the relevant Cochrane effectiveness review were not similar enough to fully integrate findings; however, we created a matrix to juxtapose findings from this review with the descriptions of behavioural support from trials in the effectiveness review.

MAIN RESULTS

We included 21 studies: 15 focused on NRT, 3 on e-cigarettes, and 3 on both. Studies took place in five high-income countries. Most studies contributed few relevant data; substantially fewer data were available on determinants of e-cigarettes. Many studies focused predominantly on issues relating to smoking cessation, and determinants of NRT/e-cigarette use was often presented as one of the themes. We identified six descriptive themes and 18 findings within those themes; from these we developed three overarching analytical themes representing key determinants of uptake and adherence to NRT and/or e-cigarettes in pregnancy. The analytical themes show that women's desire to protect their unborn babies from harm is one of the main reasons they use these products. Furthermore, women consider advice from health professionals when deciding whether to use NRT or e-cigarettes; when health professionals tell women that NRT or e-cigarettes are safer than smoking and that it is okay for them to use these in pregnancy, women report feeling more confident about using them. Conversely, women who are told that NRT or e-cigarettes are as dangerous or more dangerous than smoking and that they should not use them during pregnancy feel less confident about using them. Women's past experiences with NRT can also affect their willingness to use NRT in pregnancy; women who feel that NRT had worked for them (or someone they know) in the past were more confident about using it again. However, women who had negative experiences were more reluctant to use NRT. No trials on e-cigarette use in pregnancy were included in the Cochrane effectiveness review, so we considered only NRT findings when integrating results from this review and the effectiveness review. No qualitative studies were conducted alongside trials, making full integration of the findings challenging. Women enrolled in trials would have agreed to being allocated to NRT or control group and would have received standardised information on NRT at the start of the trial. Overall, the findings of this synthesis are less relevant to women's decisions about starting NRT in trials and more likely to help explain trial participants' adherence to NRT after starting it. We considered most findings to be of moderate certainty; we assessed findings on NRT use as being of higher certainty than those on e-cigarette use. This was mainly due to the limited data from fewer studies (only in the UK and USA) that contributed to e-cigarette findings. Overall, we judged studies to be of acceptable quality with only minor methodological issues.

AUTHORS' CONCLUSIONS

Consistent messages from health professionals, based on high-quality evidence and clearly explaining the safety of NRT and e-cigarettes compared to smoking in pregnancy, could help women use NRT and e-cigarettes more consistently/as recommended. This may improve their attitudes towards NRT or e-cigarettes, increase their willingness to use these in their attempt to quit, and subsequently encourage them to stay smoke-free.

[Pharmacotherapy for Smoking Cessation During Pregnancy - CNGOF-SFT Expert Report and Guidelines for Smoking Management During Pregnancy]

OBJECTIVE

To review and describe available pharmacotherapy interventions for smoking cessation during pregnancy: nicotine replacement therapy (NRT) and non-nicotine replacement therapy.

METHODS

The PubMed, Medline®, and Cochrane databases® (1/01/2003 au 5/04/2019) were accessed to identify relevant studies, using the search terms "tobacco use cessation devices", "nicotine replacement product or therapy", "smoking cessation", "pregnancy", "pregnant women", "varenicline", "bupropion".

RESULTS

There is no data on the impact of NRT on the rate of smoking cessation during pre conception period. According to randomised studies versus placebo, the prescription of NRT during pregnancy (16-hours patches and gums being mainly studied) is not associated with smoking cessation during pregnancy or at the end of pregnancy (LE1). Based on the analysis of all available studies, the prescription of NRT during pregnancy is associated with smoking cessation during pregnancy and at the end of pregnancy (LE2). Coadministration of different galenic forms of pharmacotherapy during pregnancy could improve efficacy subject to tolerance and remains to be studied. The prescription of NRT during pregnancy (patches and gums being mainly studied) is not associated with postpartum smoking cessation (LE1). The prescription of NRT may be associated with the occurrence of non-serious adverse reactions (headache, nausea, vomiting, etc.) (LE2). The risk of adverse effects from NRT is not increased by pregnancy (LE2). The prescription of NRT is not associated with spontaneous abortion (LE2). There is insufficient data to establish an excess risk of congenital malformations in case of the prescription of NRT. The prescription of NRT versus placebo is associated with a reduction in the risk of preterm delivery (LE2). There is insufficient data on the prescription of NRT and neonatal outcomes. The prescription of NRT (by decreasing smoking) could be associated with better development scores at 2 years of age in children born to smoking women who received NRT versus placebo (LE2). The prescription of NRT may be offered to any pregnant woman who has failed a spontaneous smoking cessation without NRT (grade B). The data of the literature do not allow recommending one form more than another (forms of rapid action versus transdermal) nor an optimal duration of treatment (professional consensus). This prescription can be initiated by the professional taking care of the pregnant woman in early pregnancy (professional consensus). It is recommended to refer the pregnant woman to a tobacco specialist to assess and adapt the initial prescription (professional consensus). Maintenance of NRT in case of misstep is associated with a reduction in smoking (LE3). These elements suggest that in the event of a misstep or resumption of smoking, it is recommended to continue nicotine substitution (grade C). In the absence of data, second-line non-nicotinic prescriptions, nortriptyline and clonidine, are not recommended during pregnancy (professional consensus). There is insufficient data and low level of evidence to assess the impact of bupropion during the three trimesters of pregnancy, and in particular the neonatal consequences. Because of its amphetamine properties, bupoprion is not recommended for smoking cessation assistance in pregnant women (grade C). The available data are very inadequate and low level of evidence to assess the impact of varenicline during pregnancy. For this reason, varenicline cannot be recommended for smoking cessation during pregnancy (professional consensus).

CONCLUSIONS

The prescription of NRT may be offered to any pregnant woman who has failed a spontaneous smoking cessation without NRT, taking into account the lower risks of premature birth in the case of NRT (grade B). This prescription can be initiated by the professional taking care of the pregnant woman in early pregnancy (professional consensus).

Pharmacological interventions for promoting smoking cessation during pregnancy

BACKGROUND

Tobacco smoking in pregnancy causes serious health problems for the developing fetus and mother. When used by non-pregnant smokers, pharmacotherapies (nicotine replacement therapy (NRT), bupropion, and varenicline) are effective for increasing smoking cessation, however their efficacy and safety in pregnancy remains unknown. Electronic cigarettes (ECs) are becoming widely used, but their efficacy and safety when used for smoking cessation in pregnancy are also unknown.

