Reported use of snus, cigarette smoke and nicotine-replacement therapies (NRTs)/e-cigarettes in Norway and Sweden
| Parameter | Total | Norway | Sweden | p-value# |
| Questionnaire adherence | ||||
| Completed at 18 weeks | 2350 (100.0) | 1818 (77.4) | 532 (22.6) | |
| Completed 34 weeks | 2365 (100.0) | 1853 (78.4) | 512 (21.7) | |
| Completed one or more | 2528 (100.0) | 1985 (78.5) | 543 (21.5) | |
| Completed both | 2187 (100.0) | 1686 (77.1) | 501 (22.9) | |
| Tobacco habits | ||||
| Ever use in life (n=2350) | ||||
| All nicotine-containing products | 840 (35.7) | 680 (37.4) | 160 (30.1) | 0.002 |
| Snus | 529 (22.5) | 434 (23.9) | 95 (17.9) | 0.003 |
| Cigarette smoke | 531 (22.6) | 423 (23.3) | 108 (20.3) | 0.15 |
| Use before pregnancy (n=2350) | ||||
| Stopped years before pregnancy | ||||
| Snus | 213 (9.6) | 165 (9.1) | 48 (9.0) | 0.97 |
| Cigarette smoke | 338 (14.4) | 276 (15.2) | 62 (11.7) | 0.04 |
| Stopped in the time before pregnancy | ||||
| Snus | 138 (5.9) | 120 (6.6) | 18 (3.4) | 0.005 |
| Cigarette smoke | 77 (3.3) | 65 (3.6) | 12 (2.3) | 0.13 |
| Snus in pregnancy (including dual users) | ||||
| At some time up to 18 weeks (n=2350) | 178 (7.6) | 149 (8.2) | 29 (5.5) | 0.035 |
| Current use at 18 weeks | 13 (0.6) | 11 (0.6) | 2 (0.4) | 0.81 |
| Stopped when recognising pregnancy | 165 (7.0) | 138 (7.6) | 27 (5.1) | |
| At some time from 18–34 weeks (n=2365) | 18 (0.8) | 14 (0.8) | 4 (0.8) | 0.95 |
| Current use at 34 weeks | 6 (0.3) | 4 (0.2) | 2 (0.4) | |
| Stopped between 18 and 34 weeks | 12 (0.5) | 10 (0.5) | 2 (0.4) | |
| Cigarette smoke in pregnancy (including dual users) | ||||
| At some time up to 18 weeks (n=2350) | 116 (4.9) | 82 (4.5) | 34 (6.4) | 0.08 |
| Current use at 18 weeks | 18 (0.8) | 14 (0.8) | 4 (0.8) | 0.84 |
| Stopped when recognising pregnancy | 98 (4.2) | 68 (3.7) | 30 (5.6) | |
| At some time from 18–34 weeks (n=2365) | 14 (0.6) | 10 (0.5) | 4 (0.8) | 0.53 |
| Current use at 34 weeks | 8 (0.3) | 6 (0.3) | 2 (0.4) | |
| Stopped between 18 and 34 weeks | 6 (0.3) | 4 (0.2) | 2 (0.4) | |
| Dual snus and cigarette smoke in pregnancy | ||||
| At some time up to 18 weeks (n=2350) | 15 (0.6) | 7 (0.4) | 8 (1.5) | 0.004 |
| Current use at 18 weeks | 0 | 0 | 0 | |
| Stopped when recognising pregnancy | 15 (0.6) | 7 (0.4) | 8 (1.5) | |
| At some time from 18–34 weeks (n=2365) | 1 (0.04) | 0 | 1 (0.2) | |
| Current use at 34 weeks | 0 | 0 | 0 | |
| Stopped between 18 and 34 weeks | 1 (0.04) | 0 | 1 (0.2) | |
| NRTs/e-cigarettes in pregnancy | ||||
| At some time up to 18 weeks (n=2350) | 5 (0.2) | 3 (0.2) | 2 (0.4) | |
| Current use at 18 weeks | 2 (0.1) | 1 (0.1) | 1 (0.2) | |
| Stopped when recognising pregnancy | 3 (0.1) | 2 (0.1) | 1 (0.2) | |
| At some time from 18–34 weeks (n=2365) | 1 (0.1) | 0 | 1 (0.2) | |
| Current use at 34 weeks | 1 (0.1) | 0 | 1 (0.2) | |
| Stopped between 18 and 34 weeks | 0 | 0 | 0 |
#: p-values in bold (p<0.05) are significant.