Table 3
Odds ratios of total and selected birth defects by paternal occupational exposure to magnetic fields above 0.1 μT in Norway 1967–95
| Crude | Adjusted† | |||||||
|---|---|---|---|---|---|---|---|---|
| Category of birth defects | Hours exposed/week | Cases (n) | OR | 95% CI | p Value* | OR | 95% CI | p Value* |
| *Test for trend across three exposure categories; †adjusted for highest family educational level, place of birth, mothers' age, and year of birth; ‡refers to the ICD-8 category 758. | ||||||||
| Any birth defect | <4 | 28937 | 1.00 | 0.0002 | 1.00 | 0.11 | ||
| 4–24 | 2831 | 0.97 | 0.93 to 1.01 | 1.03 | 0.99 to 1.07 | |||
| >24 | 1088 | 0.90 | 0.84 to 0.95 | 1.03 | 0.97 to 1.09 | |||
| All CNS defects | <4 | 1430 | 1.00 | 0.06 | 1.00 | 0.22 | ||
| 4–24 | 168 | 1.16 | 0.99 to 1.37 | 1.13 | 0.96 to 1.32 | |||
| >24 | 68 | 1.13 | 0.89 to 1.45 | 1.07 | 0.84 to 1.37 | |||
| Anencephaly | <4 | 347 | 1.00 | 0.0004 | 1.00 | 0.01 | ||
| 4–24 | 57 | 1.63 | 1.23 to 2.15 | 1.52 | 1.15 to 2.02 | |||
| >24 | 23 | 1.58 | 1.04 to 2.41 | 1.39 | 0.91 to 2.13 | |||
| Spina bifida | <4 | 535 | 1.00 | 0.29 | 1.00 | 0.24 | ||
| 4–24 | 54 | 1.00 | 0.76 to 1.32 | 0.98 | 0.74 to 1.30 | |||
| >24 | 16 | 0.71 | 0.44 to 1.17 | 0.70 | 0.42 to 1.15 | |||
| Hydrocephaly | <4 | 383 | 1.00 | 0.54 | 1.00 | 0.71 | ||
| 4–24 | 37 | 0.96 | 0.68 to 1.34 | 0.94 | 0.67 to 1.32 | |||
| >24 | 20 | 1.25 | 0.79 to 1.95 | 1.19 | 0.75 to 1.86 | |||
| Other CNS defects | <4 | 172 | 1.00 | 0.21 | 1.00 | 0.27 | ||
| 4–24 | 21 | 1.21 | 0.77 to 1.90 | 1.17 | 0.74 to 1.84 | |||
| >24 | 10 | 1.39 | 0.73 to 2.62 | 1.35 | 0.71 to 2.57 | |||
| Cardiac defects | <4 | 2184 | 1.00 | 0.74 | 1.00 | 0.42 | ||
| 4–24 | 228 | 1.03 | 0.90 to 1.19 | 1.09 | 0.95 to 1.25 | |||
| >24 | 84 | 0.92 | 0.74 to 1.14 | 1.01 | 0.81 to 1.26 | |||
| Respiratory system defects | <4 | 565 | 1.00 | 0.01 | 1.00 | 0.50 | ||
| 4–24 | 49 | 0.86 | 0.64 to 1.15 | 1.02 | 0.76 to 1.36 | |||
| >24 | 12 | 0.51 | 0.29 to 0.90 | 0.75 | 0.42 to 1.33 | |||
| Isolated cleft palate | <4 | 543 | 1.00 | 0.43 | 1.00 | 0.66 | ||
| 4–24 | 63 | 1.15 | 0.89 to 1.49 | 1.11 | 0.85 to 1.44 | |||
| >24 | 24 | 1.05 | 0.70 to 1.59 | 1.00 | 0.66 to 1.51 | |||
| Total cleft lip | <4 | 1513 | 1.00 | 0.17 | 1.00 | 0.22 | ||
| 4–24 | 163 | 1.07 | 0.91 to 1.25 | 1.06 | 0.90 to 1.25 | |||
| >24 | 73 | 1.15 | 0.91 to 1.46 | 1.14 | 0.90 to 1.44 | |||
| Genital system defects | <4 | 4265 | 1.00 | 0.06 | 1.00 | 0.65 | ||
| 4–24 | 384 | 0.89 | 0.80 to 0.99 | 0.96 | 0.87 to 1.07 | |||
| >24 | 167 | 0.93 | 0.80 to 1.09 | 1.09 | 0.93 to 1.28 | |||
| Clubfoot | <4 | 6770 | 1.00 | 0.00005 | 1.00 | 0.92 | ||
| 4–24 | 638 | 0.93 | 0.86 to 1.01 | 1.05 | 0.96 to 1.13 | |||
| >24 | 206 | 0.73 | 0.63 to 0.83 | 0.95 | 0.83 to 1.09 | |||
| Other defects‡ | <4 | 83 | 1.00 | 0.03 | 1.00 | 0.02 | ||
| 4–24 | 15 | 1.79 | 1.03 to 3.10 | 1.92 | 1.10 to 3.36 | |||
| >24 | 6 | 1.72 | 0.75 to 3.95 | 1.85 | 0.80 to 4.27 | |||
| Down's syndrome | <4 | 1205 | 1.00 | 0.44 | 1.00 | 0.52 | ||
| 4–24 | 103 | 0.85 | 0.69 to 1.04 | 0.97 | 0.79 to 1.18 | |||
| >24 | 52 | 1.03 | 0.78 to 1.36 | 1.16 | 0.88 to 1.54 | |||