OBJECTIVES

To determine the efficacy and safety of smoking cessation pharmacotherapies and ECs used during pregnancy for smoking cessation in later pregnancy and after childbirth, and to determine adherence to smoking cessation pharmacotherapies and ECs for smoking cessation during pregnancy.

SEARCH METHODS

We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (20 May 2019), trial registers, and grey literature, and checked references of retrieved studies.

SELECTION CRITERIA

Randomised controlled trials (RCTs) conducted in pregnant women, comparing smoking cessation pharmacotherapy or EC use with either placebo or no pharmacotherapy/EC control. We excluded quasi-randomised, cross-over, and within-participant designs, and RCTs with additional intervention components not matched between trial arms.

DATA COLLECTION AND ANALYSIS

We followed standard Cochrane methods. The primary efficacy outcome was smoking cessation in later pregnancy; safety was assessed by 11 outcomes (principally birth outcomes) that indicated neonatal and infant well-being. We also collated data on adherence to trial treatments. We calculated the risk ratio (RR) or mean difference (MD) and the 95% confidence intervals (CI) for each outcome for each study, where possible. We grouped eligible studies according to the type of comparison. We carried out meta-analyses where appropriate.

MAIN RESULTS

We included 11 trials that enrolled a total of 2412 pregnant women who smoked at enrolment, nine trials of NRT and two trials of bupropion as adjuncts to behavioural support, with comparable behavioural support provided in the control arms. No trials investigated varenicline or ECs. We assessed four trials as at low risk of bias overall. The overall certainty of the evidence was low across outcomes and comparisons as assessed using GRADE, with reductions in confidence due to risk of bias, imprecision, and inconsistency. Compared to placebo and non-placebo (behavioural support only) controls, there was low-certainty evidence that NRT increased the likelihood of smoking abstinence in later pregnancy (RR 1.37, 95% CI 1.08 to 1.74; I² = 34%, 9 studies, 2336 women). However, in subgroup analysis by comparator type, there was a subgroup difference between placebo-controlled and non-placebo controlled RCTs (test for subgroup differences P = 0.008). There was unclear evidence of an effect in placebo-controlled RCTs (RR 1.21, 95% CI 0.95 to 1.55; I² = 0%, 6 studies, 2063 women), whereas non-placebo-controlled trials showed clearer evidence of a benefit (RR 8.55, 95% CI 2.05 to 35.71; I² = 0%, 3 studies, 273 women). An additional subgroup analysis in which studies were grouped by the type of NRT used found no difference in the effectiveness of NRT in those using patches or fast-acting NRT (test for subgroup differences P = 0.08). There was no evidence of a difference between NRT and control groups in rates of miscarriage, stillbirth, premature birth, birthweight, low birthweight, admissions to neonatal intensive care, caesarean section, congenital abnormalities, or neonatal death. In one study infants born to women who had been randomised to NRT had higher rates of 'survival without developmental impairment' at two years of age compared to the placebo group. Non-serious adverse effects observed with NRT included headache, nausea, and local reactions (e.g. skin irritation from patches or foul taste from gum), but data could not be pooled. Adherence to NRT treatment regimens was generally low. We identified low-certainty evidence that there was no difference in smoking abstinence rates observed in later pregnancy in women using bupropion when compared to placebo control (RR 0.74, 95% CI 0.21 to 2.64; I² = 0%, 2 studies, 76 women). Evidence investigating the safety outcomes of bupropion use was sparse, but the existing evidence showed no difference between the bupropion and control group.

AUTHORS' CONCLUSIONS

NRT used for smoking cessation in pregnancy may increase smoking cessation rates in late pregnancy. However, this evidence is of low certainty, as the effect was not evident when potentially biased, non-placebo-controlled RCTs were excluded from the analysis. Future studies may therefore change this conclusion. We found no evidence that NRT has either positive or negative impacts on birth outcomes; however, the evidence for some of these outcomes was also judged to be of low certainty due to imprecision and inconsistency. We found no evidence that bupropion may be an effective aid for smoking cessation during pregnancy, and there was little evidence evaluating its safety in this population. Further research evidence on the efficacy and safety of pharmacotherapy and EC use for smoking cessation in pregnancy is needed, ideally from placebo-controlled RCTs that achieve higher adherence rates and that monitor infants' outcomes into childhood. Future RCTs of NRT should investigate higher doses than those tested in the studies included in this review.

Potential effects of using non-combustible tobacco and nicotine products during pregnancy: a systematic review

Background

The range of risk reduced alternatives to smoking tobacco is increasing and so is use among pregnant women. The substantial harms of smoking during pregnancy are well established and there is reason to believe that nicotine alone is somewhat harmful. Differences in the exposure chemistry strongly suggest that the effects of using smoke-free nicotine products (including pharmaceutical nicotine products, smokeless tobacco, and electronic cigarettes containing nicotine) fall somewhere in the range between zero risk to the risk from smoking. How much lower risk these consumption choices are in terms of pregnancy outcomes, however, remains uncertain.

Methods

We reviewed the literature on smoke-free nicotine and tobacco product exposure and birth-outcome endpoints. Studies were included if they compared outcomes to either no nicotine use or smoking. We searched Google Scholar using broad search terms and additional articles were snowballed from citations. We report what could be learned from each study, given its methods.

Results

Of the 21 studies reviewed, 12 reported on the use of nicotine replacement therapies, 7 on Swedish snus, 1 on Alaskan iq’mik, and 1 on e-cigarettes. The range of results tends to support the prediction that smoke-free product use during pregnancy probably increases the risk of some negative birth outcomes, but that any effect is less than that from smoking. However, the limitations of epidemiology are such that no more-precise a conclusion is possible.

Discussion

The available epidemiology does not change our prior beliefs, based on other evidence and knowledge, that the risks from smoke-free nicotine and tobacco are lower than those for smoking, though it suggests they are non-zero. However, it also demonstrates that the epidemiology is unlikely to provide precise quantitative estimates. This is not just a matter of lack of studies; given the inherent limitation of these studies, doubling or tripling the corpus of available studies would add little precision. For the foreseeable future, decisions about using these products will need to be made based on rough estimates, based on a variety of forms of evidence, and qualitative comparisons.

