Table 3.
The adjusted odds ratios of newborn outcomes for smoking in the 1st trimester, calculated in the subgroups of BMI categories.
| Birth Weight <10th Percentile | FGR | LBW | |
|---|---|---|---|
| BMI Categories/ Smoking Categories |
OR (95% CI); p AOR-a * (95% CI); p |
OR (95% CI); p AOR-a * (95% CI); p |
OR (95% CI); p AOR-a * (95% CI); p |
| Whole cohort (n = 801) |
|||
| Smoking in 1st trimester | 4.29 (2.22–8.26); <0.001 | 3.45 (1.11–10.7); 0.032 | 3.05 (1.44–6.46); 0.003 |
| 4.43 (2.21–8.85); <0.001 | 3.29 (1.02–10.58); 0.046 | 5.58 (1.88–16.5); 0.002 | |
| Never smokers | 1 | 1 | 1 |
| Underweight (n = 39) |
|||
| Smoking in 1st trimester | 1.50 (0.13–17.04); 0.744 | 2.58 (0.21–31.2); 0.455 | 5.17 (0.36–75.13); 0.229 |
| 0.03(0–13.68); 0.259 | 1.38(0.07–27.17); 0.833 | NA * | |
| Never smokers | 1 | 1 | 1 |
| Normal BMI (n = 534) |
|||
| Smoking in 1st trimester | 3.95 (1.58–9.88); 0.003 | 1.75 (0.22–14.13); 0.601 | 3.53 (1.24–9.99); 0.018 |
| 4.25 (1.64–11.0); 0.003 | 1.66 (0.2–13.81); 0.638 | 7.67 (1.84–31.9); 0.005 | |
| Never smokers | 1 | 1 | 1 |
| Overweight (n = 146) |
|||
| Smoking in 1st trimester | 6.00 (1.51–23.84); 0.011 | NA | 5.10 (1.12–23.16); 0.035 |
| 6.95 (1.54–31.27); 0.012 | NA | 7.84 (0.68–91.08); 0.1 | |
| Never smokers | 1 | 1 | 1 |
| Obesity (n = 82) |
|||
| Smoking in 1st trimester | 4.60 (0.87–24.32); 0.072 | 6.48 (0.92–45.57); 0.061 | 0.46 (0.05–4.03); 0.479 |
| 6.42 (0.94–44.08); 0.058 | 5.12 (0.6–43.63); 0.136 | NA * | |
| Never smokers | 1 | 1 | 1 |
| BMI ≥ 25 kg/m2 (n = 228) |
|||
| Smoking in 1st trimester | 5.53 (1.91–15.97); 0.002 | 6.60 (1.04–41.86); 0.045 | 1.92 (0.58–6.34); 0.284 |
| 6.39 (2.01–20.34); 0.002 | 6.25 (0.86–45.59); 0.071 | 3.80 (0.63–22.95); 0.145 | |
| Never smokers | 1 | 1 | 1 |
* AOR-a: adjusted odds ratios (with 95% confidence intervals, CI) calculated in the multidimensional logistic regression; the results were adjusted for: maternal age, maternal height, pre-pregnancy BMI and gestational age at birth (excluding gestational age in the study for FGR, as well as excluding BMI in the BMI category analyses); p-value was calculated in the Wald test (p < 0.05 was assumed as significant). NA: the lack of cases or controls; NA *: impossible to correct (small number of cases); BMI: body mass index (pre-pregnancy values): Underweight: <18.5 kg/m2, Normal BMI: 18.5–24.9 kg/m2, Overweight: 25.0–29.9 kg/m2; Obesity: ≥30 kg/m2; FGR: fetal growth restriction; LBW: birth weight <2500 g.