Electronic cigarettes may not be a “safer alternative” of conventional cigarettes during pregnancy: evidence from the nationally representative PRaMS data.

Introduction:
This article examines the effects of prenatal electronic cigarette (EC) use on neonatal birth outcomes compared to those of conventional cigarette (CC) smokers and complete tobacco abstainers. The study uses data from the Phase 8 survey of the Pregnancy Risk assessment Monitoring System (PRaMS) and classifies pregnant women into three groups based on their smoking behaviors in the third trimester. The association between EC use and adverse birth outcomes is then examined using survey-weighted logistic regression analyses in the matched population.

Key Points:

* The study uses data from the Phase 8 survey of the Pregnancy Risk assessment Monitoring System (PRaMS) and classifies pregnant women into three groups based on their smoking behaviors in the third trimester: complete tobacco abstinence, exclusive CC smoking, or exclusive EC use.
* Neonates of EC users were significantly more likely to be small-for-gestational-age (SGa), have low birthweight (LBW), or be born preterm compared to tobacco abstainers.
* however, the odds of EC users' pregnancies resulting in SGa, LBW, or preterm birth were not significantly lower than those of CC smokers.
* Previous studies have shown that nonsmokers have significantly different characteristics from tobacco users, and EC users and CC smokers also show significant differences in their baseline characteristics.
* To more comprehensively account for the fundamental differences in risk factors, propensity matching was induced between exclusive EC users and two reference groups (complete abstainers, exclusive CC smokers) based on the seven covariates described above.
* Survey-weighted logistic regression analyses were performed in the matched populations to demonstrate the effects of EC use on adverse birth outcomes compared to abstinence from tobacco and CC smoking in the third trimester.
* The study finds that exclusive EC use in the third trimester significantly affects birth outcomes, and the risks of using ECs are not significantly lower than those of smoking CCs.

Main Message:
The study suggests that EC use during pregnancy is not a safer alternative to CC smoking. The findings have significant clinical implications for preventing adverse birth outcomes and serve as compelling evidence for public health interventions for tobacco control. The study also highlights the need for obstetric and pediatric practice guidelines on counseling pregnant smokers who are current EC users or interested in using ECs as a smoking cessation aid.

Kim S, Oancea SC. Electronic cigarettes may not be a “safer alternative” of conventional cigarettes during pregnancy: evidence from the nationally representative PRaMS data. BMC pregnancy and childbirth. 2020;20(1):557. doi:10.1186/s12884-020-03247-6