Quitting Smoking before and after Pregnancy: Study Methods and Baseline Data from a Prospective Cohort Study. - Cruvinel E; Richter KP; Pollak KI; Ellerbeck E; Nollen NL; Gajewski B; Sullivan-Blum Z; Zhang C; Shergina E; Scheuermann TS (International journal of environmental research and public health, 2022)