Parental smoking habit | Cord blood cotinine levels (ng/mL) | |||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|
1996 98 | 2002 04 | 2008 | ||||||||||
N = 373 | N = 245 | N = 181 | ||||||||||
GM | Median | Mean (SD) | p-value | GM | Median Mean (SD) | p-value | GM | Median | Mean (SD) | p-value | ||
Nobody | 1.8 | 1.6 | 8.4 (57.4) | Ref. | 0.4 | 0.4 | 0.6 (0.8) | Ref. | 0.6 | 0.37 | 3.5 (7.9) | Ref. |
Only father | 3.1 | 2.4 | 16.2 (55.5) | 0.6 | 0.5 | 2.3 (6.4) | 0.9 | 0.31 | 7.0 (17.3) | |||
Only mother | 62.5 | 74.6 | 132.4 (183.1) | ** | 55.6 | 75.5 | 74.9 (50.0) | ** | 0.7 | 0.36 | 9.6 (27.7) | |
Both | 78.1 | 97.2 | 162.0 (170.0) | ** | 20.8 | 28.7 | 39.8 (37.6) | ** | 0.9 | 0.29 | 14.5 (36.1) |