Table 4.
The odds ratios of pregnancy-induced hypertension (PIH) for smoking in the first trimester, after dissection into pre-pregnancy BMI categories.
| Odds Ratios of PIH for Smoking in the First Trimester, in the Pre-Pregnancy BMI Categories | ||
|---|---|---|
| Cases/Controls | PIH Risk OR * (95% CI:); p | |
| Whole cohort | ||
| Smoking in the first trimester | 20/37 | 3.40 (1.90–6.09); <0.001 |
| Women who have never smoked | 102/642 | 1 |
| Underweight | ||
| Smoking in the first trimester | 2/3 | 22.00 (1.52–319.48); 0.024 |
| Women who have never smoked | 1/33 | 1 |
| Normal BMI | ||
| Smoking in the first trimester | 7/23 | 2.96 (1.21–7.26); 0.018 |
| Women who have never smoked | 47/457 | 1 |
| Overweight | ||
| Smoking in the first trimester | 6/7 | 3.89 (1.2–12.63); 0.024 |
| Women who have never smoked | 24/109 | 1 |
| Obesity | ||
| Smoking in the first trimester | 5/4 | 1.79 (0.44–7.23); 0.413 |
| Women who have never smoked | 30/43 | 1 |
* OR: crude odds ratios (CI—confidence intervals) calculated in the univariate logistic regression (p < 0.05 was assumed to be significant); PIH: pregnancy-induced hypertension; BMI: body–mass index.