Longitudinal Examination of Prenatal Tobacco Switching Behaviors and Birth Outcomes, Including Electronic Nicotine Delivery System (ENDS) and Dual Use

Cigarette and E-Cigarette Harm Perceptions During Pregnancy

BACKGROUND

Research suggests that pregnancy status (prior, current, and future intention) is associated with differences in perceived harm of electronic cigarette (e-cigarette) use during pregnancy. However, perceptions of health outcomes attributed to cigarette and e-cigarette use during pregnancy have not been explored among a sample of pregnant women who smoke.

OBJECTIVES

The purpose of this study was to explore differences in perceived harms of cigarette and e-cigarette use and perceived birth and health outcomes associated with cigarette and e-cigarette use during pregnancy among a sample of pregnant women who currently smoked.

METHODS

Using a cross-sectional online survey, we examined perceptions about cigarette and e-cigarette use during pregnancy among a sample of U.S. pregnant women ( n = 267) who smoked in the past 30 days. Participants were grouped into categories based on e-cigarette use status (current, past, and never e-cigarette users). Differences between e-cigarette use status and perceived harm (absolute of cigarettes, e-cigarettes, and relative of e-cigarettes) and perceived health outcomes attributed to smoking/e-cigarette use were examined.

RESULTS

Among our sample, 45.7%, 39.7%, and 14.6% were current, ever, and never e-cigarette users, respectively. Associations existed between e-cigarette use status and absolute perceived harm of cigarettes, relative perceived harm of e-cigarettes, and perceived health outcomes. Current e-cigarette users believed pregnant women who smoked cigarettes were more likely to lose a child because of miscarriage or sudden infant death syndrome or give birth to a child with low birth weight, reduced lung function, cleft lip, reduced brain function, or attention-deficit/hyperactivity disorder than never e-cigarette users. No associations were found between perceived birth and health outcomes of e-cigarette use by e-cigarette user status.

DISCUSSION

Pregnant women who smoked and used e-cigarettes had lower risk perceptions about e-cigarette use during pregnancy than those who only smoked. Health messages and research about the harms of nicotine exposure during pregnancy should address the risks of dual-use versus only e-cigarette use. In addition, messages about the relative harm of e-cigarettes compared to cigarettes are needed for pregnant women who smoke and have trouble quitting.

Vaping during pregnancy: a systematic review of health outcomes

INTRODUCTION

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

STUDY REGISTRATION

https://osf.io/rfx4q/ .

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

BACKGROUND

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

OBJECTIVE

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

STUDY DESIGN

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

RESULTS

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

CONCLUSION

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