Electronic cigarettes and obstetric outcomes: a prospective observational study

OBJECTIVE

To compare the obstetric outcomes and socio-demographic factors in electronic cigarette (EC) users with cigarette smokers and non-smokers in pregnancy.

DESIGN

Prospective observational cohort study.

SETTING

A large urban maternity hospital delivering almost 8500 infants per year.

POPULATION

Pregnant women attending for antenatal care.

METHODS

Electronic cigarette users at time of booking history were prospectively identified. Maternal and neonatal outcomes were compared with those of pregnant smokers and non-smokers. Multiple logistic regression analysis was performed to estimate the association between the explanatory variables and birthweight.

MAIN OUTCOMES MEASURES

Infant birthweight, gestation at delivery, incidence of low birthweight.

RESULTS

A total of 218 women with exclusive EC use and 195 women with dual use of both cigarettes and EC, had a live birth during the study period. EC users were of higher socio-economic status than smokers. Infants born to EC users had a mean birthweight of 3470 g (± 555 g), which was similar to that of non-smokers (3471 ± 504 g, P = 0.97) and significantly greater than that of smokers (3166 ± 502 g, P < 0.001). The mean birth centile of EC users was similar to non-smokers (51st centile versus 47th centile, P = 0.28) and significantly greater than that of smokers (27th centile, P < 0.001). Dual users had a mean birthweight and birth centile similar to that of smokers.

CONCLUSION

The birthweight of infants born to EC users is similar to that of non-smokers, and significantly greater than cigarette smokers. Dual users of both cigarettes and EC have a birthweight similar to that of smokers.

TWEETABLE EXTRACT

Birthweight of infants born to electronic cigarette users appears to be similar to that of non-smokers.

Practitioners' Views on Nicotine Replacement Therapy in Pregnancy during Lapse and for Harm Reduction: A Qualitative Study

Many countries, including the UK, recommend nicotine replacement therapy (NRT) for smoking cessation during pregnancy. However, adherence to NRT is generally low, smoking lapse or relapse is common and using NRT to reduce the harm from the number of cigarettes smoked is only advocated in non-pregnant smokers. Two focus groups were conducted with 13 professionals involved in antenatal stop smoking services (SSS). The data were analysed thematically. Two themes were extracted that describe health professionals' attitudes towards using NRT either during lapses or to reduce smoking in women who cannot quit (harm reduction). These are presented around a social-ecological framework describing three hierarchical levels of influence within smoking cessation support: (1) Organizational: providing NRT during lapses could be expensive for SSS though harm reduction could result in services helping a wider range of clients. (2) Interpersonal: participants felt using NRT for harm reduction was not compatible with cessation-orientated messages practitioners conveyed to clients. (3) Individual: practitioners' advice regarding using NRT during smoking lapses varied; many were generally uncomfortable about concurrent smoking and NRT use and had strong reservations about recommending NRT when smoking during all but the briefest lapses. Further evidence is required to guide policy and practice.

Neurological Effects in the Offspring After Switching From Tobacco Cigarettes to E-Cigarettes During Pregnancy in a Mouse Model

Maternal smoking is currently a public health concern and has been associated with a number of complications in the offspring. E-cigarettes are gaining popularity as a “safer” alternative to tobacco cigarettes during pregnancy, however, there are a limited number of studies to suggest that it is actually “safe.” Balb/C female mice were exposed to ambient air (n = 8; Sham), or tobacco cigarette smoke (n = 8; SE) before gestation, during gestation and lactation. A third group was exposed to cigarette smoke before gestation followed by e-cigarette aerosols during gestation and lactation (n = 8; Switch). Male offspring (12-week old, n = 10–14/group) underwent behavioral assessments to investigate short-term memory, anxiety, and activity using the novel object recognition and elevated plus maze tests. Brains were collected at postnatal day (P)1, P20, and Week 13 for global DNA methylation, epigenetic gene expression, and neuronal cell counts. The offspring from mothers switching to e-cigarettes exhibited no change in exploration/activity but showed a decrease in global DNA methylation, Aurora Kinase (Aurk) A and AurkB gene expression and a reduction in neuronal cell numbers in the cornu ammonis 1 region of the dorsal hippocampus compared with the SE group. Continuous tobacco cigarette smoke exposure during pregnancy resulted in marked neurological deficits in the offspring. Switching to e-cigarettes during pregnancy reduced these neurological deficits compared with cigarette smoke exposure. However, neurological changes were still observed, so we therefore conclude that e-cigarette use during pregnancy is not advised.

Is the apparently protective effect of maternal nicotine replacement therapy (NRT) used in pregnancy on infant development explained by smoking cessation?: secondary analyses of a randomised controlled trial

OBJECTIVE

To investigate relationships between maternal smoking status in pregnancy and infant development. The largest randomised controlled trial of nicotine replacement therapy (NRT) for smoking cessation in pregnancy, the smoking, nicotine and pregnancy (SNAP) trial, found that at 1 month after randomisation, smoking cessation rates were doubled in the NRT group compared with the placebo group. At delivery, there was no significant difference in cessation rates between groups. Surprisingly, infants born to women randomised to NRT were more likely to have unimpaired development at 2 years. We hypothesised that this apparently protective effect was due to smoking cessation caused by NRT and so, investigate this relationship using the same cohort.

DESIGN

Secondary analysis of a randomised controlled trial.

SETTING

Seven antenatal hospitals in the Midlands and North-West England.

PARTICIPANTS

Eight hundred and eighty-four pregnant smokers randomised to receive either NRT patches or visually-identical placebo in the SNAP trial. Participants' smoking behaviour were recorded at randomisation, 1 month after their target quit date and at delivery.

METHODS

Using logistic regression models, we investigated associations between participants' smoking measures and infant development (assessed using the Ages and Stages questionnaire) at 2 years.

MAIN OUTCOME MEASURES

2 year infant development.

RESULTS

Developmental impairment was reported for 12.7% of study 2 year olds. Maternal heaviness of smoking at randomisation (OR: 1.26, 95% CI: 0.82 to 1.96, p=0.091), validated smoking abstinence recorded at 1 month after a quit date (OR: 1.02, 95% CI: 0.60 to 1.74, p=0.914) and validated smoking abstinence recorded at both 1 month after a quit date and at the end of pregnancy (OR: 1.52, 95% CI: 0.81 to 2.85, p=0.795) were not independently associated with infant developmental impairment at 2 years.

