Demographic Characteristics, Perinatal Smoking Patterns, and Risk for Neonatal Health Complications Among Pregnant Smokers in the United States Who Begin Using Electronic Cigarettes During Pregnancy: A Descriptive Study Using Population-Based Surveillance Data.

Introduction: Health agencies have called for research evaluating e-cigarette (EC) use in supporting prenatal smoking cessation. This study aimed to describe (1) the characteristics of smokers who begin using electronic cigarettes (ECs) during pregnancy, (2) how frequently smokers reduce or eliminate pre- and post-natal combustible cigarette (CC) use, and (3) the risk for neonatal health complications among smokers who initiate ECs during pregnancy.

Aims and methods: Pregnant women using CCs exclusively during prepregnancy, who participated in a U.S. surveillance study, were classified by their reported late-pregnancy smoking behavior as CC-exclusive users, EC initiators, or quitters. EC initiators were further subclassified as dual users (used both ECs and CCs) or EC replacers (used ECs exclusively).

Results: Of 29 505 pregnant smokers, 1.5% reported using ECs during the last three pregnancy months. Among them, 29.7% became EC-exclusive users. EC initiators were disproportionately non-Hispanic White. Relative to quitters, EC initiators had lower income, were less likely to be married, have intended pregnancies, receive first-trimester prenatal care, and participate in a federal assistance program. Compared to CC-exclusive users, EC initiators overall, and dual users specifically, were more likely to reduce pre- and post-natal CC usage relative to prepregnancy levels. EC initiators' risk for neonatal health complications fell between quitters and CC-exclusive users, though the differences were not statistically significant.

Conclusions: Although EC initiators reduced CC use more than CC-exclusive users, only 29.7% reported complete CC cessation, and there was insufficient evidence of reduction in neonatal health complications relative to CC-exclusive users. Currently, ECs should not be considered a viable gestational smoking cessation strategy.

Implications: Health agencies have identified a critical need for research evaluating the use of e-cigarettes in supporting prenatal smoking cessation. Using the U.S. Pregnancy Risk Assessment Monitoring System surveillance study data, we provide real-world evidence that prenatal e-cigarette initiation as a smoking cessation tool is used infrequently among pregnant CCs smokers. Most using e-cigarettes in the last 3 months of pregnancy also used CCs.