Table 5.
Adjusted ORs and 95% CIs for congenital urogenital anomalies by tertiles of internal THM exposure during the first trimester of pregnancy
| THM internal dose tertile limits (µg/d) | n | First month OR* (95% CI) | n | Second month OR* (95% CI) | n | Third month OR* (95% CI) | n | First trimester OR* (95% CI) |
|---|---|---|---|---|---|---|---|---|
| TTHM | ||||||||
| 0.031–0.040 | 5 | 1 | 4 | 1 | 5 | 1 | 4 | 1 |
| 0.040–0.356 | 8 | 1.54 (0.50 to 4.77) | 10 | 2.46 (0.77 to 7.93) | 8 | 1.52 (0.49 to 4.71) | 9 | 2.19 (0.67 to 7.18) |
| 0.356–2.448 | 10 | 1.95 (0.66 to 5.76) | 9 | 2.32 (0.71 to 7.62) | 10 | 2.01 (0.68 to 5.96) | 10 | 2.49 (0.77 to 8.03) |
| p† | 0.176 | 0.174 | 0.175 | 0.115 | ||||
| Continuous (1µg/d) | 1.92 (0.69 to 5.33) | 1.99 (0.72 to 5.49) | 2.02 (0.74 to 5.50) | 2.00 (0.72 to 5.56) | ||||
| Chloroform | ||||||||
| 0.001–0.026 | 4 | 1 | 4 | 1 | 4 | 1 | 4 | 1 |
| 0.026–0.288 | 10 | 2.31 (0.72 to 7.43) | 11 | 2.45 (0.77 to 7.76) | 10 | 0.44 (0.13 to 1.44) | 9 | 2.21 (0.67 to 7.23) |
| 0.288–2.109 | 9 | 2.20 (0.67 to 7.22) | 8 | 2.02 (0.60 to 6.76) | 9 | 1.01 (0.41 to 2.53) | 10 | 2.50 (0.78 to 8.06) |
| p† | 0.180 | 0.273 | 0.174 | 0.118 | ||||
| Continuous (1µg/d) | 2.10 (0.65 to 6.74) | 2.21 (0.69 to 7.08) | 2.26 (0.71 to 7.20) | 2.22 (0.69 to 7.17) | ||||
| BDCM | ||||||||
| 0.000–0.013 | 4 | 1 | 6 | 1 | 6 | 1 | 4 | 1 |
| 0.013–0.051 | 10 | 2.40 (0.75 to 7.73) | 6 | 0.90 (0.29 to 2.83) | 6 | 0.91 (0.29 to 2.86) | 7 | 1.65 (0.48 to 5.67) |
| 0.051–0.436 | 9 | 2.27 (0.69 to 7.43) | 11 | 1.81 (0.66 to 4.96) | 11 | 1.85 (0.68 to 5.07) | 12 | 2.87 (0.92 to 8.99) |
| p† | 0.165 | 0.165 | 0.158 | 0.039 | ||||
| Continuous (0.1µg/d) | 1.55 (0.70 to 3.40) | 1.56 (0.74 to 3.29) | 1.55 (0.76 to 3.20) | 1.57 (0.74 to 3.37) | ||||
| DBCM | ||||||||
| 0.000–0.002 | 7 | 1 | 7 | 1 | 6 | 1 | 6 | 1 |
| 0.002–0.006 | 7 | 0.89 (0.31 to 2.58) | 8 | 1.08 (0.39 to 3.00) | 9 | 1.42 (0.50 to 4.02) | 6 | 0.92 (0.29 to 2.87) |
| 0.006–0.093 | 9 | 1.17 (0.43 to 3.16) | 8 | 1.06 (0.38 to 2.96) | 8 | 1.22 (0.42 to 3.56) | 11 | 1.79 (0.65 to 4.90) |
| p† | 0.700 | 0.890 | 0.670 | 0.210 | ||||
| Continuous (0.01µg/d) | 1.17 (0.78 to 1.77) | 1.17 (0.80 to 1.71) | 1.17 (0.82 to 1.66) | 1.17 (0.80 to 1.72) | ||||
*Adjusted for: age, body mass index, chronic disease, previous premature birth and infant sex.
†χ2 for linear trend.
BDCM, bromodichloromethane; DBCM, dibromochloromethane; THM, trihalomethane; TTHM, total trihalomethane.