CONCLUSION

We found no evidence that NRT treatment improved infants' developmental outcomes through smoking cessation.

TRIAL REGISTRATION NUMBER

CTA03057/0002/001-0001; Post-results.

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.

Modelling continuous abstinence rates over time from clinical trials of pharmacological interventions for smoking cessation

BACKGROUND AND AIM

It is useful, for theoretical and practical reasons, to be able to specify functions for continuous abstinence over time in smoking cessation attempts. This study aimed to find the best-fitting models of mean proportion abstinent with different smoking cessation pharmacotherapies up to 52 weeks from the quit date.

METHODS

We searched the Cochrane Database of Systematic Reviews to identify randomized controlled trials (RCTs) of pharmacological treatments to aid smoking cessation. For comparability, we selected trials that provided 12 weeks of treatment. Continuous abstinence rates for each treatment at each follow-up point in trials were extracted along with methodological details of the trial. Data points for each pharmacotherapy at each follow-up point were aggregated where the total across contributing studies included at least 1000 participants per data point. Continuous abstinence curves were modelled using a range of different functions from the quit date to 52-week follow-up. Models were compared for fit using R2 and Bayesian information criterion (BIC).

RESULTS

Studies meeting our selection criteria covered three pharmacotherapies [varenicline, nicotine replacement therapy (NRT) and bupropion] and placebo. Power functions provided the best fit (R2  > 0.99, BIC < 17.0) to continuous abstinence curves from the target quit date in all cases except for varenicline, where a logarithmic function described the curve best (R2  = 0.99, BIC = 21.2). At 52 weeks, abstinence rates were 22.5% (23.0% modelled) for varenicline, 16.7% (16.0% modelled) for bupropion, 13.0% (12.4% modelled) for NRT and 8.3% (8.9% modelled) for placebo. For varenicline, bupropion, NRT and placebo, respectively, 55.9, 65.0, 62.3 and 56.5% of participants who were abstinent at the end of treatment were still abstinent at 52 weeks.

CONCLUSIONS

Mean continuous abstinence rates up to 52 weeks from initiation of smoking cessation attempts in clinical trials can be modelled using simple power functions for placebo, nicotine replacement therapy and bupropion and a logarithmic function for varenicline. This allows accurate prediction of abstinence rates from any time point to any other time point up to 52 weeks.

Comparison of nicotine exposure during pregnancy when smoking and abstinent with nicotine replacement therapy: systematic review and meta-analysis

BACKGROUND AND AIMS

Smoking during pregnancy is strongly associated with negative pregnancy and perinatal outcomes. Some guidelines recommend nicotine replacement therapy (NRT) for smoking cessation during pregnancy, but adherence with NRT is generally poor and could be partially explained by nicotine-related safety concerns. We compared pregnant women's cotinine and nicotine exposures from smoking with those when they were abstinent from smoking and using NRT.

DESIGN

Systematic review with meta-analysis and narrative reporting. Twelve studies were included: in most, only one type of NRT was used. Seven were quality-assessed and judge of variable quality.

SETTING

Studies from any setting that reported nicotine or cotinine levels when smoking and later when abstinent and using NRT.

PARTICIPANTS

Pregnant women who smoked and became abstinent but used NRT either in a cessation study or in a study investigating other impacts of NRT.

MEASUREMENTS

We quality-assessed longitudinal cohort studies using a modified version of the Newcastle-Ottawa scale. For meta-analysis, we used mean within-person differences in cotinine or nicotine levels when smoking and at later follow-up when abstinent and using NRT. Where such data were not available, we calculated differences in group mean levels and reported these narratively, indicating where data were not completely longitudinal.

FINDINGS

Of the 12 included studies, four cotinine-measuring studies (n = 83) were combined in a random effects meta-analysis; the pooled estimate for the mean difference (95% confidence intervals) in cotinine levels between when women were smoking and abstinent but using NRT was 75.3 (57.1 to 93.4) ng/ml (I2  = 42.1%, P = 0.11). Of eight narratively-described studies, six reported lower cotinine and/or nicotine levels when abstinent and using NRT; two had mixed findings, with higher levels when abstinent but using NRT reported from at least one assay time-point.

CONCLUSIONS

Pregnant women who use nicotine replacement therapy instead of smoking reduce their nicotine exposure.

Pharmaceutical strategies for smoking cessation during pregnancy

Introduction: Tobacco use is the most preventable cause of death worldwide, with over 7 million deaths per year. Smoking during pregnancy causes harm to the mother, fetus, and can result in problems for the infant from childhood into adulthood. Practitioners should ask all expectant mothers about tobacco use. For expectant mothers who smoke or recently quit, practitioners should advice to quit and provide psychosocial interventions. Rates of smoking during pregnancy differ between geographical locations, with estimates of 10.8% in the UK and 7.2% in the US. Practitioners should provide expectant mothers unable to quit smoking with information about the risks and benefits of pharmacotherapy and use a patient-centered approach to determine the use. Although there is no definitive evidence on birth outcomes, nicotine replacement therapy and bupropion are adequate pharmacotherapies to help those unable to quit. Areas covered: Herein, this author looks at the various pharmaceutical strategies to help patients cease smoking and provides expert perspectives on the subject. Expert opinion: Additional research on pharmacotherapy is warranted, especially with varenicline. Practitioners working with pregnant patients should be familiar with the evidence for pharmacotherapy in smoking cessation during pregnancy. This evidence can be difficult to navigate due to conflicting results and limitations with the trials.

Smoking cessation strategies in pregnancy: Current concepts and controversies

Smoking during pregnancy is a risk factor associated with adverse pregnancy outcomes. Despite the fact that these outcomes are well known, a considerable proportion of pregnant women continue to smoke during this critical period. This paper evaluates critically smoking cessation interventions targeting pregnant women. We describe the findings of key published studies, review papers and expert statements to report the efficacy and safety of strategies for smoking cessation in pregnancy, including counselling and pharmacotherapy. Counselling appears to improve quit rates but mainly when used in combination with pharmacological therapy. Pharmacotherapy is recommended for women who are heavy smokers and are unable to quit smoking on their own. Nicotine replacement therapy is a reasonable first-line drug option. It is recommended that women who are pregnant, or planning to become pregnant, should be informed of potential risks for the foetus before considering smoking cessation therapy with bupropion or varenicline. Pregnant women view electronic nicotine delivery systems as being safer than combustible cigarettes, and this indeed may be the case; however, further evidence is required to assess their effectiveness as a smoking cessation aid and their safety for the mother and the child. Postpartum relapse is a significant problem, with approximately one out of two quitters relapsing in the first 2 months after delivery. These women should be considered 'at risk' and provided with ongoing support.

