Demographic and clinical characteristics of the participants (N=992)
| Secondhand smoking | Univariate analyses | ||||||||
| Variable | Total (N=992) | No (N=781) | Yes (N=211) | χ2/Z | df | P value | |||
| N | % | N | % | N | % | ||||
| Urban area | 837 | 84.4 | 681 | 87.2 | 156 | 73.9 | 22.163 | 1 | <0.001 |
| Pregnancy phase | 10.473 | 3 | 0.015 | ||||||
| First trimester | 180 | 18.1 | 138 | 17.7 | 42 | 19.9 | |||
| Second trimester | 218 | 22.0 | 188 | 24.1 | 30 | 14.2 | |||
| Third trimester | 491 | 49.5 | 380 | 48.7 | 111 | 52.6 | |||
| Postnatal | 103 | 10.4 | 75 | 9.6 | 28 | 13.3 | |||
| College and above | 674 | 67.9 | 556 | 71.2 | 118 | 55.9 | 17.776 | 1 | <0.001 |
| Employed | 612 | 61.7 | 493 | 63.1 | 119 | 56.4 | 3.180 | 1 | 0.075 |
| Have four and more family members | 492 | 49.6 | 376 | 48.1 | 116 | 55.0 | 3.103 | 1 | 0.078 |
| Monthly income≥5000 RMB | 481 | 48.5 | 395 | 50.6 | 86 | 40.8 | 6.411 | 1 | 0.011 |
| First delivery | 571 | 57.6 | 452 | 57.9 | 119 | 56.4 | 0.148 | 1 | 0.700 |
| Adverse pregnant experience | 131 | 13.2 | 102 | 13.1 | 29 | 13.7 | 0.068 | 1 | 0.795 |
| Previous natural miscarriage | 180 | 18.1 | 136 | 17.4 | 44 | 20.9 | 1.323 | 1 | 0.250 |
| Previous abortion by drugs | 288 | 29.0 | 217 | 27.8 | 71 | 33.6 | 2.773 | 1 | 0.096 |
| Placental preposition | 61 | 6.1 | 46 | 5.9 | 15 | 7.1 | 0.428 | 1 | 0.513 |
| Having physical comorbidities | 132 | 13.3 | 94 | 12.0 | 38 | 18.0 | 5.139 | 1 | 0.023 |
| Total (N=992) | No (N=781) | Yes (N=211) | Univariate analyses | ||||||
| Mean | SD | Mean | SD | Mean | SD | T/Z | df | P value | |
| Age (years) | 29.384 | 4.173 | 29.684 | 4.066 | 28.272 | 4.382 | 4.403 | 990 | <0.001 |
| BMI | 24.130 | 4.229 | 24.095 | 4.258 | 24.258 | 4.124 | −0.494 | 990 | 0.621 |
| Physical QOL | 15.214 | 2.062 | 15.237 | 2.098 | 15.129 | 1.927 | 0.673 | 990 | 0.501 |
| Psychological QOL | 15.276 | 2.435 | 15.317 | 2.350 | 15.125 | 2.729 | 1.011 | 990 | 0.312 |
| Social QOL | 15.578 | 2.406 | 15.624 | 2.327 | 15.410 | 2.678 | 1.148 | 990 | 0.251 |
| Environmental QOL | 15.079 | 2.486 | 15.154 | 2.430 | 14.801 | 2.672 | 1.832 | 990 | 0.067 |
| EPDS total score | 5.414 | 4.365 | 5.270 | 4.216 | 5.947 | 4.852 | −1.371 | -a | 0.170 |
In bold: p<0.05; a: Mann-Whitney U test.
1 RMB = 0.144 US dollar
BMI, body mass index; EPDS, Edinburgh Postnatal Depression Scale; QOL, quality of life.