Table 5.
Prevalences and prevalence odds ratios of the most common birth defects according to exposure to trihalomethanes in Taiwan 2001–2003.
| Outcomes | TTHM | TTHM | TTHM | TTHM | |
| 0–4 μg/L | 5–9 μg/L | 10–19 μg/L | 20+ μg/L | ||
| Reference | Low | Medium | High | ||
| Any birth defect | |||||
| N | 2,148 | 978 | 368 | 421 | 381 |
| P (%) | 0.540 | 0.540 | 0.660 | 0.510 | 0.510 |
| OR | 1.00 | 1.23 | 0.95 | 0.94 | |
| aOR (95% CI) | 1.00 | 1.21 (1.07–1.36) | 0.97 (0.86–1.08) | 1.00 (0.89–1.13) | |
| Anencephalus | |||||
| N | 43 | 19 | 9 | 2 | 13 |
| P (%) | 0.011 | 0.010 | 0.016 | 0.002 | 0.017 |
| OR | 1.00 | 1.54 | 0.23 | 1.65 | |
| aOR (95% CI) | 1.00 | 1.59 (0.72–3.52) | 0.23 (0.05–1.01) | 1.96 (0.94–4.07) | |
| Hydrocephalus | |||||
| N | 118 | 58 | 24 | 19 | 17 |
| P (%) | 0.030 | 0.032 | 0.043 | 0.023 | 0.023 |
| OR | 1.00 | 1.35 | 0.72 | 0.71 | |
| aOR (95% CI) | 1.00 | 1.36 (0.85–2.20) | 0.71 (0.42–1.20) | 0.74 (0.43–1.28) | |
| Ventricular septal defects | |||||
| N | 59 | 27 | 6 | 8 | 18 |
| P (%) | 0.015 | 0.015 | 0.011 | 0.010 | 0.024 |
| OR | 1.00 | 0.72 | 0.65 | 1.61 | |
| aOR (95% CI) | 1.00 | 0.74 (0.31–1.80) | 0.65 (0.29–1.43) | 1.81 (0.98–3.35) | |
| Atrial septal defects | |||||
| N | 19 | 8 | 5 | 2 | 4 |
| P (%) | 0.005 | 0.004 | 0.009 | 0.002 | 0.005 |
| OR | 1.00 | 2.03 | 0.55 | 1.21 | |
| aOR (95% CI) | 1.00 | 2.15 (0.70–6.60) | 0.53 (0.11–2.49) | 1.33 (0.39–4.58) | |
| Tetralogy of Fallot | |||||
| N | 24 | 13 | 6 | 3 | 2 |
| P (%) | 0.006 | 0.007 | 0.011 | 0.004 | 0.003 |
| OR | 1.00 | 1.50 | 0.51 | 0.37 | |
| aOR (95% CI) | 1.00 | 1.60 (0.61–4.23) | 0.46 (0.13–1.61) | 0.32 (0.07–1.47) | |
| Cleft lip with/without palate | |||||
| N | 358 | 155 | 55 | 84 | 64 |
| P (%) | 0.090 | 0.085 | 0.098 | 0.101 | 0.085 |
| OR | 1.00 | 1.15 | 1.19 | 1.00 | |
| aOR (95% CI) | 1.00 | 1.15 (0.84–1.56) | 1.20 (0.91–1.55) | 0.98 (0.73–1.32) | |
| Cleft palate | |||||
| N | 129 | 52 | 15 | 28 | 34 |
| P (%) | 0.033 | 0.029 | 0.027 | 0.034 | 0.045 |
| OR | 1.00 | 0.94 | 1.18 | 1.58 | |
| aOR (95% CI) | 1.00 | 0.94 (0.53–1.68) | 1.17 (0.74–1.86) | 1.56 (1.00–2.41) | |
| Renal agenesis & dysgenesis | |||||
| N | 76 | 33 | 14 | 13 | 16 |
| P (%) | 0.019 | 0.018 | 0.025 | 0.016 | 0.021 |
| OR | 1.00 | 1.38 | 0.87 | 1.17 | |
| aOR (95% CI) | 1.00 | 1.33 (0.71–2.48) | 0.92 (0.48–1.75) | 1.27 (0.69–2.33) | |
| Obstructive urinary tract defects | |||||
| N | 49 | 19 | 10 | 10 | 10 |
| P (%) | 0.012 | 0.010 | 0.018 | 0.012 | 0.013 |
| OR | 1.00 | 1.71 | 1.16 | 1.27 | |
| aOR (95% CI) | 1.00 | 1.65 (0.77–3.56) | 1.24 (0.57–2.67) | 1.44 (0.66–3.14) | |
| Hypospadias | |||||
| N | 72 | 43 | 8 | 14 | 7 |
| P (%) | 0.018 | 0.024 | 0.014 | 0.017 | 0.009 |
| OR | 1.00 | 0.61 | 0.72 | 0.39 | |
| aOR (95% CI) | 1.00 | 0.59 (0.28–1.26) | 0.76 (0.41–1.38) | 0.47 (0.21–1.04) | |
| Chromosome anomalies | |||||
| N | 364 | 174 | 72 | 67 | 51 |
| P (%) | 0.092 | 0.096 | 0.129 | 0.081 | 0.068 |
| OR | 1.00 | 1.35 | 0.85 | 0.71 | |
| aOR (95% CI) | 1.00 | 1.25 (0.95–1.65) | 0.93 (0.70–1.24) | 0.90 (0.66–1.24) | |
| Down syndrome | |||||
| N | 166 | 73 | 36 | 30 | 27 |
| P (%) | 0.042 | 0.040 | 0.064 | 0.036 | 0.036 |
| OR | 1.00 | 1.60 | 0.90 | 0.89 | |
| aOR (95% CI) | 1.00 | 1.48 (0.99–2.21) | 1.00 (0.65–1.54) | 1.17 (0.74–1.83) | |
| Trisomy 13 | |||||
| N | 14 | 4 | 2 | 6 | 2 |
| P (%) | 0.004 | 0.002 | 0.004 | 0.007 | 0.003 |
| OR | 1.00 | 1.63 | 3.30 | 1.21 | |
| aOR (95% CI) | 1.00 | 1.56 (0.28–8.55) | 3.36 (0.94–12.0) | 1.12 (0.20–6.29) | |
| Trisomy 18 | |||||
| N | 54 | 23 | 12 | 13 | 6 |
| P (%) | 0.014 | 0.013 | 0.021 | 0.016 | 0.008 |
| OR | 1.00 | 1.70 | 1.24 | 0.63 | |
| aOR (95% CI) | 1.00 | 1.64 (0.81–3.30) | 1.31 (0.66–2.59) | 0.81 (0.33–2.02) |
*cOR: crude odds ratio; aOR: adjusted odds ratio. Logistic regression analysis adjusting for maternal age, plurality, and population density.*Estimates not given for the following rare outcomes: spinal bifida (n = 14) microcephalus (n = 9); endocardial cushion defects (n = 7); transposition of great vessels (n = 12); choanal atresia (n = 2); dysplasia of lung (n = 9); congenital cystic kidney (n = 24).