Heat or Burn? Impacts of Intrauterine Tobacco Smoke and E-Cigarette Vapor Exposure on the Offspring's Health Outcome

Maternal smoking during pregnancy leads to gestational complications and organ disorders in the offspring. As nicotine replacement therapy is often ineffective for smoking cessation, pregnant women turn to alternatives such as heat-not-burn tobacco and e-cigarettes. Recently, the popularly of e-cigarettes has been increasing especially among the youth and pregnant women, mainly due to the advertisements claiming their safety. This has even led to some clinicians recommending their use during pregnancy. E-cigarettes heat e-liquid to produce an aerosol (e-vapor), delivering flavorings and nicotine to the user. However, e-vapor also contains toxins such as formaldehyde along with heavy metals and carcinogenic nitrosamines. In addition, specific flavoring compounds such as diacetyl can be toxic themselves or decompose into toxic compounds such as benzaldehydes. These compounds can induce toxicity, inflammation and oxidative stress in the mothers and can accumulate in the developing fetus, affecting intrauterine development. Recent animal studies suggest that maternal e-vapor exposure during pregnancy could cause respiratory and neurological disorders in the offspring. This review will examine the available literature to shed light on the current understanding of this problem-to-be from lessons learned in animal models.

Views on and experiences of electronic cigarettes: a qualitative study of women who are pregnant or have recently given birth

BACKGROUND

Electronic cigarettes (ECs) are increasingly used for reducing or stopping smoking, with some studies showing positive outcomes. However, little is known about views on ECs during pregnancy or postpartum and previous studies have nearly all been conducted in the US and have methodological limitations, such as not distinguishing between smokers and ex/non-smokers. A greater understanding of this topic will help to inform both clinicians and EC interventions. We elicited views and experiences of ECs among UK pregnant or recently pregnant women.

METHODS

We conducted semi-structured telephone interviews, using topic guides, with pregnant or recently pregnant women, who were current or recent ex-smokers. To ensure broad views of ECs were obtained, recruitment was from several geographical locations and via various avenues of recruitment. This included stop smoking services, antenatal and health visitor clinics, a pregnancy website and an informal network. Participants were 15 pregnant and 15 postpartum women, including nine current EC users, 11 ex-users, and 10 never-users. Five women who were interviewed in pregnancy were later interviewed in postpartum to explore if their views had changed. Audio data was transcribed verbatim and framework analysis was applied.

RESULTS

Five main themes emerged: motivations for use (e.g., for stopping or reducing smoking), social stigma (e.g., avoiding use in public, preferring 'discrete' NRT), using the EC (e.g., mostly used at home); consumer aspects (e.g., limited advice available), and harm perceptions (e.g., viewed as less harmful than smoking; concerns about safety and addiction).

CONCLUSIONS

ECs were viewed positively by some pregnant and postpartum women and seen as less harmful than smoking and useful as aids for reducing and stopping smoking. However, due to perceived social stigma, some women feel uncomfortable using ECs in public, especially during pregnancy, and had concerns about safety and nicotine dependence. Health professionals and designers of EC interventions need to provide women with up-to-date and consistent information and advice about safety and dependence, as well as considering the influence of social stigma.

Nicotine replacement therapy versus control for smoking cessation

BACKGROUND

Nicotine replacement therapy (NRT) aims to temporarily replace much of the nicotine from cigarettes to reduce motivation to smoke and nicotine withdrawal symptoms, thus easing the transition from cigarette smoking to complete abstinence.

OBJECTIVES

To determine the effectiveness and safety of nicotine replacement therapy (NRT), including gum, transdermal patch, intranasal spray and inhaled and oral preparations, for achieving long-term smoking cessation, compared to placebo or 'no NRT' interventions.

SEARCH METHODS

We searched the Cochrane Tobacco Addiction Group trials register for papers mentioning 'NRT' or any type of nicotine replacement therapy in the title, abstract or keywords. Date of most recent search is July 2017.

SELECTION CRITERIA

Randomized trials in people motivated to quit which compared NRT to placebo or to no treatment. We excluded trials that did not report cessation rates, and those with follow-up of less than six months, except for those in pregnancy (where less than six months, these were excluded from the main analysis). We recorded adverse events from included and excluded studies that compared NRT with placebo. Studies comparing different types, durations, and doses of NRT, and studies comparing NRT to other pharmacotherapies, are covered in separate reviews.

DATA COLLECTION AND ANALYSIS

Screening, data extraction and 'Risk of bias' assessment followed standard Cochrane methods. The main outcome measure was abstinence from smoking after at least six months of follow-up. We used the most rigorous definition of abstinence for each trial, and biochemically validated rates if available. We calculated the risk ratio (RR) for each study. Where appropriate, we performed meta-analysis using a Mantel-Haenszel fixed-effect model.

MAIN RESULTS

We identified 136 studies; 133 with 64,640 participants contributed to the primary comparison between any type of NRT and a placebo or non-NRT control group. The majority of studies were conducted in adults and had similar numbers of men and women. People enrolled in the studies typically smoked at least 15 cigarettes a day at the start of the studies. We judged the evidence to be of high quality; we judged most studies to be at high or unclear risk of bias but restricting the analysis to only those studies at low risk of bias did not significantly alter the result. The RR of abstinence for any form of NRT relative to control was 1.55 (95% confidence interval (CI) 1.49 to 1.61). The pooled RRs for each type were 1.49 (95% CI 1.40 to 1.60, 56 trials, 22,581 participants) for nicotine gum; 1.64 (95% CI 1.53 to 1.75, 51 trials, 25,754 participants) for nicotine patch; 1.52 (95% CI 1.32 to 1.74, 8 trials, 4439 participants) for oral tablets/lozenges; 1.90 (95% CI 1.36 to 2.67, 4 trials, 976 participants) for nicotine inhalator; and 2.02 (95% CI 1.49 to 2.73, 4 trials, 887 participants) for nicotine nasal spray. The effects were largely independent of the definition of abstinence, the intensity of additional support provided or the setting in which the NRT was offered. A subset of six trials conducted in pregnant women found a statistically significant benefit of NRT on abstinence close to the time of delivery (RR 1.32, 95% CI 1.04 to 1.69; 2129 participants); in the four trials that followed up participants post-partum the result was no longer statistically significant (RR 1.29, 95% CI 0.90 to 1.86; 1675 participants). Adverse events from using NRT were related to the type of product, and include skin irritation from patches and irritation to the inside of the mouth from gum and tablets. Attempts to quantitatively synthesize the incidence of various adverse effects were hindered by extensive variation in reporting the nature, timing and duration of symptoms. The odds ratio (OR) of chest pains or palpitations for any form of NRT relative to control was 1.88 (95% CI 1.37 to 2.57, 15 included and excluded trials, 11,074 participants). However, chest pains and palpitations were rare in both groups and serious adverse events were extremely rare.

