Table II.
Associations between maternal periconceptional smoking and Carnegie stages.
| Model 1a | P | Model 2b | P | |
|---|---|---|---|---|
| Effect estimate (β), 95% CI | Effect estimate (β), 95% CI | |||
| Smoking | ||||
| No | 0 (Reference) | 0 (Reference) | ||
| Yes | −0.094 (−0.278; 0.089) | 0.310 | −0.052 (−0.247; 0.143) | 0.601 |
| Cigarettes/day | −0.067 (−0.129; −0.006) | 0.031* | −0.058 (−0.122; 0.007) | 0.080 |
| Smoking, categorical | ||||
| None | 0 (Reference) | 0 (Reference) | ||
| 1–9 cigarettes/day | 0.082 (−0.142; 0.306) | 0.472 | 0.129 (−0.107; 0.365) | 0.284 |
| ≥10 cigarettes/day | −0.398 (−0.686; −0.111) | 0.007* | −0.352 (−0.648; −0.057) | 0.019* |
*
P < 0.05 (bold text).
a
Model with GA as time predictor.
b
Fully adjusted model with GA as time predictor; adjusted for alcohol use, educational level, folic acid supplement use, maternal age, mode of conception, ethnicity, fetal sex, maternal BMI, parity and vitamin use.