Adjusted ORs and 95% CIs for congenital musculoskeletal 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 | 14 | 1 | 14 | 1 | 14 | 1 | 14 | 1 |
| 0.040–0.356 | 14 | 0.92 (0.43 to 1.94) | 14 | 0.91 (0.43 to 1.92) | 15 | 0.99 (0.47 to 2.07) | 13 | 0.90 (0.42 to 1.92) |
| 0.356–2.448 | 9 | 0.63 (0.27 to 1.46) | 9 | 0.63 (0.27 to 1.47) | 8 | 0.57 (0.24 to 1.36) | 10 | 0.69 (0.31 to 1.57) |
| p† | 0.351 | 0.357 | 0.254 | 0.446 | ||||
| Continuous (1 µg/d) | 0.46 (0.14 to 1.52) | 0.54 (0.17 to 1.72) | 0.69 (0.23 to 2.04) | 0.55 (0.17 to 1.74) | ||||
| Chloroform | ||||||||
| 0.001–0.026 | 16 | 1 | 16 | 1 | 14 | 1 | 17 | 1 |
| 0.026–0.288 | 12 | 0.71 (0.33 to 1.50) | 12 | 0.69 (0.33 to 1.48) | 15 | 0.98 (0.47 to 2.04) | 11 | 0.61 (0.29 to 1.32) |
| 0.288–2.109 | 9 | 0.56 (0.25 to 1.28) | 9 | 0.56 (0.25 to 1.28) | 8 | 0.57 (0.24 to 1.37) | 9 | 0.51 (0.22 to 1.14) |
| p† | 0.175 | 0.180 | 0.258 | 0.111 | ||||
| Continuous (1 µg/d) | 0.37 (0.09 to 1.48) | 0.43 (0.11 to 1.68) | 0.55 (0.15 to 2.03) | 0.43 (0.11 to 1.71) | ||||
| BDCM | ||||||||
| 0.000–0.013 | 11 | 1 | 11 | 1 | 9 | 1 | 10 | 1 |
| 0.013–0.051 | 18 | 1.57 (0.73 to 3.35) | 16 | 1.41 (0.65 to 3.06) | 18 | 0.88 (0.36 to 2.19) | 13 | 1.18 (0.51 to 2.71) |
| 0.051–0.436 | 8 | 0.73 (0.29 to 1.84) | 10 | 0.92 (0.39 to 2.17) | 10 | 1.70 (0.78 to 3.71) | 14 | 1.29 (0.57 to 2.92) |
| p† | 0.639 | 0.944 | 0.708 | 0.406 | ||||
| Continuous (0.1 µg/d) | 0.79 (0.33 to 1.86) | 0.95 (0.45 to 2.00) | 1.15 (0.60 to 2.17) | 0.97 (0.46 to 2.06) | ||||
| DBCM | ||||||||
| 0.000–0.002 | 7 | 1 | 6 | 1 | 9 | 1 | 11 | 1 |
| 0.002–0.006 | 11 | 1.41 (0.54 to 3.65) | 13 | 2.02 (0.76 to 5.36) | 9 | 0.97 (0.38 to 2.45) | 12 | 0.95 (0.42 to 2.18) |
| 0.006–0.093 | 19 | 2.56 (1.07 to 6.13) | 18 | 2.90 (1.14 to 7.35) | 19 | 2.01 (0.90 to 4.48) | 14 | 1.16 (0.52 to 2.57) |
| p† | 0.024 | 0.023 | 0.061 | 0.578 | ||||
| Continuous (0.01 µg/d) | 1.18 (0.86 to 1.62) | 1.18 (0.90 to 1.56) | 1.20 (0.94 to 1.54) | 1.20 (0.91 to 1.58) | ||||
*Adjusted for: body mass index, fetus number, previous premature birth and infant sex.
†χ2 for linear trend.
BDCM, bromodichloromethane; DBCM, dibromochloromethane; THM, trihalomethane; TTHM, total trihalomethane.