Figures
- FIGURE 1
Percentage of women using snus and/or cigarette smoke during pregnancy based on self-reported time for stopping from those who completed both 18-week and 34-week questionnaires (n=2187). Time for stopping categories were from 1–2 weeks to >16 weeks and from <17 weeks to 30–34 weeks, respectively. Among the women who reported the use of snus, cigarette smoke or dual use at some time during pregnancy, most stopped when they recognised their pregnancy (mean pregnancy week three to four). Week 0 reflects the total percentage of women who reported any use during pregnancy. E-cigarettes and nicotine replacement therapies were not included since the rates were low.
- FIGURE 2
Factors associated with snus use during pregnancy. In multivariate analysis, the following factors were identified as associated with the use of snus at some time during pregnancy (reference categories are presented in italic for each factor): living area (countryside (village) versus city (densely populated), city (less densely populated), suburb, countryside (outside village)); grand maternal cigarette smoking (no versus yes, do not know); country of origin (rest of the world and other nordic countries combined versus Norway or Sweden); previous and/or current smoking (no versus yes); marital status (married versus cohabitant, single, divorced/separated, other). Age was used as a continuous variable. OR: odds ratio. #: in utero smoking exposure of the index woman; *: p<0.05; **: p<0.01.
Tables
- TABLE 1
Background characteristics of the study population, comparing those women who were included in the present analysis versus those who were not
Characteristics Inclusion in the present analysis Yes# (n=2528) No# (n=173) Maternal age years 32.4 (20–48)¶ 31.1 (18–44)¶ Maternal data BMI before pregnancy (n=2460) 23.2 (13.8–45.7) 23.6 (17.1–44.1) Height cm (n=2491) 168.0 (147.0–187.0) 167.4 (147.0–186.0) Weight before pregnancy kg (n=2471) 65.4 (42.5–126.0) 64.2 (42.0–116.0) Weight at inclusion kg (n=2498) 70.2 (44.8–132.7) 68.0 (45.8–117.0) Previous pregnancy 1292 (51.1) Previous pregnancies+ (n=2528) 0 1236 (48.9) 1 652 (25.8) 2 377 (14.9) 3 143 (5.7) >3 120 (4.8) Education (n=2350) Preliminary school only (9–10 years) 18 (0.8) High school only 239 (10.2) Higher education <4 years 758 (32.2) Higher education ≥4 years 1324 (56.3) Other 2 (0.1) Unknown 9 (0.4) Country of origin (n=2350) Norway 1562 (66.5) Sweden 523 (22.3) Other nordic 31 (1.3) Rest of the world 234 (10.0) Marital status (n=2350) Married 968 (41.2) Cohabitant 1313 (55.9) Single 44 (1.9) Divorced/separated 1 (0.04) Other 24 (1.0) Living environment (n=2350) City (densely populated) 916 (39.0) City (less densely populated) 882 (37.5) Suburb 373 (15.9) Countryside (in village) 127 (5.4) Countryside (outside village) 52 (2.2) Data is presented as mean (min–max) or n (%). BMI: body mass index. #: subjects were included in the present analysis if one or more questionnaires (from 18 weeks and 34 weeks) was completed. Subjects were excluded if questionnaires were not completed. Total pregnancies at 18 weeks available for inclusion was 2701. Total questionnaires completed at 18 weeks was 2350. ¶: p<0.001; +: number of reported pregnancies excluding the current pregnancy.
- TABLE 2
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.
Supplementary Material
Please note: supplementary material is not edited by the Editorial Office, and is uploaded as it has been supplied by the author.
Supplementary material 00197-2018_supp