AUTHORS' CONCLUSIONS

There is high-quality evidence that all of the licensed forms of NRT (gum, transdermal patch, nasal spray, inhalator and sublingual tablets/lozenges) can help people who make a quit attempt to increase their chances of successfully stopping smoking. NRTs increase the rate of quitting by 50% to 60%, regardless of setting, and further research is very unlikely to change our confidence in the estimate of the effect. The relative effectiveness of NRT appears to be largely independent of the intensity of additional support provided to the individual. Provision of more intense levels of support, although beneficial in facilitating the likelihood of quitting, is not essential to the success of NRT. NRT often causes minor irritation of the site through which it is administered, and in rare cases can cause non-ischaemic chest pain and palpitations.

Sex and gender differences in substance use disorders

The gender gap in substance use disorders (SUDs), characterized by greater prevalence in men, is narrowing, highlighting the importance of understanding sex and gender differences in SUD etiology and maintenance. In this critical review, we provide an overview of sex/gender differences in the biology, epidemiology and treatment of SUDs. Biological sex differences are evident across an array of systems, including brain structure and function, endocrine function, and metabolic function. Gender (i.e., environmentally and socioculturally defined roles for men and women) also contributes to the initiation and course of substance use and SUDs. Adverse medical, psychiatric, and functional consequences associated with SUDs are often more severe in women. However, men and women do not substantively differ with respect to SUD treatment outcomes. Although several trends are beginning to emerge in the literature, findings on sex and gender differences in SUDs are complicated by the interacting contributions of biological and environmental factors. Future research is needed to further elucidate sex and gender differences, especially focusing on hormonal factors in SUD course and treatment outcomes; research translating findings between animal and human models; and gender differences in understudied populations, such as those with co-occurring psychiatric disorders and gender-specific populations, such as pregnant women.

A critique of the US Surgeon General's conclusions regarding e-cigarette use among youth and young adults in the United States of America

BACKGROUND

In December 2016, the Surgeon General published a report that concluded e-cigarette use among youth and young adults is becoming a major public health concern in the United States of America.

METHODS

Re-analysis of key data sources on nicotine toxicity and prevalence of youth use of e-cigarettes cited in the Surgeon General report as the basis for its conclusions.

RESULTS

Multiple years of nationally representative surveys indicate the majority of e-cigarette use among US youth is either infrequent or experimental, and negligible among never-smoking youth. The majority of the very small proportion of US youth who use e-cigarettes on a regular basis, consume nicotine-free products. The sharpest declines in US youth smoking rates have occurred as e-cigarettes have become increasingly available. Most of the evidence presented in the Surgeon General's discussion of nicotine harm is not applicable to e-cigarette use, because it relies almost exclusively on exposure to nicotine in the cigarette smoke and not to nicotine present in e-cigarette aerosol emissions. Moreover, the referenced literature describes effects in adults, not youth, and in animal models that have little relevance to real-world e-cigarette use by youth. The Surgeon General's report is an excellent reference document for the adverse outcomes due to nicotine in combination with several other toxicants present in tobacco smoke, but fails to address the risks of nicotine decoupled from tobacco smoke constituents. The report exaggerates the toxicity of propylene glycol (PG) and vegetable glycerin (VG) by focusing on experimental conditions that do not reflect use in the real-world and provides little discussion of emerging evidence that e-cigarettes may significantly reduce harm to smokers who have completely switched.

CONCLUSIONS

The U.S. Surgeon General's claim that e-cigarette use among U.S. youth and young adults is an emerging public health concern does not appear to be supported by the best available evidence on the health risks of nicotine use and population survey data on prevalence of frequent e-cigarette use. Nonetheless, patterns of e-cigarettes use in youth must be constantly monitored for early detection of significant changes. The next US Surgeon General should consider the possibility that future generations of young Americans will be less likely to start smoking tobacco because of, not in spite of, the availability of e-cigarettes.

Prevention and Treatment of Smoking and Tobacco Use During Pregnancy in Selected Indigenous Communities in High-Income Countries of the United States, Canada, Australia, and New Zealand: An Evidence-Based Review

Tobacco smoking during pregnancy is the most important modifiable risk factor for adverse pregnancy outcomes and long-term health complications for mother and baby. Tobacco use during pregnancy has decreased in high-income countries but not in Indigenous women in Australia, New Zealand, the United States, and Canada. This evidence-based review focuses on tobacco use among Indigenous pregnant women in high-income countries that share a history of European colonization. Indigenous women are more likely to use tobacco because of socioeconomic disadvantage, social norms, and poor access to culturally appropriate tobacco cessation support. Complications arising from tobacco smoking during pregnancy, such as low birth weight, prematurity, perinatal death, and sudden infant death syndrome, are much higher in Indigenous populations. Effective approaches to cessation in pregnant nonindigenous women involves behavioral counseling, with or without nicotine replacement therapy (NRT). Higher nicotine metabolism during pregnancy and poor adherence may affect therapeutic levels of NRT. Only two randomized trials were conducted among Indigenous women: neither found a statistically significant difference in cessation rates between the treatment and comparison arms. Considerations should be given to (1) whole life course approaches to reduce tobacco use in Indigenous women, (2) prohibiting tobacco promotion and reducing access to alcohol for minors to prevent smoking initiation in Indigenous youth, and (3) training health-care professionals in culturally appropriate smoking cessation care to improve access to services. It is critical to ensure acceptability and feasibility of study designs, consult with the relevant Indigenous communities, and preempt implementation challenges. Research is needed into the effect of reducing or stopping smoking during pregnancy when using NRT on subsequent maternal and infant outcomes.

