Table 3.
The association of mothers’ prenatal tobacco smoke exposure and the prevalence of low birth weight (birth weight less than 2500 g) of children in a rural area of Shanghai in the year of 2018, China
| Variables | Low Birth Weight (LBW) | LR(a) | LR(b) | LR(c) | ||||
|---|---|---|---|---|---|---|---|---|
| Yes n (%) |
No n (%) |
OR | OR 95%CI | OR | OR 95%CI | OR | OR 95%CI | |
| Prenatal exposure to FHS | ||||||||
| Yes | 10 (12.35) | 71 (87.65) | 2.91 | 1.49–5.68 | 2.77 | 1.39–5.53 | – | – |
| No | 393 (4.62) | 8112 (95.38) | 1.00 | – | 1.00 | – | – | – |
| Prenatal exposure to SHS | ||||||||
| Yes | 149 (8.35) | 1636 (91.65) | 2.35 | 1.90–2.89 | – | – | 2.42 | 1.95–3.00 |
| No | 254 (3.73) | 6547 (96.27) | 1.00 | – | – | – | 1.00 | – |
| Birth week | ||||||||
| <37 weeks | 115 (13.53) | 735 (86.47) | 4.05 | 3.22–5.09 | 3.94 | 3.13–4.97 | 3.97 | 3.14–5.02 |
| ≥ 37 weeks | 288 (3.72) | 7448 (96.28) | 1.00 | – | 1.00 | – | 1.00 | – |
| Age (years) | ||||||||
| 19–25 | 10 (4.22) | 227 (95.78) | 1.08 | 0.56–2.08 | 0.97 | 0.49–1.91 | 0.97 | 0.49–1.88 |
| 26–30 | 113 (3.94) | 2757 (96.06) | 1.00 | – | 1.00 | – | 1.00 | – |
| 31–35 | 211 (5.47) | 3647 (94.53) | 1.41 | 1.12–1.78 | 1.48 | 1.17–1.88 | 1.59 | 1.25–2.02 |
| 36–48 | 69 (4.26) | 1552 (95.74) | 1.09 | 0.80–1.47 | 1.01 | 0.74–1.38 | 1.15 | 0.84–1.58 |
| BMI before the pregnancy | ||||||||
| Less than 18.50 | 94 (5.17) | 1725 (94.83) | 1.27 | 0.99–1.62 | – | – | 1.28 | 0.99–1.65 |
| 18.50–23.99 | 218 (4.13) | 5060 (95.87) | 1.00 | – | – | – | 1.00 | – |
| 24.00–27.00 | 31 (5.89) | 495 (94.11) | 1.45 | 0.99–2.14 | – | – | 1.23 | 0.82–1.84 |
| Over 27.00 | 60 (6.23) | 903 (93.77) | 1.54 | 1.15–2.07 | – | – | 1.33 | 0.98–1.80 |
| Education | ||||||||
| Illiterate/Primary | 5 (7.04) | 66 (92.96) | 1.68 | 0.67–4.20 | 1.62 | 0.64–4.16 | 1.55 | 0.59–4.02 |
| Junior High | 57 (7.17) | 738 (92.83) | 1.71 | 1.27–2.30 | 1.77 | 1.30–2.41 | 1.75 | 1.28–2.38 |
| Senior High | 77 (4.77) | 1536 (95.23) | 1.11 | 0.86–1.44 | 1.13 | 0.87–1.48 | 1.11 | 0.85–1.46 |
| College and above | 264 (4.32) | 5843 (95.68) | 1.00 | – | 1.00 | – | 1.00 | – |
| Gestational diabetes mellitus | ||||||||
| Yes | 39 (7.32) | 494 (92.68) | 1.67 | 1.18–2.35 | 1.47 | 1.03–2.08 | 1.38 | 0.97–1.97 |
| No | 364 (4.52) | 7689 (95.48) | 1.00 | – | 1.00 | – | 1.00 | – |
LR(a): Uni-viariate logistic regression
LR(b): Multi-viariate logistic regression to explore the association between LBW of children and prenatal FHS exposure among their mothers, with covariates adjustment of preterm birth, age of mother, education of mother and gestational diabetes mellitus (covariates adjusted during the logistic regression were selected by Directed Acyclic Graph (DAG) method)
LR(c): Multi-viariate logistic regression to explore the association between LBW of children and prenatal SHS exposure among their mothers, with covariates adjustment of preterm birth, age of mother, education of mother, BMI before pregnancy and gestational diabetes mellitus (covariates adjusted during the logistic regression were selected by Directed Acyclic Graph (DAG) method)