Comparative Risks of Electronic Versus Tobacco Cigarette Use During Pregnancy: Findings From a Low-Risk Sample [ID: 1374893]

INTRODUCTION: Harms of tobacco use in pregnancy are well studied and include low birth weight, decreased newborn well-being, and need for medical interventions after birth. Less understood is the effect of noncombustible alternatives, including electronic cigarettes (ECs). We examined whether EC use during pregnancy also increases risk of adverse birth outcomes. METHODS: Data were from the Michigan Obstetrics Initiative (OBI), a quality improvement effort involving 75 maternity hospitals, focused on safely reducing cesarean delivery rates. Our participants were nulliparous, singleton pregnancy, term delivery, and vertex fetal positioning. Data were from medical records, entered locally, and compiled centrally by OBI. RESULTS: Participants delivered since January 1, 2021, with no known pregnancy alcohol and opioid use: controls (no EC/tobacco use [n=26,394], EC only [n=493], and tobacco only [n=2,126]). After control for confounding and comparison to controls, the EC group had significantly lower birth weight; the tobacco group had reduced birth weight, and greater rates of arterial cord pH less than 7.1, 5-minute Apgar scores less than 8, and neonatal intensive care unit admission. CONCLUSION: While EC use in pregnancy reduced birth weight, most newborn risks linked to tobacco exposure were not predicted by EC use. Additional study is needed, as nonsignificant trends toward poorer outcomes for EC users were evident, and potentially significant with larger samples or when amount/timing of EC exposure is considered. Further, given this sample was low risk, cases for whom EC use led to adverse outcomes were potentially eliminated. Growing evidence suggests pregnant patients should be counseled to avoid EC use.