A systematic review of possible serious adverse health effects of nicotine replacement therapy

We conducted a systematic literature review to identify and critically evaluate studies of serious adverse health effects (SAHEs) in humans using nicotine replacement therapy (NRT) products. Serious adverse health effects refer to adverse events, leading to substantial disruption of the ability to conduct normal life functions. Strength of evidence evaluations and conclusions were also determined for the identified SAHEs. We evaluated 34 epidemiological studies and clinical trials, relating NRT use to cancer, reproduction/development, CVD, stroke and/or other SAHEs in patients, and four meta-analyses on effects in healthy populations. The overall evidence suffers from many limitations, the most significant being the short-term exposure (≤12 weeks) and follow-up to NRT product use in most of the studies, the common failure to account for changes in smoking behaviour following NRT use, and the sparse information on SAHEs by type of NRT product used. The only SAHE from NRT exposure we identified was an increase in respiratory congenital abnormalities reported in one study. Limited evidence indicated a lack of effect between NRT exposure and SAHEs for CVD and various reproduction/developmental endpoints. For cancer, stroke and other SAHEs, the evidence was inadequate to demonstrate any association with NRT use. Our conclusions agree with recent statements from authoritative bodies.

Reducing tobacco smoking and smoke exposure to prevent preterm birth and its complications

Tobacco smoking and smoke exposure during pregnancy are associated with a range of adverse health outcomes, including preterm birth. Also, children born preterm have a higher risk of complications including bronchopulmonary dysplasia and asthma when their mothers smoked during pregnancy. Smoking cessation in early pregnancy can help reduce the adverse impact on offspring health. Counselling interventions are effective in promoting smoking cessation and reducing the incidence of preterm birth. Peer support and incentive-based approaches are likely to be of additional benefit, whereas the effectiveness of pharmacological interventions, including nicotine replacement therapy, has not definitely been established. Smoke-free legislation can help reduce smoke exposure as well as maternal smoking rates at a population level, and is associated with a reduction in preterm birth. Helping future mothers to stop smoking and protect their children from second hand smoke exposure must be a key priority for health care workers and policy makers alike.

Exploring the role and function of trial steering committees: results of an expert panel meeting

BACKGROUND

The independent oversight of clinical trials, which is recommended by the Medical Research Council (MRC) Guidelines for Good Clinical Practice, is typically provided by an independent advisory Data Monitoring Committee (DMC) and an independent executive committee, to whom the DMC makes recommendations. The detailed roles and function of this executive committee, known as the Trial Steering Committee (TSC), have not previously been studied or reviewed since those originally proposed by the MRC in 1998.

METHODS

An expert panel (n = 7) was convened comprising statisticians, clinicians and trial methodologists with prior TSC experience. Twelve questions about the role and responsibilities of the TSC were discussed by the panel at two full-day meetings. Each meeting was transcribed in full and the discussions were summarised.

RESULTS

The expert panel reached agreement on the role of the TSC, to which it was accountable, the membership, the definition of independence, and the experience and training needed. The management of ethical issues, difficult/complex situations and issues the TSC should not ask the DMC to make recommendations on were more difficult to discuss without specific examples, but support existed for further work to help share issues and to provide appropriate training for TSC members. Additional topics discussed, which had not been identified by previous work relating to the DMCs but were pertinent to the role of the TSC, included the following: review of data sharing requests, indemnity, lifespan of the TSC, general TSC administration, and the roles of both the Funder and the Sponsor.

CONCLUSIONS

This paper presents recommendations that will contribute to the revision and update of the MRC TSC terms of reference. Uncertainty remains in some areas due to the absence of real-life examples; future guidance on these issues would benefit from a repository of case studies. Notably, the role of a patient and public involvement (PPI) contributor was not discussed, and further work is warranted to explore the role of a PPI contributor in independent trial oversight.

Smoking and Male Infertility: An Evidence-Based Review

Many studies have reported that the contents of cigarette smoke negatively affect sperm parameters, seminal plasma, and various other fertility factors. Nevertheless, the actual effect of smoking on male fertility is not clear. The effect of smoking on semen parameters is based on the well-established biological finding that smoking increases the presence of reactive oxygen species, thereby resulting in oxidative stress (OS). OS has devastating effects on sperm parameters, such as viability and morphology, and impairs sperm function, hence reducing male fertility. However, not all studies have come to the same conclusions. This review sheds light upon the arguable association between smoking and male fertility and also assesses the impact of non-smoking routes of tobacco consumption on male infertility. It also highlights the evidence that links smoking with male infertility, including newly emerging genetic and epigenetic data, and discusses the clinical implications thereof.

Pharmacological interventions for promoting smoking cessation during pregnancy

BACKGROUND

Smoking in pregnancy is a public health problem. When used by non-pregnant smokers, pharmacotherapies (nicotine replacement therapy (NRT), bupropion and varenicline) are effective for smoking cessation, however, their efficacy and safety in pregnancy remains unknown. Electronic Nicotine Delivery Systems (ENDS), or e-cigarettes, are becoming widely used but their efficacy and safety when used for smoking cessation in pregnancy are also unknown.

OBJECTIVES

To determine the efficacy and safety of smoking cessation pharmacotherapies (including NRT, varenicline and bupropion), other medications, or ENDS when used for smoking cessation in pregnancy.

SEARCH METHODS

We searched the Pregnancy and Childbirth Group's Trials Register (11 July 2015), checked references of retrieved studies, and contacted authors.

SELECTION CRITERIA

Randomised controlled trials (RCTs) conducted in pregnant women with designs that permit the independent effects of any type of pharmacotherapy or ENDS on smoking cessation to be ascertained were eligible for inclusion.The following RCT designs are included.Placebo-RCTs: any form of NRT, other pharmacotherapy, or ENDS, with or without behavioural support/cognitive behaviour therapy (CBT), or brief advice, compared with an identical placebo and behavioural support of similar intensity.RCTs providing a comparison between i) any form of NRT, other pharmacotherapy, or ENDS added to behavioural support/CBT, or brief advice and ii) behavioural support of similar (ideally identical) intensity.Parallel- or cluster-randomised trials were eligible for inclusion. Quasi-randomised, cross-over and within-participant designs were not, due to the potential biases associated with these designs.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed trials for inclusion and risk of bias and also independently extracted data and cross checked individual outcomes of this process to ensure accuracy. The primary efficacy outcome was smoking cessation in later pregnancy (in all but one trial, at or around delivery); safety was assessed by 11 outcomes (principally birth outcomes) that indicated neonatal and infant well-being; and we also collated data on adherence with trial treatments.

