Fig. 1.

Study enrollment flow chart. *4 women were included twice with separate pregnancies. 5 (0.2%) women reported use of e-cigarettes and/or NRTs at some time in pregnancy (stopped when recognized pregnancy or current use). Of these women, 2 reported smoking cessation when recognized pregnancy and were included in this group. The remaining 3 reported no use of snus or smoking at some time in pregnancy, but reported previous smoking and/ or use of snus and were included in these groups, respectively