Table 2.
Maternal smoking and risk of congenital heart defects in offspringa
| Exposure | Control group | Case group | Univariate logistic regression | Multivariable logistic regressionc | ||||
|---|---|---|---|---|---|---|---|---|
| (n = 504) | (n = 464) | cOR | 95% CI | P | aORb | 95% CI | P c | |
| Active smoking in 3 months before pregnancy | ||||||||
| No | 494 (98.0%) | 432 (93.1%) | 1.00 | 1.00 | ||||
| Yes | 10 (2.0%) | 32 (6.9%) | 3.66 | 1.78–7.53 | < 0.001 | 2.37 | 0.99–5.65 | 0.052 |
| Active smoking in the first trimester | ||||||||
| No | 504 (100%) | 464 (100%) | – | – | – | – | – | |
| Yes | 0 (0%) | 0 (0%) | – | – | – | – | – | |
| Passive smoking in 3 months before pregnancy | ||||||||
| No | 316 (62.7%) | 222 (47.8%) | 1.00 | 1.00 | ||||
| Yes | 188 (37.3%) | 242 (52.2%) | 1.83 | 1.42–2.37 | < 0.001 | 1.56 | 1.13–2.15 | 0.007 |
| Passive smoking in the first trimester | ||||||||
| No | 406 (80.6%) | 274 (59.1%) | 1.00 | 1.00 | ||||
| Yes | 98 (19.4%) | 190 (40.9%) | 2.87 | 2.15–3.83 | < 0.001 | 2.24 | 1.57–3.20 | < 0.001 |
Abbreviations: CI confidence interval; cOR crude odds ratio; aOR adjusted odds ratio
aData presented as number (percentage) unless otherwise indicated
bAdjusted for residence location, maternal education level (years), annual income in the past 1 year (RMB), history of adverse pregnancy outcomes, consanguineous marriage, history of congenital malformations in family, cold or fever in the periconceptional period, and personal lifestyle and habit in the periconceptional period including drinking alcohol, drinking tea, living near environmental pollution source, dyeing hair or perming and folate use
cP < 0.05 was considered to indicate a statistically significant difference