MAIN RESULTS

This review includes a total of nine trials which enrolled 2210 pregnant smokers: eight trials of NRT and one trial of bupropion as adjuncts to behavioural support/CBT. The risk of bias was generally low across trials with virtually all domains of the 'Risk of bias' assessment tool being satisfied for the majority of studies. We found no trials investigating varenicline or ENDS. Compared to placebo and non-placebo controls, there was a difference in smoking rates observed in later pregnancy favouring use of NRT (risk ratio (RR) 1.41, 95% confidence interval (CI) 1.03 to 1.93, eight studies, 2199 women).  However, subgroup analysis of placebo-RCTs provided a lower RR in favour of NRT (RR 1.28, 95% CI 0.99 to 1.66, five studies, 1926 women), whereas within the two non-placebo RCTs there was a strong positive effect of NRT, (RR 8.51, 95% CI 2.05 to 35.28, three studies, 273 women; P value for random-effects subgroup interaction test = 0.01). There were no differences between NRT and control groups in rates of miscarriage, stillbirth, premature birth, birthweight, low birthweight, admissions to neonatal intensive care, caesarean section, congenital abnormalities or neonatal death. Compared to placebo group infants, at two years of age, infants born to women who had been randomised to NRT had higher rates of 'survival without developmental impairment' (one trial). Generally, adherence with trial NRT regimens was low. Non-serious side effects observed with NRT included headache, nausea and local reactions (e.g. skin irritation from patches or foul taste from gum), but these data could not be pooled.

AUTHORS' CONCLUSIONS

NRT used in pregnancy for smoking cessation increases smoking cessation rates measured in late pregnancy by approximately 40%. There is evidence, suggesting that when potentially-biased, non-placebo RCTs are excluded from analyses, NRT is no more effective than placebo. There is no evidence that NRT used for smoking cessation in pregnancy has either positive or negative impacts on birth outcomes. However, evidence from the only trial to have followed up infants after birth, suggests use of NRT promotes healthy developmental outcomes in infants. Further research evidence on NRT efficacy and safety is needed, ideally from placebo-controlled RCTs which achieve higher adherence rates and which monitor infants' outcomes into childhood. Accruing data suggests that it would be ethical for future RCTs to investigate higher doses of NRT than those tested in the included studies.

A qualitative assessment of the perceived risks of electronic cigarette and hookah use in pregnancy

BACKGROUND

Studies reveal that electronic cigarette (e-cigarette) and hookah use are increasing among adolescents and young adults. However, the long-term health effects are unknown, especially with regards to pregnancy. Because of the increased use in women of reproductive age, and the unknown long-term health risks, our primary objectives were to determine the perceived risks of e-cigarette and hookah use in pregnancy, and learn common colloquial terms associated with e-cigarettes. Furthermore, we sought to determine if there is a stigma associated with e-cigarette use in pregnancy.

METHODS

Eleven focus groups including 87 participants were conducted immediately following regularly scheduled CenteringPregnancy® prenatal care with women at three different clinics in the greater Houston area. A minimum of two facilitators led the groups, using ten lead-in prompts, with Spanish translation as necessary. Facilitators took notes which were compared immediately following each group discussion and each group was audio recorded and transcribed. Three facilitators utilized NVivo 9.0 software to organize the transcribed data into nodes to identify major themes. To increase rigor, transcripts were further analyzed by two obstetricians who were instructed to find the major themes.

RESULTS

Analyses revealed contradicting themes concerning e-cigarette use. In general, e-cigarettes were perceived as safer alternatives to regular tobacco cigarettes, especially if used as smoking cessation devices. A major theme is that use in pregnancy is harmful to the fetus. However, it was perceived that use for smoking cessation in pregnancy may have fewer side effects. We found that a common term for e-cigarettes is "Blu." In our discussion of hookah use, participants perceived use as popular among teenagers and that use in pregnancy is dangerous for the fetus.

CONCLUSIONS

Although a strong theme emerged against hookah use, we found contradicting themes in our discussions on e-cigarette use in pregnancy. It is possible that e-cigarette use will not carry the same stigma as regular cigarette smoking in pregnancy. In addition, the impression of e-cigarettes as a healthier alternative to smoking may influence use in pregnancy. Clinicians need to be prepared for questions of e-cigarette safety and efficacy as smoking cessation devices from their pregnant patients who smoke, and women who smoke and are planning to become pregnant.

Influence of developmental nicotine exposure on the ventilatory and metabolic response to hyperthermia

To determine whether developmental nicotine exposure (DNE) alters the ventilatory and metabolic response to hyperthermia in neonatal rats (postnatal age 2-4 days), pregnant dams were exposed to nicotine (6 mg kg(-1) of nicotine tartrate daily) or saline with an osmotic mini-pump implanted subdermally on day 5 of gestation. Rat pups (a total of 72 controls and 72 DNE pups) were studied under thermoneutral conditions (chamber temperature 33°C) and during moderate thermal stress (37.5°C). In all pups, core temperature was similar to chamber temperature, with no treatment effects. The rates of pulmonary ventilation (V̇(I)), O2 consumption (V̇(O2)) and CO2 production (V̇(CO2)) did not change with hyperthermia in either control or DNE pups. However, V̇(I) was lower in DNE pups at both chamber temperatures, whereas the duration of spontaneous apnoeas was longer in DNE pups than in controls at 33°C. The V̇(I)/V̇(O2) ratio increased at 37.5°C in control pups, although it did not change in DNE pups. To simulate severe thermal stress, additional pups were studied at 33°C and 43°C. V̇(I) increased with heating in control pups but not in DNE pups. As heat stress continued, gasping was evoked in both groups, with no effect of DNE on the gasping pattern. Over a 20 min recovery period at 33°C, V̇(I) returned to baseline in control pups but remained depressed in DNE pups. In addition to altering baseline V̇(I) and apnoea duration, DNE is associated with subtle but significant alterations in the ventilatory response to hyperthermia in neonatal rats.