Investigating Pre-pregnancy and Late-Pregnancy E-cigarette Use Exposure and Gestational Diabetes Mellitus

Background and objective E-cigarette (EC) use is on the rise, particularly among young adults, yet its impact on pregnancy remains poorly understood. Among women of reproductive age, rising EC use has raised concerns about adverse outcomes in pregnancy, including gestational diabetes mellitus (GDM). More than 40% of pregnant smokers report using non-cigarette nicotine products, but clinical guidance for EC use during pregnancy is limited. While prior studies suggest associations between EC use and adverse fetal outcomes, maternal risks have been sparsely explored. This study aimed to investigate whether EC use pre- or during pregnancy is associated with GDM in U.S. women with singleton births. Methods This was a secondary analysis of Pregnancy Risk Assessment and Monitoring System data (2016-2021). All data were based on self-reported responses collected from women after the birth of their index child. Self-reported EC use was categorized as follows: (1) three months pre-pregnancy, (2) last three months of pregnancy, (3) both periods, or (4) no use. GDM diagnosis (ever/never) was also self-reported. Logistic regression models were employed to estimate odds ratios (ORs) and 95% confidence intervals (CIs), adjusting for demographic, socioeconomic, and pregnancy-related factors, using Stata 17. Results Among 204,757 women with singleton births, <5% reported EC use, with 72% quitting before the third trimester. Overall, 7.7% developed GDM. In unadjusted models, EC use pre-pregnancy was not associated with GDM (OR: 1.0; 95% CI: 0.86-1.16), while EC use during both pre-pregnancy and in the third trimester was linked to lower odds (OR: 0.71; 95% CI: 0.54-0.93). Adjusted models showed that EC use pre-pregnancy was associated with increased GDM risk (adjusted OR: 1.27; 95% CI: 1.07-1.51; p = 0.006), with no significant associations observed for other categories. Conclusions EC use pre-pregnancy was linked to higher GDM odds, after adjustment for potential confounders. These findings underscore the need for further research on timing, frequency, and health effects to inform targeted public health interventions. Understanding the effects of EC use during pregnancy is crucial for the well-being of pregnant women and their unborn children, as well as to prevent adverse pregnancy outcomes. While there have been some analyses of associations between EC use during pregnancy and fetal birth complications, there is little information about its association with maternal complications during pregnancy and labor. This research adds to the body of evidence-based information that can inform policy decisions and guideline development. More importantly, it provides preliminary insights that will help healthcare professionals more effectively counsel patients and evaluate associated risks.