Substance Use
Change in maternal e-cigarette use during pregnancy and preterm birth Xiaozhong Wen* Xiaozhong Wen Aye Moe Dhruvi Patel Gabrielle Hastings Kayla Elaine Manney
Objective: We aimed to examine the associations between changes in e-cigarette and cigarette use during pregnancy and the risk of preterm birth. 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 and during late pregnancy was self-reported. 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 OR and 95% 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: Discontinuation was 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%; adjusted OR, 0.80 [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%; adjusted OR, 1.19 [0.86-1.65]) or continued vaping only (8.8% vs 9.9%; 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%; adjusted OR, 0.69 [0.51-0.92]). Conclusion: 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.