Demographic characteristics and pregnancy history of pregnant women by objectively measured smoking status
| Non-smokers (N=6892) (reference category) | Women who undisclosed smoking (N=745) | Inactive cigarette smokers (N=431) | Active cigarette smokers (N=1559) | ||||
|---|---|---|---|---|---|---|---|
| Characteristic | % | % | OR (95% CI) | % | OR (95% CI) | % | OR (95% CI) |
| Age <30 years | |||||||
| 1987–1993 | 56.1 | 60.7 | 1.21 (0.97 to 1.51) | 59.7 | 1.16 (0.82 to 1.64) | 66.3 | 1.54 (1.29 to 1.84) |
| 1994–2003 | 47.7 | 61.9 | 1.78 (1.38 to 2.30) | 62.9 | 1.86 (1.38 to 2.51) | 62.9 | 1.86 (1.56 to 2.21) |
| 2004–2011 | 45.0 | 62.3 | 2.02 (1.34 to 3.04) | 71.4 | 3.05 (1.94 to 4.81) | 75.9 | 3.85 (2.81 to 5.27) |
| Unmarried | |||||||
| 1987–1993 | 19.0 | 40.4 | 2.88 (2.66 to 3.66) | 30.2 | 1.84 (1.23 to 2.74) | 46.8 | 3.77 (3.13 to 4.54) |
| 1994–2003 | 26.5 | 48.5 | 2.62 (2.00 to 3.45) | 37.6 | 1.67 (1.22 to 2.28) | 51.9 | 2.99 (2.51 to 3.56) |
| 2004–2011 | 29.8 | 41.5 | 1.65 (1.09 to 2.48) | 43.9 | 1.83 (1.19 to 2.80) | 57.8 | 3.22 (2.37 to 4.38) |
| <15 visits to maternity care | |||||||
| 1987–1993 | 42.2 | 45.3 | 1.13 (0.91 to 1.41) | 46.0 | 1.16 (0.81 to 1.67) | 46.8 | 1.21 (1.02 to 1.44) |
| 1994–2003 | 35.9 | 41.1 | 1.25 (0.96 to 1.61) | 34.0 | 0.92 (0.67 to 1.26) | 35.3 | 1.18 (0.99 to 1.40) |
| 2004–2011 | 37.9 | 31.1 | 0.75 (0.49 to 1.15) | 30.6 | 0.71 (0.45 to 1.12) | 32.9 | 0.80 (0.60 to 1.08) |
| Prepregnancy body mass index not normal* | |||||||
| 2004–2011 | 41.1 | 40.6 | 0.99 (0.65 to 1.51) | 39.8 | 0.96 (0.63 to 1.48) | 41.8 | 1.03 (0.74 to 1.45) |
| Socioeconomic status lower than white-collar worker | |||||||
| 1987–1993 | 35.7 | 43.4 | 1.37 (0.88 to 2.13) | 39.6 | 1.16 (0.75 to 1.80) | 46.5 | 1.56 (1.14 to 2.13) |
| 1994–2003 | 35.8 | 55.6 | 2.26 (1.74 to 2.94) | 46.9 | 1.59 (1.17 to 2.16) | 62.3 | 2.96 (2.46 to 3.55) |
| 2004–2011 | 41.7 | 57.5 | 1.89 (1.25 to 2.87) | 57.1 | 1.83 (1.18 to 2.84) | 72.7 | 3.75 (2.71 to 5.18) |
| Nulliparous | |||||||
| 1987–1993 | 44.6 | 52.8 | 1.40 (1.12 to 1.75) | 56.1 | 1.60 (0.90 to 2.87) | 49.3 | 1.21 (1.02 to 1.44) |
| 1994–2003 | 45.8 | 52.6 | 1.30 (1.02 to 1.67) | 54.1 | 1.39 (1.03 to 1.87) | 50.8 | 1.22 (1.03 to 1.45) |
| 2004–2011 | 43.6 | 46.2 | 1.23 (0.75 to 2.03) | 55.1 | 1.26 (0.78 to 2.04) | 59.4 | 1.51 (1.09 to 2.10) |
*Includes subjects with body mass index <18.5 kg/m2 and subjects with body mass index ≥25 kg/m2. These data were not available prior to 2004.