Electronic vapor products (EVPs) comprise a diverse group of devices, including electronic cigarettes (e-cigarettes). EVP users inhale an aerosol that typically contains nicotine, flavorings, and other additives (1). Nicotine is a developmental toxicant that adversely affects pregnancy and infant outcomes (2). Data from the 2015 Pregnancy Risk Assessment Monitoring System (PRAMS) for Oklahoma and Texas were analyzed to estimate population-based EVP use among women with a recent live birth. EVP use before pregnancy (defined as >3 months before pregnancy) and around the time of pregnancy (defined as any time during the 3 months before pregnancy, the last 3 months of pregnancy, or 2-6 months after delivery), reasons for EVP use, and dual use of EVPs and cigarettes were assessed. Prevalence of EVP use was 10.4% before pregnancy and 7.0% around the time of pregnancy, including 1.4% during the last 3 months of pregnancy. Among women using EVPs during the last 3 months of pregnancy, 38.4% reported use of EVPs containing nicotine, and 26.4% were unsure of nicotine content. Among women who had used EVPs and cigarettes, dual use prevalence was 38.0% in the 3 months before pregnancy, 7.7% during the last 3 months of pregnancy, and 11.8% in the 2-6 months after delivery. The most frequently reported reasons for EVP use around the time of pregnancy were curiosity (54.0%), the perception that EVPs might help with quitting or reducing cigarette smoking (45.2%), and the perception of reduced harm to the mother, when compared with cigarette smoking (45.2%). Clear messages that EVP use is not safe during pregnancy are needed, and broad, barrier-free access to evidence-based tobacco cessation strategies need to be made available.