Table 2.
Maternal smoking during pregnancy according to offspring age strata, leukemia cases, and control mothers, children <2 year, Brazil, 1999–2007.
| Tobacco smoking at pregnancy/child age | Controls (n = 423), n (%) | ALL (n = 193), n (%) | AML (n = 59), n (%) | ALL |
AML |
||
|---|---|---|---|---|---|---|---|
| OR (95% CI) |
OR Adjusteda (95% CI) |
OR (95% CI) |
OR Adjusteda (95% CI) |
||||
| MATERNAL SMOKING | |||||||
| 0–11 Months | |||||||
| No | 196 (76.9) | 72 (81.8) | 23 (82.1) | 1.00 | 1.00 | 1.00 | 1.00 |
| Yes | 59 (23.1) | 16 (18.2) | 5 (17.9) | 0.74 (0.40–1.37) | 0.65 (0.31–1.38) | 0.72 (0.26–1.98) | 0.41 (0.11–1.59) |
| 12–23 Months | |||||||
| No | 140 (83.3) | 84 (80.0) | 29 (93.5) | 1.00 | 1.00 | 1.00 | 1.00 |
| Yes | 28 (16.7) | 21 (20.0) | 2 (6.5) | 1.25 (0.67–2.34) | 1.38 (0.65–2.93) | 0.35 (0.08–1.53) | 0.46 (0.10–2.24) |
| TIME WINDOW | |||||||
| Preconceptionb | |||||||
| 0–11 Months | |||||||
| No | 176 (69.0) | 59 (67.0) | 20 (71.4) | 1.00 | 1.00 | 1.00 | 1.00 |
| Yes | 79 (31.0) | 29 (33.0) | 8 (28.6) | 0.89 (0.38–2.11) | 1.23 (0.68–2.22) | 1.10 (0.65–1.84) | 0.82 (0.30–2.25) |
| 12–23 Months | |||||||
| No | 128 (76.2) | 79 (75.2) | 27 (87.1) | 1.00 | 1.00 | 1.00 | 1.00 |
| Yes | 40 (23.8) | 26 (24.8) | 4 (12.9) | 1.05 (0.60–1.86) | 0.98 (0.50–1.92) | 0.47 (0.16–1.44) | 0.42 (0.13–1.39) |
| First trimester | |||||||
| 0–11 Months | |||||||
| No | 209 (82.0) | 71 (80.7) | 24 (85.7) | 1.00 | 1.00 | 1.00 | 1.00 |
| Yes | 46 (18.0) | 17 (19.3) | 4 (14.3) | 1.09 (0.59–2.02) | 1.03 (0.49–2.18) | 0.76 (0.25–2.29) | 0.62 (0.16–2.34) |
| 12–23 Months | |||||||
| No | 145 (86.3) | 84 (80.0) | 29 (93.5) | 1.00 | 1.00 | 1.00 | 1.00 |
| Yes | 23 (13.7) | 21 (20.0) | 2 (6.5) | 1.58 (0.82–3.02) | 1.61 (0.74–3.51) | 0.44 (0.10–1.95) | 0.41 (0.08–2.09) |
| Second trimester | |||||||
| 0–11 Months | |||||||
| No | 210 (82.4) | 76 (86.4) | 25 (89.3) | 1.00 | 1.00 | 1.00 | 1.00 |
| Yes | 45 (17.6) | 12 (13.6) | 3 (10.7) | 0.74 (0.37–1.47) | 0.93 (0.43–2.02) | 0.56 (0.16–1.94) | 0.38 (0.08–1.83) |
| 12–23 Months | |||||||
| No | 146 (86.9) | 89 (84.8) | 29 (93.5) | 1.00 | 1.00 | 1.00 | 1.00 |
| Yes | 22 (13.1) | 16 (15.2) | 2 (6.5) | 1.19 (0.60–2.39) | 1.37 (0.61–3.07) | 0.46 (0.10–2.05) | 0.44 (0.09–2.29) |
| Third trimester | |||||||
| 0–11 Months | |||||||
| No | 211 (82.7) | 76 (86.4) | 25 (89.3) | 1.00 | 1.00 | 1.00 | 1.00 |
| Yes | 44 (17.3) | 12 (13.6) | 3 (10.7) | 0.76 (0.38–1.51) | 0.97 (0.45–2.11) | 0.58 (0.17–1.99) | 0.40 (0.08–1.91) |
| 12–23 Months | |||||||
| No | 146 (86.9) | 89 (84.8) | 29 (93.5) | 1.00 | 1.00 | 1.00 | 1.00 |
| Yes | 22 (13.1) | 16 (15.2) | 2 (6.5) | 1.19 (0.60–2.39) | 1.50 (0.66–3.41) | 0.46 (0.10–2.05) | 0.49 (0.09–2.57) |
| Breastfeedingc | |||||||
| 0–11 Months | |||||||
| No | 209 (82.0) | 77 (87.5) | 26 (92.9) | 1.00 | 1.00 | 1.00 | 1.00 |
| Yes | 46 (18.0) | 11 (12.5) | 2 (7.1) | 0.65 (0.32–1.32) | 0.90 (0.42–1.96) | 0.35 (0.08–1.53) | 0.39 (0.08–1.89) |
| 12–23 Months | |||||||
| No | 148 (88.1) | 88 (83.8) | 29 (93.5) | 1.00 | 1.00 | 1.00 | 1.00 |
| Yes | 20 (11.9) | 17 (16.2) | 2 (6.5) | 1.43 (0.71–2.87) | 1.86 (0.83–4.20) | 0.51 (0.11–2.03) | 0.69 (0.14–3.53) |
aAdjusted OR by maternal age at birth, maternal education, oral contraceptives use during pregnancy, birth weight, and infant skin color.
bThree months before pregnancy.
cThree months after birth.