Table 2.
Low birth weight and small for gestation age adjusted odds (OR) ratios and 95% confidence intervals (CI) for trimester-specific and entire pregnancy exposure to internal dose THM.
| THM exposure a | Low birth weight | Small for gestation age | |
|---|---|---|---|
| OR b (95% CI) | OR c (95% CI) | ||
| TTHM d | |||
| Entire pregnancy | 1.27 (0.59–2.74) | 1.32 (0.83–2.10) | |
| First trimester | 1.03 (0.48–2.23) | 1.20 (0.75–1.91) | |
| Second trimester | 1.15 (0.53–2.47) | 1.17 (0.74–1.86) | |
| Third trimester | 1.33 (0.62–2.87) | 1.33 (0.84–2.13) | |
| Chloroform | |||
| Entire pregnancy | 1.24 (0.57–2.68) | 1.31 (0.82–20.9) | |
| First trimester | 1.15 (0.54–2.48) | 1.25 (0.78–1.99) | |
| Second trimester | 1.29 (0.60–2.76) | 1.23 (0.77–1.95) | |
| Third trimester | 1.45 (0.67–3.13) | 1.31 (0.82–2.08) | |
| BDCM d | |||
| Entire pregnancy | 1.26 (0.58–2.72) | 1.31 (0.82–2.09) | |
| First trimester | 1.28 (0.59–2.76) | 1.30 (0.82–2.08) | |
| Second trimester | 1.26 (0.58–2.73) | 1.25 (0.79–2.00) | |
| Third trimester | 1.27 (0.59–2.76) | 1.31 (0.82–2.09) | |
| DBCM d | |||
| Entire pregnancy | 3.00 (0.34–27.0) | 1.35 (0.80–2.29) | |
| First trimester | 1.76 (0.66–4.69) | 2.19 (1.20–3.99) | |
| Second trimester | 1.46 (0.62–3.42) | 1.40 (0.82–2.39) | |
| Third trimester | 1.54 (0.65–3.63) | 1.68 (0.97–2.89) | |
a Reference group below median; b Adjusted for marital status, square gestational age, maternal education, maternal smoking, paternal smoking, alcohol consumption, body mass index, blood pressure, premature baby, infant gender, and birth year; c Adjusted for parity, maternal status, maternal education, maternal smoking, body mass index, birth year; d TTHM—total trihalomethane; DBCM—dibromochloromethane, BDCM—bromodichloromethane.