Changes in e-cigarette and cigarette use during pregnancy and their association with small-for-gestational-age birth.

Background: Despite increased e-cigarette use, limited research has focused on changes in e-cigarette and combustible cigarette use around pregnancy and the subsequent effects on infant health.

Objective: This study aimed to characterize changes in e-cigarette and cigarette use from before to during pregnancy and examine their associations with small-for-gestational-age birth.

Study Design: This was a secondary data analysis of 2016-2018 data of the US Pregnancy Risk Assessment Monitoring System.