Figure 1
Figure 2
Figure 3
General characteristics and urinary cotinine values in pregnant women at term grouped by self-reported smoking habits
| Non-smokers (n=123) | Smokers (n=33) | p | |
|---|---|---|---|
| Age (years) | 33 (21–44) | 29 (21–38) | <0.001 |
| Educationa | <0.001 | ||
| Primary | 7 (5.7 %) | 3 (9.1 %) | |
| Secondary | 47 (38.2 %) | 24 (72.7 %) | |
| Tertiary | 69 (56.1 %) | 6 (18.2 %) | |
| Pre-pregnancy BMI | 22.9 (14.7–36.3) | 23.0 (16.0–36.6) | 0.469 |
| Former smokers | 52 (42.2 %) | / | |
| Number of cigarettes smoked per day during pregnancy | / | 7 (1–20) | |
| Urinary cotinine (µg/L) | 2.30 [<LOD–6.70] | 1034 [611–2668] | <0.001 |
| Urinary cotinine (µg/g creatinine) | 2.06 [<LOD–9.55] | 1305 [420–2096] | <0.001 |
Second-hand smoke (SHS) exposure and urinary cotinine in non-smoking pregnant women at term
| Non-smokers reporting no exposure to SHS (n=82) | Non-smokers reporting exposure to SHS (n=35) | p | |
|---|---|---|---|
| Age (years) | 34 (21–44) | 31 (21–37) | 0.002 |
| Educationa | 0.017 | ||
| Primary | 2 (2.4%) | 3 (8.6%) | |
| Secondary | 26(31.7%) | 18 (51.4%) | |
| Tertiary | 54 (65.9%) | 14 (40.0%) | |
| Urinary cotinine (μg/L) | 1.00 [<LOD–4.20] | 6.50 [1.40–23.8] | <0.001 |
| Urinary cotinine (µg/g creatinine) | 1.08 [<LOD–4.09] | 7.05 [1.48–22.2] | <0.001 |
Misclassification rates of self-reported smoking status with urinary cotinine concentrations based on the identified urinary cotinine cut-off values (120 µg/L and 144 µg/g creatinine) in pregnant women at term
| Non-smokers with cotinine <120 µg/L (n=120) | Smokers with cotinine >120 µg/L (n=36) | Non-smokers with cotinine <144 µg/g creatinine (n=121) | Smokers with cotinine >144 µg/g creatinine (n=35) | |
|---|---|---|---|---|
| Ratio to self-reported | ||||
| Non-smokers | 118/123 (95.9 %) | 5/123 (4.1 %) | 119/123 (96.7 %) | 4/123 (3.3 %) |
| Smokers | 2/33 (6.1 %) | 31/33 (93.9 %) | 2/33 (6.1 %) | 31/33 (93.9 %) |
| Urinary cotinine (μg/L) | 2.15 [<LOD–5.95] | 994 [577–2562] | 2.20 [<LOD–6.00] | 1034 [598–2668] |
| Urinary cotinine (µg/g creatinine) | 2.02 [<LOD–6.88] | 1315 [440–2194] | 2.03 [<LOD–7.05] | 1324 [460–2292] |