Associate Professor State University of New York at Buffalo Buffalo, New York, United States
Background: There is a rapid increase in electronic cigarette (“e-cigarette”) use among the young population, including pregnant people. Objective: We aimed to examine the associations between changes in e-cigarette and cigarette use during pregnancy and the risk of preterm birth. Design/Methods: We conducted a secondary data analysis within Phase 8 of the Pregnancy Risk Assessment Monitoring System (PRAMS, 2016-2021). Use of e-cigarettes and cigarettes before pregnancy and during late pregnancy was self-reported using a standard questionnaire. Gestational age was obtained from birth certificates, and preterm birth was defined as gestational age less than 37 weeks. Multivariable logistic regression models were used to estimate the odds ratio (OR) and 95% confidence interval (CI) for preterm birth associated with changes in e-cigarette and cigarette use during pregnancy, adjusting for socio-demographics, pregnancy-related characteristics, and other substance use. Results: In the analytic sample of 223,805 pregnant individuals, 48.7% were aged 30 or older; 15.7% were African American, 0.9% were American Indian/Alaska Native, 3.0% were multiracial, 69.0% were White, and 11.4% were Asian/Other race; 18.8% were Hispanic. Discontinuation was common during pregnancy across all subgroups by pre-pregnancy use: 78.9% among exclusive e-cigarette users, 53.8% among exclusive cigarette users, and 48.2% among dual users. The prevalence of preterm birth was 8.1% in the total sample and 7.7% among non-users of e-cigarettes/cigarettes. Among 30,809 pre-pregnancy exclusive cigarette users, quitters had a lower risk of preterm birth than continuous smokers (8.8% vs 12.0%; confounder-adjusted OR, 0.74 [95% CI, 0.66-0.82]). Among 4,090 pre-pregnancy exclusive e-cigarette users, quitters did not have a significantly different risk of preterm birth from continuous vapers (8.3% vs 11.0%; confounder-adjusted OR, 0.80 [95% CI, 0.55-1.15]). Among 6,428 pre-pregnancy dual users, compared to continuous dual users, those who continued smoking only (11.2% vs 9.9%; confounder-adjusted OR, 1.19 [0.86-1.65]) or continued vaping only (8.8% vs 9.9%; confounder-adjusted OR, 0.94 [0.61-1.46]) did not have a significantly different risk of preterm birth, but complete quitters had a lower risk of preterm birth (6.4% vs 9.9%; confounder-adjusted OR, 0.69 [0.51-0.92]).
Conclusion(s): Discontinuation of e-cigarettes and/or cigarettes was common during pregnancy. It was associated with a substantial reduction in the risk of preterm birth among exclusive cigarette users and dual users.
