Water disinfection by-products and the risk of specific birth defects: a population-based cross-sectional study in Taiwan

Table 6 Summary of the results from previous and present studies focusing on seven most common specific birth defect.

	Sweden 2000 [14]	Norway 2002 [12]	California 2003⁽¹⁾ [11]	California 2003⁽²⁾ [11]	England and Wales 2007 [13]	Taiwan 2008
Type of study	Cross-sectional, population-based	Cross-sectional, population-based	Case-control	Case-control	Cross-sectional, population-based	Cross-sectional, population-based
Study Population	115,801 births	184,676 births	539 controls	481 conrols	2,605,226 births	396,409 births
No of birth Defects	1,842	5,764	538	265	22,828	2,148
Exposure	Chlorine dioxide	Chlorination, High color	TTHMs 50–74 μg/l	TTHMs 50–74 μg/l	TTHMs >= 60 μg/l	TTHMs >= 20 μg/l
Reference	None	No chlorination, Low color	TTHMs 0 μg/l	TTHMs 0 μg/l	TTHMs <30 μg/l	TTHMs 0–4 μg/l
Anencephalus		0.79 (0.15–4.23) (n = 46)	0.55 (0.26–1.10) (n = 164)	1.80 (0.76–4.40) (n = 89)		1.96 (0.94–4.07) (n = 43)
Hydorcephalus	1.50 (0.30–7.30) (n = 36)	2.70 (0.77–9.51) (n = 68)				0.74 (0.43–1.28) (n = 118)
Ventricular septal defects		1.81 (1.05–3.09) (n = 279)			1.43 (1.00–2.04) (n = 408)	1.81 (0.98–3.35) (n = 59)
Atrial septal Defects		0.92 (0.24–1.50) (n = 73)				1.33 (0.39–4.58) (n = 19)
Cleft lip with/without palate		0.85 (0.53–1.38) (n = 248)		1.90 (0.81–4.50) (n = 117)	0.94 (0.83–1.06) (n = 2,909)	0.98 (0.73–1.32) (n = 358)
Cleft palate		1.07 (0.35–3.27) (n = 95)		1.00 (0.32–3.40) (n = 58)	0.95 (0.76–1.10) (n = 1,929)	1.56 (1.00–2.41) (n = 129)
Obstructive urinary tract defects		1.99 (0.66–5.96) (n = 102)				1.44 (0.66–3.14) (n = 49)

* Sweden 2000 [14]; California 2003⁽¹⁾: Shaw et. al. Study 1 [11]; California 2003⁽¹⁾: Shaw et. al. Study 2 [11]; Norway 2007 [12]; England and Wales 2007 [13]; Taiwan 2008: the present study.